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go/test/live.go
Austin Clements a367f44c18 cmd/compile: enable stack maps everywhere except unsafe points
This modifies issafepoint in liveness analysis to report almost every
operation as a safe point. There are four things we don't mark as
safe-points:

1. Runtime code (other than at calls).

2. go:nosplit functions (other than at calls).

3. Instructions between the load of the write barrier-enabled flag and
   the write.

4. Instructions leading up to a uintptr -> unsafe.Pointer conversion.

We'll optimize this in later CLs:

name        old time/op       new time/op       delta
Template          185ms ± 2%        190ms ± 2%   +2.95%  (p=0.000 n=10+10)
Unicode          96.3ms ± 3%       96.4ms ± 1%     ~     (p=0.905 n=10+9)
GoTypes           658ms ± 0%        669ms ± 1%   +1.72%  (p=0.000 n=10+9)
Compiler          3.14s ± 1%        3.18s ± 1%   +1.56%  (p=0.000 n=9+10)
SSA               7.41s ± 2%        7.59s ± 1%   +2.48%  (p=0.000 n=9+10)
Flate             126ms ± 1%        128ms ± 1%   +2.08%  (p=0.000 n=10+10)
GoParser          153ms ± 1%        157ms ± 2%   +2.38%  (p=0.000 n=10+10)
Reflect           437ms ± 1%        442ms ± 1%   +0.98%  (p=0.001 n=10+10)
Tar               178ms ± 1%        179ms ± 1%   +0.67%  (p=0.035 n=10+9)
XML               223ms ± 1%        229ms ± 1%   +2.58%  (p=0.000 n=10+10)
[Geo mean]        394ms             401ms        +1.75%

No effect on binary size because we're not yet emitting these extra
safe points.

For #24543.

Change-Id: I16a1eebb9183cad7cef9d53c0fd21a973cad6859
Reviewed-on: https://go-review.googlesource.com/109348
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2018-05-22 14:43:37 +00:00

