Revert "cmd/internal/gc: add internConcat for alloc-free string concatenation"
This reverts commit 42fcc6fea03673eeed1447eaab78a7df9385246e.
Change-Id: If860b7cbff5b5d288c1df1405c1765275dfba7cb
Reviewed-on: https://go-review.googlesource.com/7860
Reviewed-by: Russ Cox <rsc@golang.org>
diff --git a/src/cmd/internal/gc/lex.go b/src/cmd/internal/gc/lex.go
index 623c9a1..7470a1f 100644
--- a/src/cmd/internal/gc/lex.go
+++ b/src/cmd/internal/gc/lex.go
@@ -1511,15 +1511,6 @@
return s
}
-func internConcat(ss ...string) string {
- const bufsiz = 128 // big enough for most compiler uses; must be constant to avoid heap alloc
- b := make([]byte, 0, bufsiz)
- for _, s := range ss {
- b = append(b, s...)
- }
- return internString(b)
-}
-
func more(pp *string) bool {
p := *pp
for p != "" && yy_isspace(int(p[0])) {
diff --git a/src/cmd/internal/gc/lex_test.go b/src/cmd/internal/gc/lex_test.go
deleted file mode 100644
index 845a9d8..0000000
--- a/src/cmd/internal/gc/lex_test.go
+++ /dev/null
@@ -1,22 +0,0 @@
-// Copyright 2015 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package gc
-
-import "testing"
-
-func TestInternConcat(t *testing.T) {
- fromKind := "T"
- toKind := "E"
- var s string
- n := testing.AllocsPerRun(100, func() {
- s = internConcat("conv", fromKind, "2", toKind)
- })
- if s != "convT2E" {
- t.Fatalf("internConcat(\"conv\", \"T\", \"2\", \"E\")=%q want %q", s, "convT2E")
- }
- if n > 0 {
- t.Errorf("internConcat allocs per run=%f", n)
- }
-}
diff --git a/src/cmd/internal/gc/subr.go b/src/cmd/internal/gc/subr.go
index 43aa382..32486c7 100644
--- a/src/cmd/internal/gc/subr.go
+++ b/src/cmd/internal/gc/subr.go
@@ -3574,10 +3574,10 @@
return false
}
-// IET returns "T" if t is a concrete type, "I" if t is an interface type, and
-// "E" if t is an empty interface type.
+// type2IET returns "T" if t is a concrete type,
+// "I" if t is an interface type, and "E" if t is an empty interface type.
// It is used to build calls to the conv* and assert* runtime routines.
-func (t *Type) IET() string {
+func type2IET(t *Type) string {
if isnilinter(t) {
return "E"
}
diff --git a/src/cmd/internal/gc/walk.go b/src/cmd/internal/gc/walk.go
index 591974d..2784648 100644
--- a/src/cmd/internal/gc/walk.go
+++ b/src/cmd/internal/gc/walk.go
@@ -678,7 +678,7 @@
n1 := Nod(OADDR, n.Left, nil)
r := n.Right // i.(T)
- buf := internConcat("assert", r.Left.Type.IET(), "2", r.Type.IET())
+ buf := "assert" + type2IET(r.Left.Type) + "2" + type2IET(r.Type)
fn := syslook(buf, 1)
substArgTypes(fn, r.Left.Type, r.Type)
@@ -869,8 +869,8 @@
oktype = ok.Type
}
- fromKind := from.Type.IET()
- toKind := t.IET()
+ fromKind := type2IET(from.Type)
+ toKind := type2IET(t)
// Avoid runtime calls in a few cases of the form _, ok := i.(T).
// This is faster and shorter and allows the corresponding assertX2X2
@@ -903,7 +903,7 @@
}
resptr.Etype = 1 // addr does not escape
- buf := internConcat("assert", fromKind, "2", toKind, "2")
+ buf := "assert" + fromKind + "2" + toKind + "2"
fn := syslook(buf, 1)
substArgTypes(fn, from.Type, t)
call := mkcall1(fn, oktype, init, typename(t), from, resptr)
@@ -927,7 +927,11 @@
goto ret
}
- // Handle fast paths and special cases.
+ // Build name of function: convI2E etc.
+ // Not all names are possible
+ // (e.g., we'll never generate convE2E or convE2I).
+ buf := "conv" + type2IET(n.Left.Type) + "2" + type2IET(n.Type)
+ fn := syslook(buf, 1)
var ll *NodeList
if !Isinter(n.Left.Type) {
ll = list(ll, typename(n.Left.Type))
@@ -1006,11 +1010,6 @@
}
}
- // Build name of function: convI2E etc.
- // Not all names are possible
- // (e.g., we'll never generate convE2E or convE2I).
- buf := internConcat("conv", n.Left.Type.IET(), "2", n.Type.IET())
- fn := syslook(buf, 1)
substArgTypes(fn, n.Left.Type, n.Type)
dowidth(fn.Type)
n = Nod(OCALL, fn, nil)
