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| author | Segher Boessenkool <segher@kernel.crashing.org> | 2016-10-12 17:21:38 +0200 |
|---|---|---|
| committer | Segher Boessenkool <segher@gcc.gnu.org> | 2016-10-12 17:21:38 +0200 |
| commit | aab648a9fcf8c222ab43612915d11b093e11849d (patch) | |
| tree | c04c19ce683616d0ce012f90a973edb86373e8a4 | |
| parent | 20a6ece021473dc7f182b751bcbdaa6ad9762375 (diff) | |
| download | gcc-aab648a9fcf8c222ab43612915d11b093e11849d.zip gcc-aab648a9fcf8c222ab43612915d11b093e11849d.tar.gz gcc-aab648a9fcf8c222ab43612915d11b093e11849d.tar.bz2 | |
dce: Don't dead-code delete separately wrapped restores
If there is a separately wrapped register restore on some path that
is dead (say, control goes into an endless loop after it), then we
cannot delete that restore because that would confuse the DWARF CFI
(if there is another path joining).
This happens with gcc.dg/torture/pr53168.c, for example.
* dce.c (delete_unmarked_insns): Don't delete instructions with
a REG_CFA_RESTORE note.
From-SVN: r241060
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/dce.c | 9 |
2 files changed, 14 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 323bf35..7793544 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,10 @@ 2016-10-12 Segher Boessenkool <segher@kernel.crashing.org> + * dce.c (delete_unmarked_insns): Don't delete instructions with + a REG_CFA_RESTORE note. + +2016-10-12 Segher Boessenkool <segher@kernel.crashing.org> + * common.opt (-fshrink-wrap-separate): New flag. * doc/invoke.texi: Document it. * doc/tm.texi.in (Shrink-wrapping separate components): New subsection. @@ -587,6 +587,15 @@ delete_unmarked_insns (void) if (!dbg_cnt (dce)) continue; + if (crtl->shrink_wrapped_separate + && find_reg_note (insn, REG_CFA_RESTORE, NULL)) + { + if (dump_file) + fprintf (dump_file, "DCE: NOT deleting insn %d, it's a " + "callee-save restore\n", INSN_UID (insn)); + continue; + } + if (dump_file) fprintf (dump_file, "DCE: Deleting insn %d\n", INSN_UID (insn)); |