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| author | Richard Biener <rguenther@suse.de> | 2015-08-04 13:51:50 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2015-08-04 13:51:50 +0000 |
| commit | 59c20dc74df24fa8e14ade6aecbfd4a1c6bbe30c (patch) | |
| tree | 675f4300ac613114d6435cea0bc7cc8fdd7fcdc3 /gcc/gimple-fold.c | |
| parent | 058e4c71c29989185bf59888d85d536eed50013d (diff) | |
| download | gcc-59c20dc74df24fa8e14ade6aecbfd4a1c6bbe30c.zip gcc-59c20dc74df24fa8e14ade6aecbfd4a1c6bbe30c.tar.gz gcc-59c20dc74df24fa8e14ade6aecbfd4a1c6bbe30c.tar.bz2 | |
gimple-fold.c (gimple_fold_stmt_to_constant_1): Canonicalize bool compares on RHS.
2015-08-04 Richard Biener <rguenther@suse.de>
* gimple-fold.c (gimple_fold_stmt_to_constant_1): Canonicalize
bool compares on RHS.
* match.pd: Add X ==/!= !X is false/true pattern.
* gcc.dg/tree-ssa/ssa-ccp-38.c: New testcase.
From-SVN: r226576
Diffstat (limited to 'gcc/gimple-fold.c')
| -rw-r--r-- | gcc/gimple-fold.c | 34 |
1 files changed, 32 insertions, 2 deletions
diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c index 6c53bac..1a70d8f 100644 --- a/gcc/gimple-fold.c +++ b/gcc/gimple-fold.c @@ -5012,10 +5012,8 @@ gimple_fold_stmt_to_constant_1 (gimple stmt, tree (*valueize) (tree), further propagation. */ if (subcode == POINTER_PLUS_EXPR) { - /* Handle binary operators that can appear in GIMPLE form. */ tree op0 = (*valueize) (gimple_assign_rhs1 (stmt)); tree op1 = (*valueize) (gimple_assign_rhs2 (stmt)); - if (TREE_CODE (op0) == ADDR_EXPR && TREE_CODE (op1) == INTEGER_CST) { @@ -5027,6 +5025,38 @@ gimple_fold_stmt_to_constant_1 (gimple stmt, tree (*valueize) (tree), unshare_expr (op0), off)); } } + /* Canonicalize bool != 0 and bool == 0 appearing after + valueization. While gimple_simplify handles this + it can get confused by the ~X == 1 -> X == 0 transform + which we cant reduce to a SSA name or a constant + (and we have no way to tell gimple_simplify to not + consider those transforms in the first place). */ + else if (subcode == EQ_EXPR + || subcode == NE_EXPR) + { + tree lhs = gimple_assign_lhs (stmt); + tree op0 = gimple_assign_rhs1 (stmt); + if (useless_type_conversion_p (TREE_TYPE (lhs), + TREE_TYPE (op0))) + { + tree op1 = (*valueize) (gimple_assign_rhs2 (stmt)); + op0 = (*valueize) (op0); + if (subcode == NE_EXPR) + { + if (integer_zerop (op1)) + return op0; + else if (integer_zerop (op0)) + return op1; + } + else + { + if (integer_onep (op1)) + return op0; + else if (integer_onep (op0)) + return op1; + } + } + } return NULL_TREE; case GIMPLE_TERNARY_RHS: |