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authorJeffrey A Law <law@cygnus.com>1998-08-18 18:29:40 +0000
committerJeff Law <law@gcc.gnu.org>1998-08-18 12:29:40 -0600
commitec35104c79305d42d96c79c1a8a3c06211b70acb (patch)
tree5aed366b6918755d29ab59bf170407c3b2b93ac5 /gcc/combine.c
parente958d4576a5d91454cf9368be3a3444e7efbdb0a (diff)
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combine.c (can_combine_p): Allow combining insns with REG_RETVAL notes.
* combine.c (can_combine_p): Allow combining insns with REG_RETVAL notes. (try_combine): Allow combining insns with REG_LIBCALL notes. From-SVN: r21833
Diffstat (limited to 'gcc/combine.c')
-rw-r--r--gcc/combine.c13
1 files changed, 12 insertions, 1 deletions
diff --git a/gcc/combine.c b/gcc/combine.c
index 155585b..5c050f2 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -958,8 +958,14 @@ can_combine_p (insn, i3, pred, succ, pdest, psrc)
/* Don't substitute into an incremented register. */
|| FIND_REG_INC_NOTE (i3, dest)
|| (succ && FIND_REG_INC_NOTE (succ, dest))
+#if 0
/* Don't combine the end of a libcall into anything. */
+ /* ??? This gives worse code, and appears to be unnecessary, since no
+ pass after flow uses REG_LIBCALL/REG_RETVAL notes. Local-alloc does
+ use REG_RETVAL notes for noconflict blocks, but other code here
+ makes sure that those insns don't disappear. */
|| find_reg_note (insn, REG_RETVAL, NULL_RTX)
+#endif
/* Make sure that DEST is not used after SUCC but before I3. */
|| (succ && ! all_adjacent
&& reg_used_between_p (dest, succ, i3))
@@ -1371,7 +1377,12 @@ try_combine (i3, i2, i1)
if (GET_RTX_CLASS (GET_CODE (i3)) != 'i'
|| GET_RTX_CLASS (GET_CODE (i2)) != 'i'
|| (i1 && GET_RTX_CLASS (GET_CODE (i1)) != 'i')
- || find_reg_note (i3, REG_LIBCALL, NULL_RTX))
+#if 0
+ /* ??? This gives worse code, and appears to be unnecessary, since no
+ pass after flow uses REG_LIBCALL/REG_RETVAL notes. */
+ || find_reg_note (i3, REG_LIBCALL, NULL_RTX)
+#endif
+)
return 0;
combine_attempts++;