diff options
| -rw-r--r-- | gcc/combine.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index 9632ab2..269c02c 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -1535,7 +1535,15 @@ try_combine (i3, i2, i1) convert I2DEST to the mode of the source of NEWPAT if we can. */ m_split = split_insns (newpat, i3); - if (m_split == 0) + + /* We can only use I2DEST as a scratch reg if it doesn't overlap any + inputs of NEWPAT. */ + + /* ??? If I2DEST is not safe, and I1DEST exists, then it would be + possible to try that as a scratch reg. This would require adding + more code to make it work though. */ + + if (m_split == 0 && ! reg_overlap_mentioned_p (ni2dest, newpat)) { /* If I2DEST is a hard register or the only use of a pseudo, we can change its mode. */ |