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| author | Jim Wilson <wilson@gcc.gnu.org> | 1992-12-10 12:52:48 -0800 |
|---|---|---|
| committer | Jim Wilson <wilson@gcc.gnu.org> | 1992-12-10 12:52:48 -0800 |
| commit | a70c61d9c4b7f2f6dce6ab54aa68f12b2e42620d (patch) | |
| tree | caa934a8efb7b7850d51e138e3e3feea2d0703b6 /gcc/combine.c | |
| parent | 4090a6b33d502fbee5098555aca7d907e464f204 (diff) | |
| download | gcc-a70c61d9c4b7f2f6dce6ab54aa68f12b2e42620d.zip gcc-a70c61d9c4b7f2f6dce6ab54aa68f12b2e42620d.tar.gz gcc-a70c61d9c4b7f2f6dce6ab54aa68f12b2e42620d.tar.bz2 | |
(try_combine): Only use I2DEST as a scratch reg for
a split if it does not overlap any inputs of NEWPAT.
From-SVN: r2857
Diffstat (limited to 'gcc/combine.c')
| -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. */ |