cmd/compile: remove unused write barrier helpers

These have been unused since CL 10316.

Passes toolstash -cmp.

Change-Id: Icc19f3fcc7275fbee1c665f704e10a110ecce2a5
Reviewed-on: https://go-review.googlesource.com/21242Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

src/cmd/compile/internal/gc/builtin.go

@@ -86,34 +86,6 @@ const runtimeimport = "" +
 	"func @\"\".closechan (@\"\".hchan·1 any)\n" +
 	"var @\"\".writeBarrier struct { @\"\".enabled bool; @\"\".needed bool; @\"\".cgo bool }\n" +
 	"func @\"\".writebarrierptr (@\"\".dst·1 *any, @\"\".src·2 any)\n" +
-	"func @\"\".writebarrierstring (@\"\".dst·1 *any, @\"\".src·2 any)\n" +
-	"func @\"\".writebarrierslice (@\"\".dst·1 *any, @\"\".src·2 any)\n" +
-	"func @\"\".writebarrieriface (@\"\".dst·1 *any, @\"\".src·2 any)\n" +
-	"func @\"\".writebarrierfat01 (@\"\".dst·1 *any, _ uintptr \"unsafe-uintptr\", @\"\".src·3 any)\n" +
-	"func @\"\".writebarrierfat10 (@\"\".dst·1 *any, _ uintptr \"unsafe-uintptr\", @\"\".src·3 any)\n" +
-	"func @\"\".writebarrierfat11 (@\"\".dst·1 *any, _ uintptr \"unsafe-uintptr\", @\"\".src·3 any)\n" +
-	"func @\"\".writebarrierfat001 (@\"\".dst·1 *any, _ uintptr \"unsafe-uintptr\", @\"\".src·3 any)\n" +
-	"func @\"\".writebarrierfat010 (@\"\".dst·1 *any, _ uintptr \"unsafe-uintptr\", @\"\".src·3 any)\n" +
-	"func @\"\".writebarrierfat011 (@\"\".dst·1 *any, _ uintptr \"unsafe-uintptr\", @\"\".src·3 any)\n" +
-	"func @\"\".writebarrierfat100 (@\"\".dst·1 *any, _ uintptr \"unsafe-uintptr\", @\"\".src·3 any)\n" +
-	"func @\"\".writebarrierfat101 (@\"\".dst·1 *any, _ uintptr \"unsafe-uintptr\", @\"\".src·3 any)\n" +
-	"func @\"\".writebarrierfat110 (@\"\".dst·1 *any, _ uintptr \"unsafe-uintptr\", @\"\".src·3 any)\n" +
-	"func @\"\".writebarrierfat111 (@\"\".dst·1 *any, _ uintptr \"unsafe-uintptr\", @\"\".src·3 any)\n" +
-	"func @\"\".writebarrierfat0001 (@\"\".dst·1 *any, _ uintptr \"unsafe-uintptr\", @\"\".src·3 any)\n" +
-	"func @\"\".writebarrierfat0010 (@\"\".dst·1 *any, _ uintptr \"unsafe-uintptr\", @\"\".src·3 any)\n" +
-	"func @\"\".writebarrierfat0011 (@\"\".dst·1 *any, _ uintptr \"unsafe-uintptr\", @\"\".src·3 any)\n" +
-	"func @\"\".writebarrierfat0100 (@\"\".dst·1 *any, _ uintptr \"unsafe-uintptr\", @\"\".src·3 any)\n" +
-	"func @\"\".writebarrierfat0101 (@\"\".dst·1 *any, _ uintptr \"unsafe-uintptr\", @\"\".src·3 any)\n" +
-	"func @\"\".writebarrierfat0110 (@\"\".dst·1 *any, _ uintptr \"unsafe-uintptr\", @\"\".src·3 any)\n" +
-	"func @\"\".writebarrierfat0111 (@\"\".dst·1 *any, _ uintptr \"unsafe-uintptr\", @\"\".src·3 any)\n" +
-	"func @\"\".writebarrierfat1000 (@\"\".dst·1 *any, _ uintptr \"unsafe-uintptr\", @\"\".src·3 any)\n" +
-	"func @\"\".writebarrierfat1001 (@\"\".dst·1 *any, _ uintptr \"unsafe-uintptr\", @\"\".src·3 any)\n" +
-	"func @\"\".writebarrierfat1010 (@\"\".dst·1 *any, _ uintptr \"unsafe-uintptr\", @\"\".src·3 any)\n" +
-	"func @\"\".writebarrierfat1011 (@\"\".dst·1 *any, _ uintptr \"unsafe-uintptr\", @\"\".src·3 any)\n" +
-	"func @\"\".writebarrierfat1100 (@\"\".dst·1 *any, _ uintptr \"unsafe-uintptr\", @\"\".src·3 any)\n" +
-	"func @\"\".writebarrierfat1101 (@\"\".dst·1 *any, _ uintptr \"unsafe-uintptr\", @\"\".src·3 any)\n" +
-	"func @\"\".writebarrierfat1110 (@\"\".dst·1 *any, _ uintptr \"unsafe-uintptr\", @\"\".src·3 any)\n" +
-	"func @\"\".writebarrierfat1111 (@\"\".dst·1 *any, _ uintptr \"unsafe-uintptr\", @\"\".src·3 any)\n" +
 	"func @\"\".typedmemmove (@\"\".typ·1 *byte, @\"\".dst·2 *any, @\"\".src·3 *any)\n" +
 	"func @\"\".typedslicecopy (@\"\".typ·2 *byte, @\"\".dst·3 any, @\"\".src·4 any) (? int)\n" +
 	"func @\"\".selectnbsend (@\"\".chanType·2 *byte, @\"\".hchan·3 chan<- any, @\"\".elem·4 *any) (? bool)\n" +

