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| author | tege <tege@138bc75d-0d04-0410-961f-82ee72b054a4> | 1994-11-17 23:31:20 +0000 |
|---|---|---|
| committer | tege <tege@138bc75d-0d04-0410-961f-82ee72b054a4> | 1994-11-17 23:31:20 +0000 |
| commit | e927ecc8e796471214643f7fa533d772ae571398 (patch) | |
| tree | f42b01a7bad7022f724bea094fc0e47e0d20fffb /gcc | |
| parent | 4cbcfb8fc1545db41dba6eca21285f0fc2bf6000 (diff) | |
| download | gcc-e927ecc8e796471214643f7fa533d772ae571398.tar.gz | |
(simplify_binary_operation): Do (x - (x & y)) -> (x & ~y).
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@8494 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/cse.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/gcc/cse.c b/gcc/cse.c index 103d369f280..487cc3f33c3 100644 --- a/gcc/cse.c +++ b/gcc/cse.c @@ -3718,6 +3718,15 @@ simplify_binary_operation (code, mode, op0, op1) /* Don't let a relocatable value get a negative coeff. */ if (GET_CODE (op1) == CONST_INT && GET_MODE (op0) != VOIDmode) return plus_constant (op0, - INTVAL (op1)); + + /* (x - (x & y)) -> (x & ~y) */ + if (GET_CODE (op1) == AND) + { + if (rtx_equal_p (op0, XEXP (op1, 0))) + return cse_gen_binary (AND, mode, op0, gen_rtx (NOT, mode, XEXP (op1, 1))); + if (rtx_equal_p (op0, XEXP (op1, 1))) + return cse_gen_binary (AND, mode, op0, gen_rtx (NOT, mode, XEXP (op1, 0))); + } break; case MULT: |