diff options
Diffstat (limited to 'gcc/fold-const.c')
| -rw-r--r-- | gcc/fold-const.c | 35 |
1 files changed, 24 insertions, 11 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 5acb4ad..26cfc0e 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -2542,19 +2542,25 @@ operand_equal_p (const_tree arg0, const_tree arg1, unsigned int flags) case tcc_reference: /* If either of the pointer (or reference) expressions we are - dereferencing contain a side effect, these cannot be equal. */ - if (TREE_SIDE_EFFECTS (arg0) - || TREE_SIDE_EFFECTS (arg1)) + dereferencing contain a side effect, these cannot be equal, + but their addresses can be. */ + if ((flags & OEP_CONSTANT_ADDRESS_OF) == 0 + && (TREE_SIDE_EFFECTS (arg0) + || TREE_SIDE_EFFECTS (arg1))) return 0; switch (TREE_CODE (arg0)) { case INDIRECT_REF: + flags &= ~OEP_CONSTANT_ADDRESS_OF; + return OP_SAME (0); + case REALPART_EXPR: case IMAGPART_EXPR: return OP_SAME (0); case TARGET_MEM_REF: + flags &= ~OEP_CONSTANT_ADDRESS_OF; /* Require equal extra operands and then fall through to MEM_REF handling of the two common operands. */ if (!OP_SAME_WITH_NULL (2) @@ -2563,6 +2569,7 @@ operand_equal_p (const_tree arg0, const_tree arg1, unsigned int flags) return 0; /* Fallthru. */ case MEM_REF: + flags &= ~OEP_CONSTANT_ADDRESS_OF; /* Require equal access sizes, and similar pointer types. We can have incomplete types for array references of variable-sized arrays from the Fortran frontent @@ -2581,22 +2588,28 @@ operand_equal_p (const_tree arg0, const_tree arg1, unsigned int flags) /* Operands 2 and 3 may be null. Compare the array index by value if it is constant first as we may have different types but same value here. */ - return (OP_SAME (0) - && (tree_int_cst_equal (TREE_OPERAND (arg0, 1), - TREE_OPERAND (arg1, 1)) - || OP_SAME (1)) + if (!OP_SAME (0)) + return 0; + flags &= ~OEP_CONSTANT_ADDRESS_OF; + return ((tree_int_cst_equal (TREE_OPERAND (arg0, 1), + TREE_OPERAND (arg1, 1)) + || OP_SAME (1)) && OP_SAME_WITH_NULL (2) && OP_SAME_WITH_NULL (3)); case COMPONENT_REF: /* Handle operand 2 the same as for ARRAY_REF. Operand 0 may be NULL when we're called to compare MEM_EXPRs. */ - return OP_SAME_WITH_NULL (0) - && OP_SAME (1) - && OP_SAME_WITH_NULL (2); + if (!OP_SAME_WITH_NULL (0)) + return 0; + flags &= ~OEP_CONSTANT_ADDRESS_OF; + return OP_SAME (1) && OP_SAME_WITH_NULL (2); case BIT_FIELD_REF: - return OP_SAME (0) && OP_SAME (1) && OP_SAME (2); + if (!OP_SAME (0)) + return 0; + flags &= ~OEP_CONSTANT_ADDRESS_OF; + return OP_SAME (1) && OP_SAME (2); default: return 0; |