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rtl_data: Add sp_is_clobbered_by_asm

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Add sp_is_clobbered_by_asm to rtl_data to inform backends that the stack
pointer is clobbered by asm statement.

gcc/

	PR target/97032
	* cfgexpand.c (asm_clobber_reg_kind): Set sp_is_clobbered_by_asm
	to true if the stack pointer is clobbered by asm statement.
	* emit-rtl.h (rtl_data): Add sp_is_clobbered_by_asm.
	* config/i386/i386.c (ix86_get_drap_rtx): Set need_drap to true
	if the stack pointer is clobbered by asm statement.

gcc/testsuite/

	PR target/97032
	* gcc.target/i386/pr97032.c: New test.
This commit is contained in:
H.J. Lu 2020-09-14 08:52:27 -07:00
parent f419a01589
commit 453a20c657
4 changed files with 39 additions and 7 deletions
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14
gcc/cfgexpand.c
View File

@ -2868,11 +2868,15 @@ asm_clobber_reg_is_valid (int regno, int nregs, const char *regname)
as it was before, so no asm can validly clobber the stack pointer in
the usual sense. Adding the stack pointer to the clobber list has
traditionally had some undocumented and somewhat obscure side-effects. */
if (overlaps_hard_reg_set_p (regset, Pmode, STACK_POINTER_REGNUM)
&& warning (OPT_Wdeprecated, "listing the stack pointer register"
" %qs in a clobber list is deprecated", regname))
inform (input_location, "the value of the stack pointer after an %<asm%>"
" statement must be the same as it was before the statement");
if (overlaps_hard_reg_set_p (regset, Pmode, STACK_POINTER_REGNUM))
{
crtl->sp_is_clobbered_by_asm = true;
if (warning (OPT_Wdeprecated, "listing the stack pointer register"
" %qs in a clobber list is deprecated", regname))
inform (input_location, "the value of the stack pointer after"
" an %<asm%> statement must be the same as it was before"
" the statement");
}
return is_valid;
}

6
gcc/config/i386/i386.c
View File

@ -6968,10 +6968,12 @@ ix86_update_stack_boundary (void)
static rtx
ix86_get_drap_rtx (void)
{
/* We must use DRAP if there are outgoing arguments on stack and
/* We must use DRAP if there are outgoing arguments on stack or
the stack pointer register is clobbered by asm statment and
ACCUMULATE_OUTGOING_ARGS is false. */
if (ix86_force_drap
|| (cfun->machine->outgoing_args_on_stack
|| ((cfun->machine->outgoing_args_on_stack
|| crtl->sp_is_clobbered_by_asm)
&& !ACCUMULATE_OUTGOING_ARGS))
crtl->need_drap = true;

3
gcc/emit-rtl.h
View File

@ -281,6 +281,9 @@ struct GTY(()) rtl_data {
pass_stack_ptr_mod has run. */
bool sp_is_unchanging;
/* True if the stack pointer is clobbered by asm statement. */
bool sp_is_clobbered_by_asm;
/* Nonzero if function being compiled doesn't contain any calls
(ignoring the prologue and epilogue). This is set prior to
register allocation in IRA and is valid for the remaining

23
gcc/testsuite/gcc.target/i386/pr97032.c Normal file
View File

@ -0,0 +1,23 @@
/* { dg-do compile { target { ia32 && fstack_protector } } } */
/* { dg-options "-O2 -mincoming-stack-boundary=2 -fstack-protector-all" } */
#include <stdarg.h>
extern int *__errno_location (void);
long
sys_socketcall (int op, ...)
{
long int res;
va_list ap;
va_start (ap, op);
asm volatile ("push %%ebx; movl %2, %%ebx; int $0x80; pop %%ebx"
/* { dg-warning "listing the stack pointer register" "" { target *-*-* } .-1 } */
: "=a" (res) : "0" (102), "ri" (16), "c" (ap) : "memory", "esp");
if (__builtin_expect (res > 4294963200UL, 0))
*__errno_location () = -res;
va_end (ap);
return res;
}
/* { dg-final { scan-assembler "call\[ \t\]*_?__errno_location" } } */