2023 lines
58 KiB
C
2023 lines
58 KiB
C
/* tc-tahoe.c
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Not part of GAS yet. */
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#include "as.h"
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#include "obstack.h"
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/* this bit glommed from tahoe-inst.h */
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typedef unsigned char byte;
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typedef byte tahoe_opcodeT;
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/*
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* This is part of tahoe-ins-parse.c & friends.
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* We want to parse a tahoe instruction text into a tree defined here.
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*/
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#define TIT_MAX_OPERANDS (4) /* maximum number of operands in one
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single tahoe instruction */
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struct top /* tahoe instruction operand */
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{
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int top_ndx; /* -1, or index register. eg 7=[R7] */
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int top_reg; /* -1, or register number. eg 7 = R7 or (R7) */
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byte top_mode; /* Addressing mode byte. This byte, defines
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which of the 11 modes opcode is. */
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char top_access; /* Access type wanted for this opperand
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'b'branch ' 'no-instruction 'amrvw' */
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char top_width; /* Operand width expected, one of "bwlq?-:!" */
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char *top_error; /* Say if operand is inappropriate */
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segT seg_of_operand; /* segment as returned by expression()*/
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expressionS exp_of_operand; /* The expression as parsed by expression()*/
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byte top_dispsize; /* Number of bytes in the displacement if we
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can figure it out */
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};
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/* The addressing modes for an operand. These numbers are the acutal values
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for certain modes, so be carefull if you screw with them. */
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#define TAHOE_DIRECT_REG (0x50)
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#define TAHOE_REG_DEFERRED (0x60)
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#define TAHOE_REG_DISP (0xE0)
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#define TAHOE_REG_DISP_DEFERRED (0xF0)
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#define TAHOE_IMMEDIATE (0x8F)
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#define TAHOE_IMMEDIATE_BYTE (0x88)
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#define TAHOE_IMMEDIATE_WORD (0x89)
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#define TAHOE_IMMEDIATE_LONGWORD (0x8F)
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#define TAHOE_ABSOLUTE_ADDR (0x9F)
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#define TAHOE_DISPLACED_RELATIVE (0xEF)
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#define TAHOE_DISP_REL_DEFERRED (0xFF)
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#define TAHOE_AUTO_DEC (0x7E)
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#define TAHOE_AUTO_INC (0x8E)
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#define TAHOE_AUTO_INC_DEFERRED (0x9E)
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/* INDEXED_REG is decided by the existance or lack of a [reg] */
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/* These are encoded into top_width when top_access=='b'
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and it's a psuedo op.*/
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#define TAHOE_WIDTH_ALWAYS_JUMP '-'
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#define TAHOE_WIDTH_CONDITIONAL_JUMP '?'
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#define TAHOE_WIDTH_BIG_REV_JUMP '!'
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#define TAHOE_WIDTH_BIG_NON_REV_JUMP ':'
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/* The hex code for certain tahoe commands and modes.
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This is just for readability. */
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#define TAHOE_JMP (0x71)
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#define TAHOE_PC_REL_LONG (0xEF)
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#define TAHOE_BRB (0x11)
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#define TAHOE_BRW (0x13)
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/* These, when 'ored' with, or added to, a register number,
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set up the number for the displacement mode. */
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#define TAHOE_PC_OR_BYTE (0xA0)
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#define TAHOE_PC_OR_WORD (0xC0)
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#define TAHOE_PC_OR_LONG (0xE0)
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struct tit /* get it out of the sewer, it stands for
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tahoe instruction tree (Geeze!) */
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{
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tahoe_opcodeT tit_opcode; /* The opcode. */
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byte tit_operands; /* How many operands are here. */
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struct top tit_operand[TIT_MAX_OPERANDS]; /* Operands */
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char *tit_error; /* "" or fatal error text */
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};
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/* end: tahoe-inst.h */
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/* tahoe.c - tahoe-specific -
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Not part of gas yet.
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*/
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#include "opcode/tahoe.h"
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/* This is the number to put at the beginning of the a.out file */
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long omagic = OMAGIC;
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/* These chars start a comment anywhere in a source file (except inside
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another comment or a quoted string. */
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const char comment_chars[] = "#;";
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/* These chars only start a comment at the beginning of a line. */
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const char line_comment_chars[] = "#";
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/* Chars that can be used to separate mant from exp in floating point nums */
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const char EXP_CHARS[] = "eE";
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/* Chars that mean this number is a floating point constant
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as in 0f123.456
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or 0d1.234E-12 (see exp chars above)
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Note: The Tahoe port doesn't support floating point constants. This is
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consistant with 'as' If it's needed, I can always add it later. */
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const char FLT_CHARS[] = "df";
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/* Also be aware that MAXIMUM_NUMBER_OF_CHARS_FOR_FLOAT may have to be
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changed in read.c . Ideally it shouldn't have to know about it at all,
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but nothing is ideal around here.
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(The tahoe has plenty of room, so the change currently isn't needed.)
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*/
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static struct tit t; /* A tahoe instruction after decoding. */
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void float_cons ();
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/* A table of pseudo ops (sans .), the function called, and an integer op
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that the function is called with. */
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const pseudo_typeS md_pseudo_table[] =
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{
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{"dfloat", float_cons, 'd'},
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{"ffloat", float_cons, 'f'},
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{0}
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};
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/*
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* For Tahoe, relative addresses of "just the right length" are pretty easy.
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* The branch displacement is always the last operand, even in
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* synthetic instructions.
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* For Tahoe, we encode the relax_substateTs (in e.g. fr_substate) as:
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*
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* 4 3 2 1 0 bit number
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* ---/ /--+-------+-------+-------+-------+-------+
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* | what state ? | how long ? |
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* ---/ /--+-------+-------+-------+-------+-------+
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*
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* The "how long" bits are 00=byte, 01=word, 10=long.
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* This is a Un*x convention.
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* Not all lengths are legit for a given value of (what state).
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* The four states are listed below.
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* The "how long" refers merely to the displacement length.
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* The address usually has some constant bytes in it as well.
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*
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States for Tahoe address relaxing.
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1. TAHOE_WIDTH_ALWAYS_JUMP (-)
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Format: "b-"
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Tahoe opcodes are: (Hex)
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jr 11
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jbr 11
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Simple branch.
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Always, 1 byte opcode, then displacement/absolute.
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If word or longword, change opcode to brw or jmp.
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2. TAHOE_WIDTH_CONDITIONAL_JUMP (?)
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J<cond> where <cond> is a simple flag test.
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Format: "b?"
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Tahoe opcodes are: (Hex)
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jneq/jnequ 21
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jeql/jeqlu 31
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jgtr 41
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jleq 51
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jgeq 81
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jlss 91
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jgtru a1
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jlequ b1
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jvc c1
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jvs d1
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jlssu/jcs e1
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jgequ/jcc f1
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Always, you complement 4th bit to reverse the condition.
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Always, 1-byte opcode, then 1-byte displacement.
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3. TAHOE_WIDTH_BIG_REV_JUMP (!)
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Jbc/Jbs where cond tests a memory bit.
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Format: "rlvlb!"
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Tahoe opcodes are: (Hex)
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jbs 0e
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jbc 1e
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Always, you complement 4th bit to reverse the condition.
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Always, 1-byte opcde, longword, longword-address, 1-word-displacement
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4. TAHOE_WIDTH_BIG_NON_REV_JUMP (:)
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JaoblXX/Jbssi
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Format: "rlmlb:"
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Tahoe opcodes are: (Hex)
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aojlss 2f
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jaoblss 2f
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aojleq 3f
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jaobleq 3f
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jbssi 5f
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Always, we cannot reverse the sense of the branch; we have a word
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displacement.
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We need to modify the opcode is for class 1, 2 and 3 instructions.
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After relax() we may complement the 4th bit of 2 or 3 to reverse sense of
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branch.
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We sometimes store context in the operand literal. This way we can figure out
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after relax() what the original addressing mode was. (Was is pc_rel, or
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pc_rel_disp? That sort of thing.) */
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/* These displacements are relative to the START address of the
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displacement which is at the start of the displacement, not the end of
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the instruction. The hardware pc_rel is at the end of the instructions.
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That's why all the displacements have the length of the displacement added
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to them. (WF + length(word))
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The first letter is Byte, Word.
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2nd letter is Forward, Backward. */
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#define BF (1+ 127)
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#define BB (1+-128)
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#define WF (2+ 32767)
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#define WB (2+-32768)
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/* Dont need LF, LB because they always reach. [They are coded as 0.] */
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#define C(a,b) ENCODE_RELAX(a,b)
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/* This macro has no side-effects. */
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#define ENCODE_RELAX(what,length) (((what) << 2) + (length))
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#define RELAX_STATE(what) ((what) >> 2)
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#define RELAX_LENGTH(length) ((length) && 3)
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#define STATE_ALWAYS_BRANCH (1)
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#define STATE_CONDITIONAL_BRANCH (2)
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#define STATE_BIG_REV_BRANCH (3)
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#define STATE_BIG_NON_REV_BRANCH (4)
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#define STATE_PC_RELATIVE (5)
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#define STATE_BYTE (0)
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#define STATE_WORD (1)
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#define STATE_LONG (2)
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#define STATE_UNDF (3) /* Symbol undefined in pass1 */
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/* This is the table used by gas to figure out relaxing modes. The fields are
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forward_branch reach, backward_branch reach, number of bytes it would take,
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where the next biggest branch is. */
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const relax_typeS md_relax_table[] =
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{
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{
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1, 1, 0, 0
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}, /* error sentinel 0,0 */
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{
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1, 1, 0, 0
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}, /* unused 0,1 */
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{
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1, 1, 0, 0
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}, /* unused 0,2 */
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{
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1, 1, 0, 0
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}, /* unused 0,3 */
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/* Unconditional branch cases "jrb"
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The relax part is the actual displacement */
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{
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BF, BB, 1, C (1, 1)
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}, /* brb B`foo 1,0 */
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{
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WF, WB, 2, C (1, 2)
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}, /* brw W`foo 1,1 */
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{
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0, 0, 5, 0
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}, /* Jmp L`foo 1,2 */
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{
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1, 1, 0, 0
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}, /* unused 1,3 */
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/* Reversible Conditional Branch. If the branch won't reach, reverse
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it, and jump over a brw or a jmp that will reach. The relax part is the
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actual address. */
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{
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BF, BB, 1, C (2, 1)
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}, /* b<cond> B`foo 2,0 */
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{
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WF + 2, WB + 2, 4, C (2, 2)
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}, /* brev over, brw W`foo, over: 2,1 */
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{
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0, 0, 7, 0
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}, /* brev over, jmp L`foo, over: 2,2 */
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{
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1, 1, 0, 0
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}, /* unused 2,3 */
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/* Another type of reversable branch. But this only has a word
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displacement. */
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{
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1, 1, 0, 0
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}, /* unused 3,0 */
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{
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WF, WB, 2, C (3, 2)
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}, /* jbX W`foo 3,1 */
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{
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0, 0, 8, 0
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}, /* jrevX over, jmp L`foo, over: 3,2 */
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{
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1, 1, 0, 0
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}, /* unused 3,3 */
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/* These are the non reversable branches, all of which have a word
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displacement. If I can't reach, branch over a byte branch, to a
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jump that will reach. The jumped branch jumps over the reaching
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branch, to continue with the flow of the program. It's like playing
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leap frog. */
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{
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1, 1, 0, 0
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}, /* unused 4,0 */
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{
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WF, WB, 2, C (4, 2)
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}, /* aobl_ W`foo 4,1 */
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{
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0, 0, 10, 0
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}, /*aobl_ W`hop,br over,hop: jmp L^foo,over 4,2*/
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{
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1, 1, 0, 0
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}, /* unused 4,3 */
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/* Normal displacement mode, no jumping or anything like that.
