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binutils-gdb/gdb/ppc-sysv-tdep.c
Paul Gilliam 3d8476bc1b 2005-10-24 Paul Gilliam <pgilliam@us.ibm.com 
* ppc-sysv-tdep.c (ppc64_sysv_abi_return_value): Copy code from
	ppc_sysv_abi_return_value() to handle a vector return value.
2005-11-07 20:37:58 +00:00

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/* Target-dependent code for PowerPC systems using the SVR4 ABI
for GDB, the GNU debugger.
Copyright 2000, 2001, 2002, 2003, 2005
Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include "defs.h"
#include "gdbcore.h"
#include "inferior.h"
#include "regcache.h"
#include "value.h"
#include "gdb_string.h"
#include "gdb_assert.h"
#include "ppc-tdep.h"
#include "target.h"
#include "objfiles.h"
#include "infcall.h"
/* Pass the arguments in either registers, or in the stack. Using the
ppc sysv ABI, the first eight words of the argument list (that might
be less than eight parameters if some parameters occupy more than one
word) are passed in r3..r10 registers. float and double parameters are
passed in fpr's, in addition to that. Rest of the parameters if any
are passed in user stack.
If the function is returning a structure, then the return address is passed
in r3, then the first 7 words of the parametes can be passed in registers,
starting from r4. */
CORE_ADDR
ppc_sysv_abi_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
struct regcache *regcache, CORE_ADDR bp_addr,
int nargs, struct value **args, CORE_ADDR sp,
int struct_return, CORE_ADDR struct_addr)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
const CORE_ADDR saved_sp = read_sp ();
int argspace = 0; /* 0 is an initial wrong guess. */
int write_pass;
/* Go through the argument list twice.
Pass 1: Figure out how much new stack space is required for
arguments and pushed values. Unlike the PowerOpen ABI, the SysV
ABI doesn't reserve any extra space for parameters which are put
in registers, but does always push structures and then pass their
address.
Pass 2: Replay the same computation but this time also write the
values out to the target. */
for (write_pass = 0; write_pass < 2; write_pass++)
{
int argno;
/* Next available floating point register for float and double
arguments. */
int freg = 1;
/* Next available general register for non-float, non-vector
arguments. */
int greg = 3;
/* Next available vector register for vector arguments. */
int vreg = 2;
/* Arguments start above the "LR save word" and "Back chain". */
int argoffset = 2 * tdep->wordsize;
/* Structures start after the arguments. */
int structoffset = argoffset + argspace;
/* If the function is returning a `struct', then the first word
(which will be passed in r3) is used for struct return
address. In that case we should advance one word and start
from r4 register to copy parameters. */
if (struct_return)
{
if (write_pass)
regcache_cooked_write_signed (regcache,
tdep->ppc_gp0_regnum + greg,
struct_addr);
greg++;
}
for (argno = 0; argno < nargs; argno++)
{
struct value *arg = args[argno];
struct type *type = check_typedef (value_type (arg));
int len = TYPE_LENGTH (type);
const bfd_byte *val = value_contents (arg);
if (TYPE_CODE (type) == TYPE_CODE_FLT
&& ppc_floating_point_unit_p (current_gdbarch) && len <= 8)
{
/* Floating point value converted to "double" then
passed in an FP register, when the registers run out,
8 byte aligned stack is used. */
if (freg <= 8)
{
if (write_pass)
{
/* Always store the floating point value using
the register's floating-point format. */
gdb_byte regval[MAX_REGISTER_SIZE];
struct type *regtype
= register_type (gdbarch, tdep->ppc_fp0_regnum + freg);
convert_typed_floating (val, type, regval, regtype);
regcache_cooked_write (regcache,
tdep->ppc_fp0_regnum + freg,
regval);
}
freg++;
}
else
{
/* SysV ABI converts floats to doubles before
writing them to an 8 byte aligned stack location. */
argoffset = align_up (argoffset, 8);
if (write_pass)
{
char memval[8];
struct type *memtype;
switch (TARGET_BYTE_ORDER)
{
case BFD_ENDIAN_BIG:
memtype = builtin_type_ieee_double_big;
break;
case BFD_ENDIAN_LITTLE:
memtype = builtin_type_ieee_double_little;
break;
default:
internal_error (__FILE__, __LINE__, _("bad switch"));
}
convert_typed_floating (val, type, memval, memtype);
write_memory (sp + argoffset, val, len);
}
argoffset += 8;
}
}
else if (len == 8 && (TYPE_CODE (type) == TYPE_CODE_INT /* long long */
|| (!ppc_floating_point_unit_p (current_gdbarch) && TYPE_CODE (type) == TYPE_CODE_FLT))) /* double */
{
/* "long long" or "double" passed in an odd/even
