From 679cd8e7798db593d0973519f6d3ee7ea7659142 Mon Sep 17 00:00:00 2001 From: Mateusz Poliwczak Date: Wed, 12 Feb 2025 07:16:32 +0000 Subject: [PATCH] reflect, internal/abi: speed up TypeFor[T] MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit goos: linux goarch: amd64 pkg: reflect cpu: AMD Ryzen 5 4600G with Radeon Graphics │ /tmp/before │ /tmp/after │ │ sec/op │ sec/op vs base │ TypeForString-12 2.091n ± 1% 1.174n ± 1% -43.84% (p=0.000 n=20) TypeForError-12 7.5810n ± 3% 0.9372n ± 1% -87.64% (p=0.000 n=20) Change-Id: I22022f99b2dd2029f02d9ed8477b209adf7e9496 GitHub-Last-Rev: 64d2ac5bb2f3b2a659663832a4641ff4fc83bddd GitHub-Pull-Request: golang/go#71654 Reviewed-on: https://go-review.googlesource.com/c/go/+/648395 LUCI-TryBot-Result: Go LUCI Reviewed-by: Ian Lance Taylor Reviewed-by: Cherry Mui Auto-Submit: Ian Lance Taylor --- src/internal/abi/type.go | 6 +----- src/reflect/type.go | 14 +++++--------- 2 files changed, 6 insertions(+), 14 deletions(-) diff --git a/src/internal/abi/type.go b/src/internal/abi/type.go index 1c1793fcf5..4671b0da28 100644 --- a/src/internal/abi/type.go +++ b/src/internal/abi/type.go @@ -187,11 +187,7 @@ func TypeOf(a any) *Type { // TypeFor returns the abi.Type for a type parameter. func TypeFor[T any]() *Type { - var v T - if t := TypeOf(v); t != nil { - return t // optimize for T being a non-interface kind - } - return TypeOf((*T)(nil)).Elem() // only for an interface kind + return (*PtrType)(unsafe.Pointer(TypeOf((*T)(nil)))).Elem } func (t *Type) Kind() Kind { return t.Kind_ & KindMask } diff --git a/src/reflect/type.go b/src/reflect/type.go index 0e41a6db99..e5ee7f90d0 100644 --- a/src/reflect/type.go +++ b/src/reflect/type.go @@ -1303,6 +1303,11 @@ func TypeOf(i any) Type { return toType(abi.TypeOf(i)) } +// TypeFor returns the [Type] that represents the type argument T. +func TypeFor[T any]() Type { + return toType(abi.TypeFor[T]()) +} + // rtypeOf directly extracts the *rtype of the provided value. func rtypeOf(i any) *abi.Type { return abi.TypeOf(i) @@ -2850,12 +2855,3 @@ func addTypeBits(bv *bitVector, offset uintptr, t *abi.Type) { } } } - -// TypeFor returns the [Type] that represents the type argument T. -func TypeFor[T any]() Type { - var v T - if t := TypeOf(v); t != nil { - return t // optimize for T being a non-interface kind - } - return TypeOf((*T)(nil)).Elem() // only for an interface kind -} -- 2.50.0