summaryrefslogtreecommitdiffstats
path: root/test/prove.go
diff options
context:
space:
mode:
Diffstat (limited to 'test/prove.go')
-rw-r--r--test/prove.go1032
1 files changed, 1032 insertions, 0 deletions
diff --git a/test/prove.go b/test/prove.go
new file mode 100644
index 0000000..d37021d
--- /dev/null
+++ b/test/prove.go
@@ -0,0 +1,1032 @@
+// +build amd64
+// errorcheck -0 -d=ssa/prove/debug=1
+
+// 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 main
+
+import "math"
+
+func f0(a []int) int {
+ a[0] = 1
+ a[0] = 1 // ERROR "Proved IsInBounds$"
+ a[6] = 1
+ a[6] = 1 // ERROR "Proved IsInBounds$"
+ a[5] = 1 // ERROR "Proved IsInBounds$"
+ a[5] = 1 // ERROR "Proved IsInBounds$"
+ return 13
+}
+
+func f1(a []int) int {
+ if len(a) <= 5 {
+ return 18
+ }
+ a[0] = 1 // ERROR "Proved IsInBounds$"
+ a[0] = 1 // ERROR "Proved IsInBounds$"
+ a[6] = 1
+ a[6] = 1 // ERROR "Proved IsInBounds$"
+ a[5] = 1 // ERROR "Proved IsInBounds$"
+ a[5] = 1 // ERROR "Proved IsInBounds$"
+ return 26
+}
+
+func f1b(a []int, i int, j uint) int {
+ if i >= 0 && i < len(a) {
+ return a[i] // ERROR "Proved IsInBounds$"
+ }
+ if i >= 10 && i < len(a) {
+ return a[i] // ERROR "Proved IsInBounds$"
+ }
+ if i >= 10 && i < len(a) {
+ return a[i] // ERROR "Proved IsInBounds$"
+ }
+ if i >= 10 && i < len(a) {
+ return a[i-10] // ERROR "Proved IsInBounds$"
+ }
+ if j < uint(len(a)) {
+ return a[j] // ERROR "Proved IsInBounds$"
+ }
+ return 0
+}
+
+func f1c(a []int, i int64) int {
+ c := uint64(math.MaxInt64 + 10) // overflows int
+ d := int64(c)
+ if i >= d && i < int64(len(a)) {
+ // d overflows, should not be handled.
+ return a[i]
+ }
+ return 0
+}
+
+func f2(a []int) int {
+ for i := range a { // ERROR "Induction variable: limits \[0,\?\), increment 1$"
+ a[i+1] = i
+ a[i+1] = i // ERROR "Proved IsInBounds$"
+ }
+ return 34
+}
+
+func f3(a []uint) int {
+ for i := uint(0); i < uint(len(a)); i++ {
+ a[i] = i // ERROR "Proved IsInBounds$"
+ }
+ return 41
+}
+
+func f4a(a, b, c int) int {
+ if a < b {
+ if a == b { // ERROR "Disproved Eq64$"
+ return 47
+ }
+ if a > b { // ERROR "Disproved Less64$"
+ return 50
+ }
+ if a < b { // ERROR "Proved Less64$"
+ return 53
+ }
+ // We can't get to this point and prove knows that, so
+ // there's no message for the next (obvious) branch.
+ if a != a {
+ return 56
+ }
+ return 61
+ }
+ return 63
+}
+
+func f4b(a, b, c int) int {
+ if a <= b {
+ if a >= b {
+ if a == b { // ERROR "Proved Eq64$"
+ return 70
+ }
+ return 75
+ }
+ return 77
+ }
+ return 79
+}
+
+func f4c(a, b, c int) int {
+ if a <= b {
+ if a >= b {
+ if a != b { // ERROR "Disproved Neq64$"
+ return 73
+ }
+ return 75
+ }
+ return 77
+ }
+ return 79
+}
+
+func f4d(a, b, c int) int {
+ if a < b {
+ if a < c {
+ if a < b { // ERROR "Proved Less64$"
+ if a < c { // ERROR "Proved Less64$"
+ return 87
+ }
+ return 89
+ }
+ return 91
+ }
+ return 93
+ }
+ return 95
+}
+
+func f4e(a, b, c int) int {
+ if a < b {
+ if b > a { // ERROR "Proved Less64$"
+ return 101
+ }
+ return 103
+ }
+ return 105
+}
+
+func f4f(a, b, c int) int {
+ if a <= b {
+ if b > a {
+ if b == a { // ERROR "Disproved Eq64$"
+ return 112
+ }
+ return 114
+ }
+ if b >= a { // ERROR "Proved Leq64$"
+ if b == a { // ERROR "Proved Eq64$"
+ return 118
+ }
+ return 120
+ }
+ return 122
+ }
+ return 124
+}
+
+func f5(a, b uint) int {
+ if a == b {
+ if a <= b { // ERROR "Proved Leq64U$"
+ return 130
+ }
+ return 132
+ }
+ return 134
+}
+
+// These comparisons are compile time constants.
