mirror of
https://github.com/golang/go
synced 2024-11-05 20:16:13 -07:00
4fc45ae879
Match more patterns generated by the compiler where the index for a bound check is bounded through a AND operation, with different register sizes. These rules trigger a dozen of times in a bootstrap. Change-Id: Ic9fff16f21d08580f19a366c3ee1a372e58357d1 Reviewed-on: https://go-review.googlesource.com/37442 TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
148 lines
2.7 KiB
Go
148 lines
2.7 KiB
Go
// +build amd64
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// errorcheck -0 -d=ssa/check_bce/debug=3
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package main
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func f0(a []int) {
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a[0] = 1 // ERROR "Found IsInBounds$"
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a[0] = 1
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a[6] = 1 // ERROR "Found IsInBounds$"
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a[6] = 1
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a[5] = 1
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a[5] = 1
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}
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func f1(a [256]int, i int) {
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var j int
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useInt(a[i]) // ERROR "Found IsInBounds$"
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j = i % 256
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useInt(a[j]) // ERROR "Found IsInBounds$"
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j = i & 255
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useInt(a[j])
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j = i & 17
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useInt(a[j])
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if 4 <= i && i < len(a) {
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useInt(a[i])
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useInt(a[i-1]) // ERROR "Found IsInBounds$"
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// TODO: 'if 4 <= i && i < len(a)' gets rewritten to 'if uint(i - 4) < 256 - 4',
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// which the bounds checker cannot yet use to infer that the next line doesn't need a bounds check.
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useInt(a[i-4])
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}
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}
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func f2(a [256]int, i uint) {
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useInt(a[i]) // ERROR "Found IsInBounds$"
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j := i % 256
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useInt(a[j])
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j = i & 255
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useInt(a[j])
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j = i & 17
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useInt(a[j])
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}
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func f2a(a [35]int, i uint8) {
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useInt(a[i]) // ERROR "Found IsInBounds$"
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j := i & 34
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useInt(a[j])
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j = i & 17
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useInt(a[j])
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}
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func f2b(a [35]int, i uint16) {
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useInt(a[i]) // ERROR "Found IsInBounds$"
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j := i & 34
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useInt(a[j])
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j = i & 17
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useInt(a[j])
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}
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func f2c(a [35]int, i uint32) {
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useInt(a[i]) // ERROR "Found IsInBounds$"
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j := i & 34
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useInt(a[j])
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j = i & 17
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useInt(a[j])
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}
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func f3(a [256]int, i uint8) {
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useInt(a[i])
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useInt(a[i+10])
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useInt(a[i+14])
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}
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func f4(a [27]int, i uint8) {
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useInt(a[i%15])
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useInt(a[i%19])
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useInt(a[i%27])
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}
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func f5(a []int) {
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if len(a) > 5 {
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useInt(a[5])
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useSlice(a[6:])
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useSlice(a[:6])
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}
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}
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func f6(a [32]int, b [64]int, i int) {
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useInt(a[uint32(i*0x07C4ACDD)>>27])
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useInt(b[uint64(i*0x07C4ACDD)>>58])
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useInt(a[uint(i*0x07C4ACDD)>>59])
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// The following bounds should not be removed because they can overflow.
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useInt(a[uint32(i*0x106297f105d0cc86)>>26]) // ERROR "Found IsInBounds$"
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useInt(b[uint64(i*0x106297f105d0cc86)>>57]) // ERROR "Found IsInBounds$"
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useInt(a[int32(i*0x106297f105d0cc86)>>26]) // ERROR "Found IsInBounds$"
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useInt(b[int64(i*0x106297f105d0cc86)>>57]) // ERROR "Found IsInBounds$"
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}
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func g1(a []int) {
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for i := range a {
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a[i] = i
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useSlice(a[:i+1])
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useSlice(a[:i])
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}
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}
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func g2(a []int) {
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useInt(a[3]) // ERROR "Found IsInBounds$"
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useInt(a[2])
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useInt(a[1])
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useInt(a[0])
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}
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func g3(a []int) {
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for i := range a[:256] { // ERROR "Found IsSliceInBounds$"
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useInt(a[i]) // ERROR "Found IsInBounds$"
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}
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b := a[:256]
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for i := range b {
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useInt(b[i])
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}
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}
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func g4(a [100]int) {
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for i := 10; i < 50; i++ {
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useInt(a[i-10])
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useInt(a[i])
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useInt(a[i+25])
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useInt(a[i+50])
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// The following are out of bounds.
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useInt(a[i-11]) // ERROR "Found IsInBounds$"
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useInt(a[i+51]) // ERROR "Found IsInBounds$"
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}
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}
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//go:noinline
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func useInt(a int) {
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}
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//go:noinline
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func useSlice(a []int) {
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}
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func main() {
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}
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