register pair with the low addressed word in the odd
register and the high addressed word in the even
register, or when the registers run out an 8 byte
aligned stack location. */
if (greg > 9)
{
/* Just in case GREG was 10. */
greg = 11;
argoffset = align_up (argoffset, 8);
if (write_pass)
write_memory (sp + argoffset, val, len);
argoffset += 8;
}
else if (tdep->wordsize == 8)
{
if (write_pass)
regcache_cooked_write (regcache,
tdep->ppc_gp0_regnum + greg, val);
greg += 1;
}
else
{
/* Must start on an odd register - r3/r4 etc. */
if ((greg & 1) == 0)
greg++;
if (write_pass)
{
regcache_cooked_write (regcache,
tdep->ppc_gp0_regnum + greg + 0,
val + 0);
regcache_cooked_write (regcache,
tdep->ppc_gp0_regnum + greg + 1,
val + 4);
}
greg += 2;
}
}
else if (len == 16
&& TYPE_CODE (type) == TYPE_CODE_ARRAY
&& TYPE_VECTOR (type) && tdep->ppc_vr0_regnum >= 0)
{
/* Vector parameter passed in an Altivec register, or
when that runs out, 16 byte aligned stack location. */
if (vreg <= 13)
{
if (write_pass)
regcache_cooked_write (current_regcache,
tdep->ppc_vr0_regnum + vreg, val);
vreg++;
}
else
{
argoffset = align_up (argoffset, 16);
if (write_pass)
write_memory (sp + argoffset, val, 16);
argoffset += 16;
}
}
else if (len == 8
&& TYPE_CODE (type) == TYPE_CODE_ARRAY
&& TYPE_VECTOR (type) && tdep->ppc_ev0_regnum >= 0)
{
/* Vector parameter passed in an e500 register, or when
that runs out, 8 byte aligned stack location. Note
that since e500 vector and general purpose registers
both map onto the same underlying register set, a
"greg" and not a "vreg" is consumed here. A cooked
write stores the value in the correct locations
within the raw register cache. */
if (greg <= 10)
{
if (write_pass)
regcache_cooked_write (current_regcache,
tdep->ppc_ev0_regnum + greg, val);
greg++;
}
else
{
argoffset = align_up (argoffset, 8);
if (write_pass)
write_memory (sp + argoffset, val, 8);
argoffset += 8;
}
}
else
{
/* Reduce the parameter down to something that fits in a
"word". */
gdb_byte word[MAX_REGISTER_SIZE];
memset (word, 0, MAX_REGISTER_SIZE);
if (len > tdep->wordsize
|| TYPE_CODE (type) == TYPE_CODE_STRUCT
|| TYPE_CODE (type) == TYPE_CODE_UNION)
{
/* Structs and large values are put on an 8 byte
aligned stack ... */
structoffset = align_up (structoffset, 8);
if (write_pass)
write_memory (sp + structoffset, val, len);
/* ... and then a "word" pointing to that address is
passed as the parameter. */
store_unsigned_integer (word, tdep->wordsize,
sp + structoffset);
structoffset += len;
}
else if (TYPE_CODE (type) == TYPE_CODE_INT)
/* Sign or zero extend the "int" into a "word". */
store_unsigned_integer (word, tdep->wordsize,
unpack_long (type, val));
else
/* Always goes in the low address. */
memcpy (word, val, len);
/* Store that "word" in a register, or on the stack.
The words have "4" byte alignment. */
if (greg <= 10)
{
if (write_pass)
regcache_cooked_write (regcache,
tdep->ppc_gp0_regnum + greg, word);
greg++;
}
else
{
argoffset = align_up (argoffset, tdep->wordsize);
if (write_pass)
write_memory (sp + argoffset, word, tdep->wordsize);
argoffset += tdep->wordsize;
}
}
}
/* Compute the actual stack space requirements. */
if (!write_pass)
{
/* Remember the amount of space needed by the arguments. */
argspace = argoffset;
/* Allocate space for both the arguments and the structures. */
sp -= (argoffset + structoffset);
/* Ensure that the stack is still 16 byte aligned. */
sp = align_down (sp, 16);
}
/* The psABI says that "A caller of a function that takes a
variable argument list shall set condition register bit 6 to
1 if it passes one or more arguments in the floating-point
registers. It is strongly recommended that the caller set the
bit to 0 otherwise..." Doing this for normal functions too
shouldn't hurt. */
if (write_pass)
{
ULONGEST cr;
regcache_cooked_read_unsigned (regcache, tdep->ppc_cr_regnum, &cr);
if (freg > 1)
cr |= 0x02000000;
else
cr &= ~0x02000000;
regcache_cooked_write_unsigned (regcache, tdep->ppc_cr_regnum, cr);
}
}
/* Update %sp. */
regcache_cooked_write_signed (regcache, SP_REGNUM, sp);
/* Write the backchain (it occupies WORDSIZED bytes). */
write_memory_signed_integer (sp, tdep->wordsize, saved_sp);
/* Point the inferior function call's return address at the dummy's
breakpoint. */
regcache_cooked_write_signed (regcache, tdep->ppc_lr_regnum, bp_addr);
return sp;
}
/* Handle the return-value conventions specified by the SysV 32-bit
PowerPC ABI (including all the supplements):
no floating-point: floating-point values returned using 32-bit
general-purpose registers.
