From 86ac808fd38e590cdc5c234da9e9ea9f7c38940b Mon Sep 17 00:00:00 2001
From: Lucas Hosseini <lucas.hosseini@gmail.com>
Date: Tue, 25 Aug 2020 16:56:01 -0700
Subject: [PATCH] Add __builtin_popcountl polyfill. (#1367)

Summary: Pull Request resolved: https://github.com/facebookresearch/faiss/pull/1367

Test Plan: Imported from OSS

Reviewed By: mdouze

Differential Revision: D23314742

Pulled By: beauby

fbshipit-source-id: f15ae3a06d5cc55d4578443bc56f1af520bbc715
---
 faiss/utils/hamming.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/faiss/utils/hamming.h b/faiss/utils/hamming.h
index 2d04613ef..072e683c7 100644
--- a/faiss/utils/hamming.h
+++ b/faiss/utils/hamming.h
@@ -27,6 +27,11 @@
 
 #include <stdint.h>
 
+#ifdef _MSC_VER
+#include <intrin.h>
+#define __builtin_popcountl __popcnt64
+#endif // _MSC_VER
+
 #include <faiss/utils/Heap.h>