On Mon, 4 Nov 2013, Richard Biener wrote:
Well, you cannot use the size argument unchanged for the null return case. You could fallback to get_base_address and -1 size in that case.
Like this? Bootstrap+testsuite on x86_64-unknown-linux-gnu.(I think I'll disable cilk for my future bootstraps: it takes forever and confuses contrib/compare_tests)
2013-11-05 Marc Glisse <marc.gli...@inria.fr> PR tree-optimization/58958 gcc/ * tree-ssa-alias.c (ao_ref_init_from_ptr_and_size): Use get_addr_base_and_unit_offset instead of get_ref_base_and_extent. gcc/testsuite/ * gcc.dg/tree-ssa/pr58958.c: New file. -- Marc Glisse
Index: gcc/testsuite/gcc.dg/tree-ssa/pr58958.c =================================================================== --- gcc/testsuite/gcc.dg/tree-ssa/pr58958.c (revision 0) +++ gcc/testsuite/gcc.dg/tree-ssa/pr58958.c (working copy) @@ -0,0 +1,12 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-optimized" } */ + +double a[10]; +int f(int n){ + a[3]=9; + __builtin_memset(&a[n],3,sizeof(double)); + return a[3]==9; +} + +/* { dg-final { scan-tree-dump " == 9" "optimized" } } */ +/* { dg-final { cleanup-tree-dump "optimized" } } */ Property changes on: gcc/testsuite/gcc.dg/tree-ssa/pr58958.c ___________________________________________________________________ Added: svn:keywords ## -0,0 +1 ## +Author Date Id Revision URL \ No newline at end of property Added: svn:eol-style ## -0,0 +1 ## +native \ No newline at end of property Index: gcc/tree-ssa-alias.c =================================================================== --- gcc/tree-ssa-alias.c (revision 204381) +++ gcc/tree-ssa-alias.c (working copy) @@ -559,41 +559,50 @@ ao_ref_alias_set (ao_ref *ref) } /* Init an alias-oracle reference representation from a gimple pointer PTR and a gimple size SIZE in bytes. If SIZE is NULL_TREE the the size is assumed to be unknown. The access is assumed to be only to or after of the pointer target, not before it. */ void ao_ref_init_from_ptr_and_size (ao_ref *ref, tree ptr, tree size) { - HOST_WIDE_INT t1, t2, extra_offset = 0; + HOST_WIDE_INT t, extra_offset = 0; ref->ref = NULL_TREE; if (TREE_CODE (ptr) == SSA_NAME) { gimple stmt = SSA_NAME_DEF_STMT (ptr); if (gimple_assign_single_p (stmt) && gimple_assign_rhs_code (stmt) == ADDR_EXPR) ptr = gimple_assign_rhs1 (stmt); else if (is_gimple_assign (stmt) && gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR && host_integerp (gimple_assign_rhs2 (stmt), 0) - && (t1 = int_cst_value (gimple_assign_rhs2 (stmt))) >= 0) + && (t = int_cst_value (gimple_assign_rhs2 (stmt))) >= 0) { ptr = gimple_assign_rhs1 (stmt); - extra_offset = BITS_PER_UNIT * t1; + extra_offset = BITS_PER_UNIT * t; } } if (TREE_CODE (ptr) == ADDR_EXPR) - ref->base = get_ref_base_and_extent (TREE_OPERAND (ptr, 0), - &ref->offset, &t1, &t2); + { + ref->base = get_addr_base_and_unit_offset (TREE_OPERAND (ptr, 0), &t); + if (ref->base) + ref->offset = BITS_PER_UNIT * t; + else + { + size = NULL_TREE; + ref->offset = 0; + ref->base = get_base_address (TREE_OPERAND (ptr, 0)); + } + } else { ref->base = build2 (MEM_REF, char_type_node, ptr, null_pointer_node); ref->offset = 0; } ref->offset += extra_offset; if (size && host_integerp (size, 0) && TREE_INT_CST_LOW (size) * BITS_PER_UNIT / BITS_PER_UNIT