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The relax points to one byte before the address, thats why all
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the numbers are up by one. */
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{
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BF + 1, BB + 1, 2, C (5, 1)
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}, /* B^"foo" 5,0 */
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{
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WF + 1, WB + 1, 3, C (5, 2)
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}, /* W^"foo" 5,1 */
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{
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0, 0, 5, 0
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}, /* L^"foo" 5,2 */
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{
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1, 1, 0, 0
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}, /* unused 5,3 */
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};
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#undef C
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#undef BF
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#undef BB
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#undef WF
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#undef WB
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/* End relax stuff */
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/* Handle of the OPCODE hash table. NULL means any use before
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md_begin() will crash. */
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static struct hash_control *op_hash;
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/* Init function. Build the hash table. */
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void
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md_begin ()
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{
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struct tot *tP;
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char *errorval = 0;
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int synthetic_too = 1; /* If 0, just use real opcodes. */
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op_hash = hash_new ();
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for (tP = totstrs; *tP->name && !errorval; tP++)
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errorval = hash_insert (op_hash, tP->name, &tP->detail);
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if (synthetic_too)
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for (tP = synthetic_totstrs; *tP->name && !errorval; tP++)
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errorval = hash_insert (op_hash, tP->name, &tP->detail);
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if (errorval)
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as_fatal (errorval);
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}
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CONST char *md_shortopts = "ad:STt:V";
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struct option md_longopts[] = {
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{NULL, no_argument, NULL, 0}
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};
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size_t md_longopts_size = sizeof(md_longopts);
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int
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md_parse_option (c, arg)
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int c;
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char *arg;
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{
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switch (c)
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{
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case 'a':
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as_warn (_("The -a option doesn't exist. (Despite what the man page says!"));
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break;
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case 'd':
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as_warn (_("Displacement length %s ignored!"), arg);
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break;
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case 'S':
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as_warn (_("SYMBOL TABLE not implemented"));
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break;
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case 'T':
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as_warn (_("TOKEN TRACE not implemented"));
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break;
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case 't':
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as_warn (_("I don't need or use temp. file \"%s\"."), arg);
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break;
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case 'V':
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as_warn (_("I don't use an interpass file! -V ignored"));
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break;
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default:
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return 0;
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}
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|
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return 1;
|
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}
|
||
|
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void
|
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md_show_usage (stream)
|
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FILE *stream;
|
||
{
|
||
fprintf(stream, _("\
|
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Tahoe options:\n\
|
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-a ignored\n\
|
||
-d LENGTH ignored\n\
|
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-J ignored\n\
|
||
-S ignored\n\
|
||
-t FILE ignored\n\
|
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-T ignored\n\
|
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-V ignored\n"));
|
||
}
|
||
|
||
/* The functions in this section take numbers in the machine format, and
|
||
munges them into Tahoe byte order.
|
||
They exist primarily for cross assembly purpose. */
|
||
void /* Knows about order of bytes in address. */
|
||
md_number_to_chars (con, value, nbytes)
|
||
char con[]; /* Return 'nbytes' of chars here. */
|
||
valueT value; /* The value of the bits. */
|
||
int nbytes; /* Number of bytes in the output. */
|
||
{
|
||
number_to_chars_bigendian (con, value, nbytes);
|
||
}
|
||
|
||
#ifdef comment
|
||
void /* Knows about order of bytes in address. */
|
||
md_number_to_imm (con, value, nbytes)
|
||
char con[]; /* Return 'nbytes' of chars here. */
|
||
long int value; /* The value of the bits. */
|
||
int nbytes; /* Number of bytes in the output. */
|
||
{
|
||
md_number_to_chars (con, value, nbytes);
|
||
}
|
||
|
||
#endif /* comment */
|
||
|
||
void
|
||
tc_apply_fix (fixP, val)
|
||
fixS *fixP;
|
||
long val;
|
||
{
|
||
/* should never be called */
|
||
know (0);
|
||
}
|
||
|
||
void /* Knows about order of bytes in address. */
|
||
md_number_to_disp (con, value, nbytes)
|
||
char con[]; /* Return 'nbytes' of chars here. */
|
||
long int value; /* The value of the bits. */
|
||
int nbytes; /* Number of bytes in the output. */
|
||
{
|
||
md_number_to_chars (con, value, nbytes);
|
||
}
|
||
|
||
void /* Knows about order of bytes in address. */
|
||
md_number_to_field (con, value, nbytes)
|
||
char con[]; /* Return 'nbytes' of chars here. */
|
||
long int value; /* The value of the bits. */
|
||
int nbytes; /* Number of bytes in the output. */
|
||
{
|
||
md_number_to_chars (con, value, nbytes);
|
||
}
|
||
|
||
/* Put the bits in an order that a tahoe will understand, despite the ordering
|
||
of the native machine.
|
||
On Tahoe: first 4 bytes are normal unsigned big endian long,
|
||
next three bytes are symbolnum, in kind of 3 byte big endian (least sig. byte last).
|
||
The last byte is broken up with bit 7 as pcrel,
|
||
bits 6 & 5 as length,
|
||
bit 4 as extern and the last nibble as 'undefined'. */
|
||
|
||
#if comment
|
||
void
|
||
md_ri_to_chars (ri_p, ri)
|
||
struct relocation_info *ri_p, ri;
|
||
{
|
||
byte the_bytes[sizeof (struct relocation_info)];
|
||
/* The reason I can't just encode these directly into ri_p is that
|
||
ri_p may point to ri. */
|
||
|
||
/* This is easy */
|
||
md_number_to_chars (the_bytes, ri.r_address, sizeof (ri.r_address));
|
||
|
||
/* now the fun stuff */
|
||
the_bytes[4] = (ri.r_symbolnum >> 16) & 0x0ff;
|
||
the_bytes[5] = (ri.r_symbolnum >> 8) & 0x0ff;
|
||
the_bytes[6] = ri.r_symbolnum & 0x0ff;
|
||
the_bytes[7] = (((ri.r_extern << 4) & 0x10) | ((ri.r_length << 5) & 0x60) |
|
||
((ri.r_pcrel << 7) & 0x80)) & 0xf0;
|
||
|
||
bcopy (the_bytes, (char *) ri_p, sizeof (struct relocation_info));
|
||
}
|
||
|
||
#endif /* comment */
|
||
|
||
/* Put the bits in an order that a tahoe will understand, despite the ordering
|
||
of the native machine.
|
||
On Tahoe: first 4 bytes are normal unsigned big endian long,
|
||
next three bytes are symbolnum, in kind of 3 byte big endian (least sig. byte last).
|
||
The last byte is broken up with bit 7 as pcrel,
|
||
bits 6 & 5 as length,
|
||
bit 4 as extern and the last nibble as 'undefined'. */
|
||
|
||
void
|
||
tc_aout_fix_to_chars (where, fixP, segment_address_in_file)
|
||
char *where;
|
||
fixS *fixP;
|
||
relax_addressT segment_address_in_file;
|
||
{
|
||
long r_symbolnum;
|
||
|
||
know (fixP->fx_addsy != NULL);
|
||
|
||
md_number_to_chars (where,
|
||
fixP->fx_frag->fr_address + fixP->fx_where - segment_address_in_file,
|
||
4);
|
||
|
||
r_symbolnum = (S_IS_DEFINED (fixP->fx_addsy)
|
||
? S_GET_TYPE (fixP->fx_addsy)
|
||
: fixP->fx_addsy->sy_number);
|
||
|
||
where[4] = (r_symbolnum >> 16) & 0x0ff;
|
||
where[5] = (r_symbolnum >> 8) & 0x0ff;
|
||
where[6] = r_symbolnum & 0x0ff;
|
||
where[7] = (((is_pcrel (fixP) << 7) & 0x80)
|
||
| ((((fixP->fx_type == FX_8 || fixP->fx_type == FX_PCREL8
|
||
? 0
|
||
: (fixP->fx_type == FX_16 || fixP->fx_type == FX_PCREL16
|
||
? 1
|
||
: (fixP->fx_type == FX_32 || fixP->fx_type == FX_PCREL32
|
||
? 2
|
||
: 42)))) << 5) & 0x60)
|
||
| ((!S_IS_DEFINED (fixP->fx_addsy) << 4) & 0x10));
|
||
}
|
||
|
||
/* Relocate byte stuff */
|
||
|
||
/* This is for broken word. */
|
||
const int md_short_jump_size = 3;
|
||
|
||
void
|
||
md_create_short_jump (ptr, from_addr, to_addr, frag, to_symbol)
|
||
char *ptr;
|
||
addressT from_addr, to_addr;
|
||
fragS *frag;
|
||
symbolS *to_symbol;
|
||
{
|
||
valueT offset;
|
||
|
||
offset = to_addr - (from_addr + 1);
|
||
*ptr++ = TAHOE_BRW;
|
||
md_number_to_chars (ptr, offset, 2);
|
||
}
|
||
|
||
const int md_long_jump_size = 6;
|
||
const int md_reloc_size = 8; /* Size of relocation record */
|
||
|
||
void
|
||
md_create_long_jump (ptr, from_addr, to_addr, frag, to_symbol)
|
||
char *ptr;
|
||
addressT from_addr, to_addr;
|
||
fragS *frag;
|
||
symbolS *to_symbol;
|
||
{
|
||
valueT offset;
|
||
|
||
offset = to_addr - (from_addr + 4);
|
||
*ptr++ = TAHOE_JMP;
|
||
*ptr++ = TAHOE_PC_REL_LONG;
|
||
md_number_to_chars (ptr, offset, 4);
|
||
}
|
||
|
||
/*
|
||
* md_estimate_size_before_relax()
|
||
*
|
||
* Called just before relax().
