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| author | Geoff Keating <geoffk@ozemail.com.au> | 1999-03-24 00:39:44 +0000 |
|---|---|---|
| committer | Jeff Law <law@gcc.gnu.org> | 1999-03-23 17:39:44 -0700 |
| commit | a9d9c1084d76b99a63a8510670bcd9b5e5ef7316 (patch) | |
| tree | f9e23ad5170412869b42e94ba91c892f28a7326e /gcc/fold-const.c | |
| parent | db4237a4cb3744c130f307431ed6bb9cafa05f7f (diff) | |
| download | gcc-a9d9c1084d76b99a63a8510670bcd9b5e5ef7316.zip gcc-a9d9c1084d76b99a63a8510670bcd9b5e5ef7316.tar.gz gcc-a9d9c1084d76b99a63a8510670bcd9b5e5ef7316.tar.bz2 | |
* fold-const.c (fold): Recognise a rotate by an unsigned amount.
From-SVN: r25937
Diffstat (limited to 'gcc/fold-const.c')
| -rw-r--r-- | gcc/fold-const.c | 52 |
1 files changed, 36 insertions, 16 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 492f1b8..4faac0c 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -5007,6 +5007,8 @@ fold (expr) tree01 = TREE_OPERAND (arg0, 1); tree11 = TREE_OPERAND (arg1, 1); + STRIP_NOPS (tree01); + STRIP_NOPS (tree11); code01 = TREE_CODE (tree01); code11 = TREE_CODE (tree11); if (code01 == INTEGER_CST @@ -5017,22 +5019,40 @@ fold (expr) == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0))))) return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0), code0 == LSHIFT_EXPR ? tree01 : tree11); - else if (code11 == MINUS_EXPR - && TREE_CODE (TREE_OPERAND (tree11, 0)) == INTEGER_CST - && TREE_INT_CST_HIGH (TREE_OPERAND (tree11, 0)) == 0 - && TREE_INT_CST_LOW (TREE_OPERAND (tree11, 0)) - == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0))) - && operand_equal_p (tree01, TREE_OPERAND (tree11, 1), 0)) - return build (code0 == LSHIFT_EXPR ? LROTATE_EXPR : RROTATE_EXPR, - type, TREE_OPERAND (arg0, 0), tree01); - else if (code01 == MINUS_EXPR - && TREE_CODE (TREE_OPERAND (tree01, 0)) == INTEGER_CST - && TREE_INT_CST_HIGH (TREE_OPERAND (tree01, 0)) == 0 - && TREE_INT_CST_LOW (TREE_OPERAND (tree01, 0)) - == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0))) - && operand_equal_p (tree11, TREE_OPERAND (tree01, 1), 0)) - return build (code0 != LSHIFT_EXPR ? LROTATE_EXPR : RROTATE_EXPR, - type, TREE_OPERAND (arg0, 0), tree11); + else if (code11 == MINUS_EXPR) + { + tree tree110, tree111; + tree110 = TREE_OPERAND (tree11, 0); + tree111 = TREE_OPERAND (tree11, 1); + STRIP_NOPS (tree110); + STRIP_NOPS (tree111); + if (TREE_CODE (tree110) == INTEGER_CST + && TREE_INT_CST_HIGH (tree110) == 0 + && (TREE_INT_CST_LOW (tree110) + == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))) + && operand_equal_p (tree01, tree111, 0)) + return build ((code0 == LSHIFT_EXPR + ? LROTATE_EXPR + : RROTATE_EXPR), + type, TREE_OPERAND (arg0, 0), tree01); + } + else if (code01 == MINUS_EXPR) + { + tree tree010, tree011; + tree010 = TREE_OPERAND (tree01, 0); + tree011 = TREE_OPERAND (tree01, 1); + STRIP_NOPS (tree010); + STRIP_NOPS (tree011); + if (TREE_CODE (tree010) == INTEGER_CST + && TREE_INT_CST_HIGH (tree010) == 0 + && (TREE_INT_CST_LOW (tree010) + == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))) + && operand_equal_p (tree11, tree011, 0)) + return build ((code0 != LSHIFT_EXPR + ? LROTATE_EXPR + : RROTATE_EXPR), + type, TREE_OPERAND (arg0, 0), tree11); + } } goto associate; |