+func f6a(a uint8) int {
+ if a < a { // ERROR "Disproved Less8U$"
+ return 140
+ }
+ return 151
+}
+
+func f6b(a uint8) int {
+ if a < a { // ERROR "Disproved Less8U$"
+ return 140
+ }
+ return 151
+}
+
+func f6x(a uint8) int {
+ if a > a { // ERROR "Disproved Less8U$"
+ return 143
+ }
+ return 151
+}
+
+func f6d(a uint8) int {
+ if a <= a { // ERROR "Proved Leq8U$"
+ return 146
+ }
+ return 151
+}
+
+func f6e(a uint8) int {
+ if a >= a { // ERROR "Proved Leq8U$"
+ return 149
+ }
+ return 151
+}
+
+func f7(a []int, b int) int {
+ if b < len(a) {
+ a[b] = 3
+ if b < len(a) { // ERROR "Proved Less64$"
+ a[b] = 5 // ERROR "Proved IsInBounds$"
+ }
+ }
+ return 161
+}
+
+func f8(a, b uint) int {
+ if a == b {
+ return 166
+ }
+ if a > b {
+ return 169
+ }
+ if a < b { // ERROR "Proved Less64U$"
+ return 172
+ }
+ return 174
+}
+
+func f9(a, b bool) int {
+ if a {
+ return 1
+ }
+ if a || b { // ERROR "Disproved Arg$"
+ return 2
+ }
+ return 3
+}
+
+func f10(a string) int {
+ n := len(a)
+ // We optimize comparisons with small constant strings (see cmd/compile/internal/gc/walk.go),
+ // so this string literal must be long.
+ if a[:n>>1] == "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" {
+ return 0
+ }
+ return 1
+}
+
+func f11a(a []int, i int) {
+ useInt(a[i])
+ useInt(a[i]) // ERROR "Proved IsInBounds$"
+}
+
+func f11b(a []int, i int) {
+ useSlice(a[i:])
+ useSlice(a[i:]) // ERROR "Proved IsSliceInBounds$"
+}
+
+func f11c(a []int, i int) {
+ useSlice(a[:i])
+ useSlice(a[:i]) // ERROR "Proved IsSliceInBounds$"
+}
+
+func f11d(a []int, i int) {
+ useInt(a[2*i+7])
+ useInt(a[2*i+7]) // ERROR "Proved IsInBounds$"
+}
+
+func f12(a []int, b int) {
+ useSlice(a[:b])
+}
+
+func f13a(a, b, c int, x bool) int {
+ if a > 12 {
+ if x {
+ if a < 12 { // ERROR "Disproved Less64$"
+ return 1
+ }
+ }
+ if x {
+ if a <= 12 { // ERROR "Disproved Leq64$"
+ return 2
+ }
+ }
+ if x {
+ if a == 12 { // ERROR "Disproved Eq64$"
+ return 3
+ }
+ }
+ if x {
+ if a >= 12 { // ERROR "Proved Leq64$"
+ return 4
+ }
+ }
+ if x {
+ if a > 12 { // ERROR "Proved Less64$"
+ return 5
+ }
+ }
+ return 6
+ }
+ return 0
+}
+
+func f13b(a int, x bool) int {
+ if a == -9 {
+ if x {
+ if a < -9 { // ERROR "Disproved Less64$"
+ return 7
+ }
+ }
+ if x {
+ if a <= -9 { // ERROR "Proved Leq64$"
+ return 8
+ }
+ }
+ if x {
+ if a == -9 { // ERROR "Proved Eq64$"
+ return 9
+ }
+ }
+ if x {
+ if a >= -9 { // ERROR "Proved Leq64$"
+ return 10
+ }
+ }
+ if x {
+ if a > -9 { // ERROR "Disproved Less64$"
+ return 11
+ }
+ }
+ return 12
+ }
+ return 0
+}
+
+func f13c(a int, x bool) int {
+ if a < 90 {
+ if x {
+ if a < 90 { // ERROR "Proved Less64$"
+ return 13
+ }
+ }
+ if x {
+ if a <= 90 { // ERROR "Proved Leq64$"
+ return 14
+ }
+ }
+ if x {
+ if a == 90 { // ERROR "Disproved Eq64$"
