https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103194
--- Comment #12 from Hongtao.liu <crazylht at gmail dot com> --- (In reply to Hongtao.liu from comment #9) > (In reply to H.J. Lu from comment #6) > > Created attachment 51785 [details] > > The v2 incomplete patch > > > > Hongtao, please finish it. Thanks. > > I'm trying to handle narrowing part in match.pd and add else return; when > precision is not equal. > > (for bit_op (bit_and bit_xor bit_ior) > (simplify > (bit_op (convert@0 @1) (convert@2 @3)) > (if (INTEGRAL_TYPE_P (type) > && INTEGRAL_TYPE_P (TREE_TYPE (@1)) > && tree_nop_conversion_p (TREE_TYPE (@1), TREE_TYPE (@3)) > && single_use (@0) > && single_use (@2) > && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (@1))) > (with { tree type1 = TREE_TYPE (@1); } > (convert (bit_op @1 (convert:type1 @3))))))) > > (for bit_op (bit_and bit_xor bit_ior) > (simplify > (bit_op (convert@0 @1) INTEGER_CST@2) > (if (INTEGRAL_TYPE_P (type) > && INTEGRAL_TYPE_P (TREE_TYPE (@1)) > && single_use (@0) > && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (@1))) > (convert (bit_op @1 { fold_convert (TREE_TYPE (@1), @2); }))))) Since there's infinite loop, i'll still handle conversions in tree-ssa-ccp.c as HJ's attached patch.