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| author | Yat Long Poon <yatlong.poon@arm.com> | 2025-02-13 18:00:50 +0000 |
|---|---|---|
| committer | Wilco Dijkstra <wilco.dijkstra@arm.com> | 2025-02-27 17:08:42 +0000 |
| commit | 194185c28954dfa11a6ded8b32f34fee680d3218 (patch) | |
| tree | d1b4dd99c947354854b323e049c9e54c9556deb4 | |
| parent | 4b0bb84eb7e52a135c873fd9d0fc6c30599aedf4 (diff) | |
| download | glibc-194185c28954dfa11a6ded8b32f34fee680d3218.tar.xz glibc-194185c28954dfa11a6ded8b32f34fee680d3218.zip | |
AArch64: Improve codegen for SVE erfcf
Reduce number of MOV/MOVPRFXs and use unpredicated FMUL.
Replace MUL with LSL. Speedup on Neoverse V1: 6%.
Reviewed-by: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
(cherry picked from commit f5ff34cb3c75ec1061c75bb9188b3c1176426947)
| -rw-r--r-- | sysdeps/aarch64/fpu/erfcf_sve.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/sysdeps/aarch64/fpu/erfcf_sve.c b/sysdeps/aarch64/fpu/erfcf_sve.c index ecacb933ac..e4869263e3 100644 --- a/sysdeps/aarch64/fpu/erfcf_sve.c +++ b/sysdeps/aarch64/fpu/erfcf_sve.c @@ -76,7 +76,7 @@ svfloat32_t SV_NAME_F1 (erfc) (svfloat32_t x, const svbool_t pg) svuint32_t i = svqadd (svreinterpret_u32 (z), dat->off_idx); /* Lookup erfc(r) and 2/sqrt(pi)*exp(-r^2) in tables. */ - i = svmul_x (pg, i, 2); + i = svlsl_x (svptrue_b32 (), i, 1); const float32_t *p = &__v_erfcf_data.tab[0].erfc - 2 * dat->off_arr; svfloat32_t erfcr = svld1_gather_index (pg, p, i); svfloat32_t scale = svld1_gather_index (pg, p + 1, i); @@ -84,15 +84,15 @@ svfloat32_t SV_NAME_F1 (erfc) (svfloat32_t x, const svbool_t pg) /* erfc(x) ~ erfc(r) - scale * d * poly(r, d). */ svfloat32_t r = svsub_x (pg, z, shift); svfloat32_t d = svsub_x (pg, a, r); - svfloat32_t d2 = svmul_x (pg, d, d); - svfloat32_t r2 = svmul_x (pg, r, r); + svfloat32_t d2 = svmul_x (svptrue_b32 (), d, d); + svfloat32_t r2 = svmul_x (svptrue_b32 (), r, r); svfloat32_t coeffs = svld1rq (svptrue_b32 (), &dat->third); - svfloat32_t third = svdup_lane (coeffs, 0); svfloat32_t p1 = r; - svfloat32_t p2 = svmls_lane (third, r2, coeffs, 1); - svfloat32_t p3 = svmul_x (pg, r, svmla_lane (sv_f32 (-0.5), r2, coeffs, 0)); + svfloat32_t p2 = svmls_lane (sv_f32 (dat->third), r2, coeffs, 1); + svfloat32_t p3 + = svmul_x (svptrue_b32 (), r, svmla_lane (sv_f32 (-0.5), r2, coeffs, 0)); svfloat32_t p4 = svmla_lane (sv_f32 (dat->two_over_five), r2, coeffs, 2); p4 = svmls_x (pg, sv_f32 (dat->tenth), r2, p4); |