+ return 15
+ }
+ }
+ if x {
+ if a >= 90 { // ERROR "Disproved Leq64$"
+ return 16
+ }
+ }
+ if x {
+ if a > 90 { // ERROR "Disproved Less64$"
+ return 17
+ }
+ }
+ return 18
+ }
+ return 0
+}
+
+func f13d(a int) int {
+ if a < 5 {
+ if a < 9 { // ERROR "Proved Less64$"
+ return 1
+ }
+ }
+ return 0
+}
+
+func f13e(a int) int {
+ if a > 9 {
+ if a > 5 { // ERROR "Proved Less64$"
+ return 1
+ }
+ }
+ return 0
+}
+
+func f13f(a int64) int64 {
+ if a > math.MaxInt64 {
+ if a == 0 { // ERROR "Disproved Eq64$"
+ return 1
+ }
+ }
+ return 0
+}
+
+func f13g(a int) int {
+ if a < 3 {
+ return 5
+ }
+ if a > 3 {
+ return 6
+ }
+ if a == 3 { // ERROR "Proved Eq64$"
+ return 7
+ }
+ return 8
+}
+
+func f13h(a int) int {
+ if a < 3 {
+ if a > 1 {
+ if a == 2 { // ERROR "Proved Eq64$"
+ return 5
+ }
+ }
+ }
+ return 0
+}
+
+func f13i(a uint) int {
+ if a == 0 {
+ return 1
+ }
+ if a > 0 { // ERROR "Proved Less64U$"
+ return 2
+ }
+ return 3
+}
+
+func f14(p, q *int, a []int) {
+ // This crazy ordering usually gives i1 the lowest value ID,
+ // j the middle value ID, and i2 the highest value ID.
+ // That used to confuse CSE because it ordered the args
+ // of the two + ops below differently.
+ // That in turn foiled bounds check elimination.
+ i1 := *p
+ j := *q
+ i2 := *p
+ useInt(a[i1+j])
+ useInt(a[i2+j]) // ERROR "Proved IsInBounds$"
+}
+
+func f15(s []int, x int) {
+ useSlice(s[x:])
+ useSlice(s[:x]) // ERROR "Proved IsSliceInBounds$"
+}
+
+func f16(s []int) []int {
+ if len(s) >= 10 {
+ return s[:10] // ERROR "Proved IsSliceInBounds$"
+ }
+ return nil
+}
+
+func f17(b []int) {
+ for i := 0; i < len(b); i++ { // ERROR "Induction variable: limits \[0,\?\), increment 1$"
+ // This tests for i <= cap, which we can only prove
+ // using the derived relation between len and cap.
+ // This depends on finding the contradiction, since we
+ // don't query this condition directly.
+ useSlice(b[:i]) // ERROR "Proved IsSliceInBounds$"
+ }
+}
+
+func f18(b []int, x int, y uint) {
+ _ = b[x]
+ _ = b[y]
+
+ if x > len(b) { // ERROR "Disproved Less64$"
+ return
+ }
+ if y > uint(len(b)) { // ERROR "Disproved Less64U$"
+ return
+ }
+ if int(y) > len(b) { // ERROR "Disproved Less64$"
+ return
+ }
+}
+
+func f19() (e int64, err error) {
+ // Issue 29502: slice[:0] is incorrectly disproved.
+ var stack []int64
+ stack = append(stack, 123)
+ if len(stack) > 1 {
+ panic("too many elements")
+ }
+ last := len(stack) - 1
+ e = stack[last]
+ // Buggy compiler prints "Disproved Leq64" for the next line.
+ stack = stack[:last] // ERROR "Proved IsSliceInBounds"
+ return e, nil
+}
+
+func sm1(b []int, x int) {
+ // Test constant argument to slicemask.
+ useSlice(b[2:8]) // ERROR "Proved slicemask not needed$"
+ // Test non-constant argument with known limits.