|
||
* Any symbol that is now undefined will not become defined, so we assumed
|
||
* that it will be resolved by the linker.
|
||
* Return the correct fr_subtype in the frag, for relax()
|
||
* Return the initial "guess for fr_var" to caller. (How big I think this
|
||
* will be.)
|
||
* The guess for fr_var is ACTUALLY the growth beyond fr_fix.
|
||
* Whatever we do to grow fr_fix or fr_var contributes to our returned value.
|
||
* Although it may not be explicit in the frag, pretend fr_var starts with a
|
||
* 0 value.
|
||
*/
|
||
int
|
||
md_estimate_size_before_relax (fragP, segment_type)
|
||
register fragS *fragP;
|
||
segT segment_type; /* N_DATA or N_TEXT. */
|
||
{
|
||
register char *p;
|
||
register int old_fr_fix;
|
||
/* int pc_rel; FIXME: remove this */
|
||
|
||
old_fr_fix = fragP->fr_fix;
|
||
switch (fragP->fr_subtype)
|
||
{
|
||
case ENCODE_RELAX (STATE_PC_RELATIVE, STATE_UNDF):
|
||
if (S_GET_SEGMENT (fragP->fr_symbol) == segment_type)
|
||
{
|
||
/* The symbol was in the same segment as the opcode, and it's
|
||
a real pc_rel case so it's a relaxable case. */
|
||
fragP->fr_subtype = ENCODE_RELAX (STATE_PC_RELATIVE, STATE_BYTE);
|
||
}
|
||
else
|
||
{
|
||
/* This case is still undefined, so asume it's a long word for the
|
||
linker to fix. */
|
||
p = fragP->fr_literal + old_fr_fix;
|
||
*p |= TAHOE_PC_OR_LONG;
|
||
/* We now know how big it will be, one long word. */
|
||
fragP->fr_fix += 1 + 4;
|
||
fix_new (fragP, old_fr_fix + 1, fragP->fr_symbol,
|
||
fragP->fr_offset, FX_PCREL32, NULL);
|
||
frag_wane (fragP);
|
||
}
|
||
break;
|
||
|
||
case ENCODE_RELAX (STATE_CONDITIONAL_BRANCH, STATE_UNDF):
|
||
if (S_GET_SEGMENT (fragP->fr_symbol) == segment_type)
|
||
{
|
||
fragP->fr_subtype = ENCODE_RELAX (STATE_CONDITIONAL_BRANCH, STATE_BYTE);
|
||
}
|
||
else
|
||
{
|
||
p = fragP->fr_literal + old_fr_fix;
|
||
*fragP->fr_opcode ^= 0x10; /* Reverse sense of branch. */
|
||
*p++ = 6;
|
||
*p++ = TAHOE_JMP;
|
||
*p++ = TAHOE_PC_REL_LONG;
|
||
fragP->fr_fix += 1 + 1 + 1 + 4;
|
||
fix_new (fragP, old_fr_fix + 3, fragP->fr_symbol,
|
||
fragP->fr_offset, FX_PCREL32, NULL);
|
||
frag_wane (fragP);
|
||
}
|
||
break;
|
||
|
||
case ENCODE_RELAX (STATE_BIG_REV_BRANCH, STATE_UNDF):
|
||
if (S_GET_SEGMENT (fragP->fr_symbol) == segment_type)
|
||
{
|
||
fragP->fr_subtype =
|
||
ENCODE_RELAX (STATE_BIG_REV_BRANCH, STATE_WORD);
|
||
}
|
||
else
|
||
{
|
||
p = fragP->fr_literal + old_fr_fix;
|
||
*fragP->fr_opcode ^= 0x10; /* Reverse sense of branch. */
|
||
*p++ = 0;
|
||
*p++ = 6;
|
||
*p++ = TAHOE_JMP;
|
||
*p++ = TAHOE_PC_REL_LONG;
|
||
fragP->fr_fix += 2 + 2 + 4;
|
||
fix_new (fragP, old_fr_fix + 4, fragP->fr_symbol,
|
||
fragP->fr_offset, FX_PCREL32, NULL);
|
||
frag_wane (fragP);
|
||
}
|
||
break;
|
||
|
||
case ENCODE_RELAX (STATE_BIG_NON_REV_BRANCH, STATE_UNDF):
|
||
if (S_GET_SEGMENT (fragP->fr_symbol) == segment_type)
|
||
{
|
||
fragP->fr_subtype = ENCODE_RELAX (STATE_BIG_NON_REV_BRANCH, STATE_WORD);
|
||
}
|
||
else
|
||
{
|
||
p = fragP->fr_literal + old_fr_fix;
|
||
*p++ = 2;
|
||
*p++ = 0;
|
||
*p++ = TAHOE_BRB;
|
||
*p++ = 6;
|
||
*p++ = TAHOE_JMP;
|
||
*p++ = TAHOE_PC_REL_LONG;
|
||
fragP->fr_fix += 2 + 2 + 2 + 4;
|
||
fix_new (fragP, old_fr_fix + 6, fragP->fr_symbol,
|
||
fragP->fr_offset, FX_PCREL32, NULL);
|
||
frag_wane (fragP);
|
||
}
|
||
break;
|
||
|
||
case ENCODE_RELAX (STATE_ALWAYS_BRANCH, STATE_UNDF):
|
||
if (S_GET_SEGMENT (fragP->fr_symbol) == segment_type)
|
||
{
|
||
fragP->fr_subtype = ENCODE_RELAX (STATE_ALWAYS_BRANCH, STATE_BYTE);
|
||
}
|
||
else
|
||
{
|
||
p = fragP->fr_literal + old_fr_fix;
|
||
*fragP->fr_opcode = TAHOE_JMP;
|
||
*p++ = TAHOE_PC_REL_LONG;
|
||
fragP->fr_fix += 1 + 4;
|
||
fix_new (fragP, old_fr_fix + 1, fragP->fr_symbol,
|
||
fragP->fr_offset, FX_PCREL32, NULL);
|
||
frag_wane (fragP);
|
||
}
|
||
break;
|
||
|
||
default:
|
||
break;
|
||
}
|
||
return (fragP->fr_var + fragP->fr_fix - old_fr_fix);
|
||
} /* md_estimate_size_before_relax() */
|
||
|
||
/*
|
||
* md_convert_frag();
|
||
*
|
||
* Called after relax() is finished.
|
||
* In: Address of frag.
|
||
* fr_type == rs_machine_dependent.
|
||
* fr_subtype is what the address relaxed to.
|
||
*
|
||
* Out: Any fixSs and constants are set up.
|
||
* Caller will turn frag into a ".space 0".
|
||
*/
|
||
void
|
||
md_convert_frag (headers, seg, fragP)
|
||
object_headers *headers;
|
||
segT seg;
|
||
register fragS *fragP;
|
||
{
|
||
register char *addressP; /* -> _var to change. */
|
||
register char *opcodeP; /* -> opcode char(s) to change. */
|
||
register short int length_code; /* 2=long 1=word 0=byte */
|
||
register short int extension = 0; /* Size of relaxed address.
