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| author | H.J. Lu <hongjiu.lu@intel.com> | 2018-09-04 20:42:06 +0000 |
|---|---|---|
| committer | H.J. Lu <hjl@gcc.gnu.org> | 2018-09-04 13:42:06 -0700 |
| commit | 6bc088ca0e315896c3efe1ed273f6a345e5418b8 (patch) | |
| tree | 3d3d5fc25fe9c14be6b2a015025f3846801904d4 /gcc/dwarf2out.c | |
| parent | 8f93810d3b7cc7540e31397697f5df9db18daba4 (diff) | |
| download | gcc-6bc088ca0e315896c3efe1ed273f6a345e5418b8.zip gcc-6bc088ca0e315896c3efe1ed273f6a345e5418b8.tar.gz gcc-6bc088ca0e315896c3efe1ed273f6a345e5418b8.tar.bz2 | |
DWARF: Allow hard frame pointer even if frame pointer isn't used
r251028
commit cd557ff63f388ad27c376d0a225e74d3594a6f9d
Author: hjl <hjl@138bc75d-0d04-0410-961f-82ee72b054a4>
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.
frame pointer may not be available even if -fno-omit-frame-pointer is
used. When this happened, arg pointer may be eliminated by hard frame
pointer. Since hard frame pointer is encoded with DW_OP_fbreg which
uses the DW_AT_frame_base attribute, not hard frame pointer directly,
we should allow hard frame pointer when generating DWARF info even if
frame pointer isn't used.
gcc/
PR debug/86593
* dwarf2out.c (based_loc_descr): Allow hard frame pointer even
if frame pointer isn't used.
(compute_frame_pointer_to_fb_displacement): Likewise.
gcc/testsuite/
PR debug/86593
* g++.dg/pr86593.C: New test.
From-SVN: r264096
Diffstat (limited to 'gcc/dwarf2out.c')
| -rw-r--r-- | gcc/dwarf2out.c | 25 |
1 files changed, 12 insertions, 13 deletions
diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c index 77317ed..40cfdf5 100644 --- a/gcc/dwarf2out.c +++ b/gcc/dwarf2out.c @@ -14325,13 +14325,13 @@ based_loc_descr (rtx reg, poly_int64 offset, if (elim != reg) { + /* Allow hard frame pointer here even if frame pointer + isn't used since hard frame pointer is encoded with + DW_OP_fbreg which uses the DW_AT_frame_base attribute, + not hard frame pointer directly. */ elim = strip_offset_and_add (elim, &offset); - gcc_assert ((SUPPORTS_STACK_ALIGNMENT - && (elim == hard_frame_pointer_rtx - || elim == stack_pointer_rtx)) - || elim == (frame_pointer_needed - ? hard_frame_pointer_rtx - : stack_pointer_rtx)); + gcc_assert (elim == hard_frame_pointer_rtx + || elim == stack_pointer_rtx); /* If drap register is used to align stack, use frame pointer + offset to access stack variables. If stack @@ -20512,14 +20512,13 @@ compute_frame_pointer_to_fb_displacement (poly_int64 offset) in which to eliminate. This is because it's stack pointer isn't directly accessible as a register within the ISA. To work around 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, we won't need one either. We can use + hard frame pointer in debug info even if frame pointer isn't used + since hard frame pointer in debug info is encoded with DW_OP_fbreg + which uses the DW_AT_frame_base attribute, not hard frame pointer + directly. */ frame_pointer_fb_offset_valid - = ((SUPPORTS_STACK_ALIGNMENT - && (elim == hard_frame_pointer_rtx - || elim == stack_pointer_rtx)) - || elim == (frame_pointer_needed - ? hard_frame_pointer_rtx - : stack_pointer_rtx)); + = (elim == hard_frame_pointer_rtx || elim == stack_pointer_rtx); } /* Generate a DW_AT_name attribute given some string value to be included as |