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authorRichard Henderson <rth@redhat.com>2003-01-23 18:59:58 -0800
committerRichard Henderson <rth@gcc.gnu.org>2003-01-23 18:59:58 -0800
commit3de9c088e8349dbf2af82c6ae947e9fe84b356e2 (patch)
tree795011f29c3d8a47649c42e9fa9e483f0e44bbb2 /gcc
parent8bef0925e831b8b5092b6282cb5d8b68dad62cc0 (diff)
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ifcvt.c (noce_process_if_block): Re-add check vs X being changed in no-else-block case.
* ifcvt.c (noce_process_if_block): Re-add check vs X being changed in no-else-block case. Add commentary. From-SVN: r61695
Diffstat (limited to 'gcc')
-rw-r--r--gcc/ChangeLog5
-rw-r--r--gcc/ifcvt.c13
2 files changed, 15 insertions, 3 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e937cf4..e71d35e 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2003-01-23 Richard Henderson <rth@redhat.com>
+
+ * ifcvt.c (noce_process_if_block): Re-add check vs X being changed
+ in no-else-block case. Add commentary.
+
2003-01-23 Kaveh R. Ghazi <ghazi@caip.rutgers.edu>
* configure.in: Revert last change.
diff --git a/gcc/ifcvt.c b/gcc/ifcvt.c
index 341e755..ed04aef 100644
--- a/gcc/ifcvt.c
+++ b/gcc/ifcvt.c
@@ -1802,15 +1802,22 @@ noce_process_if_block (ce_info)
else
{
insn_b = prev_nonnote_insn (if_info.cond_earliest);
+ /* We're going to be moving the evaluation of B down from above
+ COND_EARLIEST to JUMP. Make sure the relevant data is still
+ intact. */
if (! insn_b
|| GET_CODE (insn_b) != INSN
|| (set_b = single_set (insn_b)) == NULL_RTX
|| ! rtx_equal_p (x, SET_DEST (set_b))
- || reg_overlap_mentioned_p (x, cond)
- || reg_overlap_mentioned_p (x, a)
|| reg_overlap_mentioned_p (x, SET_SRC (set_b))
|| modified_between_p (SET_SRC (set_b),
- PREV_INSN (if_info.cond_earliest), jump))
+ PREV_INSN (if_info.cond_earliest), jump)
+ /* Likewise with X. In particular this can happen when
+ noce_get_condition looks farther back in the instruction
+ stream than one might expect. */
+ || reg_overlap_mentioned_p (x, cond)
+ || reg_overlap_mentioned_p (x, a)
+ || modified_between_p (x, PREV_INSN (if_info.cond_earliest), jump))
insn_b = set_b = NULL_RTX;
}
b = (set_b ? SET_SRC (set_b) : x);