https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112776
--- Comment #1 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The trunk branch has been updated by Lehua Ding <lh...@gcc.gnu.org>: https://gcc.gnu.org/g:923a67f17badcbe6e2b2e5d3570a265443258c8e commit r14-6027-g923a67f17badcbe6e2b2e5d3570a265443258c8e Author: Juzhe-Zhong <juzhe.zh...@rivai.ai> Date: Fri Dec 1 08:39:57 2023 +0800 RISC-V: Fix VSETVL PASS regression This patch fix 2 regression (one is bug regression, the other is performance regression). Those 2 regressions are both we are comparing ratio for same AVL in wrong place. 1. BUG regression: avl_single-84.c: f0: li a5,999424 add a1,a1,a5 li a4,299008 add a5,a0,a5 addi a3,a4,992 addi a5,a5,576 addi a1,a1,576 vsetvli a4,zero,e8,m2,ta,ma add a0,a0,a3 vlm.v v1,0(a5) vsm.v v1,0(a1) vl1re64.v v1,0(a0) beq a2,zero,.L10 li a5,0 vsetvli zero,zero,e64,m1,tu,ma ---> This is totally incorrect since the ratio above is 4, wheras it is demanding ratio = 64 here. .L3: fcvt.d.lu fa5,a5 addi a5,a5,1 fadd.d fa5,fa5,fa0 vfmv.s.f v1,fa5 bne a5,a2,.L3 vfmv.f.s fa0,v1 ret .L10: vsetvli zero,zero,e64,m1,ta,ma vfmv.f.s fa0,v1 ret 2. Performance regression: before this patch: vsetvli a5,a4,e8,m1,ta,ma vsetvli zero,a5,e32,m1,tu,ma vmv.s.x v2,zero vmv.s.x v1,zero vsetvli zero,a5,e32,m4,tu,ma vle32.v v4,0(a1) vfmul.vv v4,v4,v4 vfredosum.vs v1,v4,v2 vfmv.f.s fa5,v1 fsw fa5,0(a0) sub a4,a4,a5 bne a4,zero,.L2 ret After this patch: vsetvli a5,a4,e32,m4,tu,ma vle32.v v4,0(a1) vmv.s.x v2,zero vmv.s.x v1,zero vfmul.vv v4,v4,v4 vfredosum.vs v1,v4,v2 vfmv.f.s fa5,v1 fsw fa5,0(a0) sub a4,a4,a5 bne a4,zero,.L2 ret Tested rv64gcv_zvfh_zfh passed no regression. zvl256b/zvl512b/zvl1024b/zve64d is runing. PR target/112776 gcc/ChangeLog: * config/riscv/riscv-vsetvl.cc (pre_vsetvl::pre_global_vsetvl_info): Fix ratio. gcc/testsuite/ChangeLog: * gcc.target/riscv/rvv/vsetvl/avl_single-84.c: Adapt test. * gcc.target/riscv/rvv/vsetvl/pr111037-3.c: Ditto. * gcc.target/riscv/rvv/vsetvl/pr112776.c: New test.
