From 07e30f69140929c63642e2ae84e250caab8c1c68 Mon Sep 17 00:00:00 2001
From: "Thatikonda.Varunreddy" <Thatikonda.Varunreddy@fujitsu.com>
Date: Mon, 14 Apr 2025 11:51:58 +0530
Subject: [PATCH] Implement fvec_inner_product_sve for FP32 inner product using
 SVE

Signed-off-by: Thatikonda.Varunreddy <Thatikonda.Varunreddy@fujitsu.com>
---
 src/simd/distances_sve.cc | 22 ++++++++++++++++++++++
 src/simd/distances_sve.h  |  3 +++
 src/simd/hook.cc          |  2 +-
 3 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/src/simd/distances_sve.cc b/src/simd/distances_sve.cc
index 3b774f191..94211f263 100644
--- a/src/simd/distances_sve.cc
+++ b/src/simd/distances_sve.cc
@@ -40,6 +40,28 @@ fvec_L2sqr_sve(const float* x, const float* y, size_t d) {
     return svaddv_f32(svptrue_b32(), sum);
 }
 
+float
+fvec_inner_product_sve(const float* x, const float* y, size_t d) {
+    svfloat32_t sum = svdup_f32(0.0f);
+    size_t i = 0;
+
+    svbool_t pg = svptrue_b32();
+
+    while (i < d) {
+        if (d - i < svcntw())
+            pg = svwhilelt_b32(i, d);
+
+        svfloat32_t a = svld1_f32(pg, x + i);
+        svfloat32_t b = svld1_f32(pg, y + i);
+        sum = svmla_f32_m(pg, sum, a, b);
+        i += svcntw();
+    }
+
+    float result = svaddv_f32(svptrue_b32(), sum);
+
+    return result;
+}
+
 float
 fp16_vec_L2sqr_sve(const knowhere::fp16* x, const knowhere::fp16* y, size_t d) {
     svfloat32_t sum1 = svdup_f32(0.0f);
diff --git a/src/simd/distances_sve.h b/src/simd/distances_sve.h
index 99af193a8..4f9d79c15 100644
--- a/src/simd/distances_sve.h
+++ b/src/simd/distances_sve.h
@@ -22,6 +22,9 @@ namespace faiss {
 float
 fvec_L2sqr_sve(const float* x, const float* y, size_t d);
 
+float
+fvec_inner_product_sve(const float* x, const float* y, size_t d);
+
 float
 fp16_vec_L2sqr_sve(const knowhere::fp16* x, const knowhere::fp16* y, size_t d);
 
diff --git a/src/simd/hook.cc b/src/simd/hook.cc
index f16caa366..23922db89 100644
--- a/src/simd/hook.cc
+++ b/src/simd/hook.cc
@@ -445,7 +445,7 @@ fvec_hook(std::string& simd_type) {
         fvec_madd = fvec_madd_sve;
         fvec_madd_and_argmin = fvec_madd_and_argmin_sve;
 
-        fvec_inner_product = fvec_inner_product_neon;
+        fvec_inner_product = fvec_inner_product_sve;
         fvec_L2sqr_ny = fvec_L2sqr_ny_sve;
         fvec_inner_products_ny = fvec_inner_products_ny_neon;