From d7af7dd7cb395bc256f126c841139330afdde9a6 Mon Sep 17 00:00:00 2001
From: Vincent Rabaud <vrabaud@google.com>
Date: Mon, 8 Dec 2025 10:20:49 +0100
Subject: [PATCH] Get code to compile with older VS with partial AVX2 support.

This is inspired by
https://aomedia.googlesource.com/aom/+/b2f80f721fe87547e3bae73be550e3d75ba478ad/aom_ports/msvc.h#57
This was reported on https://github.com/opencv/opencv/pull/28139

Change-Id: Iad38d842ef1647fc1a578a851b3593281855e30e
---
 src/dsp/cpu.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/dsp/cpu.h b/src/dsp/cpu.h
index 6462d870..23154723 100644
--- a/src/dsp/cpu.h
+++ b/src/dsp/cpu.h
@@ -94,6 +94,17 @@
 #define WEBP_HAVE_AVX2
 #endif
 
+#if defined(WEBP_MSC_AVX2) && _MSC_VER <= 1900
+#include <immintrin.h>
+
+static WEBP_INLINE int _mm256_extract_epi32(__m256i a, const int i) {
+  return a.m256i_i32[i & 7];
+}
+static WEBP_INLINE int _mm256_cvtsi256_si32(__m256i a) {
+  return _mm256_extract_epi32(a, 0);
+}
+#endif
+
 #undef WEBP_MSC_AVX2
 #undef WEBP_MSC_SSE41
 #undef WEBP_MSC_SSE2