692 lines
19 KiB
Go

// errorcheckwithauto -0 -l -live -wb=0 -d=ssa/insert_resched_checks/off
// +build !ppc64,!ppc64le
// ppc64 needs a better tighten pass to make f18 pass
// rescheduling checks need to be turned off because there are some live variables across the inserted check call
// 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.
// liveness tests with inlining disabled.
// see also live2.go.
package main
func printnl()
//go:noescape
func printpointer(**int)
//go:noescape
func printintpointer(*int)
//go:noescape
func printstringpointer(*string)
//go:noescape
func printstring(string)
//go:noescape
func printbytepointer(*byte)
func printint(int)
func f1() {
var x *int
printpointer(&x) // ERROR "live at call to printpointer: x$"
printpointer(&x) // ERROR "live at call to printpointer: x$"
}
func f2(b bool) {
if b {
printint(0) // nothing live here
return
}
var x *int
printpointer(&x) // ERROR "live at call to printpointer: x$"
printpointer(&x) // ERROR "live at call to printpointer: x$"
}
func f3(b1, b2 bool) {
// Here x and y are ambiguously live. In previous go versions they
// were marked as live throughout the function to avoid being
// poisoned in GODEBUG=gcdead=1 mode; this is now no longer the
// case.
printint(0)
if b1 == false {
printint(0)
return
}
if b2 {
var x *int
printpointer(&x) // ERROR "live at call to printpointer: x$"
printpointer(&x) // ERROR "live at call to printpointer: x$"
} else {
var y *int
printpointer(&y) // ERROR "live at call to printpointer: y$"
printpointer(&y) // ERROR "live at call to printpointer: y$"
}
printint(0) // ERROR "f3: x \(type \*int\) is ambiguously live$" "f3: y \(type \*int\) is ambiguously live$" "live at call to printint: x y$"
}
// The old algorithm treated x as live on all code that
// could flow to a return statement, so it included the
// function entry and code above the declaration of x
// but would not include an indirect use of x in an infinite loop.
// Check that these cases are handled correctly.
func f4(b1, b2 bool) { // x not live here
if b2 {
printint(0) // x not live here
return
}
var z **int
x := new(int)
*x = 42
z = &x
printint(**z) // ERROR "live at call to printint: x$"
if b2 {
printint(1) // x not live here
return
}
for {
printint(**z) // ERROR "live at call to printint: x$"
}
}
func f5(b1 bool) {
var z **int
if b1 {
x := new(int)
*x = 42
z = &x
} else {
y := new(int)
*y = 54
z = &y
}
printint(**z) // ERROR "f5: x \(type \*int\) is ambiguously live$" "f5: y \(type \*int\) is ambiguously live$" "live at call to printint: x y$"
}
// confusion about the _ result used to cause spurious "live at entry to f6: _".
func f6() (_, y string) {
y = "hello"
return
}
// confusion about addressed results used to cause "live at entry to f7: x".
func f7() (x string) {
_ = &x
x = "hello"
return
}
// ignoring block returns used to cause "live at entry to f8: x, y".
func f8() (x, y string) {
return g8()
}
func g8() (string, string)
// ignoring block assignments used to cause "live at entry to f9: x"
// issue 7205
var i9 interface{}
func f9() bool {
g8()
x := i9
y := interface{}(str()) // ERROR "live at call to convT2Estring: .autotmp_[0-9]+ x.data$" "live at call to str: x.data$"
i9 = y // make y escape so the line above has to call convT2E
return x != y
}
// liveness formerly confused by UNDEF followed by RET,
// leading to "live at entry to f10: ~r1" (unnamed result).
func f10() string {
panic(1)
}
// liveness formerly confused by select, thinking runtime.selectgo
// can return to next instruction; it always jumps elsewhere.
// note that you have to use at least two cases in the select
// to get a true select; smaller selects compile to optimized helper functions.
var c chan *int
