diff options
| author | rth <rth@138bc75d-0d04-0410-961f-82ee72b054a4> | 2000-09-18 18:24:32 +0000 |
|---|---|---|
| committer | rth <rth@138bc75d-0d04-0410-961f-82ee72b054a4> | 2000-09-18 18:24:32 +0000 |
| commit | 069a05d1dee193f4df79d3e4b3bc067ebced3954 (patch) | |
| tree | ddee6e9c6a5df5d1308e04b8d34274665f561576 /gcc/simplify-rtx.c | |
| parent | bc8f8789e48ff14bedd9f87d767f83d57fb761aa (diff) | |
| download | gcc-069a05d1dee193f4df79d3e4b3bc067ebced3954.tar.gz | |
* combine.c (combine_simplify_rtx): Use gen_unary to distribute
the NOT for De Morgan's rule.
* simplify-rtx.c (simplify_unary_operation): Simplify a BImode NOT
of a comparison to the reverse comparison.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@36506 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/simplify-rtx.c')
| -rw-r--r-- | gcc/simplify-rtx.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c index 1e130768eed..eb1ac584dbb 100644 --- a/gcc/simplify-rtx.c +++ b/gcc/simplify-rtx.c @@ -583,10 +583,21 @@ simplify_unary_operation (code, mode, op, op_mode) aren't constant. */ switch (code) { - case NEG: case NOT: - /* (not (not X)) == X, similarly for NEG. */ - if (GET_CODE (op) == code) + /* (not (not X)) == X. */ + if (GET_CODE (op) == NOT) + return XEXP (op, 0); + + /* (not (eq X Y)) == (ne X Y), etc. */ + if (mode == BImode && GET_RTX_CLASS (GET_CODE (op)) == '<' + && can_reverse_comparison_p (op, NULL_RTX)) + return gen_rtx_fmt_ee (reverse_condition (GET_CODE (op)), + op_mode, XEXP (op, 0), XEXP (op, 1)); + break; + + case NEG: + /* (neg (neg X)) == X. */ + if (GET_CODE (op) == NEG) return XEXP (op, 0); break; |