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Commit eeff8fa4 authored by David Chase's avatar David Chase Committed by Brad Fitzpatrick
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cmd/compile: remove now-irrelevant test 

This test measures "line churn" which was minimized to help
improve the debugger experience.  With proper is_stmt markers,
this is no longer necessary, and it is more accurate (for
profiling) to allow line numbers to vary willy-nilly.

"Debugger experience" is now better measured by
cmd/compile/internal/ssa/debug_test.go

This CL made the obsoleting change:
https://go-review.googlesource.com/c/go/+/102435

Change-Id: I874ab89f3b243b905aaeba7836118f632225a667
Reviewed-on: https://go-review.googlesource.com/113155
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
parent 15f2cbf4
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test/fixedbugs/issue18902.go deleted 100644 → 0
View file @ 15f2cbf4
// run
// +build !nacl,!js
// Copyright 2016 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.
// Runs a build -S to capture the assembly language
// output, checks that the line numbers associated with
// the stream of instructions do not change "too much".
// The changes that fixes this (that reduces the amount
// of change) does so by treating register spill, reload,
// copy, and rematerializations as being "unimportant" and
// just assigns them the line numbers of whatever "real"
// instructions preceded them.
// nacl is excluded because this runs a compiler.
package main
import (
"bufio"
"bytes"
"fmt"
"os"
"os/exec"
"strconv"
"strings"
)
// updateEnv modifies env to ensure that key=val
func updateEnv(env *[]string, key, val string) {
if val != "" {
var found bool
key = key + "="
for i, kv := range *env {
if strings.HasPrefix(kv, key) {
(*env)[i] = key + val
found = true
break
}
}
if !found {
*env = append(*env, key+val)
}
}
}
func main() {
testarch := os.Getenv("TESTARCH") // Targets other platform in test compilation.
debug := os.Getenv("TESTDEBUG") != "" // Output the relevant assembly language.
cmd := exec.Command("go", "tool", "compile", "-S", "fixedbugs/issue18902b.go")
var buf bytes.Buffer
cmd.Stdout = &buf
cmd.Stderr = &buf
cmd.Env = os.Environ()
if testarch != "" {
updateEnv(&cmd.Env, "GOARCH", testarch)
updateEnv(&cmd.Env, "GOOS", "linux") // Simplify multi-arch testing
}
err := cmd.Run()
if err != nil {
fmt.Printf("%s\n%s", err, buf.Bytes())
return
}
begin := "\"\".(*gcSortBuf).flush" // Text at beginning of relevant dissassembly.
s := buf.String()
i := strings.Index(s, begin)
if i < 0 {
fmt.Printf("Failed to find expected symbol %s in output\n%s\n", begin, s)
return
}
s = s[i:]
r := strings.NewReader(s)
scanner := bufio.NewScanner(r)
first := true // The first line after the begin text will be skipped
beforeLineNumber := "issue18902b.go:" // Text preceding line number in each line.
lbln := len(beforeLineNumber)
var scannedCount, changes, sumdiffs float64
prevVal := 0
for scanner.Scan() {
line := scanner.Text()
if first {
first = false
continue
}
i = strings.Index(line, beforeLineNumber)
if i < 0 {
// Done reading lines
const minLines = 150
if scannedCount <= minLines { // When test was written, 251 lines observed on amd64; arm64 now obtains 184
fmt.Printf("Scanned only %d lines, was expecting more than %d\n", int(scannedCount), minLines)
return
}
// Note: when test was written, before changes=92, after=50 (was 62 w/o rematerialization NoXPos in *Value.copyInto())
// and before sumdiffs=784, after=180 (was 446 w/o rematerialization NoXPos in *Value.copyInto())
// Set the dividing line between pass and fail at the midpoint.
// Normalize against instruction count in case we unroll loops, etc.
if changes/scannedCount >= (50+92)/(2*scannedCount) || sumdiffs/scannedCount >= (180+784)/(2*scannedCount) {
fmt.Printf("Line numbers change too much, # of changes=%.f, sumdiffs=%.f, # of instructions=%.f\n", changes, sumdiffs, scannedCount)
}
return
}
scannedCount++
i += lbln
lineVal, err := strconv.Atoi(line[i : i+3])
if err != nil {
fmt.Printf("Expected 3-digit line number after %s in %s\n", beforeLineNumber, line)
}
