On Thu, Jan 11, 2018 at 11:07 AM, Uros Bizjak <ubiz...@gmail.com> wrote: > On Wed, Jan 10, 2018 at 9:40 PM, H.J. Lu <hongjiu...@intel.com> wrote: >> When a function call is removed, it may become a leaf function. But if >> argument may be passed on stack, we need to align the stack frame when >> there is no tail call. >> >> Tested on Linux/i686 and Linux/x86-64. >> >> OK for trunk? >> >> H.J. >> --- >> gcc/ >> >> PR target/83330 >> * config/i386/i386.c (ix86_compute_frame_layout): Align stack >> frame if argument is passed on stack. >> >> gcc/testsuite/ >> >> PR target/83330 >> * gcc.target/i386/pr83330.c: New test. > > LGTM. >
Here is the backport for GCC 7. OK for gcc-7-branch after a few days? Thanks. -- H.J.
From 28be904309cb8e6568e26f47a9746c709ac65fb8 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" <hjl.to...@gmail.com> Date: Thu, 6 Jul 2017 08:58:46 -0700 Subject: [PATCH] i386: Align stack frame if argument is passed on stack When a function call is removed, it may become a leaf function. But if argument may be passed on stack, we need to align the stack frame when there is no tail call. gcc/ Backport from mainline PR target/83330 * config/i386/i386.c (ix86_function_arg_advance): Set outgoing_args_on_stack to true if there are outgoing arguments on stack. (ix86_function_arg): Likewise. (ix86_compute_frame_layout): Align stack frame if argument is passed on stack. * config/i386/i386.h (machine_function): Add outgoing_args_on_stack. gcc/testsuite/ Backport from mainline PR target/83330 * gcc.target/i386/pr83330.c: New test. --- gcc/config/i386/i386.c | 19 +++++++++++++++++-- gcc/config/i386/i386.h | 3 +++ gcc/testsuite/gcc.target/i386/pr83330.c | 29 +++++++++++++++++++++++++++++ 3 files changed, 49 insertions(+), 2 deletions(-) create mode 100644 gcc/testsuite/gcc.target/i386/pr83330.c diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c index 8a3782c0298..4cc59e164ed 100644 --- a/gcc/config/i386/i386.c +++ b/gcc/config/i386/i386.c @@ -9799,7 +9799,13 @@ ix86_function_arg_advance (cumulative_args_t cum_v, machine_mode mode, /* For pointers passed in memory we expect bounds passed in Bounds Table. */ if (!nregs) - cum->bnds_in_bt = chkp_type_bounds_count (type); + { + /* Track if there are outgoing arguments on stack. */ + if (cum->caller) + cfun->machine->outgoing_args_on_stack = true; + + cum->bnds_in_bt = chkp_type_bounds_count (type); + } } /* Define where to put the arguments to a function. @@ -10128,6 +10134,10 @@ ix86_function_arg (cumulative_args_t cum_v, machine_mode omode, else arg = function_arg_32 (cum, mode, omode, type, bytes, words); + /* Track if there are outgoing arguments on stack. */ + if (arg == NULL_RTX && cum->caller) + cfun->machine->outgoing_args_on_stack = true; + return arg; } @@ -12557,11 +12567,16 @@ ix86_compute_frame_layout (struct ix86_frame *frame) frame->va_arg_size = ix86_varargs_gpr_size + ix86_varargs_fpr_size; offset += frame->va_arg_size; - /* Align start of frame for local function. */ + /* Align start of frame for local function. When a function call + is removed, it may become a leaf function. But if argument may + be passed on stack, we need to align the stack when there is no + tail call. */ if (stack_realign_fp || offset != frame->sse_reg_save_offset || size != 0 || !crtl->is_leaf + || (!crtl->tail_call_emit + && cfun->machine->outgoing_args_on_stack) || cfun->calls_alloca || ix86_current_function_calls_tls_descriptor) offset = ROUND_UP (offset, stack_alignment_needed); diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h index 9c776dc5172..7c651d7b944 100644 --- a/gcc/config/i386/i386.h +++ b/gcc/config/i386/i386.h @@ -2570,6 +2570,9 @@ struct GTY(()) machine_function { pass arguments and can be used for indirect sibcall. */ BOOL_BITFIELD arg_reg_available : 1; + /* Nonzero if the function places outgoing arguments on stack. */ + BOOL_BITFIELD outgoing_args_on_stack : 1; + /* During prologue/epilogue generation, the current frame state. Otherwise, the frame state at the end of the prologue. */ struct machine_frame_state fs; diff --git a/gcc/testsuite/gcc.target/i386/pr83330.c b/gcc/testsuite/gcc.target/i386/pr83330.c new file mode 100644 index 00000000000..9040168377a --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr83330.c @@ -0,0 +1,29 @@ +/* { dg-do run { target int128 } } */ +/* { dg-options "-O2 -fno-tree-dce -mno-push-args" } */ + +typedef unsigned long long u64; +typedef unsigned __int128 u128; + +u64 v; +u64 g; + +u64 __attribute__ ((noinline, noclone)) +bar (u128 d, u64 e, u64 f, u64 g, u128 h) +{ + (void)d, (void)e, (void)f, (void)g, (void)h; + return 0; +} + +static u64 +foo (void) +{ + (void)(v - bar (0, 0, 0, 0, 0)); + return g; +} + +int +main (void) +{ + (void)foo (); + return 0; +} -- 2.14.3