On 9/16/26 9:16 AM, [email protected] wrote:
From: Kyrylo Tkachov <[email protected]> A signed value clamped to the range of a narrower unsigned type is unsigned saturating truncation. Recognize nested MIN and MAX operations in either order. Keep the clamp match independent of use count. At this use, require an exact zero lower bound, the maximum upper bound, and one use of the outer clamp. The inner clamp can have other uses. With AArch64 -O2 -march=armv8-a -fopenmp-simd: before: clamp_u16_4: ldr q0, [x1] movi v30.4s, 0xff, msl 8 movi v31.4s, 0 smin v30.4s, v0.4s, v30.4s smax v30.4s, v30.4s, v31.4s xtn v30.4h, v30.4s str d30, [x0] ret after: clamp_u16_4: ldr q31, [x1] movi v30.4s, 0 smax v30.4s, v31.4s, v30.4s uqxtn v30.4h, v30.4s str d30, [x0] ret Runtime tests cover both clamp orders, two widths, and LTO. Target tests cover valid bounds, invalid bounds, and extra uses of each clamp. Bootstrapped and tested on aarch64-none-linux-gnu. Ok for trunk? Changes since v3: - Make the clamp match independent of use count. - Check the outer clamp use at the consumer. - Match the zero bound with integer_zerop. gcc/ChangeLog: * match-sat-alu.pd (integer_constant_clamp): New match. (unsigned_integer_narrow_clip): Add the constant-clamp form. gcc/testsuite/ChangeLog: * gcc.dg/vect/vect-sat-trunc-clamp-1.c: New test. * gcc.target/aarch64/vect-sat-trunc-clamp-inner-use-1.c: Likewise. * gcc.target/aarch64/vect-sat-trunc-clamp-multi-use-1.c: Likewise. * gcc.target/aarch64/vect-sat-trunc-clamp-u-1.c: Likewise. * gcc.target/aarch64/vect-sat-trunc-clamp-u-negative-1.c: Likewise. Signed-off-by: Kyrylo Tkachov <[email protected]>
OK jeff