var b bool
// this used to have a spurious "live at entry to f11a: ~r0"
func f11a() *int {
select { // ERROR "live at call to selectgo: .autotmp_[0-9]+$"
case <-c:
return nil
case <-c:
return nil
}
}
func f11b() *int {
p := new(int)
if b {
// At this point p is dead: the code here cannot
// get to the bottom of the function.
// This used to have a spurious "live at call to printint: p".
printint(1) // nothing live here!
select { // ERROR "live at call to selectgo: .autotmp_[0-9]+$"
case <-c:
return nil
case <-c:
return nil
}
}
println(*p)
return nil
}
var sink *int
func f11c() *int {
p := new(int)
sink = p // prevent stack allocation, otherwise p is rematerializeable
if b {
// Unlike previous, the cases in this select fall through,
// so we can get to the println, so p is not dead.
printint(1) // ERROR "live at call to printint: p$"
select { // ERROR "live at call to selectgo: .autotmp_[0-9]+ p$"
case <-c:
case <-c:
}
}
println(*p)
return nil
}
// similarly, select{} does not fall through.
// this used to have a spurious "live at entry to f12: ~r0".
func f12() *int {
if b {
select {}
} else {
return nil
}
}
// incorrectly placed VARDEF annotations can cause missing liveness annotations.
// this used to be missing the fact that s is live during the call to g13 (because it is
// needed for the call to h13).
func f13() {
s := g14()
s = h13(s, g13(s)) // ERROR "live at call to g13: s.ptr$"
}
func g13(string) string
func h13(string, string) string
// more incorrectly placed VARDEF.
func f14() {
x := g14()
printstringpointer(&x) // ERROR "live at call to printstringpointer: x$"
}
func g14() string
// Checking that various temporaries do not persist or cause
// ambiguously live values that must be zeroed.
// The exact temporary names are inconsequential but we are
// trying to check that there is only one at any given site,
// and also that none show up in "ambiguously live" messages.
var m map[string]int
var mi map[interface{}]int
// str and iface are used to ensure that a temp is required for runtime calls below.
func str() string
func iface() interface{}
func f16() {
if b {
delete(mi, iface()) // ERROR "live at call to mapdelete: .autotmp_[0-9]+$"
}
delete(mi, iface()) // ERROR "live at call to mapdelete: .autotmp_[0-9]+$"
delete(mi, iface()) // ERROR "live at call to mapdelete: .autotmp_[0-9]+$"
}
var m2s map[string]*byte
var m2 map[[2]string]*byte
var x2 [2]string
var bp *byte
func f17a(p *byte) { // ERROR "live at entry to f17a: p$"
if b {
m2[x2] = p // ERROR "live at call to mapassign: p$"
}
m2[x2] = p // ERROR "live at call to mapassign: p$"
m2[x2] = p // ERROR "live at call to mapassign: p$"
}
func f17b(p *byte) { // ERROR "live at entry to f17b: p$"
// key temporary
if b {
m2s[str()] = p // ERROR "live at call to mapassign_faststr: p$" "live at call to str: p$"
}
m2s[str()] = p // ERROR "live at call to mapassign_faststr: p$" "live at call to str: p$"
m2s[str()] = p // ERROR "live at call to mapassign_faststr: p$" "live at call to str: p$"
}
func f17c() {
// key and value temporaries
if b {
m2s[str()] = f17d() // ERROR "live at call to f17d: .autotmp_[0-9]+$" "live at call to mapassign_faststr: .autotmp_[0-9]+$"
}
m2s[str()] = f17d() // ERROR "live at call to f17d: .autotmp_[0-9]+$" "live at call to mapassign_faststr: .autotmp_[0-9]+$"
m2s[str()] = f17d() // ERROR "live at call to f17d: .autotmp_[0-9]+$" "live at call to mapassign_faststr: .autotmp_[0-9]+$"
}
func f17d() *byte
func g18() [2]string
func f18() {
// key temporary for mapaccess.
// temporary introduced by orderexpr.
var z *byte
if b {
z = m2[g18()] // ERROR "live at call to mapaccess1: .autotmp_[0-9]+$"
}
z = m2[g18()] // ERROR "live at call to mapaccess1: .autotmp_[0-9]+$"
