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| author | Jim Wilson <wilson@gcc.gnu.org> | 1994-08-18 11:09:33 -0700 |
|---|---|---|
| committer | Jim Wilson <wilson@gcc.gnu.org> | 1994-08-18 11:09:33 -0700 |
| commit | 07d0cbddd457e587413cc203a724165676855099 (patch) | |
| tree | 8dc5f8fa7ec9d2fed443ac00751555e824560565 /gcc | |
| parent | 0179115349c9520a592a9981716ccbf5062169e6 (diff) | |
| download | gcc-07d0cbddd457e587413cc203a724165676855099.zip gcc-07d0cbddd457e587413cc203a724165676855099.tar.gz gcc-07d0cbddd457e587413cc203a724165676855099.tar.bz2 | |
(distribute_notes...
(distribute_notes, case REG_UNUSED): Ignore notes when
from_insn != i3 only if the notes would remain as REG_UNUSED notes.
From-SVN: r7942
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/combine.c | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index 275b94b..a4913ae 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -10342,10 +10342,7 @@ distribute_notes (notes, from_insn, i3, i2, elim_i2, elim_i1) switch (REG_NOTE_KIND (note)) { case REG_UNUSED: - /* If this note is from any insn other than i3, then we have no - use for it, and must ignore it. - - Any clobbers for i3 may still exist, and so we must process + /* Any clobbers for i3 may still exist, and so we must process REG_UNUSED notes from that insn. Any clobbers from i2 or i1 can only exist if they were added by @@ -10355,14 +10352,18 @@ distribute_notes (notes, from_insn, i3, i2, elim_i2, elim_i1) if it is for the same register as the original i3 dest. In that case, we will notice that the register is set in i3, and then add a REG_UNUSED note for the destination of i3, which - is wrong. */ - if (from_insn != i3) - break; + is wrong. However, it is possible to have REG_UNUSED notes from + i2 or i1 for register which were both used and clobbered, so + we keep notes from i2 or i1 if they will turn into REG_DEAD + notes. */ /* If this register is set or clobbered in I3, put the note there unless there is one already. */ - else if (reg_set_p (XEXP (note, 0), PATTERN (i3))) + if (reg_set_p (XEXP (note, 0), PATTERN (i3))) { + if (from_insn != i3) + break; + if (! (GET_CODE (XEXP (note, 0)) == REG ? find_regno_note (i3, REG_UNUSED, REGNO (XEXP (note, 0))) : find_reg_note (i3, REG_UNUSED, XEXP (note, 0)))) |