------- Comment #7 from spop at gcc dot gnu dot org 2008-10-15 21:28 ------- split_constant_offset does not handle correctly the offset of &s.c[1] as this is an ADDR_EXPR whose op0 was set by extract_ops_from_tree to itself, an ADDR_EXPR. Now this code is not handled in split_constant_offset_1 as this calls
if (!handled_component_p (op0)) return false; and returns false. This is an early return that stops the extraction of the base address of the array: s.c[0] and the offset 4. This is probably due to the fact that extract_ops_from_tree does return the expression itself for ADDR_EXPRs in this case: else if (grhs_class == GIMPLE_SINGLE_RHS) { *op1_p = expr; *op2_p = NULL_TREE; } I wonder if the fix could be to handle ADDR_EXPRs as GIMPLE_UNARY_RHS instead of GIMPLE_SINGLE_RHS: else if (grhs_class == GIMPLE_UNARY_RHS) { *op1_p = TREE_OPERAND (expr, 0); *op2_p = NULL_TREE; } in which case that would solve the base and offset computations. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37573