if prevVal == 0 {
prevVal = lineVal
}
diff := lineVal - prevVal
if diff < 0 {
diff = -diff
}
if diff != 0 {
changes++
sumdiffs += float64(diff)
}
// If things change too much, set environment variable TESTDEBUG to help figure out what's up.
// The "before" behavior can be recreated in DebugFriendlySetPosFrom (currently in gc/ssa.go)
// by inserting unconditional
// s.SetPos(v.Pos)
// at the top of the function.
if debug {
fmt.Printf("%d %.f %.f %s\n", lineVal, changes, sumdiffs, line)
}
prevVal = lineVal
}
if err := scanner.Err(); err != nil {
fmt.Println("Reading standard input:", err)
return
}
}
test/fixedbugs/issue18902b.go deleted 100644 → 0
View file @ 15f2cbf4
// skip
// Copyright 2016 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 foo
import (
"unsafe"
)
type gcMaxTreeNodeVal uint64
var work struct {
full uint64 // lock-free list of full blocks workbuf
empty uint64 // lock-free list of empty blocks workbuf
pad0 [64]uint8 // prevents false-sharing between full/empty and nproc/nwait
bytesMarked uint64
markrootNext uint32 // next markroot job
markrootJobs uint32 // number of markroot jobs
nproc uint32
tstart int64
nwait uint32
ndone uint32
}
type gcShardQueue1 struct {
partial *workbuf
full *workbuf
n uintptr
maxTree gcMaxTreeNodeVal
}
type gcShardQueue struct {
gcShardQueue1
pad [64 - unsafe.Sizeof(gcShardQueue1{})]byte
}
const gcSortBufPointers = (64 << 10) / 8
type gcSortBuf struct {
buf *gcSortArray
tmp *gcSortArray
n uintptr
}
//go:notinheap
type gcSortArray [gcSortBufPointers]uintptr
const (
_DebugGC = 0
_ConcurrentSweep = true
_FinBlockSize = 4 * 1024
sweepMinHeapDistance = 1024 * 1024
gcShardShift = 2 + 20
gcShardBytes = 1 << gcShardShift
)
//go:notinheap
type mheap struct {
shardQueues []gcShardQueue
_ uint32 // align uint64 fields on 32-bit for atomics
pagesInUse uint64 // pages of spans in stats _MSpanInUse; R/W with mheap.lock
spanBytesAlloc uint64 // bytes of spans allocated this cycle; updated atomically
pagesSwept uint64 // pages swept this cycle; updated atomically
sweepPagesPerByte float64 // proportional sweep ratio; written with lock, read without
largefree uint64 // bytes freed for large objects (>maxsmallsize)
nlargefree uint64 // number of frees for large objects (>maxsmallsize)
nsmallfree [67]uint64 // number of frees for small objects (<=maxsmallsize)
bitmap uintptr // Points to one byte past the end of the bitmap
bitmap_mapped uintptr
arena_start uintptr
arena_used uintptr // always mHeap_Map{Bits,Spans} before updating
arena_end uintptr
arena_reserved bool
}
var mheap_ mheap
type lfnode struct {
next uint64
pushcnt uintptr
}
type workbufhdr struct {
node lfnode // must be first
next *workbuf
nobj int
}
//go:notinheap
type workbuf struct {
workbufhdr
obj [(2048 - unsafe.Sizeof(workbufhdr{})) / 8]uintptr
}
//go:noinline
func (b *workbuf) checkempty() {
if b.nobj != 0 {
b.nobj = 0
}
}
func putempty(b *workbuf) {
b.checkempty()
lfstackpush(&work.empty, &b.node)
}
//go:noinline
func lfstackpush(head *uint64, node *lfnode) {
}
//go:noinline
func (q *gcShardQueue) add(qidx uintptr, ptrs []uintptr, spare *workbuf) *workbuf {
return spare
}
func (b *gcSortBuf) flush() {
if b.n == 0 {
return
}
const sortDigitBits = 11
buf, tmp := b.buf[:b.n], b.tmp[:b.n]
moreBits := true
for shift := uint(gcShardShift); moreBits; shift += sortDigitBits {
const k = 1 << sortDigitBits
var pos [k]uint16
nshift := shift + sortDigitBits
nbits := buf[0] >> nshift
moreBits = false
for _, v := range buf {
pos[(v>>shift)%k]++
moreBits = moreBits || v>>nshift != nbits
}
var sum uint16
for i, count := range &pos {
pos[i] = sum
sum += count
}
for _, v := range buf {
digit := (v >> shift) % k
tmp[pos[digit]] = v
pos[digit]++
}
buf, tmp = tmp, buf
}
start := mheap_.arena_start
i0 := 0
shard0 := (buf[0] - start) / gcShardBytes
var spare *workbuf
for i, p := range buf {
shard := (p - start) / gcShardBytes
if shard != shard0 {
spare = mheap_.shardQueues[shard0].add(shard0, buf[i0:i], spare)
i0, shard0 = i, shard
}
}
spare = mheap_.shardQueues[shard0].add(shard0, buf[i0:], spare)
b.n = 0
if spare != nil {
putempty(spare)
}
}
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