|
||
Added to fr_fix: incl. ALL var chars. */
|
||
register symbolS *symbolP;
|
||
register long int where;
|
||
register long int address_of_var;
|
||
/* Where, in file space, is _var of *fragP? */
|
||
register long int target_address;
|
||
/* Where, in file space, does addr point? */
|
||
|
||
know (fragP->fr_type == rs_machine_dependent);
|
||
length_code = RELAX_LENGTH (fragP->fr_subtype);
|
||
know (length_code >= 0 && length_code < 3);
|
||
where = fragP->fr_fix;
|
||
addressP = fragP->fr_literal + where;
|
||
opcodeP = fragP->fr_opcode;
|
||
symbolP = fragP->fr_symbol;
|
||
know (symbolP);
|
||
target_address = S_GET_VALUE (symbolP) + fragP->fr_offset;
|
||
address_of_var = fragP->fr_address + where;
|
||
switch (fragP->fr_subtype)
|
||
{
|
||
case ENCODE_RELAX (STATE_PC_RELATIVE, STATE_BYTE):
|
||
/* *addressP holds the registers number, plus 0x10, if it's deferred
|
||
mode. To set up the right mode, just OR the size of this displacement */
|
||
/* Byte displacement. */
|
||
*addressP++ |= TAHOE_PC_OR_BYTE;
|
||
*addressP = target_address - (address_of_var + 2);
|
||
extension = 2;
|
||
break;
|
||
|
||
case ENCODE_RELAX (STATE_PC_RELATIVE, STATE_WORD):
|
||
/* Word displacement. */
|
||
*addressP++ |= TAHOE_PC_OR_WORD;
|
||
md_number_to_chars (addressP, target_address - (address_of_var + 3), 2);
|
||
extension = 3;
|
||
break;
|
||
|
||
case ENCODE_RELAX (STATE_PC_RELATIVE, STATE_LONG):
|
||
/* Long word displacement. */
|
||
*addressP++ |= TAHOE_PC_OR_LONG;
|
||
md_number_to_chars (addressP, target_address - (address_of_var + 5), 4);
|
||
extension = 5;
|
||
break;
|
||
|
||
case ENCODE_RELAX (STATE_CONDITIONAL_BRANCH, STATE_BYTE):
|
||
*addressP = target_address - (address_of_var + 1);
|
||
extension = 1;
|
||
break;
|
||
|
||
case ENCODE_RELAX (STATE_CONDITIONAL_BRANCH, STATE_WORD):
|
||
*opcodeP ^= 0x10; /* Reverse sense of test. */
|
||
*addressP++ = 3; /* Jump over word branch */
|
||
*addressP++ = TAHOE_BRW;
|
||
md_number_to_chars (addressP, target_address - (address_of_var + 4), 2);
|
||
extension = 4;
|
||
break;
|
||
|
||
case ENCODE_RELAX (STATE_CONDITIONAL_BRANCH, STATE_LONG):
|
||
*opcodeP ^= 0x10; /* Reverse sense of test. */
|
||
*addressP++ = 6;
|
||
*addressP++ = TAHOE_JMP;
|
||
*addressP++ = TAHOE_PC_REL_LONG;
|
||
md_number_to_chars (addressP, target_address, 4);
|
||
extension = 7;
|
||
break;
|
||
|
||
case ENCODE_RELAX (STATE_ALWAYS_BRANCH, STATE_BYTE):
|
||
*addressP = target_address - (address_of_var + 1);
|
||
extension = 1;
|
||
break;
|
||
|
||
case ENCODE_RELAX (STATE_ALWAYS_BRANCH, STATE_WORD):
|
||
*opcodeP = TAHOE_BRW;
|
||
md_number_to_chars (addressP, target_address - (address_of_var + 2), 2);
|
||
extension = 2;
|
||
break;
|
||
|
||
case ENCODE_RELAX (STATE_ALWAYS_BRANCH, STATE_LONG):
|
||
*opcodeP = TAHOE_JMP;
|
||
*addressP++ = TAHOE_PC_REL_LONG;
|
||
md_number_to_chars (addressP, target_address - (address_of_var + 5), 4);
|
||
extension = 5;
|
||
break;
|
||
|
||
case ENCODE_RELAX (STATE_BIG_REV_BRANCH, STATE_WORD):
|
||
md_number_to_chars (addressP, target_address - (address_of_var + 2), 2);
|
||
extension = 2;
|
||
break;
|
||
|
||
case ENCODE_RELAX (STATE_BIG_REV_BRANCH, STATE_LONG):
|
||
*opcodeP ^= 0x10;
|
||
*addressP++ = 0;
|
||
*addressP++ = 6;
|
||
*addressP++ = TAHOE_JMP;
|
||
*addressP++ = TAHOE_PC_REL_LONG;
|
||
md_number_to_chars (addressP, target_address, 4);
|
||
extension = 8;
|
||
break;
|
||
|
||
case ENCODE_RELAX (STATE_BIG_NON_REV_BRANCH, STATE_WORD):
|
||
md_number_to_chars (addressP, target_address - (address_of_var + 2), 2);
|
||
extension = 2;
|
||
break;
|
||
|
||
case ENCODE_RELAX (STATE_BIG_NON_REV_BRANCH, STATE_LONG):
|
||
*addressP++ = 0;
|
||
*addressP++ = 2;
|
||
*addressP++ = TAHOE_BRB;
|
||
*addressP++ = 6;
|
||
*addressP++ = TAHOE_JMP;
|
||
*addressP++ = TAHOE_PC_REL_LONG;
|
||
md_number_to_chars (addressP, target_address, 4);
|
||
extension = 10;
|
||
break;
|
||
|
||
default:
|
||
BAD_CASE (fragP->fr_subtype);
|
||
break;
|
||
}
|
||
fragP->fr_fix += extension;
|
||
} /* md_convert_frag */
|
||
|
||
|
||
/* This is the stuff for md_assemble. */
|
||
#define FP_REG 13
|
||
#define SP_REG 14
|
||
#define PC_REG 15
|
||
#define BIGGESTREG PC_REG
|
||
|
||
/*
|
||
* Parse the string pointed to by START
|
||
* If it represents a valid register, point START to the character after
|
||
* the last valid register char, and return the register number (0-15).
|
||
* If invalid, leave START alone, return -1.
|
||
* The format has to be exact. I don't do things like eat leading zeros
|
||
* or the like.
|
||
* Note: This doesn't check for the next character in the string making
|
||
* this invalid. Ex: R123 would return 12, it's the callers job to check
|
||
* what start is point to apon return.
|
||
*
|
||
* Valid registers are R1-R15, %1-%15, FP (13), SP (14), PC (15)
|
||
* Case doesn't matter.
|
||
*/
|
||
int
|
||
tahoe_reg_parse (start)
|
||
char **start; /* A pointer to the string to parse. */
|
||
{
|
||
register char *regpoint = *start;
|
||
register int regnum = -1;
|
||
|
||
switch (*regpoint++)
|
||
{
|
||
case '%': /* Registers can start with a %,
|
||
R or r, and then a number. */
|
||
case 'R':
|
||
case 'r':
|
||
if (isdigit (*regpoint))
|
||
{
|
||
/* Got the first digit. */
|
||
regnum = *regpoint++ - '0';
|
||
if ((regnum == 1) && isdigit (*regpoint))
|
||
{
|
||
/* Its a two digit number. */
|
||
regnum = 10 + (*regpoint++ - '0');
|
||
if (regnum > BIGGESTREG)
|
||
{ /* Number too big? */
|
||
regnum = -1;
|
||
}
|
||
}
|
||
}
|
||
break;
|
||
case 'F': /* Is it the FP */
|
||
case 'f':
|
||
switch (*regpoint++)
|
||
{
|
||
case 'p':
|
||
case 'P':
|
||
regnum = FP_REG;
|
||
}
|
||
break;
|
||
case 's': /* How about the SP */
|
||
case 'S':
|
||
switch (*regpoint++)
|
||
{
|
||
case 'p':
|
||
case 'P':
|
||
regnum = SP_REG;
|
||
}
|
||
break;
|
||
case 'p': /* OR the PC even */
|
||
case 'P':
|
||
switch (*regpoint++)
|
||
{
|
||
case 'c':
|
||
case 'C':
|
||
regnum = PC_REG;
|
||
}
|
||
break;
|
||
}
|
||
|
||
if (regnum != -1)
|
||
{ /* No error, so move string pointer */
|
||
*start = regpoint;
|
||
}
|
||
return regnum; /* Return results */
|
||
} /* tahoe_reg_parse */
|
||
|
||
/*
|
||
* This chops up an operand and figures out its modes and stuff.
|
||
* It's a little touchy about extra characters.
|
||
* Optex to start with one extra character so it can be overwritten for
|
||
* the backward part of the parsing.
|
||
* You can't put a bunch of extra characters in side to
|
||
* make the command look cute. ie: * foo ( r1 ) [ r0 ]
|
||
* If you like doing a lot of typing, try COBOL!
|
||
* Actually, this parser is a little weak all around. It's designed to be
|
||
* used with compliers, so I emphisise correct decoding of valid code quickly
|
||
* rather that catching every possable error.
|
||
* Note: This uses the expression function, so save input_line_pointer before
|
||
* calling.
|
||
*
|
||
* Sperry defines the semantics of address modes (and values)
|
||
* by a two-letter code, explained here.
|
||
*
|
||
* letter 1: access type
|
||
*
|
||
* a address calculation - no data access, registers forbidden
|
||
* b branch displacement
|
||
* m read - let go of bus - write back "modify"
|
||
* r read
|
||
* w write
|
||
* v bit field address: like 'a' but registers are OK
|
||
*
|
||
* letter 2: data type (i.e. width, alignment)
|
||
*
|
||
* b byte
|
||
* w word
|
||
* l longword
|
||
* q quadword (Even regs < 14 allowed) (if 12, you get a warning)
|
||
* - unconditional synthetic jbr operand
|
||
* ? simple synthetic reversable branch operand
|
||
* ! complex synthetic reversable branch operand
|
||
* : complex synthetic non-reversable branch operand
|
||
*
|
||
* The '-?!:' letter 2's are not for external consumption. They are used
|
||
* by GAS for psuedo ops relaxing code.
|
||
*
|
||
* After parsing topP has:
|
||
*
|
||
* top_ndx: -1, or the index register. eg 7=[R7]
|
||
* top_reg: -1, or register number. eg 7 = R7 or (R7)
|
||
* top_mode: The addressing mode byte. This byte, defines which of
|
||
* the 11 modes opcode is.
|
||
* top_access: Access type wanted for this opperand 'b'branch ' '
|
||
* no-instruction 'amrvw'
|
||
* top_width: Operand width expected, one of "bwlq?-:!"
|
||
* exp_of_operand: The expression as parsed by expression()
|
||
* top_dispsize: Number of bytes in the displacement if we can figure it
|
||
* out and it's relavent.
|
||
*
|
||
* Need syntax checks built.
