From 079a03638c5c38918f608c496ca1032a9ddc26c9 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Mon, 7 Aug 2017 11:49:10 +0000 Subject: [PATCH] i386: Don't use frame pointer without stack access When there is no stack access, there is no need to use frame pointer even if -fno-omit-frame-pointer is used. gcc/ PR target/81736 * config/i386/i386.c (ix86_finalize_stack_realign_flags): Renamed to ... (ix86_finalize_stack_frame_flags): This. Also clear frame_pointer_needed if -fno-omit-frame-pointer is used without stack access. (ix86_expand_prologue): Replace ix86_finalize_stack_realign_flags with ix86_finalize_stack_frame_flags. (ix86_expand_epilogue): Likewise. (ix86_expand_split_stack_prologue): Likewise. gcc/testsuite/ PR target/81736 * gcc.target/i386/pr81736-1.c: New test. * gcc.target/i386/pr81736-2.c: Likewise. * gcc.target/i386/pr81736-3.c: Likewise. * gcc.target/i386/pr81736-4.c: Likewise. From-SVN: r250916 --- gcc/ChangeLog | 13 ++++++++++++ gcc/config/i386/i386.c | 26 ++++++++++++----------- gcc/testsuite/ChangeLog | 8 +++++++ gcc/testsuite/gcc.target/i386/pr81736-1.c | 13 ++++++++++++ gcc/testsuite/gcc.target/i386/pr81736-2.c | 14 ++++++++++++ gcc/testsuite/gcc.target/i386/pr81736-3.c | 11 ++++++++++ gcc/testsuite/gcc.target/i386/pr81736-4.c | 11 ++++++++++ 7 files changed, 84 insertions(+), 12 deletions(-) create mode 100644 gcc/testsuite/gcc.target/i386/pr81736-1.c create mode 100644 gcc/testsuite/gcc.target/i386/pr81736-2.c create mode 100644 gcc/testsuite/gcc.target/i386/pr81736-3.c create mode 100644 gcc/testsuite/gcc.target/i386/pr81736-4.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index a78b1a742f4..01eb3354dc5 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,16 @@ +2017-08-07 H.J. Lu + + PR target/81736 + * config/i386/i386.c (ix86_finalize_stack_realign_flags): Renamed + to ... + (ix86_finalize_stack_frame_flags): This. Also clear + frame_pointer_needed if -fno-omit-frame-pointer is used without + stack access. + (ix86_expand_prologue): Replace ix86_finalize_stack_realign_flags + with ix86_finalize_stack_frame_flags. + (ix86_expand_epilogue): Likewise. + (ix86_expand_split_stack_prologue): Likewise. + 2017-08-07 H.J. Lu PR target/81743 diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c index c0b6015991d..4683da3f24d 100644 --- a/gcc/config/i386/i386.c +++ b/gcc/config/i386/i386.c @@ -14116,22 +14116,24 @@ output_probe_stack_range (rtx reg, rtx end) return ""; } -/* Finalize stack_realign_needed flag, which will guide prologue/epilogue - to be generated in correct form. */ +/* Finalize stack_realign_needed and frame_pointer_needed flags, which + will guide prologue/epilogue to be generated in correct form. */ + static void -ix86_finalize_stack_realign_flags (void) +ix86_finalize_stack_frame_flags (void) { /* Check if stack realign is really needed after reload, and stores result in cfun */ unsigned int incoming_stack_boundary = (crtl->parm_stack_boundary > ix86_incoming_stack_boundary ? crtl->parm_stack_boundary : ix86_incoming_stack_boundary); - unsigned int stack_realign + bool stack_realign = (incoming_stack_boundary < (crtl->is_leaf && !ix86_current_function_calls_tls_descriptor ? crtl->max_used_stack_slot_alignment : crtl->stack_alignment_needed)); bool recompute_frame_layout_p = false; + bool omit_frame_pointer = flag_omit_frame_pointer != 0; if (crtl->stack_realign_finalized) { @@ -14142,13 +14144,13 @@ ix86_finalize_stack_realign_flags (void) } /* If the only reason for frame_pointer_needed is that we conservatively - assumed stack realignment might be needed, but in the end nothing that - needed the stack alignment had been spilled, clear