From: Joe Ramsay <Joe.Ramsay@arm.com>
Date: Mon, 27 Nov 2023 17:02:55 +0000 (+0000)
Subject: aarch64: Improve special-case handling in AdvSIMD double-precision libmvec routines
X-Git-Tag: glibc-2.39~235
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7b12776584c51dbecb1033e107f6b9f45de47a1b;p=thirdparty%2Fglibc.git

aarch64: Improve special-case handling in AdvSIMD double-precision libmvec routines

Avoids emitting many saves/restores of vector registers, reduces the
amount of code generated around the scalar fallback.
---

diff --git a/sysdeps/aarch64/fpu/v_math.h b/sysdeps/aarch64/fpu/v_math.h
index cfc87f8dd0f..d286eb81b3e 100644
--- a/sysdeps/aarch64/fpu/v_math.h
+++ b/sysdeps/aarch64/fpu/v_math.h
@@ -137,7 +137,13 @@ v_lookup_u64 (const uint64_t *tab, uint64x2_t idx)
 static inline float64x2_t
 v_call_f64 (double (*f) (double), float64x2_t x, float64x2_t y, uint64x2_t p)
 {
-  return (float64x2_t){ p[0] ? f (x[0]) : y[0], p[1] ? f (x[1]) : y[1] };
+  double p1 = p[1];
+  double x1 = x[1];
+  if (__glibc_likely (p[0]))
+    y[0] = f (x[0]);
+  if (__glibc_likely (p1))
+    y[1] = f (x1);
+  return y;
 }
 static inline float64x2_t
 v_call2_f64 (double (*f) (double, double), float64x2_t x1, float64x2_t x2,