On 11/6/24 4:47 AM, Alexey Merzlyakov wrote:
This patch adds optimization of the following patterns: (zero_extend:M (subreg:N (not:O==M (X:Q==M)))) -> (xor:M (zero_extend:M (subreg:N (X:M)), mask)) ... where the mask is GET_MODE_MASK (N). For the cases when X:M doesn't have any non-zero bits outside of mode N, (zero_extend:M (subreg:N (X:M)) could be simplified to just (X:M) and whole optimization will be: (zero_extend:M (subreg:N (not:M (X:M)))) -> (xor:M (X:M, mask)) Patch targets to handle code patterns like: not a0,a0 andi a0,a0,0xff to be optimized to: xori a0,a0,255 Change was locally tested for x86_64 and AArch64 (as most common) and for RV-64 and MIPS-32 targets (as having an effect from this optimization): no regressions for all cases. gcc/ChangeLog: * simplify-rtx.cc (simplify_context::simplify_unary_operation_1): Simplify ZERO_EXTEND (SUBREG (NOT X)) to XOR (X, GET_MODE_MASK(SUBREG)) when X doesn't have any non-zero bits outside of SUBREG mode. gcc/testsuite/ChangeLog: * gcc.target/riscv/pr112398.c: New test. Signed-off-by: Alexey Merzlyakov<alexey.merzlya...@samsung.com>
Thanks. I just pushed this to the trunk. Jeff