82 lines
3.4 KiB
Diff
82 lines
3.4 KiB
Diff
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commit 75179275ecc35724a058676199188e0d13e65054
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Author: law <law@138bc75d-0d04-0410-961f-82ee72b054a4>
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Date: Fri Nov 3 20:30:53 2017 +0000
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* config/i386/i386.c (ix86_emit_restore_reg_using_pop): Prototype.
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(ix86_adjust_stack_and_probe_stack_clash): Use a push/pop sequence
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to probe at the start of a noreturn function.
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* gcc.target/i386/stack-check-12.c: New test.
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git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@254396 138bc75d-0d04-0410-961f-82ee72b054a4
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diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
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index fd74f1f6c0c..3c828ba492d 100644
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--- a/gcc/config/i386/i386.c
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+++ b/gcc/config/i386/i386.c
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@@ -96,6 +96,7 @@ static rtx legitimize_dllimport_symbol (rtx, bool);
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static rtx legitimize_pe_coff_extern_decl (rtx, bool);
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static rtx legitimize_pe_coff_symbol (rtx, bool);
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static void ix86_print_operand_address_as (FILE *, rtx, addr_space_t, bool);
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+static void ix86_emit_restore_reg_using_pop (rtx);
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#ifndef CHECK_STACK_LIMIT
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#define CHECK_STACK_LIMIT (-1)
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@@ -13287,10 +13288,13 @@ ix86_adjust_stack_and_probe_stack_clash (const HOST_WIDE_INT size)
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no probes are needed. */
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if (!size)
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{
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+ struct ix86_frame frame;
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+ ix86_compute_frame_layout (&frame);
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+
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/* However, the allocation of space via pushes for register
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saves could be viewed as allocating space, but without the
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need to probe. */
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- if (m->frame.nregs || m->frame.nsseregs || frame_pointer_needed)
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+ if (frame.nregs || frame.nsseregs || frame_pointer_needed)
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dump_stack_clash_frame_info (NO_PROBE_SMALL_FRAME, true);
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else
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dump_stack_clash_frame_info (NO_PROBE_NO_FRAME, false);
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@@ -13312,8 +13316,14 @@ ix86_adjust_stack_and_probe_stack_clash (const HOST_WIDE_INT size)
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we just probe when we cross PROBE_INTERVAL. */
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if (TREE_THIS_VOLATILE (cfun->decl))
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{
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- emit_stack_probe (plus_constant (Pmode, stack_pointer_rtx,
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- -GET_MODE_SIZE (word_mode)));
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+ /* We can safely use any register here since we're just going to push
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+ its value and immediately pop it back. But we do try and avoid
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+ argument passing registers so as not to introduce dependencies in
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+ the pipeline. For 32 bit we use %esi and for 64 bit we use %rax. */
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+ rtx dummy_reg = gen_rtx_REG (word_mode, TARGET_64BIT ? AX_REG : SI_REG);
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+ rtx_insn *insn = emit_insn (gen_push (dummy_reg));
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+ RTX_FRAME_RELATED_P (insn) = 1;
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+ ix86_emit_restore_reg_using_pop (dummy_reg);
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emit_insn (gen_blockage ());
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}
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diff --git a/gcc/testsuite/gcc.target/i386/stack-check-12.c b/gcc/testsuite/gcc.target/i386/stack-check-12.c
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new file mode 100644
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index 00000000000..cb69bb08086
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--- /dev/null
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+++ b/gcc/testsuite/gcc.target/i386/stack-check-12.c
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@@ -0,0 +1,19 @@
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+/* { dg-do compile } */
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+/* { dg-options "-O2 -fstack-clash-protection -mtune=generic" } */
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+/* { dg-require-effective-target supports_stack_clash_protection } */
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+
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+__attribute__ ((noreturn)) void exit (int);
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+
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+__attribute__ ((noreturn)) void
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+f (void)
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+{
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+ asm volatile ("nop" ::: "edi");
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+ exit (1);
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+}
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+
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+/* { dg-final { scan-assembler-not "or\[ql\]" } } */
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+/* { dg-final { scan-assembler "pushl %esi" { target ia32 } } } */
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+/* { dg-final { scan-assembler "popl %esi" { target ia32 } } }*/
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+/* { dg-final { scan-assembler "pushq %rax" { target { ! ia32 } } } } */
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+/* { dg-final { scan-assembler "popq %rax" { target { ! ia32 } } } }*/
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+
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