|
||
*/
|
||
|
||
void
|
||
tip_op (optex, topP)
|
||
char *optex; /* The users text input, with one leading character */
|
||
struct top *topP; /* The tahoe instruction with some fields already set:
|
||
in: access, width
|
||
out: ndx, reg, mode, error, dispsize */
|
||
|
||
{
|
||
int mode = 0; /* This operand's mode. */
|
||
char segfault = *optex; /* To keep the back parsing from freaking. */
|
||
char *point = optex + 1; /* Parsing from front to back. */
|
||
char *end; /* Parsing from back to front. */
|
||
int reg = -1; /* major register, -1 means absent */
|
||
int imreg = -1; /* Major register in immediate mode */
|
||
int ndx = -1; /* index register number, -1 means absent */
|
||
char dec_inc = ' '; /* Is the SP auto-incremented '+' or
|
||
auto-decremented '-' or neither ' '. */
|
||
int immediate = 0; /* 1 if '$' immediate mode */
|
||
int call_width = 0; /* If the caller casts the displacement */
|
||
int abs_width = 0; /* The width of the absolute displacment */
|
||
int com_width = 0; /* Displacement width required by branch */
|
||
int deferred = 0; /* 1 if '*' deferral is used */
|
||
byte disp_size = 0; /* How big is this operand. 0 == don't know */
|
||
char *op_bad = ""; /* Bad operand error */
|
||
|
||
char *tp, *temp, c; /* Temporary holders */
|
||
|
||
char access = topP->top_access; /* Save on a deref. */
|
||
char width = topP->top_width;
|
||
|
||
int really_none = 0; /* Empty expressions evaluate to 0
|
||
but I need to know if it's there or not */
|
||
expressionS *expP; /* -> expression values for this operand */
|
||
|
||
/* Does this command restrict the displacement size. */
|
||
if (access == 'b')
|
||
com_width = (width == 'b' ? 1 :
|
||
(width == 'w' ? 2 :
|
||
(width == 'l' ? 4 : 0)));
|
||
|
||
*optex = '\0'; /* This is kind of a back stop for all
|
||
the searches to fail on if needed.*/
|
||
if (*point == '*')
|
||
{ /* A dereference? */
|
||
deferred = 1;
|
||
point++;
|
||
}
|
||
|
||
/* Force words into a certain mode */
|
||
/* Bitch, Bitch, Bitch! */
|
||
/*
|
||
* Using the ^ operator is ambigous. If I have an absolute label
|
||
* called 'w' set to, say 2, and I have the expression 'w^1', do I get
|
||
* 1, forced to be in word displacement mode, or do I get the value of
|
||
* 'w' or'ed with 1 (3 in this case).
|
||
* The default is 'w' as an offset, so that's what I use.
|
||
* Stick with `, it does the same, and isn't ambig.
|
||
*/
|
||
|
||
if (*point != '\0' && ((point[1] == '^') || (point[1] == '`')))
|
||
switch (*point)
|
||
{
|
||
case 'b':
|
||
case 'B':
|
||
case 'w':
|
||
case 'W':
|
||
case 'l':
|
||
case 'L':
|
||
if (com_width)
|
||
as_warn (_("Casting a branch displacement is bad form, and is ignored."));
|
||
else
|
||
{
|
||
c = (isupper (*point) ? tolower (*point) : *point);
|
||
call_width = ((c == 'b') ? 1 :
|
||
((c == 'w') ? 2 : 4));
|
||
}
|
||
point += 2;
|
||
break;
|
||
}
|
||
|
||
/* Setting immediate mode */
|
||
if (*point == '$')
|
||
{
|
||
immediate = 1;
|
||
point++;
|
||
}
|
||
|
||
/*
|
||
* I've pulled off all the easy stuff off the front, move to the end and
|
||
* yank.
|
||
*/
|
||
|
||
for (end = point; *end != '\0'; end++) /* Move to the end. */
|
||
;
|
||
|
||
if (end != point) /* Null string? */
|
||
end--;
|
||
|
||
if (end > point && *end == ' ' && end[-1] != '\'')
|
||
end--; /* Hop white space */
|
||
|
||
/* Is this an index reg. */
|
||
if ((*end == ']') && (end[-1] != '\''))
|
||
{
|
||
temp = end;
|
||
|
||
/* Find opening brace. */
|
||
for (--end; (*end != '[' && end != point); end--)
|
||
;
|
||
|
||
/* If I found the opening brace, get the index register number. */
|
||
if (*end == '[')
|
||
{
|
||
tp = end + 1; /* tp should point to the start of a reg. */
|
||
ndx = tahoe_reg_parse (&tp);
|
||
if (tp != temp)
|
||
{ /* Reg. parse error. */
|
||
ndx = -1;
|
||
}
|
||
else
|
||
{
|
||
end--; /* Found it, move past brace. */
|
||
}
|
||
if (ndx == -1)
|
||
{
|
||
op_bad = _("Couldn't parse the [index] in this operand.");
|
||
end = point; /* Force all the rest of the tests to fail. */
|
||
}
|
||
}
|
||
else
|
||
{
|
||
op_bad = _("Couldn't find the opening '[' for the index of this operand.");
|
||
end = point; /* Force all the rest of the tests to fail. */
|
||
}
|
||
}
|
||
|
||
/* Post increment? */
|
||
if (*end == '+')
|
||
{
|
||
dec_inc = '+';
|
||
/* was: *end--; */
|
||
end--;
|
||
}
|
||
|
||
/* register in parens? */
|
||
if ((*end == ')') && (end[-1] != '\''))
|
||
{
|
||
temp = end;
|
||
|
||
/* Find opening paren. */
|
||
for (--end; (*end != '(' && end != point); end--)
|
||
;
|
||
|
||
/* If I found the opening paren, get the register number. */
|
||
if (*end == '(')
|
||
{
|
||
tp = end + 1;
|
||
reg = tahoe_reg_parse (&tp);
|
||
if (tp != temp)
|
||
{
|
||
/* Not a register, but could be part of the expression. */
|
||
reg = -1;
|
||
end = temp; /* Rest the pointer back */
|
||
}
|
||
else
|
||
{
|
||
end--; /* Found the reg. move before opening paren. */
|
||
}
|
||
}
|
||
else
|
||
{
|
||
op_bad = _("Couldn't find the opening '(' for the deref of this operand.");
|
||
end = point; /* Force all the rest of the tests to fail. */
|
||
}
|
||
}
|
||
|
||
/* Pre decrement? */
|
||
if (*end == '-')
|
||
{
|
||
if (dec_inc != ' ')
|
||
{
|
||
op_bad = _("Operand can't be both pre-inc and post-dec.");
|
||
end = point;
|
||
}
|
||
else
|
||
{
|
||
dec_inc = '-';
|
||
/* was: *end--; */
|
||
end--;
|
||
}
|
||
}
|
||
|
||
/*
|
||
* Everything between point and end is the 'expression', unless it's
|
||
* a register name.
|
||
*/
|
||
|
||
c = end[1];
|
||
end[1] = '\0';
|
||
|
||
tp = point;
|
||
imreg = tahoe_reg_parse (&point); /* Get the immediate register
|
||
if it is there.*/
|
||
if (*point != '\0')
|
||
{
|
||
/* If there is junk after point, then the it's not immediate reg. */
|
||
point = tp;
|
||
imreg = -1;
|
||
}
|
||
|
||
if (imreg != -1 && reg != -1)
|
||
op_bad = _("I parsed 2 registers in this operand.");
|
||
|
||
/*
|
||
* Evaluate whats left of the expression to see if it's valid.
|
||
* Note again: This assumes that the calling expression has saved
|
||
* input_line_pointer. (Nag, nag, nag!)
|
||
*/
|
||
|
||
if (*op_bad == '\0')
|
||
{
|
||
/* Statement has no syntax goofs yet: let's sniff the expression. */
|
||
input_line_pointer = point;
|
||
expP = &(topP->exp_of_operand);
|
||
topP->seg_of_operand = expression (expP);
|
||
switch (expP->X_op)
|
||
{
|
||
case O_absent:
|
||
/* No expression. For BSD4.2 compatibility, missing expression is
|
||
absolute 0 */
|
||
expP->X_op = O_constant;
|
||
expP->X_add_number = 0;
|
||
really_none = 1;
|
||
case O_constant:
|
||
/* for SEG_ABSOLUTE, we shouldnt need to set X_op_symbol,
|
||
X_add_symbol to any particular value. */
|
||
/* But, we will program defensively. Since this situation occurs
|
||
rarely so it costs us little to do so. */
|
||
expP->X_add_symbol = NULL;
|
||
expP->X_op_symbol = NULL;
|
||
/* How many bytes are needed to express this abs value? */
|
||
abs_width =
|
||
((((expP->X_add_number & 0xFFFFFF80) == 0) ||
|
||
((expP->X_add_number & 0xFFFFFF80) == 0xFFFFFF80)) ? 1 :
|
||
(((expP->X_add_number & 0xFFFF8000) == 0) ||
|
||
((expP->X_add_number & 0xFFFF8000) == 0xFFFF8000)) ? 2 : 4);
|
||
|
||
case O_symbol:
|
||
break;
|
||
|
||
default:
|
||
/*
|
||
* Major bug. We can't handle the case of a operator
|
||
* expression in a synthetic opcode variable-length
|
||
* instruction. We don't have a frag type that is smart
|
||
* enough to relax a operator, and so we just force all
|
||
* operators to behave like SEG_PASS1s. Clearly, if there is
|
||
* a demand we can invent a new or modified frag type and
|
||
* then coding up a frag for this case will be easy.
|
||
*/
|
||
need_pass_2 = 1;
|
||
op_bad = _("Can't relocate expression error.");
|
||
break;
|
||
|
||
case O_big:
|
||
/* This is an error. Tahoe doesn't allow any expressions
|
||
bigger that a 32 bit long word. Any bigger has to be referenced
|
||
by address. */
|
||
op_bad = _("Expression is too large for a 32 bits.");
|
||
break;
|
||
}
|
||
if (*input_line_pointer != '\0')
|
||
{
|
||
op_bad = _("Junk at end of expression.");
|
||
}
|
||
}
|
||
|
||
end[1] = c;
|
||
|
||
/* I'm done, so restore optex */
|
||
*optex = segfault;
|
||
|
||
/*
|
||
* At this point in the game, we (in theory) have all the components of
|
||
* the operand at least parsed. Now it's time to check for syntax/semantic
|
||
* errors, and build the mode.
