From d411dc58841c92d1100d9c0beb81a10818d6ae95 Mon Sep 17 00:00:00 2001
From: Albert Strasheim <albert@cloudflare.com>
Date: Sun, 2 Feb 2014 12:52:52 -0800
Subject: [PATCH] crc32c: choose function in static initialization

Before: 4.430 micros/op 225732 ops/sec; 881.8 MB/s (4K per op)
After: 4.125 micros/op 242425 ops/sec; 947.0 MB/s (4K per op)
---
 util/crc32c.cc | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/util/crc32c.cc b/util/crc32c.cc
index bca955a09..5008dddee 100644
--- a/util/crc32c.cc
+++ b/util/crc32c.cc
@@ -333,17 +333,14 @@ static bool isSSE42() {
 }
 
 typedef void (*Function)(uint64_t*, uint8_t const**);
-static Function func = nullptr;
 
 static inline Function Choose_CRC32() {
   return isSSE42() ? Fast_CRC32 : Slow_CRC32;
 }
 
+static Function func = Choose_CRC32();
+
 static inline void CRC32(uint64_t* l, uint8_t const **p) {
-  if (func != nullptr) {
-    return func(l, p);
-  }
-  func = Choose_CRC32();
   func(l, p);
 }