Altivec: 128-bit vectors returned using vector registers.
e500: 64-bit vectors returned using the full full 64 bit EV
register, floating-point values returned using 32-bit
general-purpose registers.
GCC (broken): Small struct values right (instead of left) aligned
when returned in general-purpose registers. */
static enum return_value_convention
do_ppc_sysv_return_value (struct gdbarch *gdbarch, struct type *type,
struct regcache *regcache, void *readbuf,
const void *writebuf, int broken_gcc)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
gdb_assert (tdep->wordsize == 4);
if (TYPE_CODE (type) == TYPE_CODE_FLT
&& TYPE_LENGTH (type) <= 8
&& ppc_floating_point_unit_p (gdbarch))
{
if (readbuf)
{
/* Floats and doubles stored in "f1". Convert the value to
the required type. */
gdb_byte regval[MAX_REGISTER_SIZE];
struct type *regtype = register_type (gdbarch,
tdep->ppc_fp0_regnum + 1);
regcache_cooked_read (regcache, tdep->ppc_fp0_regnum + 1, regval);
convert_typed_floating (regval, regtype, readbuf, type);
}
if (writebuf)
{
/* Floats and doubles stored in "f1". Convert the value to
the register's "double" type. */
gdb_byte regval[MAX_REGISTER_SIZE];
struct type *regtype = register_type (gdbarch, tdep->ppc_fp0_regnum);
convert_typed_floating (writebuf, type, regval, regtype);
regcache_cooked_write (regcache, tdep->ppc_fp0_regnum + 1, regval);
}
return RETURN_VALUE_REGISTER_CONVENTION;
}
if ((TYPE_CODE (type) == TYPE_CODE_INT && TYPE_LENGTH (type) == 8)
|| (TYPE_CODE (type) == TYPE_CODE_FLT && TYPE_LENGTH (type) == 8))
{
if (readbuf)
{
/* A long long, or a double stored in the 32 bit r3/r4. */
regcache_cooked_read (regcache, tdep->ppc_gp0_regnum + 3,
(bfd_byte *) readbuf + 0);
regcache_cooked_read (regcache, tdep->ppc_gp0_regnum + 4,
(bfd_byte *) readbuf + 4);
}
if (writebuf)
{
/* A long long, or a double stored in the 32 bit r3/r4. */
regcache_cooked_write (regcache, tdep->ppc_gp0_regnum + 3,
(const bfd_byte *) writebuf + 0);
regcache_cooked_write (regcache, tdep->ppc_gp0_regnum + 4,
(const bfd_byte *) writebuf + 4);
}
return RETURN_VALUE_REGISTER_CONVENTION;
}
if (TYPE_CODE (type) == TYPE_CODE_INT
&& TYPE_LENGTH (type) <= tdep->wordsize)
{
if (readbuf)
{
/* Some sort of integer stored in r3. Since TYPE isn't
bigger than the register, sign extension isn't a problem
- just do everything unsigned. */
ULONGEST regval;
regcache_cooked_read_unsigned (regcache, tdep->ppc_gp0_regnum + 3,
&regval);
store_unsigned_integer (readbuf, TYPE_LENGTH (type), regval);
}
if (writebuf)
{
/* Some sort of integer stored in r3. Use unpack_long since
that should handle any required sign extension. */
regcache_cooked_write_unsigned (regcache, tdep->ppc_gp0_regnum + 3,
unpack_long (type, writebuf));
}
return RETURN_VALUE_REGISTER_CONVENTION;
}
if (TYPE_LENGTH (type) == 16
&& TYPE_CODE (type) == TYPE_CODE_ARRAY
&& TYPE_VECTOR (type) && tdep->ppc_vr0_regnum >= 0)
{
if (readbuf)
{
/* Altivec places the return value in "v2". */
regcache_cooked_read (regcache, tdep->ppc_vr0_regnum + 2, readbuf);
}
if (writebuf)
{
/* Altivec places the return value in "v2". */
regcache_cooked_write (regcache, tdep->ppc_vr0_regnum + 2, writebuf);
}
return RETURN_VALUE_REGISTER_CONVENTION;
}
if (TYPE_LENGTH (type) == 8
&& TYPE_CODE (type) == TYPE_CODE_ARRAY
