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mips.h (mips_output_conditional_branch): New function.

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* mips.h (mips_output_conditional_branch): New function.
	(mips_adjust_insn_length): Likewise.
	(ASSEMBLER_SCRATCH_REGNUM): New macro.
	(ADJUST_INSN_LENGTH): Likewise.
	* mips.c (print_operand): Add `F' and `W' for floating-point
	comparison opcodes.
	(machine_dependent_reorg): Adjust MIPS16 code; instruction-lengths
	are now in bytes.
	(mips_adjust_insn_length): New function.
	(mips_output_conditional_branch): New function.
	* mips.md (length): Adjust attribute definition to handle
	conditional branches.  	Change lengths to bytes, rather than
	instructions throughout.  Remove length attribute from
	instructions whose length is four bytes, and rely on the default
	instead.
	(dslot): Fix typo in comment.
	Reword conditional branch patterns to use
	mips_output_conditional_branch.

From-SVN: r27369
This commit is contained in:
Mark Mitchell 1999-06-05 11:12:58 +00:00 committed by Mark Mitchell
parent 29bbeb1c2b
commit 0ff8379990
4 changed files with 1005 additions and 732 deletions
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21
gcc/ChangeLog
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@ -1,3 +1,24 @@
Sat Jun 5 12:11:24 1999 Mark Mitchell <mark@codesourcery.com>
* mips.h (mips_output_conditional_branch): New function.
(mips_adjust_insn_length): Likewise.
(ASSEMBLER_SCRATCH_REGNUM): New macro.
(ADJUST_INSN_LENGTH): Likewise.
* mips.c (print_operand): Add `F' and `W' for floating-point
comparison opcodes.
(machine_dependent_reorg): Adjust MIPS16 code; instruction-lengths
are now in bytes.
(mips_adjust_insn_length): New function.
(mips_output_conditional_branch): New function.
* mips.md (length): Adjust attribute definition to handle
conditional branches. Change lengths to bytes, rather than
instructions throughout. Remove length attribute from
instructions whose length is four bytes, and rely on the default
instead.
(dslot): Fix typo in comment.
Reword conditional branch patterns to use
mips_output_conditional_branch.
Fri Jun 4 13:30:27 1999 Rainer Orth <ro@TechFak.Uni-Bielefeld.DE>
* alpha/osf.h (CPP_SUBTARGET_SPEC): Handle -threads.

