From cb9cc622d06097dbfcf99a4ab4520ce51a0c02cc Mon Sep 17 00:00:00 2001
From: Jean Pierre Cimalando <jp-dev@inbox.ru>
Date: Tue, 16 Feb 2021 00:36:46 +0100
Subject: [PATCH] Rewrite SIMD sum 4-to-1

---
 src/sfizz/Interpolators.hpp | 31 ++++---------------------------
 1 file changed, 4 insertions(+), 27 deletions(-)

diff --git a/src/sfizz/Interpolators.hpp b/src/sfizz/Interpolators.hpp
index 8080dbdc..2585704e 100644
--- a/src/sfizz/Interpolators.hpp
+++ b/src/sfizz/Interpolators.hpp
@@ -11,6 +11,7 @@
 #include <simde/simde-features.h>
 #if SIMDE_NATURAL_VECTOR_SIZE_GE(128)
 #include <simde/x86/sse.h>
+#include <simde/arm/neon/addv.h>
 #endif
 
 namespace sfz {
@@ -63,15 +64,7 @@ public:
         simde__m128 x = simde_mm_sub_ps(simde_mm_setr_ps(-1, 0, 1, 2), simde_mm_set1_ps(coeff));
         simde__m128 h = hermite3x4(x);
         simde__m128 y = simde_mm_mul_ps(h, simde_mm_loadu_ps(values - 1));
-        // sum 4 to 1
-        simde__m128 xmm0 = y;
-        simde__m128 xmm1 = simde_mm_shuffle_ps(xmm0, xmm0, 0xe5);
-        simde__m128 xmm2 = simde_mm_movehl_ps(xmm0, xmm0);
-        xmm1 = simde_mm_add_ss(xmm1, xmm0);
-        xmm0 = simde_mm_shuffle_ps(xmm0, xmm0, 0xe7);
-        xmm2 = simde_mm_add_ss(xmm2, xmm1);
-        xmm0 = simde_mm_add_ss(xmm0, xmm2);
-        return simde_mm_cvtss_f32(xmm0);
+        return simde_vaddvq_f32(y);
     }
 };
 #endif
@@ -107,15 +100,7 @@ public:
         simde__m128 x = simde_mm_sub_ps(simde_mm_setr_ps(-1, 0, 1, 2), simde_mm_set1_ps(coeff));
         simde__m128 h = bspline3x4(x);
         simde__m128 y = simde_mm_mul_ps(h, simde_mm_loadu_ps(values - 1));
-        // sum 4 to 1
-        simde__m128 xmm0 = y;
-        simde__m128 xmm1 = simde_mm_shuffle_ps(xmm0, xmm0, 0xe5);
-        simde__m128 xmm2 = simde_mm_movehl_ps(xmm0, xmm0);
-        xmm1 = simde_mm_add_ss(xmm1, xmm0);
-        xmm0 = simde_mm_shuffle_ps(xmm0, xmm0, 0xe7);
-        xmm2 = simde_mm_add_ss(xmm2, xmm1);
-        xmm0 = simde_mm_add_ss(xmm0, xmm2);
-        return simde_mm_cvtss_f32(xmm0);
+        return simde_vaddvq_f32(y);
     }
 };
 #endif
@@ -218,15 +203,7 @@ public:
             i += 4;
         } while (i < Points);
 
-        // sum 4 to 1
-        simde__m128 xmm0 = y;
-        simde__m128 xmm1 = simde_mm_shuffle_ps(xmm0, xmm0, 0xe5);
-        simde__m128 xmm2 = simde_mm_movehl_ps(xmm0, xmm0);
-        xmm1 = simde_mm_add_ss(xmm1, xmm0);
-        xmm0 = simde_mm_shuffle_ps(xmm0, xmm0, 0xe7);
-        xmm2 = simde_mm_add_ss(xmm2, xmm1);
-        xmm0 = simde_mm_add_ss(xmm0, xmm2);
-        return simde_mm_cvtss_f32(xmm0);
+        return simde_vaddvq_f32(y);
     }
 };
 #endif