&& TYPE_VECTOR (type) && tdep->ppc_ev0_regnum >= 0)
{
/* The e500 ABI places return values for the 64-bit DSP types
(__ev64_opaque__) in r3. However, in GDB-speak, ev3
corresponds to the entire r3 value for e500, whereas GDB's r3
only corresponds to the least significant 32-bits. So place
the 64-bit DSP type's value in ev3. */
if (readbuf)
regcache_cooked_read (regcache, tdep->ppc_ev0_regnum + 3, readbuf);
if (writebuf)
regcache_cooked_write (regcache, tdep->ppc_ev0_regnum + 3, writebuf);
return RETURN_VALUE_REGISTER_CONVENTION;
}
if (broken_gcc && TYPE_LENGTH (type) <= 8)
{
/* GCC screwed up for structures or unions whose size is less
than or equal to 8 bytes.. Instead of left-aligning, it
right-aligns the data into the buffer formed by r3, r4. */
gdb_byte regvals[MAX_REGISTER_SIZE * 2];
int len = TYPE_LENGTH (type);
int offset = (2 * tdep->wordsize - len) % tdep->wordsize;
if (readbuf)
{
regcache_cooked_read (regcache, tdep->ppc_gp0_regnum + 3,
regvals + 0 * tdep->wordsize);
if (len > tdep->wordsize)
regcache_cooked_read (regcache, tdep->ppc_gp0_regnum + 4,
regvals + 1 * tdep->wordsize);
memcpy (readbuf, regvals + offset, len);
}
if (writebuf)
{
memset (regvals, 0, sizeof regvals);
memcpy (regvals + offset, writebuf, len);
regcache_cooked_write (regcache, tdep->ppc_gp0_regnum + 3,
regvals + 0 * tdep->wordsize);
if (len > tdep->wordsize)
regcache_cooked_write (regcache, tdep->ppc_gp0_regnum + 4,
regvals + 1 * tdep->wordsize);
}
return RETURN_VALUE_REGISTER_CONVENTION;
}
if (TYPE_LENGTH (type) <= 8)
{
if (readbuf)
{
/* This matches SVr4 PPC, it does not match GCC. */
/* The value is right-padded to 8 bytes and then loaded, as
two "words", into r3/r4. */
gdb_byte regvals[MAX_REGISTER_SIZE * 2];
regcache_cooked_read (regcache, tdep->ppc_gp0_regnum + 3,
regvals + 0 * tdep->wordsize);
if (TYPE_LENGTH (type) > tdep->wordsize)
regcache_cooked_read (regcache, tdep->ppc_gp0_regnum + 4,
regvals + 1 * tdep->wordsize);
memcpy (readbuf, regvals, TYPE_LENGTH (type));
}
if (writebuf)
{
/* This matches SVr4 PPC, it does not match GCC. */
/* The value is padded out to 8 bytes and then loaded, as
two "words" into r3/r4. */
gdb_byte regvals[MAX_REGISTER_SIZE * 2];
memset (regvals, 0, sizeof regvals);
memcpy (regvals, writebuf, TYPE_LENGTH (type));
regcache_cooked_write (regcache, tdep->ppc_gp0_regnum + 3,
regvals + 0 * tdep->wordsize);
if (TYPE_LENGTH (type) > tdep->wordsize)
regcache_cooked_write (regcache, tdep->ppc_gp0_regnum + 4,
regvals + 1 * tdep->wordsize);
}
return RETURN_VALUE_REGISTER_CONVENTION;
}
return RETURN_VALUE_STRUCT_CONVENTION;
}
enum return_value_convention
ppc_sysv_abi_return_value (struct gdbarch *gdbarch, struct type *valtype,
struct regcache *regcache, gdb_byte *readbuf,
const gdb_byte *writebuf)
{
return do_ppc_sysv_return_value (gdbarch, valtype, regcache, readbuf,
writebuf, 0);
}
enum return_value_convention
ppc_sysv_abi_broken_return_value (struct gdbarch *gdbarch,
struct type *valtype,
struct regcache *regcache,
gdb_byte *readbuf, const gdb_byte *writebuf)
{
return do_ppc_sysv_return_value (gdbarch, valtype, regcache, readbuf,
writebuf, 1);
}
/* The helper function for 64-bit SYSV push_dummy_call. Converts the
function's code address back into the function's descriptor
address.
