runtime: unify memeq and memequal

They do the same thing, except memequal also has the short-circuit
check if the two pointers are equal.

A) We might as well always do the short-circuit check, it is only 2 instructions.
B) The extra function call (memequal->memeq) is expensive.

benchmark                 old ns/op     new ns/op     delta
BenchmarkArrayEqual-8     8.56          5.31          -37.97%

No noticeable affect on the former memeq user (maps).

Fixes #14302

Change-Id: I85d1ada59ed11e64dd6c54667f79d32cc5f81948
Reviewed-on: https://go-review.googlesource.com/19843
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

1 files changed, 0 insertions, 7 deletions

diff --git a/src/runtime/alg.go b/src/runtime/alg.go
index 541649c62d..9e19119f4a 100644
--- a/src/runtime/alg.go
+++ b/src/runtime/alg.go
@@ -172,13 +172,6 @@ func nilinterhash(p unsafe.Pointer, h uintptr) uintptr {
 	}
 }
 
-func memequal(p, q unsafe.Pointer, size uintptr) bool {
-	if p == q {
-		return true
-	}
-	return memeq(p, q, size)
-}
-
 func memequal0(p, q unsafe.Pointer) bool {
 	return true
 }