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| author | Jakub Jelinek <jakub@redhat.com> | 2005-06-01 12:13:36 +0200 |
|---|---|---|
| committer | Jakub Jelinek <jakub@gcc.gnu.org> | 2005-06-01 12:13:36 +0200 |
| commit | dcd25113c6c37534621934617f07776b9212ef33 (patch) | |
| tree | d4483d63d139eff9738f540f3168a9f08952531c /gcc/fold-const.c | |
| parent | a00cb0b926ac650709e3816bc967c8795869c116 (diff) | |
| download | gcc-dcd25113c6c37534621934617f07776b9212ef33.zip gcc-dcd25113c6c37534621934617f07776b9212ef33.tar.gz gcc-dcd25113c6c37534621934617f07776b9212ef33.tar.bz2 | |
* fold-const.c (fold_ternary): Optimize BIT_FIELD_REF of VECTOR_CST.
From-SVN: r100442
Diffstat (limited to 'gcc/fold-const.c')
| -rw-r--r-- | gcc/fold-const.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 18e92e2..13984d1 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -10284,6 +10284,29 @@ fold_ternary (enum tree_code code, tree type, tree op0, tree op1, tree op2) } return NULL_TREE; + case BIT_FIELD_REF: + if (TREE_CODE (arg0) == VECTOR_CST + && type == TREE_TYPE (TREE_TYPE (arg0)) + && host_integerp (arg1, 1) + && host_integerp (op2, 1)) + { + unsigned HOST_WIDE_INT width = tree_low_cst (arg1, 1); + unsigned HOST_WIDE_INT idx = tree_low_cst (op2, 1); + + if (width != 0 + && simple_cst_equal (arg1, TYPE_SIZE (type)) == 1 + && (idx % width) == 0 + && (idx = idx / width) + < TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0))) + { + tree elements = TREE_VECTOR_CST_ELTS (arg0); + while (idx-- > 0) + elements = TREE_CHAIN (elements); + return TREE_VALUE (elements); + } + } + return NULL_TREE; + default: return NULL_TREE; } /* switch (code) */ |