Find a value for the TOC register. Every symbol should have both
".FN" and "FN" in the minimal symbol table. "FN" points at the
FN's descriptor, while ".FN" points at the entry point (which
matches FUNC_ADDR). Need to reverse from FUNC_ADDR back to the
FN's descriptor address (while at the same time being careful to
find "FN" in the same object file as ".FN"). */
static int
convert_code_addr_to_desc_addr (CORE_ADDR code_addr, CORE_ADDR *desc_addr)
{
struct obj_section *dot_fn_section;
struct minimal_symbol *dot_fn;
struct minimal_symbol *fn;
CORE_ADDR toc;
/* Find the minimal symbol that corresponds to CODE_ADDR (should
have a name of the form ".FN"). */
dot_fn = lookup_minimal_symbol_by_pc (code_addr);
if (dot_fn == NULL || SYMBOL_LINKAGE_NAME (dot_fn)[0] != '.')
return 0;
/* Get the section that contains CODE_ADDR. Need this for the
"objfile" that it contains. */
dot_fn_section = find_pc_section (code_addr);
if (dot_fn_section == NULL || dot_fn_section->objfile == NULL)
return 0;
/* Now find the corresponding "FN" (dropping ".") minimal symbol's
address. Only look for the minimal symbol in ".FN"'s object file
- avoids problems when two object files (i.e., shared libraries)
contain a minimal symbol with the same name. */
fn = lookup_minimal_symbol (SYMBOL_LINKAGE_NAME (dot_fn) + 1, NULL,
dot_fn_section->objfile);
if (fn == NULL)
return 0;
/* Found a descriptor. */
(*desc_addr) = SYMBOL_VALUE_ADDRESS (fn);
return 1;
}
/* Pass the arguments in either registers, or in the stack. Using the
ppc 64 bit SysV ABI.
This implements a dumbed down version of the ABI. It always writes
values to memory, GPR and FPR, even when not necessary. Doing this
greatly simplifies the logic. */
CORE_ADDR
ppc64_sysv_abi_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
struct regcache *regcache, CORE_ADDR bp_addr,
int nargs, struct value **args, CORE_ADDR sp,
int struct_return, CORE_ADDR struct_addr)
{
CORE_ADDR func_addr = find_function_addr (function, NULL);
struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
/* By this stage in the proceedings, SP has been decremented by "red
zone size" + "struct return size". Fetch the stack-pointer from
before this and use that as the BACK_CHAIN. */
const CORE_ADDR back_chain = read_sp ();
/* See for-loop comment below. */
int write_pass;
/* Size of the Altivec's vector parameter region, the final value is
computed in the for-loop below. */
LONGEST vparam_size = 0;
/* Size of the general parameter region, the final value is computed
in the for-loop below. */
LONGEST gparam_size = 0;
/* Kevin writes ... I don't mind seeing tdep->wordsize used in the
calls to align_up(), align_down(), etc. because this makes it
easier to reuse this code (in a copy/paste sense) in the future,
but it is a 64-bit ABI and asserting that the wordsize is 8 bytes
at some point makes it easier to verify that this function is
correct without having to do a non-local analysis to figure out
the possible values of tdep->wordsize. */
gdb_assert (tdep->wordsize == 8);
/* Go through the argument list twice.
Pass 1: Compute the function call's stack space and register
requirements.
Pass 2: Replay the same computation but this time also write the
values out to the target. */
for (write_pass = 0; write_pass < 2; write_pass++)
{
int argno;
/* Next available floating point register for float and double
arguments. */
int freg = 1;
/* Next available general register for non-vector (but possibly
float) arguments. */
int greg = 3;
/* Next available vector register for vector arguments. */
int vreg = 2;
/* The address, at which the next general purpose parameter
(integer, struct, float, ...) should be saved. */
CORE_ADDR gparam;
/* Address, at which the next Altivec vector parameter should be
saved. */
CORE_ADDR vparam;
if (!write_pass)
{
/* During the first pass, GPARAM and VPARAM are more like
offsets (start address zero) than addresses. That way
the accumulate the total stack space each region
requires. */
gparam = 0;
vparam = 0;
}
else
{
/* Decrement the stack pointer making space for the Altivec
and general on-stack parameters. Set vparam and gparam
to their corresponding regions. */
vparam = align_down (sp - vparam_size, 16);
gparam = align_down (vparam - gparam_size, 16);
/* Add in space for the TOC, link editor double word,
compiler double word, LR save area, CR save area. */
sp = align_down (gparam - 48, 16);
}
/* If the function is returning a `struct', then there is an
extra hidden parameter (which will be passed in r3)
containing the address of that struct.. In that case we
should advance one word and start from r4 register to copy
parameters. This also consumes one on-stack parameter slot. */
if (struct_return)
{
if (write_pass)
regcache_cooked_write_signed (regcache,
tdep->ppc_gp0_regnum + greg,
struct_addr);
greg++;
gparam = align_up (gparam + tdep->wordsize, tdep->wordsize);
}
for (argno = 0; argno < nargs; argno++)
{
struct value *arg = args[argno];
struct type *type = check_typedef (value_type (arg));
const bfd_byte *val = value_contents (arg);
if (TYPE_CODE (type) == TYPE_CODE_FLT && TYPE_LENGTH (type) <= 8)
{
/* Floats and Doubles go in f1 .. f13. They also
consume a left aligned GREG,, and can end up in
memory. */
if (write_pass)
{
if (ppc_floating_point_unit_p (current_gdbarch)
&& freg <= 13)
{
gdb_byte regval[MAX_REGISTER_SIZE];
struct type *regtype
= register_type (gdbarch, tdep->ppc_fp0_regnum);
convert_typed_floating (val, type, regval, regtype);
regcache_cooked_write (regcache,
tdep->ppc_fp0_regnum + freg,
regval);
}
if (greg <= 10)
{
/* The ABI states "Single precision floating
point values are mapped to the first word in
a single doubleword" and "... floating point
values mapped to the first eight doublewords
of the parameter save area are also passed in
general registers").
