diff options
Diffstat (limited to 'gcc/tree-ssa-ccp.c')
| -rw-r--r-- | gcc/tree-ssa-ccp.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/gcc/tree-ssa-ccp.c b/gcc/tree-ssa-ccp.c index 622fe146315..5551df2d5a3 100644 --- a/gcc/tree-ssa-ccp.c +++ b/gcc/tree-ssa-ccp.c @@ -839,8 +839,40 @@ static bool ccp_finalize (void) { bool something_changed; + unsigned i; do_dbg_cnt (); + + /* Derive alignment and misalignment information from partially + constant pointers in the lattice. */ + for (i = 1; i < num_ssa_names; ++i) + { + tree name = ssa_name (i); + prop_value_t *val; + struct ptr_info_def *pi; + unsigned int tem, align; + + if (!name + || !POINTER_TYPE_P (TREE_TYPE (name))) + continue; + + val = get_value (name); + if (val->lattice_val != CONSTANT + || TREE_CODE (val->value) != INTEGER_CST) + continue; + + /* Trailing constant bits specify the alignment, trailing value + bits the misalignment. */ + tem = val->mask.low; + align = (tem & -tem); + if (align == 1) + continue; + + pi = get_ptr_info (name); + pi->align = align; + pi->misalign = TREE_INT_CST_LOW (val->value) & (align - 1); + } + /* Perform substitutions based on the known constant values. */ something_changed = substitute_and_fold (get_constant_value, ccp_fold_stmt, true); @@ -1981,6 +2013,7 @@ evaluate_stmt (gimple stmt) && !is_constant) { enum gimple_code code = gimple_code (stmt); + tree fndecl; val.lattice_val = VARYING; val.value = NULL_TREE; val.mask = double_int_minus_one; @@ -2026,6 +2059,33 @@ evaluate_stmt (gimple stmt) || POINTER_TYPE_P (TREE_TYPE (rhs1))) val = bit_value_binop (code, TREE_TYPE (rhs1), rhs1, rhs2); } + else if (code == GIMPLE_CALL + && (fndecl = gimple_call_fndecl (stmt)) + && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL) + { + switch (DECL_FUNCTION_CODE (fndecl)) + { + case BUILT_IN_MALLOC: + case BUILT_IN_REALLOC: + case BUILT_IN_CALLOC: + val.lattice_val = CONSTANT; + val.value = build_int_cst (TREE_TYPE (gimple_get_lhs (stmt)), 0); + val.mask = shwi_to_double_int + (~(((HOST_WIDE_INT) MALLOC_ABI_ALIGNMENT) + / BITS_PER_UNIT - 1)); + break; + + case BUILT_IN_ALLOCA: + val.lattice_val = CONSTANT; + val.value = build_int_cst (TREE_TYPE (gimple_get_lhs (stmt)), 0); + val.mask = shwi_to_double_int + (~(((HOST_WIDE_INT) BIGGEST_ALIGNMENT) + / BITS_PER_UNIT - 1)); + break; + + default:; + } + } is_constant = (val.lattice_val == CONSTANT); } |