On 8/5/2026 5:45 AM, [email protected] wrote:
From: Kyrylo Tkachov <[email protected]> A lane of A | B is zero exactly when the corresponding lanes of A and of B are both zero, so (A == 0) & (B == 0) -> (A | B) == 0 and the De Morgan dual for inequality. The existing scalar rule already implements this identity. Extend it to vector integers and use a view conversion when the operands differ only in element signedness. Extend the related all-ones rule in the same way. typedef int v4si __attribute__((vector_size (16))); v4si f (v4si a, v4si b) { return (a == 0) & (b == 0); } aarch64 -O3 before: cmeq v0.4s, v0.4s, #0 cmeq v1.4s, v1.4s, #0 and v0.16b, v0.16b, v1.16b after: orr v0.16b, v0.16b, v1.16b cmeq v0.4s, v0.4s, #0 Add vector_nop_conversion_p for the element-wise property shared by these rules and the existing nop_convert matcher. Bootstrapped and tested on aarch64-none-linux-gnu. Ok for trunk? Thanks, Kyrill gcc/ChangeLog: * match.pd (nop_convert): Use vector_nop_conversion_p. ((A == 0) & (B == 0), (A != 0) | (B != 0)): Extend the existing simplifications to vector operands. ((A == -1) & (B == -1), (A != -1) | (B != -1)): Likewise. * tree.cc (vector_nop_conversion_p): New function. * tree.h (vector_nop_conversion_p): Declare. gcc/testsuite/ChangeLog: * gcc.dg/tree-ssa/vec-mask-zero-1.c: New test. Signed-off-by: Kyrylo Tkachov <[email protected]>
OK jeff