|
||
* This is what I have:
|
||
* deferred = 1 if '*'
|
||
* call_width = 0,1,2,4
|
||
* abs_width = 0,1,2,4
|
||
* com_width = 0,1,2,4
|
||
* immediate = 1 if '$'
|
||
* ndx = -1 or reg num
|
||
* dec_inc = '-' or '+' or ' '
|
||
* reg = -1 or reg num
|
||
* imreg = -1 or reg num
|
||
* topP->exp_of_operand
|
||
* really_none
|
||
*/
|
||
/* Is there a displacement size? */
|
||
disp_size = (call_width ? call_width :
|
||
(com_width ? com_width :
|
||
abs_width ? abs_width : 0));
|
||
|
||
if (*op_bad == '\0')
|
||
{
|
||
if (imreg != -1)
|
||
{
|
||
/* Rn */
|
||
mode = TAHOE_DIRECT_REG;
|
||
if (deferred || immediate || (dec_inc != ' ') ||
|
||
(reg != -1) || !really_none)
|
||
op_bad = _("Syntax error in direct register mode.");
|
||
else if (ndx != -1)
|
||
op_bad = _("You can't index a register in direct register mode.");
|
||
else if (imreg == SP_REG && access == 'r')
|
||
op_bad =
|
||
_("SP can't be the source operand with direct register addressing.");
|
||
else if (access == 'a')
|
||
op_bad = _("Can't take the address of a register.");
|
||
else if (access == 'b')
|
||
op_bad = _("Direct Register can't be used in a branch.");
|
||
else if (width == 'q' && ((imreg % 2) || (imreg > 13)))
|
||
op_bad = _("For quad access, the register must be even and < 14.");
|
||
else if (call_width)
|
||
op_bad = _("You can't cast a direct register.");
|
||
|
||
if (*op_bad == '\0')
|
||
{
|
||
/* No errors, check for warnings */
|
||
if (width == 'q' && imreg == 12)
|
||
as_warn (_("Using reg 14 for quadwords can tromp the FP register."));
|
||
|
||
reg = imreg;
|
||
}
|
||
|
||
/* We know: imm = -1 */
|
||
}
|
||
else if (dec_inc == '-')
|
||
{
|
||
/* -(SP) */
|
||
mode = TAHOE_AUTO_DEC;
|
||
if (deferred || immediate || !really_none)
|
||
op_bad = _("Syntax error in auto-dec mode.");
|
||
else if (ndx != -1)
|
||
op_bad = _("You can't have an index auto dec mode.");
|
||
else if (access == 'r')
|
||
op_bad = _("Auto dec mode cant be used for reading.");
|
||
else if (reg != SP_REG)
|
||
op_bad = _("Auto dec only works of the SP register.");
|
||
else if (access == 'b')
|
||
op_bad = _("Auto dec can't be used in a branch.");
|
||
else if (width == 'q')
|
||
op_bad = _("Auto dec won't work with quadwords.");
|
||
|
||
/* We know: imm = -1, dec_inc != '-' */
|
||
}
|
||
else if (dec_inc == '+')
|
||
{
|
||
if (immediate || !really_none)
|
||
op_bad = _("Syntax error in one of the auto-inc modes.");
|
||
else if (deferred)
|
||
{
|
||
/* *(SP)+ */
|
||
mode = TAHOE_AUTO_INC_DEFERRED;
|
||
if (reg != SP_REG)
|
||
op_bad = _("Auto inc deferred only works of the SP register.");
|
||
else if (ndx != -1)
|
||
op_bad = _("You can't have an index auto inc deferred mode.");
|
||
else if (access == 'b')
|
||
op_bad = _("Auto inc can't be used in a branch.");
|
||
}
|
||
else
|
||
{
|
||
/* (SP)+ */
|
||
mode = TAHOE_AUTO_INC;
|
||
if (access == 'm' || access == 'w')
|
||
op_bad = _("You can't write to an auto inc register.");
|
||
else if (reg != SP_REG)
|
||
op_bad = _("Auto inc only works of the SP register.");
|
||
else if (access == 'b')
|
||
op_bad = _("Auto inc can't be used in a branch.");
|
||
else if (width == 'q')
|
||
op_bad = _("Auto inc won't work with quadwords.");
|
||
else if (ndx != -1)
|
||
op_bad = _("You can't have an index in auto inc mode.");
|
||
}
|
||
|
||
/* We know: imm = -1, dec_inc == ' ' */
|
||
}
|
||
else if (reg != -1)
|
||
{
|
||
if ((ndx != -1) && (reg == SP_REG))
|
||
op_bad = _("You can't index the sp register.");
|
||
if (deferred)
|
||
{
|
||
/* *<disp>(Rn) */
|
||
mode = TAHOE_REG_DISP_DEFERRED;
|
||
if (immediate)
|
||
op_bad = _("Syntax error in register displaced mode.");
|
||
}
|
||
else if (really_none)
|
||
{
|
||
/* (Rn) */
|
||
mode = TAHOE_REG_DEFERRED;
|
||
/* if reg = SP then cant be indexed */
|
||
}
|
||
else
|
||
{
|
||
/* <disp>(Rn) */
|
||
mode = TAHOE_REG_DISP;
|
||
}
|
||
|
||
/* We know: imm = -1, dec_inc == ' ', Reg = -1 */
|
||
}
|
||
else
|
||
{
|
||
if (really_none)
|
||
op_bad = _("An offest is needed for this operand.");
|
||
if (deferred && immediate)
|
||
{
|
||
/* *$<ADDR> */
|
||
mode = TAHOE_ABSOLUTE_ADDR;
|
||
disp_size = 4;
|
||
}
|
||
else if (immediate)
|
||
{
|
||
/* $<disp> */
|
||
mode = TAHOE_IMMEDIATE;
|
||
if (ndx != -1)
|
||
op_bad = _("You can't index a register in immediate mode.");
|
||
if (access == 'a')
|
||
op_bad = _("Immediate access can't be used as an address.");
|
||
/* ponder the wisdom of a cast because it doesn't do any good. */
|
||
}
|
||
else if (deferred)
|
||
{
|
||
/* *<disp> */
|
||
mode = TAHOE_DISP_REL_DEFERRED;
|
||
}
|
||
else
|
||
{
|
||
/* <disp> */
|
||
mode = TAHOE_DISPLACED_RELATIVE;
|
||
}
|
||
}
|
||
}
|
||
|
||
/*
|
||
* At this point, all the errors we can do have be checked for.
|
||
* We can build the 'top'. */
|
||
|
||
topP->top_ndx = ndx;
|
||
topP->top_reg = reg;
|
||
topP->top_mode = mode;
|
||
topP->top_error = op_bad;
|
||
topP->top_dispsize = disp_size;
|
||
} /* tip_op */
|
||
|
||
/*
|
||
* t i p ( )
|
||
*
|
||
* This converts a string into a tahoe instruction.
|
||
* The string must be a bare single instruction in tahoe (with BSD4 frobs)
|
||
* format.
|
||
* It provides at most one fatal error message (which stops the scan)
|
||
* some warning messages as it finds them.
|
||
* The tahoe instruction is returned in exploded form.
|
||
*
|
||
* The exploded instruction is returned to a struct tit of your choice.
|
||
* #include "tahoe-inst.h" to know what a struct tit is.
|
||
*
|
||
*/
|
||
|
||
static void
|
||
tip (titP, instring)
|
||
struct tit *titP; /* We build an exploded instruction here. */
|
||
char *instring; /* Text of a vax instruction: we modify. */
|
||
{
|
||
register struct tot_wot *twP = NULL; /* How to bit-encode this opcode. */
|
||
register char *p; /* 1/skip whitespace.2/scan vot_how */
|
||
register char *q; /* */
|
||
register unsigned char count; /* counts number of operands seen */
|
||
register struct top *operandp;/* scan operands in struct tit */
|
||
register char *alloperr = ""; /* error over all operands */
|
||
register char c; /* Remember char, (we clobber it
|
||
with '\0' temporarily). */
|
||
char *save_input_line_pointer;
|
||
|
||
if (*instring == ' ')
|
||
++instring; /* Skip leading whitespace. */
|
||
for (p = instring; *p && *p != ' '; p++)
|
||
; /* MUST end in end-of-string or
|
||
exactly 1 space. */
|
||
/* Scanned up to end of operation-code. */
|
||
/* Operation-code is ended with whitespace. */
|
||
if (p == instring)
|
||
{
|
||
titP->tit_error = _("No operator");
|
||
count = 0;
|
||
titP->tit_opcode = 0;
|
||
}
|
||
else
|
||
{
|
||
c = *p;
|
||
*p = '\0';
|
||
/*
|
||
* Here with instring pointing to what better be an op-name, and p
|
||
* pointing to character just past that.
|
||
* We trust instring points to an op-name, with no whitespace.
|
||
*/
|
||
twP = (struct tot_wot *) hash_find (op_hash, instring);
|
||
*p = c; /* Restore char after op-code. */
|
||
if (twP == 0)
|
||
{
|
||
titP->tit_error = _("Unknown operator");
|
||
count = 0;
|
||
titP->tit_opcode = 0;
|
||
}
|
||
else
|
||
{
|
||
/*
|
||
* We found a match! So let's pick up as many operands as the
|
||
* instruction wants, and even gripe if there are too many.
|
||
* We expect comma to seperate each operand.
|
||
* We let instring track the text, while p tracks a part of the
|
||
* struct tot.
|
||
*/
|
||
|
||
count = 0; /* no operands seen yet */
|
||
instring = p + (*p != '\0'); /* point past the operation code */
|
||
/* tip_op() screws with the input_line_pointer, so save it before
|
||
I jump in */
|
||
save_input_line_pointer = input_line_pointer;
|
||
for (p = twP->args, operandp = titP->tit_operand;
|
||
!*alloperr && *p;
|
||
operandp++, p += 2)
|
||
{
|
||
/*
|
||
* Here to parse one operand. Leave instring pointing just
|
||
* past any one ',' that marks the end of this operand.
|
||
*/
|
||
if (!p[1])
|
||
as_fatal (_("Compiler bug: ODD number of bytes in arg structure %s."),
|
||
twP->args);
|
||
else if (*instring)
|
||
{
|
||
for (q = instring; (*q != ',' && *q != '\0'); q++)
|
||
{
|
||
if (*q == '\'' && q[1] != '\0') /* Jump quoted characters */
|
||
q++;
|
||
}
|
||
c = *q;
|
||
/*
|
||
* Q points to ',' or '\0' that ends argument. C is that
|
||
* character.