src/cmd/compile/internal/gc/builtin/runtime.go

@@ -113,39 +113,6 @@ var writeBarrier struct {
 }
 
 func writebarrierptr(dst *any, src any)
-func writebarrierstring(dst *any, src any)
-func writebarrierslice(dst *any, src any)
-func writebarrieriface(dst *any, src any)
-
-// The unused *byte argument makes sure that src is 2-pointer-aligned,
-// which is the maximum alignment on NaCl amd64p32
-// (and possibly on 32-bit systems if we start 64-bit aligning uint64s).
-// The bitmap in the name tells which words being copied are pointers.
-func writebarrierfat01(dst *any, _ uintptr, src any)
-func writebarrierfat10(dst *any, _ uintptr, src any)
-func writebarrierfat11(dst *any, _ uintptr, src any)
-func writebarrierfat001(dst *any, _ uintptr, src any)
-func writebarrierfat010(dst *any, _ uintptr, src any)
-func writebarrierfat011(dst *any, _ uintptr, src any)
-func writebarrierfat100(dst *any, _ uintptr, src any)
-func writebarrierfat101(dst *any, _ uintptr, src any)
-func writebarrierfat110(dst *any, _ uintptr, src any)
-func writebarrierfat111(dst *any, _ uintptr, src any)
-func writebarrierfat0001(dst *any, _ uintptr, src any)
-func writebarrierfat0010(dst *any, _ uintptr, src any)
-func writebarrierfat0011(dst *any, _ uintptr, src any)
-func writebarrierfat0100(dst *any, _ uintptr, src any)
-func writebarrierfat0101(dst *any, _ uintptr, src any)
-func writebarrierfat0110(dst *any, _ uintptr, src any)
-func writebarrierfat0111(dst *any, _ uintptr, src any)
-func writebarrierfat1000(dst *any, _ uintptr, src any)
-func writebarrierfat1001(dst *any, _ uintptr, src any)
-func writebarrierfat1010(dst *any, _ uintptr, src any)
-func writebarrierfat1011(dst *any, _ uintptr, src any)
-func writebarrierfat1100(dst *any, _ uintptr, src any)
-func writebarrierfat1101(dst *any, _ uintptr, src any)
-func writebarrierfat1110(dst *any, _ uintptr, src any)
-func writebarrierfat1111(dst *any, _ uintptr, src any)
 
 // *byte is really *runtime.Type
 func typedmemmove(typ *byte, dst *any, src *any)

src/cmd/compile/internal/gc/order.go

@@ -422,6 +422,8 @@ func ordermapassign(n *Node, order *Order) {
 		order.out = append(order.out, n)
 
 		// We call writebarrierfat only for values > 4 pointers long. See walk.go.
+		// TODO(mdempsky): writebarrierfat doesn't exist anymore, but removing that
+		// logic causes net/http's tests to become flaky; see CL 21242.
 		if (n.Left.Op == OINDEXMAP || (needwritebarrier(n.Left, n.Right) && n.Left.Type.Width > int64(4*Widthptr))) && !isaddrokay(n.Right) {
 			m := n.Left
 			n.Left = ordertemp(m.Type, order, false)

src/runtime/mbarrier.go

@@ -159,31 +159,6 @@ func writebarrierptr_nostore(dst *uintptr, src uintptr) {
 	writebarrierptr_nostore1(dst, src)
 }
 