z = m2[g18()] // ERROR "live at call to mapaccess1: .autotmp_[0-9]+$"
printbytepointer(z)
}
var ch chan *byte
// byteptr is used to ensure that a temp is required for runtime calls below.
func byteptr() *byte
func f19() {
// dest temporary for channel receive.
var z *byte
if b {
z = <-ch // ERROR "live at call to chanrecv1: .autotmp_[0-9]+$"
}
z = <-ch // ERROR "live at call to chanrecv1: .autotmp_[0-9]+$"
z = <-ch // ERROR "live at call to chanrecv1: .autotmp_[0-9]+$"
printbytepointer(z)
}
func f20() {
// src temporary for channel send
if b {
ch <- byteptr() // ERROR "live at call to chansend1: .autotmp_[0-9]+$"
}
ch <- byteptr() // ERROR "live at call to chansend1: .autotmp_[0-9]+$"
ch <- byteptr() // ERROR "live at call to chansend1: .autotmp_[0-9]+$"
}
func f21() {
// key temporary for mapaccess using array literal key.
var z *byte
if b {
z = m2[[2]string{"x", "y"}] // ERROR "live at call to mapaccess1: .autotmp_[0-9]+$"
}
z = m2[[2]string{"x", "y"}] // ERROR "live at call to mapaccess1: .autotmp_[0-9]+$"
z = m2[[2]string{"x", "y"}] // ERROR "live at call to mapaccess1: .autotmp_[0-9]+$"
printbytepointer(z)
}
func f23() {
// key temporary for two-result map access using array literal key.
var z *byte
var ok bool
if b {
z, ok = m2[[2]string{"x", "y"}] // ERROR "live at call to mapaccess2: .autotmp_[0-9]+$"
}
z, ok = m2[[2]string{"x", "y"}] // ERROR "live at call to mapaccess2: .autotmp_[0-9]+$"
z, ok = m2[[2]string{"x", "y"}] // ERROR "live at call to mapaccess2: .autotmp_[0-9]+$"
printbytepointer(z)
print(ok)
}
func f24() {
// key temporary for map access using array literal key.
// value temporary too.
if b {
m2[[2]string{"x", "y"}] = nil // ERROR "live at call to mapassign: .autotmp_[0-9]+$"
}
m2[[2]string{"x", "y"}] = nil // ERROR "live at call to mapassign: .autotmp_[0-9]+$"
m2[[2]string{"x", "y"}] = nil // ERROR "live at call to mapassign: .autotmp_[0-9]+$"
}
// defer should not cause spurious ambiguously live variables
func f25(b bool) {
defer g25()
if b {
return
}
var x string
x = g14()
printstring(x)
}
func g25()
// non-escaping ... slices passed to function call should die on return,
// so that the temporaries do not stack and do not cause ambiguously
// live variables.
func f26(b bool) {
if b {
print26((*int)(nil), (*int)(nil), (*int)(nil)) // ERROR "live at call to print26: .autotmp_[0-9]+$"
}
print26((*int)(nil), (*int)(nil), (*int)(nil)) // ERROR "live at call to print26: .autotmp_[0-9]+$"
print26((*int)(nil), (*int)(nil), (*int)(nil)) // ERROR "live at call to print26: .autotmp_[0-9]+$"
printnl()
}
//go:noescape
func print26(...interface{})
// non-escaping closures passed to function call should die on return
func f27(b bool) {
x := 0
if b {
call27(func() { x++ }) // ERROR "live at call to call27: .autotmp_[0-9]+$"
}
call27(func() { x++ }) // ERROR "live at call to call27: .autotmp_[0-9]+$"
call27(func() { x++ }) // ERROR "live at call to call27: .autotmp_[0-9]+$"
printnl()
}
// but defer does escape to later execution in the function
func f27defer(b bool) {
x := 0
if b {
defer call27(func() { x++ }) // ERROR "live at call to deferproc: .autotmp_[0-9]+$" "live at call to deferreturn: .autotmp_[0-9]+$"
}
defer call27(func() { x++ }) // ERROR "f27defer: .autotmp_[0-9]+ \(type struct { F uintptr; x \*int }\) is ambiguously live$" "live at call to deferproc: .autotmp_[0-9]+ .autotmp_[0-9]+$" "live at call to deferreturn: .autotmp_[0-9]+ .autotmp_[0-9]+$"
printnl() // ERROR "live at call to printnl: .autotmp_[0-9]+ .autotmp_[0-9]+$"
} // ERROR "live at call to deferreturn: .autotmp_[0-9]+ .autotmp_[0-9]+$"
// and newproc (go) escapes to the heap
func f27go(b bool) {
x := 0
if b {
go call27(func() { x++ }) // ERROR "live at call to newobject: &x$" "live at call to newproc: &x$"
