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| author | Richard Guenther <rguenther@suse.de> | 2009-04-09 08:05:43 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2009-04-09 08:05:43 +0000 |
| commit | f76968e6d5ab3ca8bd5b64ba0143197c00f59943 (patch) | |
| tree | a08a54da6efd905c9042e644d8017899d9d9c0f1 /gcc/tree-ssa-ccp.c | |
| parent | c90c5fb5a5e09a6405c7dbfa145bf3a9baf70fad (diff) | |
| download | gcc-f76968e6d5ab3ca8bd5b64ba0143197c00f59943.zip gcc-f76968e6d5ab3ca8bd5b64ba0143197c00f59943.tar.gz gcc-f76968e6d5ab3ca8bd5b64ba0143197c00f59943.tar.bz2 | |
tree-ssa-ccp.c (maybe_fold_stmt_addition): Move non-constant indices into an array reference if possible.
2009-04-09 Richard Guenther <rguenther@suse.de>
* tree-ssa-ccp.c (maybe_fold_stmt_addition): Move non-constant
indices into an array reference if possible.
* tree-ssa-forwprop.c (tree_ssa_forward_propagate_single_use_vars):
Fold POINTER_PLUS_EXPR statements with invariant address.
* gcc.dg/tree-ssa/ssa-ccp-25.c: New testcase.
* gcc.dg/tree-ssa/ssa-ccp-26.c: Likewise.
From-SVN: r145799
Diffstat (limited to 'gcc/tree-ssa-ccp.c')
| -rw-r--r-- | gcc/tree-ssa-ccp.c | 39 |
1 files changed, 36 insertions, 3 deletions
diff --git a/gcc/tree-ssa-ccp.c b/gcc/tree-ssa-ccp.c index a678504..226fd3d 100644 --- a/gcc/tree-ssa-ccp.c +++ b/gcc/tree-ssa-ccp.c @@ -2114,14 +2114,47 @@ maybe_fold_stmt_addition (tree res_type, tree op0, tree op1) tree ptd_type; tree t; - /* It had better be a constant. */ - if (TREE_CODE (op1) != INTEGER_CST) - return NULL_TREE; /* The first operand should be an ADDR_EXPR. */ if (TREE_CODE (op0) != ADDR_EXPR) return NULL_TREE; op0 = TREE_OPERAND (op0, 0); + /* It had better be a constant. */ + if (TREE_CODE (op1) != INTEGER_CST) + { + /* Or op0 should now be A[0] and the non-constant offset defined + via a multiplication by the array element size. */ + if (TREE_CODE (op0) == ARRAY_REF + && integer_zerop (TREE_OPERAND (op0, 1)) + && TREE_CODE (op1) == SSA_NAME + && host_integerp (TYPE_SIZE_UNIT (TREE_TYPE (op0)), 1)) + { + gimple offset_def = SSA_NAME_DEF_STMT (op1); + if (!is_gimple_assign (offset_def)) + return NULL_TREE; + + if (gimple_assign_rhs_code (offset_def) == MULT_EXPR + && TREE_CODE (gimple_assign_rhs2 (offset_def)) == INTEGER_CST + && tree_int_cst_equal (gimple_assign_rhs2 (offset_def), + TYPE_SIZE_UNIT (TREE_TYPE (op0)))) + return build1 (ADDR_EXPR, res_type, + build4 (ARRAY_REF, TREE_TYPE (op0), + TREE_OPERAND (op0, 0), + gimple_assign_rhs1 (offset_def), + TREE_OPERAND (op0, 2), + TREE_OPERAND (op0, 3))); + else if (integer_onep (TYPE_SIZE_UNIT (TREE_TYPE (op0))) + && gimple_assign_rhs_code (offset_def) != MULT_EXPR) + return build1 (ADDR_EXPR, res_type, + build4 (ARRAY_REF, TREE_TYPE (op0), + TREE_OPERAND (op0, 0), + op1, + TREE_OPERAND (op0, 2), + TREE_OPERAND (op0, 3))); + } + return NULL_TREE; + } + /* If the first operand is an ARRAY_REF, expand it so that we can fold the offset into it. */ while (TREE_CODE (op0) == ARRAY_REF) |