http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47538
--- Comment #13 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-01-31 11:55:03 UTC --- Can we use sth like Index: tree-ssa-ccp.c =================================================================== --- tree-ssa-ccp.c (revision 169434) +++ tree-ssa-ccp.c (working copy) @@ -1770,9 +1770,38 @@ bit_value_binop_1 (enum tree_code code, { bool uns = (TREE_CODE (r1type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (r1type) ? 0 : TYPE_UNSIGNED (r1type)); + /* Assume we'll get a constant result. Use an initial varying value, we fall back to varying in the end if necessary. */ *mask = double_int_minus_one; + + /* We have some sizetype issues, drop to varying in case there are + mismatches. */ + switch (code) + { + case LSHIFT_EXPR: + case RSHIFT_EXPR: + case LROTATE_EXPR: + case RROTATE_EXPR: + if ((TREE_CODE (type) == INTEGER_TYPE + && TYPE_IS_SIZETYPE (type) ? 0 : TYPE_UNSIGNED (type)) != uns) + return; + break; + + case EQ_EXPR: + case NE_EXPR: + case LT_EXPR: + case LE_EXPR: + case GE_EXPR: + case GT_EXPR: + if ((TREE_CODE (r2type) == INTEGER_TYPE + && TYPE_IS_SIZETYPE (r2type) ? 0 : TYPE_UNSIGNED (r2type)) != uns) + return; + break; + + default:; + } + instead? It makes it more obvious what happens (IMHO).