From b4becd5d48c553589e5ad399ecfecf84cb44e258 Mon Sep 17 00:00:00 2001
From: Marcus Holland-Moritz <github@mhxnet.de>
Date: Mon, 4 Sep 2023 22:50:44 +0200
Subject: [PATCH] Simplify multiversioning using target_clones()

---
 src/dwarfs/similarity_ordering.cpp | 21 +++------------------
 test/multiversioning_benchmark.cpp | 21 +++------------------
 2 files changed, 6 insertions(+), 36 deletions(-)

diff --git a/src/dwarfs/similarity_ordering.cpp b/src/dwarfs/similarity_ordering.cpp
index 341d2b4e..c2864fad 100644
--- a/src/dwarfs/similarity_ordering.cpp
+++ b/src/dwarfs/similarity_ordering.cpp
@@ -79,25 +79,10 @@ int distance(std::array<T, N> const& a, std::array<T, N> const& b) {
 
 #ifdef DWARFS_MULTIVERSIONING
 #ifdef __clang__
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wunused-function"
-__attribute__((target("avx512vpopcntdq"))) int
-distance(std::array<uint64_t, 4> const& a, std::array<uint64_t, 4> const& b) {
-  return distance<uint64_t, 4>(a, b);
-}
+__attribute__((target_clones("avx512vpopcntdq", "popcnt", "default")))
+#else
+__attribute__((target_clones("popcnt", "default")))
 #endif
-
-__attribute__((target("popcnt"))) int
-distance(std::array<uint64_t, 4> const& a, std::array<uint64_t, 4> const& b) {
-  return distance<uint64_t, 4>(a, b);
-}
-#ifdef __clang__
-#pragma clang diagnostic pop
-#endif
-#endif
-
-#ifdef DWARFS_MULTIVERSIONING
-__attribute__((target("default")))
 #endif
 int distance(std::array<uint64_t, 4> const& a, std::array<uint64_t, 4> const& b) {
   return distance<uint64_t, 4>(a, b);
diff --git a/test/multiversioning_benchmark.cpp b/test/multiversioning_benchmark.cpp
index bcf73e47..1cc97c7e 100644
--- a/test/multiversioning_benchmark.cpp
+++ b/test/multiversioning_benchmark.cpp
@@ -46,25 +46,10 @@ int distance(std::array<T, N> const& a, std::array<T, N> const& b) {
 
 #ifdef DWARFS_MULTIVERSIONING
 #ifdef __clang__
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wunused-function"
-__attribute__((target("avx512vpopcntdq"))) int
-distance(std::array<uint64_t, 4> const& a, std::array<uint64_t, 4> const& b) {
-  return distance<uint64_t, 4>(a, b);
-}
+__attribute__((target_clones("avx512vpopcntdq", "popcnt", "default")))
+#else
+__attribute__((target_clones("popcnt", "default")))
 #endif
-
-__attribute__((target("popcnt"))) int
-distance(std::array<uint64_t, 4> const& a, std::array<uint64_t, 4> const& b) {
-  return distance<uint64_t, 4>(a, b);
-}
-#ifdef __clang__
-#pragma clang diagnostic pop
-#endif
-#endif
-
-#ifdef DWARFS_MULTIVERSIONING
-__attribute__((target("default")))
 #endif
 int distance(std::array<uint64_t, 4> const& a, std::array<uint64_t, 4> const& b) {
   return distance<uint64_t, 4>(a, b);