|
||
*/
|
||
*q = '\0';
|
||
operandp->top_access = p[0];
|
||
operandp->top_width = p[1];
|
||
tip_op (instring - 1, operandp);
|
||
*q = c; /* Restore input text. */
|
||
if (*(operandp->top_error))
|
||
{
|
||
alloperr = operandp->top_error;
|
||
}
|
||
instring = q + (c ? 1 : 0); /* next operand (if any) */
|
||
count++; /* won another argument, may have an operr */
|
||
}
|
||
else
|
||
alloperr = _("Not enough operands");
|
||
}
|
||
/* Restore the pointer. */
|
||
input_line_pointer = save_input_line_pointer;
|
||
|
||
if (!*alloperr)
|
||
{
|
||
if (*instring == ' ')
|
||
instring++; /* Skip whitespace. */
|
||
if (*instring)
|
||
alloperr = _("Too many operands");
|
||
}
|
||
titP->tit_error = alloperr;
|
||
}
|
||
}
|
||
|
||
titP->tit_opcode = twP->code; /* The op-code. */
|
||
titP->tit_operands = count;
|
||
} /* tip */
|
||
|
||
/* md_assemble() emit frags for 1 instruction */
|
||
void
|
||
md_assemble (instruction_string)
|
||
char *instruction_string; /* A string: assemble 1 instruction. */
|
||
{
|
||
char *p;
|
||
register struct top *operandP;/* An operand. Scans all operands. */
|
||
/* char c_save; fixme: remove this line *//* What used to live after an expression. */
|
||
/* struct frag *fragP; fixme: remove this line *//* Fragment of code we just made. */
|
||
/* register struct top *end_operandP; fixme: remove this line *//* -> slot just after last operand
|
||
Limit of the for (each operand). */
|
||
register expressionS *expP; /* -> expression values for this operand */
|
||
|
||
/* These refer to an instruction operand expression. */
|
||
segT to_seg; /* Target segment of the address. */
|
||
|
||
register valueT this_add_number;
|
||
register symbolS *this_add_symbol; /* +ve (minuend) symbol. */
|
||
|
||
/* tahoe_opcodeT opcode_as_number; fixme: remove this line *//* The opcode as a number. */
|
||
char *opcodeP; /* Where it is in a frag. */
|
||
/* char *opmodeP; fixme: remove this line *//* Where opcode type is, in a frag. */
|
||
|
||
int dispsize; /* From top_dispsize: tahoe_operand_width
|
||
(in bytes) */
|
||
int is_undefined; /* 1 if operand expression's
|
||
segment not known yet. */
|
||
int pc_rel; /* Is this operand pc relative? */
|
||
|
||
/* Decode the operand. */
|
||
tip (&t, instruction_string);
|
||
|
||
/*
|
||
* Check to see if this operand decode properly.
|
||
* Notice that we haven't made any frags yet.
|
||
* If it goofed, then this instruction will wedge in any pass,
|
||
* and we can safely flush it, without causing interpass symbol phase
|
||
* errors. That is, without changing label values in different passes.
|
||
*/
|
||
if (*t.tit_error)
|
||
{
|
||
as_warn (_("Ignoring statement due to \"%s\""), t.tit_error);
|
||
}
|
||
else
|
||
{
|
||
/* We saw no errors in any operands - try to make frag(s) */
|
||
/* Emit op-code. */
|
||
/* Remember where it is, in case we want to modify the op-code later. */
|
||
opcodeP = frag_more (1);
|
||
*opcodeP = t.tit_opcode;
|
||
/* Now do each operand. */
|
||
for (operandP = t.tit_operand;
|
||
operandP < t.tit_operand + t.tit_operands;
|
||
operandP++)
|
||
{ /* for each operand */
|
||
expP = &(operandP->exp_of_operand);
|
||
if (operandP->top_ndx >= 0)
|
||
{
|
||
/* Indexed addressing byte
|
||
Legality of indexed mode already checked: it is OK */
|
||
FRAG_APPEND_1_CHAR (0x40 + operandP->top_ndx);
|
||
} /* if(top_ndx>=0) */
|
||
|
||
/* Here to make main operand frag(s). */
|
||
this_add_number = expP->X_add_number;
|
||
this_add_symbol = expP->X_add_symbol;
|
||
to_seg = operandP->seg_of_operand;
|
||
know (to_seg == SEG_UNKNOWN || \
|
||
to_seg == SEG_ABSOLUTE || \
|
||
to_seg == SEG_DATA || \
|
||
to_seg == SEG_TEXT || \
|
||
to_seg == SEG_BSS);
|
||
is_undefined = (to_seg == SEG_UNKNOWN);
|
||
/* Do we know how big this opperand is? */
|
||
dispsize = operandP->top_dispsize;
|
||
pc_rel = 0;
|
||
/* Deal with the branch possabilities. (Note, this doesn't include
|
||
jumps.)*/
|
||
if (operandP->top_access == 'b')
|
||
{
|
||
/* Branches must be expressions. A psuedo branch can also jump to
|
||
an absolute address. */
|
||
if (to_seg == now_seg || is_undefined)
|
||
{
|
||
/* If is_undefined, then it might BECOME now_seg by relax time. */
|
||
if (dispsize)
|
||
{
|
||
/* I know how big the branch is supposed to be (it's a normal
|
||
branch), so I set up the frag, and let GAS do the rest. */
|
||
p = frag_more (dispsize);
|
||
fix_new (frag_now, p - frag_now->fr_literal,
|
||
this_add_symbol, this_add_number,
|
||
size_to_fx (dispsize, 1),
|
||
NULL);
|
||
}
|
||
else
|
||
{
|
||
/* (to_seg==now_seg || to_seg == SEG_UNKNOWN) && dispsize==0 */
|
||
/* If we don't know how big it is, then its a synthetic branch,
|
||
so we set up a simple relax state. */
|
||
switch (operandP->top_width)
|
||
{
|
||
case TAHOE_WIDTH_CONDITIONAL_JUMP:
|
||
/* Simple (conditional) jump. I may have to reverse the
|
||
condition of opcodeP, and then jump to my destination.
|
||
I set 1 byte aside for the branch off set, and could need 6
|
||
more bytes for the pc_rel jump */
|
||
frag_var (rs_machine_dependent, 7, 1,
|
||
ENCODE_RELAX (STATE_CONDITIONAL_BRANCH,
|
||
is_undefined ? STATE_UNDF : STATE_BYTE),
|
||
this_add_symbol, this_add_number, opcodeP);
|
||
break;
|
||
case TAHOE_WIDTH_ALWAYS_JUMP:
|
||
/* Simple (unconditional) jump. I may have to convert this to
|
||
a word branch, or an absolute jump. */
|
||
frag_var (rs_machine_dependent, 5, 1,
|
||
ENCODE_RELAX (STATE_ALWAYS_BRANCH,
|
||
is_undefined ? STATE_UNDF : STATE_BYTE),
|
||
this_add_symbol, this_add_number, opcodeP);
|
||
break;
|
||
/* The smallest size for the next 2 cases is word. */
|
||
case TAHOE_WIDTH_BIG_REV_JUMP:
|
||
frag_var (rs_machine_dependent, 8, 2,
|
||
ENCODE_RELAX (STATE_BIG_REV_BRANCH,
|
||
is_undefined ? STATE_UNDF : STATE_WORD),
|
||
this_add_symbol, this_add_number,
|
||
opcodeP);
|
||
break;
|
||
case TAHOE_WIDTH_BIG_NON_REV_JUMP:
|
||
frag_var (rs_machine_dependent, 10, 2,
|
||
ENCODE_RELAX (STATE_BIG_NON_REV_BRANCH,
|
||
is_undefined ? STATE_UNDF : STATE_WORD),
|
||
this_add_symbol, this_add_number,
|
||
opcodeP);
|
||
break;
|
||
default:
|
||
as_fatal (_("Compliler bug: Got a case (%d) I wasn't expecting."),
|
||
operandP->top_width);
|
||
}
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* to_seg != now_seg && to_seg != seg_unknown (still in branch)
|
||
In other words, I'm jumping out of my segment so extend the
|
||
branches to jumps, and let GAS fix them. */
|
||
|
||
/* These are "branches" what will always be branches around a jump
|
||
to the correct addresss in real life.
|
||
If to_seg is SEG_ABSOLUTE, just encode the branch in,
|
||
else let GAS fix the address. */
|
||
|
||
switch (operandP->top_width)
|
||
{
|
||
/* The theory:
|
||
For SEG_ABSOLUTE, then mode is ABSOLUTE_ADDR, jump
|
||
to that addresss (not pc_rel).