}
go call27(func() { x++ }) // ERROR "live at call to newobject: &x$"
printnl()
}
//go:noescape
func call27(func())
// concatstring slice should die on return
var s1, s2, s3, s4, s5, s6, s7, s8, s9, s10 string
func f28(b bool) {
if b {
printstring(s1 + s2 + s3 + s4 + s5 + s6 + s7 + s8 + s9 + s10) // ERROR "live at call to concatstrings: .autotmp_[0-9]+$" "live at call to printstring: .autotmp_[0-9]+$"
}
printstring(s1 + s2 + s3 + s4 + s5 + s6 + s7 + s8 + s9 + s10) // ERROR "live at call to concatstrings: .autotmp_[0-9]+$" "live at call to printstring: .autotmp_[0-9]+$"
printstring(s1 + s2 + s3 + s4 + s5 + s6 + s7 + s8 + s9 + s10) // ERROR "live at call to concatstrings: .autotmp_[0-9]+$" "live at call to printstring: .autotmp_[0-9]+$"
}
// map iterator should die on end of range loop
func f29(b bool) {
if b {
for k := range m { // ERROR "live at call to mapiterinit: .autotmp_[0-9]+$" "live at call to mapiternext: .autotmp_[0-9]+$"
printstring(k) // ERROR "live at call to printstring: .autotmp_[0-9]+$"
}
}
for k := range m { // ERROR "live at call to mapiterinit: .autotmp_[0-9]+$" "live at call to mapiternext: .autotmp_[0-9]+$"
printstring(k) // ERROR "live at call to printstring: .autotmp_[0-9]+$"
}
for k := range m { // ERROR "live at call to mapiterinit: .autotmp_[0-9]+$" "live at call to mapiternext: .autotmp_[0-9]+$"
printstring(k) // ERROR "live at call to printstring: .autotmp_[0-9]+$"
}
}
// copy of array of pointers should die at end of range loop
var pstructarr [10]pstruct
// Struct size choosen to make pointer to element in pstructarr
// not computable by strength reduction.
type pstruct struct {
intp *int
_ [8]byte
}
func f30(b bool) {
// two live temps during printintpointer(p):
// in the copy of p.intp and
// the internal iterator pointer if a pointer to pstruct in pstructarr
// can not be easily computed by strength reduction.
if b {
for _, p := range pstructarr {
printintpointer(p.intp) // ERROR "live at call to printintpointer: .autotmp_[0-9]+ .autotmp_[0-9]+$"
}
}
for _, p := range pstructarr {
printintpointer(p.intp) // ERROR "live at call to printintpointer: .autotmp_[0-9]+ .autotmp_[0-9]+$"
}
for _, p := range pstructarr {
printintpointer(p.intp) // ERROR "live at call to printintpointer: .autotmp_[0-9]+ .autotmp_[0-9]+$"
}
}
// conversion to interface should not leave temporary behind
func f31(b1, b2, b3 bool) {
if b1 {
g31(str()) // ERROR "live at call to convT2Estring: .autotmp_[0-9]+$" "live at call to g31: .autotmp_[0-9]+$"
}
if b2 {
h31(str()) // ERROR "live at call to convT2Estring: .autotmp_[0-9]+ .autotmp_[0-9]+$" "live at call to h31: .autotmp_[0-9]+$" "live at call to newobject: .autotmp_[0-9]+$"
}
if b3 {
panic(str()) // ERROR "live at call to convT2Estring: .autotmp_[0-9]+$" "live at call to gopanic: .autotmp_[0-9]+$"
}
print(b3)
}
func g31(interface{})
func h31(...interface{})
// non-escaping partial functions passed to function call should die on return
type T32 int
func (t *T32) Inc() { // ERROR "live at entry to \(\*T32\).Inc: t$"
*t++
}
var t32 T32
func f32(b bool) {
if b {
call32(t32.Inc) // ERROR "live at call to call32: .autotmp_[0-9]+$"
}
call32(t32.Inc) // ERROR "live at call to call32: .autotmp_[0-9]+$"
call32(t32.Inc) // ERROR "live at call to call32: .autotmp_[0-9]+$"
}
//go:noescape
func call32(func())
// temporaries introduced during if conditions and && || expressions
// should die once the condition has been acted upon.
var m33 map[interface{}]int
func f33() {
if m33[byteptr()] == 0 { // ERROR "live at call to mapaccess1: .autotmp_[0-9]+$"
printnl()
return
} else {
printnl()
}
printnl()
}
func f34() {
if m33[byteptr()] == 0 { // ERROR "live at call to mapaccess1: .autotmp_[0-9]+$"
