From c2d436dcfad64d5cc301cf05d446f7a93c19133e Mon Sep 17 00:00:00 2001
From: zhangyunhao <zhangyunhao@bytedance.com>
Date: Tue, 19 Apr 2022 14:44:03 +0800
Subject: [PATCH] hash/maphash: use fastrand64 in MakeSeed

Change-Id: I5ccbcea4c53658136b25ca608faec19eeec2e908
Reviewed-on: https://go-review.googlesource.com/c/go/+/400915
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Wayne Zuo <wdvxdr@golangcn.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
---
 src/hash/maphash/maphash.go | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/src/hash/maphash/maphash.go b/src/hash/maphash/maphash.go
index 783690ea00..dfacd021db 100644
--- a/src/hash/maphash/maphash.go
+++ b/src/hash/maphash/maphash.go
@@ -252,21 +252,20 @@ func (h *Hash) Sum64() uint64 {
 
 // MakeSeed returns a new random seed.
 func MakeSeed() Seed {
-	var s1, s2 uint64
+	var s uint64
 	for {
-		s1 = uint64(runtime_fastrand())
-		s2 = uint64(runtime_fastrand())
+		s = runtime_fastrand64()
 		// We use seed 0 to indicate an uninitialized seed/hash,
 		// so keep trying until we get a non-zero seed.
-		if s1|s2 != 0 {
+		if s != 0 {
 			break
 		}
 	}
-	return Seed{s: s1<<32 + s2}
+	return Seed{s: s}
 }
 
-//go:linkname runtime_fastrand runtime.fastrand
-func runtime_fastrand() uint32
+//go:linkname runtime_fastrand64 runtime.fastrand64
+func runtime_fastrand64() uint64
 
 func rthash(ptr *byte, len int, seed uint64) uint64 {
 	if len == 0 {