-//go:nosplit
-func writebarrierstring(dst *[2]uintptr, src [2]uintptr) {
-	writebarrierptr(&dst[0], src[0])
-	dst[1] = src[1]
-}
-
-//go:nosplit
-func writebarrierslice(dst *[3]uintptr, src [3]uintptr) {
-	writebarrierptr(&dst[0], src[0])
-	dst[1] = src[1]
-	dst[2] = src[2]
-}
-
-//go:nosplit
-func writebarrieriface(dst *[2]uintptr, src [2]uintptr) {
-	writebarrierptr(&dst[0], src[0])
-	writebarrierptr(&dst[1], src[1])
-}
-
-//go:generate go run wbfat_gen.go -- wbfat.go
-//
-// The above line generates multiword write barriers for
-// all the combinations of ptr+scalar up to four words.
-// The implementations are written to wbfat.go.
-
 // typedmemmove copies a value of type t to dst from src.
 //go:nosplit
 func typedmemmove(typ *_type, dst, src unsafe.Pointer) {

src/runtime/wbfat.go

-// generated by wbfat_gen.go; use go generate
-
-package runtime
-
-//go:nosplit
-func writebarrierfat01(dst *[2]uintptr, _ uintptr, src [2]uintptr) {
-	dst[0] = src[0]
-	writebarrierptr(&dst[1], src[1])
-}
-
-//go:nosplit
-func writebarrierfat10(dst *[2]uintptr, _ uintptr, src [2]uintptr) {
-	writebarrierptr(&dst[0], src[0])
-	dst[1] = src[1]
-}
-
-//go:nosplit
-func writebarrierfat11(dst *[2]uintptr, _ uintptr, src [2]uintptr) {
-	writebarrierptr(&dst[0], src[0])
-	writebarrierptr(&dst[1], src[1])
-}
-
-//go:nosplit
-func writebarrierfat001(dst *[3]uintptr, _ uintptr, src [3]uintptr) {
-	dst[0] = src[0]
-	dst[1] = src[1]
-	writebarrierptr(&dst[2], src[2])
-}
-
-//go:nosplit
-func writebarrierfat010(dst *[3]uintptr, _ uintptr, src [3]uintptr) {
-	dst[0] = src[0]
-	writebarrierptr(&dst[1], src[1])
-	dst[2] = src[2]
-}
-
-//go:nosplit
-func writebarrierfat011(dst *[3]uintptr, _ uintptr, src [3]uintptr) {
-	dst[0] = src[0]
-	writebarrierptr(&dst[1], src[1])
-	writebarrierptr(&dst[2], src[2])
-}
-
-//go:nosplit
-func writebarrierfat100(dst *[3]uintptr, _ uintptr, src [3]uintptr) {
-	writebarrierptr(&dst[0], src[0])
-	dst[1] = src[1]
-	dst[2] = src[2]
-}
-
-//go:nosplit
-func writebarrierfat101(dst *[3]uintptr, _ uintptr, src [3]uintptr) {
-	writebarrierptr(&dst[0], src[0])
-	dst[1] = src[1]
-	writebarrierptr(&dst[2], src[2])
-}
-
-//go:nosplit
-func writebarrierfat110(dst *[3]uintptr, _ uintptr, src [3]uintptr) {
-	writebarrierptr(&dst[0], src[0])
-	writebarrierptr(&dst[1], src[1])
-	dst[2] = src[2]
-}
-
-//go:nosplit
-func writebarrierfat111(dst *[3]uintptr, _ uintptr, src [3]uintptr) {
-	writebarrierptr(&dst[0], src[0])
-	writebarrierptr(&dst[1], src[1])
-	writebarrierptr(&dst[2], src[2])
-}
-
-//go:nosplit
-func writebarrierfat0001(dst *[4]uintptr, _ uintptr, src [4]uintptr) {
-	dst[0] = src[0]
-	dst[1] = src[1]
-	dst[2] = src[2]
-	writebarrierptr(&dst[3], src[3])
-}
-
-//go:nosplit
-func writebarrierfat0010(dst *[4]uintptr, _ uintptr, src [4]uintptr) {
-	dst[0] = src[0]
-	dst[1] = src[1]
-	writebarrierptr(&dst[2], src[2])
-	dst[3] = src[3]
-}
-
-//go:nosplit
-func writebarrierfat0011(dst *[4]uintptr, _ uintptr, src [4]uintptr) {
-	dst[0] = src[0]
-	dst[1] = src[1]
-	writebarrierptr(&dst[2], src[2])
-	writebarrierptr(&dst[3], src[3])
-}
-
-//go:nosplit
-func writebarrierfat0100(dst *[4]uintptr, _ uintptr, src [4]uintptr) {
-	dst[0] = src[0]
-	writebarrierptr(&dst[1], src[1])
-	dst[2] = src[2]
-	dst[3] = src[3]
-}
-
-//go:nosplit
-func writebarrierfat0101(dst *[4]uintptr, _ uintptr, src [4]uintptr) {
-	dst[0] = src[0]
-	writebarrierptr(&dst[1], src[1])
-	dst[2] = src[2]
-	writebarrierptr(&dst[3], src[3])
-}
-
-//go:nosplit
-func writebarrierfat0110(dst *[4]uintptr, _ uintptr, src [4]uintptr) {
-	dst[0] = src[0]
-	writebarrierptr(&dst[1], src[1])
-	writebarrierptr(&dst[2], src[2])
-	dst[3] = src[3]
-}
-
-//go:nosplit
-func writebarrierfat0111(dst *[4]uintptr, _ uintptr, src [4]uintptr) {
-	dst[0] = src[0]
-	writebarrierptr(&dst[1], src[1])
-	writebarrierptr(&dst[2], src[2])
-	writebarrierptr(&dst[3], src[3])
-}
-
-//go:nosplit
-func writebarrierfat1000(dst *[4]uintptr, _ uintptr, src [4]uintptr) {
-	writebarrierptr(&dst[0], src[0])
-	dst[1] = src[1]
-	dst[2] = src[2]
-	dst[3] = src[3]
-}
-
-//go:nosplit
-func writebarrierfat1001(dst *[4]uintptr, _ uintptr, src [4]uintptr) {
-	writebarrierptr(&dst[0], src[0])
-	dst[1] = src[1]
-	dst[2] = src[2]
-	writebarrierptr(&dst[3], src[3])
-}
-
-//go:nosplit
-func writebarrierfat1010(dst *[4]uintptr, _ uintptr, src [4]uintptr) {
-	writebarrierptr(&dst[0], src[0])
-	dst[1] = src[1]
-	writebarrierptr(&dst[2], src[2])
-	dst[3] = src[3]
-}
-
-//go:nosplit
-func writebarrierfat1011(dst *[4]uintptr, _ uintptr, src [4]uintptr) {
-	writebarrierptr(&dst[0], src[0])
-	dst[1] = src[1]
-	writebarrierptr(&dst[2], src[2])
-	writebarrierptr(&dst[3], src[3])
-}
-
-//go:nosplit
-func writebarrierfat1100(dst *[4]uintptr, _ uintptr, src [4]uintptr) {
-	writebarrierptr(&dst[0], src[0])
-	writebarrierptr(&dst[1], src[1])
-	dst[2] = src[2]
-	dst[3] = src[3]
-}
-
-//go:nosplit
-func writebarrierfat1101(dst *[4]uintptr, _ uintptr, src [4]uintptr) {
-	writebarrierptr(&dst[0], src[0])
-	writebarrierptr(&dst[1], src[1])
-	dst[2] = src[2]
-	writebarrierptr(&dst[3], src[3])
-}
-
-//go:nosplit
-func writebarrierfat1110(dst *[4]uintptr, _ uintptr, src [4]uintptr) {
-	writebarrierptr(&dst[0], src[0])
-	writebarrierptr(&dst[1], src[1])
-	writebarrierptr(&dst[2], src[2])
-	dst[3] = src[3]
-}
-
-//go:nosplit
-func writebarrierfat1111(dst *[4]uintptr, _ uintptr, src [4]uintptr) {
-	writebarrierptr(&dst[0], src[0])
-	writebarrierptr(&dst[1], src[1])
-	writebarrierptr(&dst[2], src[2])
-	writebarrierptr(&dst[3], src[3])
-}

