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va-ppc.h (__va_start_common): Let __builtin_saveregs do the work.

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* va-ppc.h (__va_start_common): Let __builtin_saveregs do the work.
        * rs6000.c (expand_builtin_saveregs): For V4, initialize a private
        va_list struct, and return a pointer to it.
        (setup_incoming_varargs): V4 save area based off virtual_stack_vars
        instead of frame_pointer.

From-SVN: r26710
This commit is contained in:
Richard Henderson 1999-04-30 08:06:23 -07:00 • committed by Richard Henderson
parent d8f8e9ba17
commit 2c4974b72a
3 changed files with 88 additions and 30 deletions
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8
gcc/ChangeLog
View file

@ -1,3 +1,11 @@
Fri Apr 30 13:55:43 1999 Richard Henderson <rth@cygnus.com>
* va-ppc.h (__va_start_common): Let __builtin_saveregs do the work.
* rs6000.c (expand_builtin_saveregs): For V4, initialize a private
va_list struct, and return a pointer to it.
(setup_incoming_varargs): V4 save area based off virtual_stack_vars
instead of frame_pointer.
Thu Apr 29 23:02:22 1999 Mark Mitchell <mark@codesourcery.com>
* emit-rtl.c (start_sequence): Expand comments.

77
gcc/config/rs6000/rs6000.c
View file

@ -1633,7 +1633,8 @@ setup_incoming_varargs (cum, mode, type, pretend_size, no_rtl)
{
rs6000_sysv_varargs_p = 1;
if (! no_rtl)
save_area = plus_constant (frame_pointer_rtx, RS6000_VARARGS_OFFSET);
save_area = plus_constant (virtual_stack_vars_rtx,
- RS6000_VARARGS_OFFSET);
}
else
rs6000_sysv_varargs_p = 0;
@ -1704,13 +1705,83 @@ setup_incoming_varargs (cum, mode, type, pretend_size, no_rtl)
On the Power/PowerPC return the address of the area on the stack
used to hold arguments. Under AIX, this includes the 8 word register
save area. Under V.4 this does not. */
save area.
Under V.4, things are more complicated. We do not have access to
all of the virtual registers required for va_start to do its job,
so we construct the va_list in its entirity here, and reduce va_start
to a block copy. This is similar to the way we do things on Alpha. */
struct rtx_def *
expand_builtin_saveregs (args)
tree args ATTRIBUTE_UNUSED;
{
return virtual_incoming_args_rtx;
rtx block, mem_gpr_fpr, mem_reg_save_area, mem_overflow, tmp;
tree fntype;
int stdarg_p;
HOST_WIDE_INT words, gpr, fpr;
if (DEFAULT_ABI != ABI_V4 && DEFAULT_ABI != ABI_SOLARIS)
return virtual_incoming_args_rtx;
fntype = TREE_TYPE (current_function_decl);
stdarg_p = (TYPE_ARG_TYPES (fntype) != 0
&& (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
!= void_type_node));
/* Allocate the va_list constructor. */
block = assign_stack_local (BLKmode, 3 * UNITS_PER_WORD, BITS_PER_WORD);
RTX_UNCHANGING_P (block) = 1;
RTX_UNCHANGING_P (XEXP (block, 0)) = 1;
mem_gpr_fpr = change_address (block, word_mode, XEXP (block, 0));
mem_overflow = change_address (block, ptr_mode,
plus_constant (XEXP (block, 0),
UNITS_PER_WORD));
mem_reg_save_area = change_address (block, ptr_mode,
plus_constant (XEXP (block, 0),
2 * UNITS_PER_WORD));
/* Construct the two characters of `gpr' and `fpr' as a unit. */
words = current_function_args_info.words - !stdarg_p;
gpr = (words > 8 ? 8 : words);
fpr = current_function_args_info.fregno - 33;
if (BYTES_BIG_ENDIAN)
{
HOST_WIDE_INT bits = gpr << 8 | fpr;
if (HOST_BITS_PER_WIDE_INT >= BITS_PER_WORD)
tmp = GEN_INT (bits << (BITS_PER_WORD - 16));
else
{
bits <<= BITS_PER_WORD - HOST_BITS_PER_WIDE_INT - 16;
tmp = immed_double_const (0, bits, word_mode);
}
}
else
tmp = GEN_INT (fpr << 8 | gpr);
emit_move_insn (mem_gpr_fpr, tmp);
/* Find the overflow area. */
if (words <= 8)
tmp = virtual_incoming_args_rtx;
else
tmp = expand_binop (Pmode, add_optab, virtual_incoming_args_rtx,
GEN_INT ((words - 8) * UNITS_PER_WORD),
mem_overflow, 0, OPTAB_WIDEN);
if (tmp != mem_overflow)
emit_move_insn (mem_overflow, tmp);
/* Find the register save area. */
tmp = expand_binop (Pmode, add_optab, virtual_stack_vars_rtx,
GEN_INT (-RS6000_VARARGS_SIZE),
mem_reg_save_area, 0, OPTAB_WIDEN);
if (tmp != mem_reg_save_area)
emit_move_insn (mem_reg_save_area, tmp);
/* Return the address of the va_list constructor. */
return XEXP (block, 0);
}

33
gcc/ginclude/va-ppc.h
View file

@ -59,34 +59,13 @@ typedef struct {
((TYPE *) (void *) (&(((__va_regsave_t *) \
(AP)->reg_save_area)->__gp_save[(int)(AP)->gpr])))
/* Common code for va_start for both varargs and stdarg. This depends
on the format of rs6000_args in rs6000.h. The fields used are:
/* Common code for va_start for both varargs and stdarg. We allow all
the work to be done by __builtin_saveregs. It returns a pointer to
a va_list that was constructed on the stack; we must simply copy it
to the user's variable. */
#0 WORDS # words used for GP regs/stack values
#1 FREGNO next available FP register
#2 NARGS_PROTOTYPE # args left in the current prototype
#3 ORIG_NARGS original value of NARGS_PROTOTYPE
#4 VARARGS_OFFSET offset from frame pointer of varargs area */
#define __va_words __builtin_args_info (0)
#define __va_fregno __builtin_args_info (1)
#define __va_nargs __builtin_args_info (2)
#define __va_orig_nargs __builtin_args_info (3)
#define __va_varargs_offset __builtin_args_info (4)
#define __va_start_common(AP, FAKE) \
__extension__ ({ \
register int __words = __va_words - FAKE; \
\
(AP)->gpr = (__words < 8) ? __words : 8; \
(AP)->fpr = __va_fregno - 33; \
(AP)->reg_save_area = (((char *) __builtin_frame_address (0)) \
+ __va_varargs_offset); \
__va_overflow(AP) = ((char *)__builtin_saveregs () \
+ (((__words >= 8) ? __words - 8 : 0) \
* sizeof (long))); \
(void)0; \
})
#define __va_start_common(AP, FAKE) \
__builtin_memcpy ((AP), __builtin_saveregs (), sizeof(__gnuc_va_list))
#ifdef _STDARG_H /* stdarg.h support */