|
||
For other segs, address is a long word PC rel jump. */
|
||
case TAHOE_WIDTH_CONDITIONAL_JUMP:
|
||
/* b<cond> */
|
||
/* To reverse the condition in a TAHOE branch,
|
||
complement bit 4 */
|
||
*opcodeP ^= 0x10;
|
||
p = frag_more (7);
|
||
*p++ = 6;
|
||
*p++ = TAHOE_JMP;
|
||
*p++ = (operandP->top_mode ==
|
||
TAHOE_ABSOLUTE_ADDR ? TAHOE_ABSOLUTE_ADDR :
|
||
TAHOE_PC_REL_LONG);
|
||
fix_new (frag_now, p - frag_now->fr_literal,
|
||
this_add_symbol, this_add_number,
|
||
(to_seg != SEG_ABSOLUTE) ? FX_PCREL32 : FX_32, NULL);
|
||
/*
|
||
* Now (eg) BLEQ 1f
|
||
* JMP foo
|
||
* 1:
|
||
*/
|
||
break;
|
||
case TAHOE_WIDTH_ALWAYS_JUMP:
|
||
/* br, just turn it into a jump */
|
||
*opcodeP = TAHOE_JMP;
|
||
p = frag_more (5);
|
||
*p++ = (operandP->top_mode ==
|
||
TAHOE_ABSOLUTE_ADDR ? TAHOE_ABSOLUTE_ADDR :
|
||
TAHOE_PC_REL_LONG);
|
||
fix_new (frag_now, p - frag_now->fr_literal,
|
||
this_add_symbol, this_add_number,
|
||
(to_seg != SEG_ABSOLUTE) ? FX_PCREL32 : FX_32, NULL);
|
||
/* Now (eg) JMP foo */
|
||
break;
|
||
case TAHOE_WIDTH_BIG_REV_JUMP:
|
||
p = frag_more (8);
|
||
*opcodeP ^= 0x10;
|
||
*p++ = 0;
|
||
*p++ = 6;
|
||
*p++ = TAHOE_JMP;
|
||
*p++ = (operandP->top_mode ==
|
||
TAHOE_ABSOLUTE_ADDR ? TAHOE_ABSOLUTE_ADDR :
|
||
TAHOE_PC_REL_LONG);
|
||
fix_new (frag_now, p - frag_now->fr_literal,
|
||
this_add_symbol, this_add_number,
|
||
(to_seg != SEG_ABSOLUTE) ? FX_PCREL32 : FX_32, NULL);
|
||
/*
|
||
* Now (eg) ACBx 1f
|
||
* JMP foo
|
||
* 1:
|
||
*/
|
||
break;
|
||
case TAHOE_WIDTH_BIG_NON_REV_JUMP:
|
||
p = frag_more (10);
|
||
*p++ = 0;
|
||
*p++ = 2;
|
||
*p++ = TAHOE_BRB;
|
||
*p++ = 6;
|
||
*p++ = TAHOE_JMP;
|
||
*p++ = (operandP->top_mode ==
|
||
TAHOE_ABSOLUTE_ADDR ? TAHOE_ABSOLUTE_ADDR :
|
||
TAHOE_PC_REL_LONG);
|
||
fix_new (frag_now, p - frag_now->fr_literal,
|
||
this_add_symbol, this_add_number,
|
||
(to_seg != SEG_ABSOLUTE) ? FX_PCREL32 : FX_32, NULL);
|
||
/*
|
||
* Now (eg) xOBxxx 1f
|
||
* BRB 2f
|
||
* 1: JMP @#foo
|
||
* 2:
|
||
*/
|
||
break;
|
||
case 'b':
|
||
case 'w':
|
||
as_warn (_("Real branch displacements must be expressions."));
|
||
break;
|
||
default:
|
||
as_fatal (_("Complier error: I got an unknown synthetic branch :%c"),
|
||
operandP->top_width);
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* It ain't a branch operand. */
|
||
switch (operandP->top_mode)
|
||
{
|
||
/* Auto-foo access, only works for one reg (SP)
|
||
so the only thing needed is the mode. */
|
||
case TAHOE_AUTO_DEC:
|
||
case TAHOE_AUTO_INC:
|
||
case TAHOE_AUTO_INC_DEFERRED:
|
||
FRAG_APPEND_1_CHAR (operandP->top_mode);
|
||
break;
|
||
|
||
/* Numbered Register only access. Only thing needed is the
|
||
mode + Register number */
|
||
case TAHOE_DIRECT_REG:
|
||
case TAHOE_REG_DEFERRED:
|
||
FRAG_APPEND_1_CHAR (operandP->top_mode + operandP->top_reg);
|
||
break;
|
||
|
||
/* An absolute address. It's size is always 5 bytes.
|
||
(mode_type + 4 byte address). */
|
||
case TAHOE_ABSOLUTE_ADDR:
|
||
know ((this_add_symbol == NULL));
|
||
p = frag_more (5);
|
||
*p = TAHOE_ABSOLUTE_ADDR;
|
||
md_number_to_chars (p + 1, this_add_number, 4);
|
||
break;
|
||
|
||
/* Immediate data. If the size isn't known, then it's an address
|
||
+ and offset, which is 4 bytes big. */
|
||
case TAHOE_IMMEDIATE:
|
||
if (this_add_symbol != NULL)
|
||
{
|
||
p = frag_more (5);
|
||
*p++ = TAHOE_IMMEDIATE_LONGWORD;
|
||
fix_new (frag_now, p - frag_now->fr_literal,
|
||
this_add_symbol, this_add_number,
|
||
FX_32, NULL);
|
||
}
|
||
else
|
||
{
|
||
/* It's a integer, and I know it's size. */
|
||
if ((unsigned) this_add_number < 0x40)
|
||
{
|
||
/* Will it fit in a literal? */
|
||
FRAG_APPEND_1_CHAR ((byte) this_add_number);
|
||
}
|
||
else
|
||
{
|
||
p = frag_more (dispsize + 1);
|
||
switch (dispsize)
|
||
{
|
||
case 1:
|
||
*p++ = TAHOE_IMMEDIATE_BYTE;
|
||
*p = (byte) this_add_number;
|
||
break;
|
||
case 2:
|
||
*p++ = TAHOE_IMMEDIATE_WORD;
|
||
md_number_to_chars (p, this_add_number, 2);
|
||
break;
|
||
case 4:
|
||
*p++ = TAHOE_IMMEDIATE_LONGWORD;
|
||
md_number_to_chars (p, this_add_number, 4);
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
break;
|
||
|
||
/* Distance from the PC. If the size isn't known, we have to relax
|
||
into it. The difference between this and disp(sp) is that
|
||
this offset is pc_rel, and disp(sp) isn't.
|
||
Note the drop through code. */
|
||
|
||
case TAHOE_DISPLACED_RELATIVE:
|
||
case TAHOE_DISP_REL_DEFERRED:
|
||
operandP->top_reg = PC_REG;
|
||
pc_rel = 1;
|
||
|
||
/* Register, plus a displacement mode. Save the register number,
|
||
and weather its deffered or not, and relax the size if it isn't
|
||
known. */
|
||
case TAHOE_REG_DISP:
|
||
case TAHOE_REG_DISP_DEFERRED:
|
||
if (operandP->top_mode == TAHOE_DISP_REL_DEFERRED ||
|
||
operandP->top_mode == TAHOE_REG_DISP_DEFERRED)
|
||
operandP->top_reg += 0x10; /* deffered mode is always 0x10 higher
|
||
than it's non-deffered sibling. */
|
||
|
||
/* Is this a value out of this segment?
|
||
The first part of this conditional is a cludge to make gas
|
||
produce the same output as 'as' when there is a lable, in
|
||
the current segment, displaceing a register. It's strange,
|
||
and no one in their right mind would do it, but it's easy
|
||
to cludge. */
|
||
if ((dispsize == 0 && !pc_rel) ||
|
||
(to_seg != now_seg && !is_undefined && to_seg != SEG_ABSOLUTE))
|
||
dispsize = 4;
|
||
|
||
if (dispsize == 0)
|
||
{
|
||
/*
|
||
* We have a SEG_UNKNOWN symbol, or the size isn't cast.
|
||
* It might turn out to be in the same segment as
|
||
* the instruction, permitting relaxation.
|
||
*/
|
||
p = frag_var (rs_machine_dependent, 5, 2,
|
||
ENCODE_RELAX (STATE_PC_RELATIVE,
|
||
is_undefined ? STATE_UNDF : STATE_BYTE),
|
||
this_add_symbol, this_add_number, 0);
|
||
*p = operandP->top_reg;
|
||
}
|
||
else
|
||
{
|
||
/* Either this is an abs, or a cast. */
|
||
p = frag_more (dispsize + 1);
|
||
switch (dispsize)
|
||
{
|
||
case 1:
|
||
*p = TAHOE_PC_OR_BYTE + operandP->top_reg;
|
||
break;
|
||
case 2:
|
||
*p = TAHOE_PC_OR_WORD + operandP->top_reg;
|
||
break;
|
||
case 4:
|
||
*p = TAHOE_PC_OR_LONG + operandP->top_reg;
|
||
break;
|
||
};
|
||
fix_new (frag_now, p + 1 - frag_now->fr_literal,
|
||
this_add_symbol, this_add_number,
|
||
size_to_fx (dispsize, pc_rel), NULL);
|
||
}
|
||
break;
|
||
default:
|
||
as_fatal (_("Barf, bad mode %x\n"), operandP->top_mode);
|
||
}
|
||
}
|
||
} /* for(operandP) */
|
||
} /* if(!need_pass_2 && !goofed) */
|
||
} /* tahoe_assemble() */
|
||
|
||
/* We have no need to default values of symbols. */
|
||
|
||
/* ARGSUSED */
|
||
symbolS *
|
||
md_undefined_symbol (name)
|
||
char *name;
|
||
{
|
||
return 0;
|
||
} /* md_undefined_symbol() */
|
||
|
||
/* Round up a section size to the appropriate boundary. */
|
||
valueT
|
||
md_section_align (segment, size)
|
||
segT segment;
|
||
valueT size;
|
||
{
|
||
return ((size + 7) & ~7); /* Round all sects to multiple of 8 */
|
||
} /* md_section_align() */
|
||
|
||
/* Exactly what point is a PC-relative offset relative TO?
|
||
On the sparc, they're relative to the address of the offset, plus
|
||
its size. This gets us to the following instruction.
|
||
(??? Is this right? FIXME-SOON) */
|
||
long
|
||
md_pcrel_from (fixP)
|
||
fixS *fixP;
|
||
{
|
||
return (((fixP->fx_type == FX_8
|
||
|| fixP->fx_type == FX_PCREL8)
|
||
? 1
|
||
: ((fixP->fx_type == FX_16
|
||
|| fixP->fx_type == FX_PCREL16)
|
||
? 2
|
||
: ((fixP->fx_type == FX_32
|
||
|| fixP->fx_type == FX_PCREL32)
|
||
? 4
|
||
: 0))) + fixP->fx_where + fixP->fx_frag->fr_address);
|
||
} /* md_pcrel_from() */
|
||
|
||
int
|
||
tc_is_pcrel (fixP)
|
||
fixS *fixP;
|
||
{
|
||
/* should never be called */
|
||
know (0);
|
||
return (0);
|
||
} /* tc_is_pcrel() */
|