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10c11b867a
This is the final (I hope!) problem pattern mentioned in PR37749: https://bugs.llvm.org/show_bug.cgi?id=37749 We are trying to avoid an AVX1 sinkhole caused by having 256-bit bitwise logic ops but no other 256-bit integer ops. We've already solved the simple logic ops, but 'andn' is an x86 special. I looked at alternative solutions like extending the generic DAG combine or trying to wait until the ANDNP node is created, but those are bigger patches that can over-reach. Ie, splitting to 128-bit does not look like a win in most cases with >1 256-bit op. The pattern matching is cluttered with bitcasts because of our i64 element canonicalization. For the affected test, we have this vector-type-legalized sequence: t29: v8i32 = concat_vectors t27, t28 t30: v4i64 = bitcast t29 t18: v8i32 = BUILD_VECTOR Constant:i32<-1>, Constant:i32<-1>, ... t31: v4i64 = bitcast t18 t32: v4i64 = xor t30, t31 t9: v8i32 = BUILD_VECTOR Constant:i32<255>, Constant:i32<255>, ... t34: v4i64 = bitcast t9 t35: v4i64 = and t32, t34 t36: v8i32 = bitcast t35 t37: v4i32 = extract_subvector t36, Constant:i64<0> t38: v4i32 = extract_subvector t36, Constant:i64<4> Differential Revision: https://reviews.llvm.org/D52318 llvm-svn: 343008