This code interprets that to mean: store it,
left aligned, in the general register. */
gdb_byte regval[MAX_REGISTER_SIZE];
memset (regval, 0, sizeof regval);
memcpy (regval, val, TYPE_LENGTH (type));
regcache_cooked_write (regcache,
tdep->ppc_gp0_regnum + greg,
regval);
}
write_memory (gparam, val, TYPE_LENGTH (type));
}
/* Always consume parameter stack space. */
freg++;
greg++;
gparam = align_up (gparam + TYPE_LENGTH (type), tdep->wordsize);
}
else if (TYPE_LENGTH (type) == 16 && TYPE_VECTOR (type)
&& TYPE_CODE (type) == TYPE_CODE_ARRAY
&& tdep->ppc_vr0_regnum >= 0)
{
/* In the Altivec ABI, vectors go in the vector
registers v2 .. v13, or when that runs out, a vector
annex which goes above all the normal parameters.
NOTE: cagney/2003-09-21: This is a guess based on the
PowerOpen Altivec ABI. */
if (vreg <= 13)
{
if (write_pass)
regcache_cooked_write (regcache,
tdep->ppc_vr0_regnum + vreg, val);
vreg++;
}
else
{
if (write_pass)
write_memory (vparam, val, TYPE_LENGTH (type));
vparam = align_up (vparam + TYPE_LENGTH (type), 16);
}
}
else if ((TYPE_CODE (type) == TYPE_CODE_INT
|| TYPE_CODE (type) == TYPE_CODE_ENUM
|| TYPE_CODE (type) == TYPE_CODE_PTR)
&& TYPE_LENGTH (type) <= 8)
{
/* Scalars and Pointers get sign[un]extended and go in
gpr3 .. gpr10. They can also end up in memory. */
if (write_pass)
{
/* Sign extend the value, then store it unsigned. */
ULONGEST word = unpack_long (type, val);
/* Convert any function code addresses into
descriptors. */
if (TYPE_CODE (type) == TYPE_CODE_PTR
&& TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_FUNC)
{
CORE_ADDR desc = word;
convert_code_addr_to_desc_addr (word, &desc);
word = desc;
}
if (greg <= 10)
regcache_cooked_write_unsigned (regcache,
tdep->ppc_gp0_regnum +
greg, word);
write_memory_unsigned_integer (gparam, tdep->wordsize,
word);
}
greg++;
gparam = align_up (gparam + TYPE_LENGTH (type), tdep->wordsize);
}
else
{
int byte;
for (byte = 0; byte < TYPE_LENGTH (type);
byte += tdep->wordsize)
{
if (write_pass && greg <= 10)
{
gdb_byte regval[MAX_REGISTER_SIZE];
int len = TYPE_LENGTH (type) - byte;
if (len > tdep->wordsize)
len = tdep->wordsize;
memset (regval, 0, sizeof regval);
/* WARNING: cagney/2003-09-21: As best I can
tell, the ABI specifies that the value should
be left aligned. Unfortunately, GCC doesn't
do this - it instead right aligns even sized
values and puts odd sized values on the
stack. Work around that by putting both a
left and right aligned value into the
register (hopefully no one notices :-^).