frame_pointer_needed - and say we don't need stack realignment. */ - if (stack_realign + assumed stack realignment might be needed or -fno-omit-frame-pointer + is used, but in the end nothing that needed the stack alignment had + been spilled nor stack access, clear frame_pointer_needed and say we + don't need stack realignment. */ + if (stack_realign == omit_frame_pointer && frame_pointer_needed && crtl->is_leaf - && flag_omit_frame_pointer && crtl->sp_is_unchanging && !ix86_current_function_calls_tls_descriptor && !crtl->accesses_prior_frames @@ -14339,7 +14341,7 @@ ix86_expand_prologue (void) if (ix86_function_naked (current_function_decl)) return; - ix86_finalize_stack_realign_flags (); + ix86_finalize_stack_frame_flags (); /* DRAP should not coexist with stack_realign_fp */ gcc_assert (!(crtl->drap_reg && stack_realign_fp)); @@ -15203,7 +15205,7 @@ ix86_expand_epilogue (int style) return; } - ix86_finalize_stack_realign_flags (); + ix86_finalize_stack_frame_flags (); frame = m->frame; m->fs.sp_realigned = stack_realign_fp; @@ -15738,7 +15740,7 @@ ix86_expand_split_stack_prologue (void) gcc_assert (flag_split_stack && reload_completed); - ix86_finalize_stack_realign_flags (); + ix86_finalize_stack_frame_flags (); frame = cfun->machine->frame; allocate = frame.stack_pointer_offset - INCOMING_FRAME_SP_OFFSET; diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index bf161a31141..0e750328645 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,11 @@ +2017-08-07 H.J. Lu + + PR target/81736 + * gcc.target/i386/pr81736-1.c: New test. + * gcc.target/i386/pr81736-2.c: Likewise. + * gcc.target/i386/pr81736-3.c: Likewise. + * gcc.target/i386/pr81736-4.c: Likewise. + 2017-08-07 Marek Polacek PR middle-end/81737 diff --git a/gcc/testsuite/gcc.target/i386/pr81736-1.c b/gcc/testsuite/gcc.target/i386/pr81736-1.c new file mode 100644 index 00000000000..92c7bc97a0d --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr81736-1.c @@ -0,0 +1,13 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fno-omit-frame-pointer" } */ + +extern int i; + +int +foo (void) +{ + return i; +} + +/* No need to use a frame pointer. */ +/* { dg-final { scan-assembler-not "%\[re\]bp" } } */ diff --git a/gcc/testsuite/gcc.target/i386/pr81736-2.c b/gcc/testsuite/gcc.target/i386/pr81736-2.c new file mode 100644 index 00000000000..a3720879937 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr81736-2.c @@ -0,0 +1,14 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fno-omit-frame-pointer" } */ + +int +#ifndef __x86_64__ +__attribute__((regparm(3))) +#endif +foo (int i) +{ + return i; +} + +/* No need to use a frame pointer. */ +/* { dg-final { scan-assembler-not "%\[re\]bp" } } */ diff --git a/gcc/testsuite/gcc.target/i386/pr81736-3.c b/gcc/testsuite/gcc.target/i386/pr81736-3.c new file mode 100644 index 00000000000..c3bde7dd933 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr81736-3.c @@ -0,0 +1,11 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fno-omit-frame-pointer" } */ + +void +foo (void) +{ + asm ("# " : : : "ebx"); +} + +/* Need to use a frame pointer. */ +/* { dg-final { scan-assembler "%\[re\]bp" } } */ diff --git a/gcc/testsuite/gcc.target/i386/pr81736-4.c b/gcc/testsuite/gcc.target/i386/pr81736-4.c new file mode 100644 index 00000000000..25f50016a64 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr81736-4.c @@ -0,0 +1,11 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fno-omit-frame-pointer" } */ + +int +foo (int i1, int i2, int i3, int i4, int i5, int i6, int i7) +{ + return i7; +} + +/* Need to use a frame pointer. */ +/* { dg-final { scan-assembler "%\[re\]bp" } } */ -- 2.30.2