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| author | Roger Sayle <roger@eyesopen.com> | 2002-06-07 23:50:31 +0000 |
|---|---|---|
| committer | Roger Sayle <sayle@gcc.gnu.org> | 2002-06-07 23:50:31 +0000 |
| commit | bc9c18c3193347c70989e21c036cc5c298021569 (patch) | |
| tree | 5f3c718932f00c23a8fca6901ef2f8a9bc17139e /gcc/simplify-rtx.c | |
| parent | 437f1df1afacb10132608f3cf27f4289c1bdbe1c (diff) | |
| download | gcc-bc9c18c3193347c70989e21c036cc5c298021569.zip gcc-bc9c18c3193347c70989e21c036cc5c298021569.tar.gz gcc-bc9c18c3193347c70989e21c036cc5c298021569.tar.bz2 | |
simplify-rtx.c (simplify_gen_relational): Simplify RTL of the form (ne (comp x y) 0) into (comp x y) where comp is a...
* simplify-rtx.c (simplify_gen_relational): Simplify RTL of the form
(ne (comp x y) 0) into (comp x y) where comp is a comparison code.
Simplify (eq (comp x y) 0) into (revcomp x y) if the sense of the
comparison code comp can be reversed.
From-SVN: r54357
Diffstat (limited to 'gcc/simplify-rtx.c')
| -rw-r--r-- | gcc/simplify-rtx.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c index 6ec33a3..5db501e 100644 --- a/gcc/simplify-rtx.c +++ b/gcc/simplify-rtx.c @@ -232,10 +232,31 @@ simplify_gen_relational (code, mode, cmp_mode, op0, op1) if ((tem = simplify_relational_operation (code, cmp_mode, op0, op1)) != 0) return tem; + /* For the following tests, ensure const0_rtx is op1. */ + if (op0 == const0_rtx && swap_commutative_operands_p (op0, op1)) + tem = op0, op0 = op1, op1 = tem, code = swap_condition (code); + /* If op0 is a compare, extract the comparison arguments from it. */ if (GET_CODE (op0) == COMPARE && op1 == const0_rtx) op1 = XEXP (op0, 1), op0 = XEXP (op0, 0); + /* If op0 is a comparison, extract the comparison arguments form it. */ + if (code == NE && op1 == const0_rtx + && GET_RTX_CLASS (GET_CODE (op0)) == '<') + return op0; + else if (code == EQ && op1 == const0_rtx) + { + /* The following tests GET_RTX_CLASS (GET_CODE (op0)) == '<'. */ + enum rtx_code new = reversed_comparison_code (op0, NULL_RTX); + if (new != UNKNOWN) + { + code = new; + mode = cmp_mode; + op1 = XEXP (op0, 1); + op0 = XEXP (op0, 0); + } + } + /* Put complex operands first and constants second. */ if (swap_commutative_operands_p (op0, op1)) tem = op0, op0 = op1, op1 = tem, code = swap_condition (code); |