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| author | law <law@138bc75d-0d04-0410-961f-82ee72b054a4> | 1999-12-16 09:42:57 +0000 |
|---|---|---|
| committer | law <law@138bc75d-0d04-0410-961f-82ee72b054a4> | 1999-12-16 09:42:57 +0000 |
| commit | f9b38ae975be2dfbecba0329ddd719867ee82354 (patch) | |
| tree | 4b4c3de06f5bc7eb77643be40e61c0348ad5ca95 | |
| parent | ea7a8fa168f85be113935435c780b2b77c94f10f (diff) | |
| download | ppe42-gcc-f9b38ae975be2dfbecba0329ddd719867ee82354.tar.gz ppe42-gcc-f9b38ae975be2dfbecba0329ddd719867ee82354.zip | |
* combine.c (simplify_comparison): Reduce (OP (MINUS A B) 0)
to (OP A B).
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@30970 138bc75d-0d04-0410-961f-82ee72b054a4
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/combine.c | 8 |
2 files changed, 13 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index acce2bf876c..35343e3bb33 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +Thu Dec 16 02:41:26 1999 Richard Henderson (rth@cygnus.com) + + * combine.c (simplify_comparison): Reduce (OP (MINUS A B) 0) + to (OP A B). + Thu Dec 16 02:26:11 1999 Jeffrey A Law (law@cygnus.com) * h8300.md (HImode preinc peephole): Fix typo. diff --git a/gcc/combine.c b/gcc/combine.c index 5dc4fc8879b..3599168769f 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -10320,6 +10320,14 @@ simplify_comparison (code, pop0, pop1) break; case MINUS: + /* (op (minus A B) 0) -> (op A B) */ + if (op1 == const0_rtx) + { + op1 = XEXP (op0, 1); + op0 = XEXP (op0, 0); + continue; + } + /* (eq (minus A B) C) -> (eq A (plus B C)) or (eq B (minus A C)), whichever simplifies. We can only do this for equality comparisons due to pathological cases involving |