Arrrgh! */
/* Left aligned (8 byte values such as pointers
fill the buffer). */
memcpy (regval, val + byte, len);
/* Right aligned (but only if even). */
if (len == 1 || len == 2 || len == 4)
memcpy (regval + tdep->wordsize - len,
val + byte, len);
regcache_cooked_write (regcache, greg, regval);
}
greg++;
}
if (write_pass)
/* WARNING: cagney/2003-09-21: Strictly speaking, this
isn't necessary, unfortunately, GCC appears to get
"struct convention" parameter passing wrong putting
odd sized structures in memory instead of in a
register. Work around this by always writing the
value to memory. Fortunately, doing this
simplifies the code. */
write_memory (gparam, val, TYPE_LENGTH (type));
if (write_pass)
/* WARNING: cagney/2004-06-20: It appears that GCC
likes to put structures containing a single
floating-point member in an FP register instead of
general general purpose. */
/* Always consume parameter stack space. */
gparam = align_up (gparam + TYPE_LENGTH (type), tdep->wordsize);
}
}
if (!write_pass)
{
/* Save the true region sizes ready for the second pass. */
vparam_size = vparam;
/* Make certain that the general parameter save area is at
least the minimum 8 registers (or doublewords) in size. */
if (greg < 8)
gparam_size = 8 * tdep->wordsize;
else
gparam_size = gparam;
}
}
/* Update %sp. */
regcache_cooked_write_signed (regcache, SP_REGNUM, sp);
/* Write the backchain (it occupies WORDSIZED bytes). */
write_memory_signed_integer (sp, tdep->wordsize, back_chain);
/* Point the inferior function call's return address at the dummy's
breakpoint. */
regcache_cooked_write_signed (regcache, tdep->ppc_lr_regnum, bp_addr);
/* Use the func_addr to find the descriptor, and use that to find
the TOC. */
{
CORE_ADDR desc_addr;
if (convert_code_addr_to_desc_addr (func_addr, &desc_addr))
{
/* The TOC is the second double word in the descriptor. */
CORE_ADDR toc =
read_memory_unsigned_integer (desc_addr + tdep->wordsize,
tdep->wordsize);
regcache_cooked_write_unsigned (regcache,
tdep->ppc_gp0_regnum + 2, toc);
}
}
return sp;
}
/* The 64 bit ABI retun value convention.
Return non-zero if the return-value is stored in a register, return
0 if the return-value is instead stored on the stack (a.k.a.,
struct return convention).
For a return-value stored in a register: when WRITEBUF is non-NULL,
copy the buffer to the corresponding register return-value location
location; when READBUF is non-NULL, fill the buffer from the
corresponding register return-value location. */
enum return_value_convention
ppc64_sysv_abi_return_value (struct gdbarch *gdbarch, struct type *valtype,
struct regcache *regcache, gdb_byte *readbuf,
const gdb_byte *writebuf)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
/* This function exists to support a calling convention that
requires floating-point registers. It shouldn't be used on
processors that lack them. */
gdb_assert (ppc_floating_point_unit_p (gdbarch));
/* Floats and doubles in F1. */
if (TYPE_CODE (valtype) == TYPE_CODE_FLT && TYPE_LENGTH (valtype) <= 8)
{
gdb_byte regval[MAX_REGISTER_SIZE];
struct type *regtype = register_type (gdbarch, tdep->ppc_fp0_regnum);
if (writebuf != NULL)
{
convert_typed_floating (writebuf, valtype, regval, regtype);
regcache_cooked_write (regcache, tdep->ppc_fp0_regnum + 1, regval);
}
if (readbuf != NULL)
{
regcache_cooked_read (regcache, tdep->ppc_fp0_regnum + 1, regval);
convert_typed_floating (regval, regtype, readbuf, valtype);
}
return RETURN_VALUE_REGISTER_CONVENTION;
}
/* Integers in r3. */
if ((TYPE_CODE (valtype) == TYPE_CODE_INT
|| TYPE_CODE (valtype) == TYPE_CODE_ENUM)
&& TYPE_LENGTH (valtype) <= 8)
{
if (writebuf != NULL)
{
/* Be careful to sign extend the value. */
regcache_cooked_write_unsigned (regcache, tdep->ppc_gp0_regnum + 3,
unpack_long (valtype, writebuf));
}
if (readbuf != NULL)
{
/* Extract the integer from r3. Since this is truncating the
value, there isn't a sign extension problem. */
ULONGEST regval;
regcache_cooked_read_unsigned (regcache, tdep->ppc_gp0_regnum + 3,
&regval);
store_unsigned_integer (readbuf, TYPE_LENGTH (valtype), regval);
}
return RETURN_VALUE_REGISTER_CONVENTION;
}
