https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110660
--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Pan Li <pa...@gcc.gnu.org>: https://gcc.gnu.org/g:dd0197fb4cdee8cd5f78fea9a965c96d7ca47229 commit r14-4277-gdd0197fb4cdee8cd5f78fea9a965c96d7ca47229 Author: Juzhe-Zhong <juzhe.zh...@rivai.ai> Date: Tue Sep 26 17:50:37 2023 +0800 MATCH: Optimize COND_ADD_LEN reduction pattern This patch leverage this commit: https://gcc.gnu.org/git/gitweb.cgi?p=gcc.git;h=62b505a4d5fc89 to optimize COND_LEN_ADD reduction pattern. We are doing optimization of VEC_COND_EXPR + COND_LEN_ADD -> COND_LEN_ADD. Consider thsi following case: void pr11594 (uint64_t *restrict a, uint64_t *restrict b, int loop_size) { uint64_t result = 0; for (int i = 0; i < loop_size; i++) { if (b[i] <= a[i]) { result += a[i]; } } a[0] = result; } Before this patch: vsetvli a7,zero,e64,m1,ta,ma vmv.v.i v2,0 vmv1r.v v3,v2 --- redundant .L3: vsetvli a5,a2,e64,m1,ta,ma vle64.v v1,0(a3) vle64.v v0,0(a1) slli a6,a5,3 vsetvli a7,zero,e64,m1,ta,ma sub a2,a2,a5 vmsleu.vv v0,v0,v1 add a1,a1,a6 vmerge.vvm v1,v3,v1,v0 ---- redundant. add a3,a3,a6 vsetvli zero,a5,e64,m1,tu,ma vadd.vv v2,v2,v1 bne a2,zero,.L3 li a5,0 vsetvli a4,zero,e64,m1,ta,ma vmv.s.x v1,a5 vredsum.vs v2,v2,v1 vmv.x.s a5,v2 sd a5,0(a0) ret After this patch: vsetvli a6,zero,e64,m1,ta,ma vmv.v.i v1,0 .L3: vsetvli a5,a2,e64,m1,ta,ma vle64.v v2,0(a4) vle64.v v0,0(a1) slli a3,a5,3 vsetvli a6,zero,e64,m1,ta,ma sub a2,a2,a5 vmsleu.vv v0,v0,v2 add a1,a1,a3 vsetvli zero,a5,e64,m1,tu,mu add a4,a4,a3 vadd.vv v1,v1,v2,v0.t bne a2,zero,.L3 li a5,0 vsetivli zero,1,e64,m1,ta,ma vmv.s.x v2,a5 vsetvli a5,zero,e64,m1,ta,ma vredsum.vs v1,v1,v2 vmv.x.s a5,v1 sd a5,0(a0) ret Bootstrap && Regression is running. Ok for trunk when testing passes ? PR tree-optimization/111594 PR tree-optimization/110660 gcc/ChangeLog: * match.pd: Optimize COND_LEN_ADD reduction. gcc/testsuite/ChangeLog: * gcc.target/riscv/rvv/autovec/cond/cond_reduc-1.c: New test. * gcc.target/riscv/rvv/autovec/cond/pr111594.c: New test.