Assert for SUPPORTS_STACK_ALIGNMENT was added for dynamic stack alignment. At the time, arg_pointer_rtx would only be eliminated by either hard_frame_pointer_rtx or stack_pointer_rtx only when dynamic stack alignment is supported. With commit cd557ff63f388ad27c376d0a225e74d3594a6f9d Author: hjl Date: Thu Aug 10 15:29:05 2017 +0000 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 and caller's frame pointer is unchanged. this can happen when there is no dynamic stack alignment. This patch relaxes SUPPORTS_STACK_ALIGNMENT with !crtl->stack_realign_tried to allow arg_pointer_rtx to be eliminated by either hard_frame_pointer_rtx or stack_pointer_rtx when there is no dynamic stack alignment at all. gcc/ PR debug/86593 * dwarf2out.c (based_loc_descr): Replace SUPPORTS_STACK_ALIGNMENT with (SUPPORTS_STACK_ALIGNMENT || !crtl->stack_realign_tried). (compute_frame_pointer_to_fb_displacement): Likewise. gcc/testsuite/ PR debug/86593 * g++.dg/pr86593.C: New test. --- gcc/dwarf2out.c | 6 ++++-- gcc/testsuite/g++.dg/pr86593.C | 11 +++++++++++ 2 files changed, 15 insertions(+), 2 deletions(-) create mode 100644 gcc/testsuite/g++.dg/pr86593.C diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c index b67481dd2db..6ecdc4562d0 100644 --- a/gcc/dwarf2out.c +++ b/gcc/dwarf2out.c @@ -14304,7 +14304,8 @@ based_loc_descr (rtx reg, poly_int64 offset, if (elim != reg) { elim = strip_offset_and_add (elim, &offset); - gcc_assert ((SUPPORTS_STACK_ALIGNMENT + gcc_assert (((SUPPORTS_STACK_ALIGNMENT + || !crtl->stack_realign_tried) && (elim == hard_frame_pointer_rtx || elim == stack_pointer_rtx)) || elim == (frame_pointer_needed @@ -20492,7 +20493,8 @@ compute_frame_pointer_to_fb_displacement (poly_int64 offset) this, assume that while we cannot provide a proper value for frame_pointer_fb_offset, we won't need one either. */ frame_pointer_fb_offset_valid - = ((SUPPORTS_STACK_ALIGNMENT + = (((SUPPORTS_STACK_ALIGNMENT + || !crtl->stack_realign_tried) && (elim == hard_frame_pointer_rtx || elim == stack_pointer_rtx)) || elim == (frame_pointer_needed diff --git a/gcc/testsuite/g++.dg/pr86593.C b/gcc/testsuite/g++.dg/pr86593.C new file mode 100644 index 00000000000..f4de0c1166a --- /dev/null +++ b/gcc/testsuite/g++.dg/pr86593.C @@ -0,0 +1,11 @@ +// { dg-options "-O -g -fno-omit-frame-pointer" } + +struct Foo +{ + int bar(int a, int b, int c, int i1, int i2, int i3, int d); +}; + +int Foo::bar(int a, int b, int c, int i1, int i2, int i3, int d) +{ + return 0; +} -- 2.17.1