src/runtime/wbfat_gen.go

-// Copyright 2014 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.
-
-// +build ignore
-
-package main
-
-import (
-	"flag"
-	"fmt"
-	"log"
-	"os"
-)
-
-func main() {
-	flag.Parse()
-	if flag.NArg() > 0 {
-		f, err := os.Create(flag.Arg(0))
-		if err != nil {
-			log.Fatal(err)
-		}
-		os.Stdout = f
-	}
-	fmt.Printf("// generated by wbfat_gen.go; use go generate\n\n")
-	fmt.Printf("package runtime\n")
-	for i := uint(2); i <= 4; i++ {
-		for j := 1; j < 1<<i; j++ {
-			fmt.Printf("\n//go:nosplit\n")
-			fmt.Printf("func writebarrierfat%0*b(dst *[%d]uintptr, _ uintptr, src [%d]uintptr) {\n", int(i), j, i, i)
-			for k := uint(0); k < i; k++ {
-				if j&(1<<(i-1-k)) != 0 {
-					fmt.Printf("\twritebarrierptr(&dst[%d], src[%d])\n", k, k)
-				} else {
-					fmt.Printf("\tdst[%d] = src[%d]\n", k, k)
-				}
-			}
-			fmt.Printf("}\n")
-		}
-	}
-}