317
gcc/config/mips/mips.c
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@ -4594,7 +4594,9 @@ mips_debugger_offset (addr, offset)
'L' print low-order register of double-word register operand.
'M' print high-order register of double-word register operand.
'C' print part of opcode for a branch condition.
'F' print part of opcode for a floating-point branch condition.
'N' print part of opcode for a branch condition, inverted.
'W' print part of opcode for a floating-point branch condition, inverted.
'S' X is CODE_LABEL, print with prefix of "LS" (for embedded switch).
'B' print 'z' for EQ, 'n' for NE
'b' print 'n' for EQ, 'z' for NE
@ -4792,6 +4794,24 @@ print_operand (file, op, letter)
abort_with_insn (op, "PRINT_OPERAND, invalid insn for %%N");
}
else if (letter == 'F')
switch (code)
{
case EQ: fputs ("c1f", file); break;
case NE: fputs ("c1t", file); break;
default:
abort_with_insn (op, "PRINT_OPERAND, invalid insn for %%F");
}
else if (letter == 'W')
switch (code)
{
case EQ: fputs ("c1t", file); break;
case NE: fputs ("c1f", file); break;
default:
abort_with_insn (op, "PRINT_OPERAND, invalid insn for %%W");
}
else if (letter == 'S')
{
char buffer[100];
@ -8332,7 +8352,7 @@ machine_dependent_reorg (first)
insns_len = 0;
for (insn = first; insn; insn = NEXT_INSN (insn))
{
insns_len += get_attr_length (insn) * 2;
insns_len += get_attr_length (insn);
/* ??? We put switch tables in .text, but we don't define
JUMP_TABLES_IN_TEXT_SECTION, so get_attr_length will not
@ -8440,7 +8460,7 @@ machine_dependent_reorg (first)
}
}
addr += get_attr_length (insn) * 2;
addr += get_attr_length (insn);
/* ??? We put switch tables in .text, but we don't define
JUMP_TABLES_IN_TEXT_SECTION, so get_attr_length will not
@ -8520,3 +8540,296 @@ highpart_shift_operator (x, mode)
|| code == ROTATERT
|| code == ROTATE);
}
/* Return the length of INSN. LENGTH is the initial length computed by
attributes in the machine-description file. */
int
mips_adjust_insn_length (insn, length)
rtx insn;
int length;
{
/* A unconditional jump has an unfilled delay slot if it is not part
of a sequence. A conditional jump normally has a delay slot, but
does not on MIPS16. */
if (simplejump_p (insn)
|| (!TARGET_MIPS16 && (GET_CODE (insn) == JUMP_INSN
|| GET_CODE (insn) == CALL_INSN)))
length += 4;
/* All MIPS16 instructions are a measly two bytes. */
if (TARGET_MIPS16)
length /= 2;
return length;
}
/* Output assembly instructions to peform a conditional branch.
INSN is the branch instruction. OPERANDS[0] is the condition.
OPERANDS[1] is the target of the branch. OPERANDS[2] is the target
of the first operand to the condition. If TWO_OPERANDS_P is
non-zero the comparison takes two operands; OPERANDS[3] will be the
second operand.
If INVERTED_P is non-zero we are to branch if the condition does
not hold. If FLOAT_P is non-zero this is a floating-point comparison.
LENGTH is the length (in bytes) of the sequence we are to generate.
That tells us whether to generate a simple conditional branch, or a
reversed conditional branch around a `jr' instruction. */
char *
mips_output_conditional_branch (insn,
operands,
two_operands_p,
float_p,
inverted_p,
length)
rtx insn;
rtx *operands;
int two_operands_p;
int float_p;
int inverted_p;
int length;
{
static char buffer[200];
/* The kind of comparison we are doing. */
enum rtx_code code = GET_CODE (operands[0]);
/* Non-zero if the opcode for the comparison needs a `z' indicating
that it is a comparision against zero. */
int need_z_p;
/* A string to use in the assembly output to represent the first
operand. */
char *op1 = "%z2";
/* A string to use in the assembly output to represent the second
operand. Use the hard-wired zero register if there's no second
operand. */
char *op2 = (two_operands_p ? ",%z3" : ",%.");
/* The operand-printing string for the comparison. */
char *comp = (float_p ? "%F0" : "%C0");
/* The operand-printing string for the inverted comparison. */
char *inverted_comp = (float_p ? "%W0" : "%N0");
/* The MIPS processors (for levels of the ISA at least two), have
"likely" variants of each branch instruction. These instructions
annul the instruction in the delay slot if the branch is not
taken. */
mips_branch_likely = (final_sequence && INSN_ANNULLED_BRANCH_P (insn));
if (!two_operands_p)
{
/* To compute whether than A > B, for example, we normally
subtract B from A and then look at the sign bit. But, if we
are doing an unsigned comparison, and B is zero, we don't
have to do the subtraction. Instead, we can just check to
see if A is non-zero. Thus, we change the CODE here to
reflect the simpler comparison operation. */
switch (code)
{
case GTU:
code = NE;
break;
case LEU:
code = EQ;
break;
case GEU:
/* A condition which will always be true. */
code = EQ;
op1 = "%.";
break;
case LTU:
/* A condition which will always be false. */
code = NE;
op1 = "%.";
break;
default:
/* Not a special case. */
}
}
/* Relative comparisons are always done against zero. But
equality comparisons are done between two operands, and therefore
do not require a `z' in the assembly language output. */
need_z_p = (!float_p && code != EQ && code != NE);
/* For comparisons against zero, the zero is not provided
explicitly. */
if (need_z_p)
op2 = "";
/* Begin by terminating the buffer. That way we can always use
strcat to add to it. */
buffer[0] = '\0';
switch (length)
{
case 4:
case 8:
/* Just a simple conditional branch. */
if (float_p)
sprintf (buffer, "%%*b%s%%?\t%%Z2%%1",
inverted_p ? inverted_comp : comp);
else
sprintf (buffer, "%%*b%s%s%%?\t%s%s,%%1",
inverted_p ? inverted_comp : comp,
need_z_p ? "z" : "",
op1,
op2);
return buffer;
case 12:
case 16:
{
/* Generate a reversed conditional branch around ` j'
instruction:
.set noreorder
.set nomacro
bc l
nop
j target
.set macro
.set reorder
l:
Because we have to jump four bytes *past* the following
instruction if this branch was annulled, we can't just use
a label, as in the picture above; there's no way to put the
label after the next instruction, as the assembler does not
accept `.L+4' as the target of a branch. (We can't just
wait until the next instruction is output; it might be a
macro and take up more than four bytes. Once again, we see
why we want to eliminate macros.)
If the branch is annulled, we jump four more bytes that we
would otherwise; that way we skip the annulled instruction
in the delay slot. */
char *target
= ((mips_branch_likely || length == 16) ? ".+16" : ".+12");
char *c;
strcpy (buffer, "%(%<");
c = strchr (buffer, '\0');
/* Generate the reversed comparision. This takes four
bytes. */
if (float_p)
sprintf (c, "%%*b%s\t%%Z2%s",
inverted_p ? comp : inverted_comp,
target);
else
sprintf (c, "%%*b%s%s\t%s%s,%s",
inverted_p ? comp : inverted_comp,
need_z_p ? "z" : "",
op1,
op2,
target);
strcat (c, "\n\tnop\n\tj\t%1");
if (length == 16)
/* The delay slot was unfilled. Since we're inside
.noreorder, the assembler will not fill in the NOP for
us, so we must do it ourselves. */
strcat (buffer, "\n\tnop");
strcat (buffer, "%>%)");
return buffer;
}
/* We do not currently use this code. It handles jumps to
arbitrary locations, using `jr', even across a 256MB boundary.
We could add a -mhuge switch, and then use this code instead of
the `j' alternative above when -mhuge was used. */
#if 0
case 16:
case 20:
{
/* Generate a reversed conditional branch around a `jr'
instruction:
.set noreorder
.set nomacro
.set noat
bc l
la $at, target
jr $at
.set at
.set macro
.set reorder
l:
Not pretty, but allows a conditional branch anywhere in the
32-bit address space. If the original branch is annulled,
then the instruction in the delay slot should be executed
only if the branch is taken. The la instruction is really
a macro which will usually take eight bytes, but sometimes
takes only four, if the instruction to which we're jumping
gets its own entry in the global pointer table, which will
happen if its a case label. The assembler will then
generate only a four-byte sequence, rather than eight, and
there seems to be no way to tell it not to. Thus, we can't
just use a `.+x' addressing form; we don't know what value
to give for `x'.
So, we resort to using the explicit relocation syntax
available in the assembler and do:
lw $at,%got_page(target)($gp)
daddiu $at,$at,%got_ofst(target)
That way, this always takes up eight bytes, and we can use
the `.+x' form. Of course, these explicit machinations
with relocation will not work with old assemblers. Then
again, neither do out-of-range branches, so we haven't lost
anything. */
/* The target of the reversed branch. */
char *target
= ((mips_branch_likely || length == 20) ? ".+20" : ".+16");
char *at_register = mips_reg_names[ASSEMBLER_SCRATCH_REGNUM];
char *gp_register = mips_reg_names[PIC_OFFSET_TABLE_REGNUM];
char *c;
strcpy (buffer, "%(%<%[");
c = strchr (buffer, '\0');
/* Generate the reversed comparision. This takes four
bytes. */
if (float_p)
sprintf (c, "%%*b%s\t%%Z2%s",
inverted_p ? comp : inverted_comp,
target);
else
sprintf (c, "%%*b%s%s\t%s%s,%s",
inverted_p ? comp : inverted_comp,
need_z_p ? "z" : "",
op1,
op2,
target);
c = strchr (buffer, '\0');
/* Generate the load-address, and jump. This takes twelve
bytes, for a total of 16. */
sprintf (c,
"\n\tlw\t%s,%%%%got_page(%%1)(%s)\n\tdaddiu\t%s,%s,%%%%got_ofst(%%1)\n\tjr\t%s",
at_register,
gp_register,
at_register,
at_register,
at_register);
if (length == 20)
/* The delay slot was unfilled. Since we're inside
.noreorder, the assembler will not fill in the NOP for
us, so we must do it ourselves. */
strcat (buffer, "\n\tnop");
strcat (buffer, "%]%>%)");
return buffer;
}
#endif
default:
abort ();
}
/* NOTREACHED */
return 0;
}

