go/types/typeutil: make Hasher stateless

This CL makes Hasher an empty struct: consequently, Hashers are stateless and all are equivalent. Whatever optimization benefit Hasher had when it was introduced is no longer evident: the benchmark added in this CL went from 5.2ms (using the old hasher) to 3.3ms (without). It also simplifies the API and relaxes the concurrency constraints. Fixes golang/go#69407 Change-Id: Ic6fa54451bee20cba72cd7133cf9afd38e7c3ca8 Reviewed-on: https://go-review.googlesource.com/c/tools/+/612496 Reviewed-by: Robert Findley <[email protected]> LUCI-TryBot-Result: Go LUCI <[email protected]>
golang · Dec 27, 2024 · 412b5e9 · 412b5e9
1 parent 6d4eee4
commit 412b5e9
Show file tree

Hide file tree

Showing 3 changed files with 140 additions and 152 deletions.
diff --git a/go/ssa/interp/value.go b/go/ssa/interp/value.go
@@ -99,10 +99,7 @@ var (
 // hashType returns a hash for t such that
 // types.Identical(x, y) => hashType(x) == hashType(y).
 func hashType(t types.Type) int {
-	mu.Lock()
-	h := int(hasher.Hash(t))
-	mu.Unlock()
-	return h
+	return int(hasher.Hash(t))
 }
 
 // usesBuiltinMap returns true if the built-in hash function and