diff options
Diffstat (limited to 'gcc/tree-ssa-alias.c')
| -rw-r--r-- | gcc/tree-ssa-alias.c | 51 |
1 files changed, 47 insertions, 4 deletions
diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c index 1e80f49..67ba8f1 100644 --- a/gcc/tree-ssa-alias.c +++ b/gcc/tree-ssa-alias.c @@ -1616,21 +1616,25 @@ stmt_may_clobber_ref_p (gimple stmt, tree ref) static bool stmt_kills_ref_p_1 (gimple stmt, ao_ref *ref) { + /* For a must-alias check we need to be able to constrain + the access properly. */ + ao_ref_base (ref); + if (ref->max_size == -1) + return false; + if (gimple_has_lhs (stmt) && TREE_CODE (gimple_get_lhs (stmt)) != SSA_NAME) { tree base, lhs = gimple_get_lhs (stmt); HOST_WIDE_INT size, offset, max_size; - ao_ref_base (ref); base = get_ref_base_and_extent (lhs, &offset, &size, &max_size); /* We can get MEM[symbol: sZ, index: D.8862_1] here, so base == ref->base does not always hold. */ if (base == ref->base) { /* For a must-alias check we need to be able to constrain - the accesses properly. */ - if (size != -1 && size == max_size - && ref->max_size != -1) + the access properly. */ + if (size != -1 && size == max_size) { if (offset <= ref->offset && offset + size >= ref->offset + ref->max_size) @@ -1638,6 +1642,45 @@ stmt_kills_ref_p_1 (gimple stmt, ao_ref *ref) } } } + + if (is_gimple_call (stmt)) + { + tree callee = gimple_call_fndecl (stmt); + if (callee != NULL_TREE + && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL) + switch (DECL_FUNCTION_CODE (callee)) + { + case BUILT_IN_MEMCPY: + case BUILT_IN_MEMPCPY: + case BUILT_IN_MEMMOVE: + case BUILT_IN_MEMSET: + { + tree dest = gimple_call_arg (stmt, 0); + tree len = gimple_call_arg (stmt, 2); + tree base = NULL_TREE; + HOST_WIDE_INT offset = 0; + if (!host_integerp (len, 0)) + return false; + if (TREE_CODE (dest) == ADDR_EXPR) + base = get_addr_base_and_unit_offset (TREE_OPERAND (dest, 0), + &offset); + else if (TREE_CODE (dest) == SSA_NAME) + base = dest; + if (base + && base == ao_ref_base (ref)) + { + HOST_WIDE_INT size = TREE_INT_CST_LOW (len); + if (offset <= ref->offset / BITS_PER_UNIT + && (offset + size + >= ((ref->offset + ref->max_size + BITS_PER_UNIT - 1) + / BITS_PER_UNIT))) + return true; + } + } + default:; + } + + } return false; } |