13
gcc/config/mips/mips.h
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@ -233,6 +233,8 @@ extern int mips16_gp_offset_p ();
extern int mips16_constant ();
extern int mips16_constant_after_function_p ();
extern int build_mips16_call_stub ();
extern char *mips_output_conditional_branch ();
extern int mips_adjust_insn_length ();
/* Recognition functions that return if a condition is true. */
extern int address_operand ();
@ -1686,6 +1688,9 @@ extern char mips_hard_regno_mode_ok[][FIRST_PSEUDO_REGISTER];
a fixed register, and will not be used for anything else. */
#define FRAME_POINTER_REGNUM (GP_REG_FIRST + 1)
/* Temporary scratch register for use by the assembler. */
#define ASSEMBLER_SCRATCH_REGNUM (GP_REG_FIRST + 1)
/* $30 is not available on the mips16, so we use $17 as the frame
pointer. */
#define HARD_FRAME_POINTER_REGNUM \
@ -3769,6 +3774,14 @@ while (0)
#define ADJUST_COST(INSN,LINK,DEP_INSN,COST) \
if (REG_NOTE_KIND (LINK) != 0) \
(COST) = 0; /* Anti or output dependence. */
/* If defined, modifies the length assigned to instruction INSN as a
function of the context in which it is used. LENGTH is an lvalue
that contains the initially computed length of the insn and should
be updated with the correct length of the insn. */
#define ADJUST_INSN_LENGTH(INSN, LENGTH) \
((LENGTH) = mips_adjust_insn_length ((INSN), (LENGTH)))
/* Optionally define this if you have added predicates to
`MACHINE.c'. This macro is called within an initializer of an

1386
gcc/config/mips/mips.md
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