From 61959ba10bd5595e6114712abcbce5bcea36c9bf Mon Sep 17 00:00:00 2001 From: Jeff Law Date: Fri, 3 Nov 2017 14:30:53 -0600 Subject: [PATCH] i386.c (ix86_emit_restore_reg_using_pop): Prototype. * config/i386/i386.c (ix86_emit_restore_reg_using_pop): Prototype. (ix86_adjust_stack_and_probe_stack_clash): Use a push/pop sequence to probe at the start of a noreturn function. * gcc.target/i386/stack-check-12.c: New test. From-SVN: r254396 --- gcc/ChangeLog | 6 ++++++ gcc/config/i386/i386.c | 12 ++++++++++-- gcc/testsuite/ChangeLog | 4 ++++ .../gcc.target/i386/stack-check-12.c | 19 +++++++++++++++++++ 4 files changed, 39 insertions(+), 2 deletions(-) create mode 100644 gcc/testsuite/gcc.target/i386/stack-check-12.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 98cd5a41b65..99f8aba9f6b 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2017-11-03 Jeff Law + + * config/i386/i386.c (ix86_emit_restore_reg_using_pop): Prototype. + (ix86_adjust_stack_and_probe_stack_clash): Use a push/pop sequence + to probe at the start of a noreturn function. + 2017-11-03 Jakub Jelinek PR tree-optimization/78821 diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c index 25b28a1a088..1b837554609 100644 --- a/gcc/config/i386/i386.c +++ b/gcc/config/i386/i386.c @@ -101,6 +101,8 @@ static void ix86_print_operand_address_as (FILE *, rtx, addr_space_t, bool); static bool ix86_save_reg (unsigned int, bool, bool); static bool ix86_function_naked (const_tree); static bool ix86_notrack_prefixed_insn_p (rtx); +static void ix86_emit_restore_reg_using_pop (rtx); + #ifndef CHECK_STACK_LIMIT #define CHECK_STACK_LIMIT (-1) @@ -12124,8 +12126,14 @@ ix86_adjust_stack_and_probe_stack_clash (const HOST_WIDE_INT size) we just probe when we cross PROBE_INTERVAL. */ if (TREE_THIS_VOLATILE (cfun->decl)) { - emit_stack_probe (plus_constant (Pmode, stack_pointer_rtx, - -GET_MODE_SIZE (word_mode))); + /* We can safely use any register here since we're just going to push + its value and immediately pop it back. But we do try and avoid + argument passing registers so as not to introduce dependencies in + the pipeline. For 32 bit we use %esi and for 64 bit we use %rax. */ + rtx dummy_reg = gen_rtx_REG (word_mode, TARGET_64BIT ? AX_REG : SI_REG); + rtx_insn *insn = emit_insn (gen_push (dummy_reg)); + RTX_FRAME_RELATED_P (insn) = 1; + ix86_emit_restore_reg_using_pop (dummy_reg); emit_insn (gen_blockage ()); } diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 69d8b6b510d..4cc2cedc0dc 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2017-11-03 Jeff Law + + * gcc.target/i386/stack-check-12.c: New test. + 2017-11-03 Jakub Jelinek PR tree-optimization/78821 diff --git a/gcc/testsuite/gcc.target/i386/stack-check-12.c b/gcc/testsuite/gcc.target/i386/stack-check-12.c new file mode 100644 index 00000000000..cb69bb08086 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/stack-check-12.c @@ -0,0 +1,19 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fstack-clash-protection -mtune=generic" } */ +/* { dg-require-effective-target supports_stack_clash_protection } */ + +__attribute__ ((noreturn)) void exit (int); + +__attribute__ ((noreturn)) void +f (void) +{ + asm volatile ("nop" ::: "edi"); + exit (1); +} + +/* { dg-final { scan-assembler-not "or\[ql\]" } } */ +/* { dg-final { scan-assembler "pushl %esi" { target ia32 } } } */ +/* { dg-final { scan-assembler "popl %esi" { target ia32 } } }*/ +/* { dg-final { scan-assembler "pushq %rax" { target { ! ia32 } } } } */ +/* { dg-final { scan-assembler "popq %rax" { target { ! ia32 } } } }*/ + -- 2.30.2