https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88483
--- Comment #5 from hjl at gcc dot gnu.org <hjl at gcc dot gnu.org> --- Author: hjl Date: Wed May 22 18:53:37 2019 New Revision: 271517 URL: https://gcc.gnu.org/viewcvs?rev=271517&root=gcc&view=rev Log: x86: Don't allocate stack frame nor align stack if not needed get_frame_size () returns used stack slots during compilation, which may be optimized out later. This patch does the followings: 1. Add stack_frame_required to machine_function to indicate that the function needs a stack frame. 2. Change ix86_find_max_used_stack_alignment to set stack_frame_required. 3. Always call ix86_find_max_used_stack_alignment to check if stack frame is needed. Tested on i686 and x86-64 with --with-arch=native --with-cpu=native Tested on AVX512 machine configured with --with-arch=native --with-cpu=native gcc/ PR target/88483 * config/i386/i386-options.c (ix86_init_machine_status): Set stack_frame_required to true. * config/i386/i386.c (ix86_get_frame_size): New function. (ix86_frame_pointer_required): Replace get_frame_size with ix86_get_frame_size. (ix86_compute_frame_layout): Likewise. (ix86_find_max_used_stack_alignment): Changed to void. Set stack_frame_required. (ix86_finalize_stack_frame_flags): Always call ix86_find_max_used_stack_alignment. Replace get_frame_size with ix86_get_frame_size. * config/i386/i386.h (machine_function): Add stack_frame_required. gcc/testsuite/ PR target/88483 * gcc.target/i386/stackalign/pr88483-1.c: New test. * gcc.target/i386/stackalign/pr88483-2.c: Likewise. Added: trunk/gcc/testsuite/gcc.target/i386/stackalign/pr88483-1.c trunk/gcc/testsuite/gcc.target/i386/stackalign/pr88483-2.c Modified: trunk/gcc/ChangeLog trunk/gcc/config/i386/i386-options.c trunk/gcc/config/i386/i386.c trunk/gcc/config/i386/i386.h trunk/gcc/testsuite/ChangeLog
