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IBM Z: Define probe_stack expander

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Probes emitted by the common code routines still use a store.  Define
the "probe_stack" pattern to use a compare instead.

gcc/ChangeLog:

2020-05-14  Andreas Krebbel  <krebbel@linux.ibm.com>

	* config/s390/s390.c (s390_emit_stack_probe): Call the probe_stack
	expander.
	* config/s390/s390.md ("@probe_stack2<mode>", "probe_stack"): New
	expanders.

gcc/testsuite/ChangeLog:

2020-05-14  Andreas Krebbel  <krebbel@linux.ibm.com>

	* gcc.target/s390/stack-clash-2.c: New test.
This commit is contained in:
Andreas Krebbel 2020-05-14 08:16:27 +02:00
parent 868d351e23
commit 0473885be8
5 changed files with 46 additions and 5 deletions
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7
gcc/ChangeLog
View file

@ -1,3 +1,10 @@
2020-05-14 Andreas Krebbel <krebbel@linux.ibm.com>
* config/s390/s390.c (s390_emit_stack_probe): Call the probe_stack
expander.
* config/s390/s390.md ("@probe_stack2<mode>", "probe_stack"): New
expanders.
2020-05-14 Andreas Krebbel <krebbel@linux.ibm.com>
* config/s390/s390.c (allocate_stack_space): Add missing updates

7
gcc/config/s390/s390.c
View file

@ -10946,10 +10946,9 @@ s390_prologue_plus_offset (rtx target, rtx reg, rtx offset, bool frame_related_p
static void
s390_emit_stack_probe (rtx addr)
{
rtx tmp = gen_rtx_MEM (Pmode, addr);
MEM_VOLATILE_P (tmp) = 1;
s390_emit_compare (EQ, gen_rtx_REG (Pmode, 0), tmp);
emit_insn (gen_blockage ());
rtx mem = gen_rtx_MEM (Pmode, addr);
MEM_VOLATILE_P (mem) = 1;
emit_insn (gen_probe_stack (mem));
}
/* Use a runtime loop if we have to emit more probes than this. */

16
gcc/config/s390/s390.md
View file

@ -11017,8 +11017,22 @@
emit_move_insn (operands[0], virtual_stack_dynamic_rtx);
DONE;
})
})
(define_expand "@probe_stack2<mode>"
[(set (reg:CCZ CC_REGNUM)
(compare:CCZ (reg:P 0)
(match_operand 0 "memory_operand")))
(unspec_volatile [(const_int 0)] UNSPECV_BLOCKAGE)]
"")
(define_expand "probe_stack"
[(match_operand 0 "memory_operand")]
""
{
emit_insn (gen_probe_stack2 (Pmode, operands[0]));
DONE;
})
;
; setjmp instruction pattern.

4
gcc/testsuite/ChangeLog
View file

@ -1,3 +1,7 @@
2020-05-14 Andreas Krebbel <krebbel@linux.ibm.com>
* gcc.target/s390/stack-clash-2.c: New test.
2020-05-14 Andreas Krebbel <krebbel@linux.ibm.com>
* gcc.target/s390/stack-clash-1.c: New test.

17
gcc/testsuite/gcc.target/s390/stack-clash-2.c Normal file
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@ -0,0 +1,17 @@
/* { dg-do compile } */
/* { dg-options "-O2 -march=z900 -fstack-clash-protection" } */
extern void bar (char *);
void
foo ()
{
char * mem = __builtin_alloca (20000);
bar (mem);
}
/* For alloca a common code routine emits the probes. Make sure the
"probe_stack" expander is used in that case. We want to use mem
compares instead of stores. */
/* { dg-final { scan-assembler-times "cg\t" 5 { target lp64 } } } */
/* { dg-final { scan-assembler-times "c\t" 5 { target { ! lp64 } } } } */