printnl()
return
}
printnl()
}
func f35() {
if m33[byteptr()] == 0 && m33[byteptr()] == 0 { // ERROR "live at call to mapaccess1: .autotmp_[0-9]+$" "f35: .autotmp_[0-9]+ \(type interface \{\}\) is ambiguously live$"
printnl()
return
}
printnl()
}
func f36() {
if m33[byteptr()] == 0 || m33[byteptr()] == 0 { // ERROR "live at call to mapaccess1: .autotmp_[0-9]+$" "f36: .autotmp_[0-9]+ \(type interface \{\}\) is ambiguously live$"
printnl()
return
}
printnl()
}
func f37() {
if (m33[byteptr()] == 0 || m33[byteptr()] == 0) && m33[byteptr()] == 0 { // ERROR "live at call to mapaccess1: .autotmp_[0-9]+$" "f37: .autotmp_[0-9]+ \(type interface \{\}\) is ambiguously live$"
printnl()
return
}
printnl()
}
// select temps should disappear in the case bodies
var c38 chan string
func fc38() chan string
func fi38(int) *string
func fb38() *bool
func f38(b bool) {
// we don't care what temps are printed on the lines with output.
// we care that the println lines have no live variables
// and therefore no output.
if b {
select { // ERROR "live at call to selectgo:( .autotmp_[0-9]+)+$"
case <-fc38():
printnl()
case fc38() <- *fi38(1): // ERROR "live at call to fc38:( .autotmp_[0-9]+)+$" "live at call to fi38:( .autotmp_[0-9]+)+$"
printnl()
case *fi38(2) = <-fc38(): // ERROR "live at call to fc38:( .autotmp_[0-9]+)+$" "live at call to fi38:( .autotmp_[0-9]+)+$"
printnl()
case *fi38(3), *fb38() = <-fc38(): // ERROR "live at call to fb38:( .autotmp_[0-9]+)+$" "live at call to fc38:( .autotmp_[0-9]+)+$" "live at call to fi38:( .autotmp_[0-9]+)+$"
printnl()
}
printnl()
}
printnl()
}
// issue 8097: mishandling of x = x during return.
func f39() (x []int) {
x = []int{1}
printnl() // ERROR "live at call to printnl: .autotmp_[0-9]+$"
return x
}
func f39a() (x []int) {
x = []int{1}
printnl() // ERROR "live at call to printnl: .autotmp_[0-9]+$"
return
}
func f39b() (x [10]*int) {
x = [10]*int{}
x[0] = new(int) // ERROR "live at call to newobject: x$"
printnl() // ERROR "live at call to printnl: x$"
return x
}
func f39c() (x [10]*int) {
x = [10]*int{}
x[0] = new(int) // ERROR "live at call to newobject: x$"
printnl() // ERROR "live at call to printnl: x$"
return
}
// issue 8142: lost 'addrtaken' bit on inlined variables.
// no inlining in this test, so just checking that non-inlined works.
type T40 struct {
m map[int]int
}
//go:noescape
func useT40(*T40)
func newT40() *T40 {
ret := T40{}
ret.m = make(map[int]int, 42) // ERROR "live at call to makemap: &ret$"
return &ret
}
func bad40() {
t := newT40()
_ = t
printnl()
}
func good40() {
ret := T40{}
ret.m = make(map[int]int) // ERROR "live at call to fastrand: .autotmp_[0-9]+ ret$"
t := &ret
printnl() // ERROR "live at call to printnl: .autotmp_[0-9]+ ret$"
useT40(t) // ERROR "live at call to useT40: .autotmp_[0-9]+ ret$"
}
func ddd1(x, y *int) { // ERROR "live at entry to ddd1: x y$"
ddd2(x, y) // ERROR "live at call to ddd2: .autotmp_[0-9]+$"
printnl()
// Note: no .?autotmp live at printnl. See issue 16996.
}
func ddd2(a ...*int) { // ERROR "live at entry to ddd2: a$"
sink = a[0]
}
// issue 16016: autogenerated wrapper should have arguments live
type T struct{}
func (*T) Foo(ptr *int) {}
type R struct{ *T } // ERRORAUTO "live at entry to \(\*R\)\.Foo: \.this ptr" "live at entry to R\.Foo: \.this ptr"
// issue 18860: output arguments must be live all the time if there is a defer.
// In particular, at printint r must be live.
func f41(p, q *int) (r *int) { // ERROR "live at entry to f41: p q$"
r = p
defer func() { // ERROR "live at call to deferproc: q r$" "live at call to deferreturn: r$"
recover()
}()
printint(0) // ERROR "live at call to printint: q r$"
r = q
return // ERROR "live at call to deferreturn: r$"
}