/* All pointers live in r3. */
if (TYPE_CODE (valtype) == TYPE_CODE_PTR)
{
/* All pointers live in r3. */
if (writebuf != NULL)
regcache_cooked_write (regcache, tdep->ppc_gp0_regnum + 3, writebuf);
if (readbuf != NULL)
regcache_cooked_read (regcache, tdep->ppc_gp0_regnum + 3, readbuf);
return RETURN_VALUE_REGISTER_CONVENTION;
}
/* Array type has more than one use. */
if (TYPE_CODE (valtype) == TYPE_CODE_ARRAY)
{
/* Small character arrays are returned, right justified, in r3. */
if (TYPE_LENGTH (valtype) <= 8
&& TYPE_CODE (TYPE_TARGET_TYPE (valtype)) == TYPE_CODE_INT
&& TYPE_LENGTH (TYPE_TARGET_TYPE (valtype)) == 1)
{
int offset = (register_size (gdbarch, tdep->ppc_gp0_regnum + 3)
- TYPE_LENGTH (valtype));
if (writebuf != NULL)
regcache_cooked_write_part (regcache, tdep->ppc_gp0_regnum + 3,
offset, TYPE_LENGTH (valtype), writebuf);
if (readbuf != NULL)
regcache_cooked_read_part (regcache, tdep->ppc_gp0_regnum + 3,
offset, TYPE_LENGTH (valtype), readbuf);
return RETURN_VALUE_REGISTER_CONVENTION;
}
/* A VMX vector is returned in v2. */
if (TYPE_CODE (valtype) == TYPE_CODE_ARRAY
&& TYPE_VECTOR (valtype) && tdep->ppc_vr0_regnum >= 0)
{
if (readbuf)
regcache_cooked_read (regcache, tdep->ppc_vr0_regnum + 2, readbuf);
if (writebuf)
regcache_cooked_write (regcache, tdep->ppc_vr0_regnum + 2, writebuf);
return RETURN_VALUE_REGISTER_CONVENTION;
}
}
/* Big floating point values get stored in adjacent floating
point registers, starting with F1. */
if (TYPE_CODE (valtype) == TYPE_CODE_FLT
&& (TYPE_LENGTH (valtype) == 16 || TYPE_LENGTH (valtype) == 32))
{
if (writebuf || readbuf != NULL)
{
int i;
for (i = 0; i < TYPE_LENGTH (valtype) / 8; i++)
{
if (writebuf != NULL)
regcache_cooked_write (regcache, tdep->ppc_fp0_regnum + 1 + i,
(const bfd_byte *) writebuf + i * 8);
if (readbuf != NULL)
regcache_cooked_read (regcache, tdep->ppc_fp0_regnum + 1 + i,
(bfd_byte *) readbuf + i * 8);
}
}
return RETURN_VALUE_REGISTER_CONVENTION;
}
/* Complex values get returned in f1:f2, need to convert. */
if (TYPE_CODE (valtype) == TYPE_CODE_COMPLEX
&& (TYPE_LENGTH (valtype) == 8 || TYPE_LENGTH (valtype) == 16))
{
if (regcache != NULL)
{
int i;
for (i = 0; i < 2; i++)
{
gdb_byte regval[MAX_REGISTER_SIZE];
struct type *regtype =
register_type (current_gdbarch, tdep->ppc_fp0_regnum);
if (writebuf != NULL)
{
convert_typed_floating ((const bfd_byte *) writebuf +
i * (TYPE_LENGTH (valtype) / 2),
valtype, regval, regtype);
regcache_cooked_write (regcache,
tdep->ppc_fp0_regnum + 1 + i,
regval);
}
if (readbuf != NULL)
{
regcache_cooked_read (regcache,
tdep->ppc_fp0_regnum + 1 + i,
regval);
convert_typed_floating (regval, regtype,
(bfd_byte *) readbuf +
i * (TYPE_LENGTH (valtype) / 2),
valtype);
}
}
}
return RETURN_VALUE_REGISTER_CONVENTION;
}
/* Big complex values get stored in f1:f4. */
if (TYPE_CODE (valtype) == TYPE_CODE_COMPLEX && TYPE_LENGTH (valtype) == 32)
{
if (regcache != NULL)
{
int i;
for (i = 0; i < 4; i++)
{
if (writebuf != NULL)
regcache_cooked_write (regcache, tdep->ppc_fp0_regnum + 1 + i,
(const bfd_byte *) writebuf + i * 8);
if (readbuf != NULL)
regcache_cooked_read (regcache, tdep->ppc_fp0_regnum + 1 + i,
(bfd_byte *) readbuf + i * 8);
}
}
return RETURN_VALUE_REGISTER_CONVENTION;
}
return RETURN_VALUE_STRUCT_CONVENTION;
}
CORE_ADDR
ppc64_sysv_abi_adjust_breakpoint_address (struct gdbarch *gdbarch,
CORE_ADDR bpaddr)
{
/* PPC64 SYSV specifies that the minimal-symbol "FN" should point at
a function-descriptor while the corresponding minimal-symbol
".FN" should point at the entry point. Consequently, a command
like "break FN" applied to an object file with only minimal
symbols, will insert the breakpoint into the descriptor at "FN"
and not the function at ".FN". Avoid this confusion by adjusting
any attempt to set a descriptor breakpoint into a corresponding
function breakpoint. Note that GDB warns the user when this
adjustment is applied - that's ok as otherwise the user will have
no way of knowing why their breakpoint at "FN" resulted in the
program stopping at ".FN". */
return gdbarch_convert_from_func_ptr_addr (gdbarch, bpaddr, &current_target);
}
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