+ if cap(b) > 10 {
+ useSlice(b[2:])
+ }
+}
+
+func lim1(x, y, z int) {
+ // Test relations between signed and unsigned limits.
+ if x > 5 {
+ if uint(x) > 5 { // ERROR "Proved Less64U$"
+ return
+ }
+ }
+ if y >= 0 && y < 4 {
+ if uint(y) > 4 { // ERROR "Disproved Less64U$"
+ return
+ }
+ if uint(y) < 5 { // ERROR "Proved Less64U$"
+ return
+ }
+ }
+ if z < 4 {
+ if uint(z) > 4 { // Not provable without disjunctions.
+ return
+ }
+ }
+}
+
+// fence1–4 correspond to the four fence-post implications.
+
+func fence1(b []int, x, y int) {
+ // Test proofs that rely on fence-post implications.
+ if x+1 > y {
+ if x < y { // ERROR "Disproved Less64$"
+ return
+ }
+ }
+ if len(b) < cap(b) {
+ // This eliminates the growslice path.
+ b = append(b, 1) // ERROR "Disproved Less64U$"
+ }
+}
+
+func fence2(x, y int) {
+ if x-1 < y {
+ if x > y { // ERROR "Disproved Less64$"
+ return
+ }
+ }
+}
+
+func fence3(b, c []int, x, y int64) {
+ if x-1 >= y {
+ if x <= y { // Can't prove because x may have wrapped.
+ return
+ }
+ }
+
+ if x != math.MinInt64 && x-1 >= y {
+ if x <= y { // ERROR "Disproved Leq64$"
+ return
+ }
+ }
+
+ c[len(c)-1] = 0 // Can't prove because len(c) might be 0
+
+ if n := len(b); n > 0 {
+ b[n-1] = 0 // ERROR "Proved IsInBounds$"
+ }
+}
+
+func fence4(x, y int64) {
+ if x >= y+1 {
+ if x <= y {
+ return
+ }
+ }
+ if y != math.MaxInt64 && x >= y+1 {
+ if x <= y { // ERROR "Disproved Leq64$"
+ return
+ }
+ }
+}
+
+// Check transitive relations
+func trans1(x, y int64) {
+ if x > 5 {
+ if y > x {
+ if y > 2 { // ERROR "Proved Less64$"
+ return
+ }
+ } else if y == x {
+ if y > 5 { // ERROR "Proved Less64$"
+ return
+ }
+ }
+ }
+ if x >= 10 {
+ if y > x {
+ if y > 10 { // ERROR "Proved Less64$"
+ return
+ }
+ }
+ }
+}
+
+func trans2(a, b []int, i int) {
+ if len(a) != len(b) {
+ return
+ }
+
+ _ = a[i]
+ _ = b[i] // ERROR "Proved IsInBounds$"
+}
+
+func trans3(a, b []int, i int) {
+ if len(a) > len(b) {
+ return
+ }
+
+ _ = a[i]
+ _ = b[i] // ERROR "Proved IsInBounds$"
+}
+
+// Derived from nat.cmp
+func natcmp(x, y []uint) (r int) {
+ m := len(x)
+ n := len(y)
+ if m != n || m == 0 {
+ return
+ }
+
+ i := m - 1
+ for i > 0 && // ERROR "Induction variable: limits \(0,\?\], increment 1$"
+ x[i] == // ERROR "Proved IsInBounds$"
+ y[i] { // ERROR "Proved IsInBounds$"
+ i--
+ }
+
+ switch {
+ case x[i] < // todo, cannot prove this because it's dominated by i<=0 || x[i]==y[i]
+ y[i]: // ERROR "Proved IsInBounds$"
+ r = -1
+ case x[i] > // ERROR "Proved IsInBounds$"
+ y[i]: // ERROR "Proved IsInBounds$"
+ r = 1
+ }
+ return
+}
+
+func suffix(s, suffix string) bool {
+ // todo, we're still not able to drop the bound check here in the general case
+ return len(s) >= len(suffix) && s[len(s)-len(suffix):] == suffix
+}
+
+func constsuffix(s string) bool {
+ return suffix(s, "abc") // ERROR "Proved IsSliceInBounds$"
+}
+
+// oforuntil tests the pattern created by OFORUNTIL blocks. These are
+// handled by addLocalInductiveFacts rather than findIndVar.
+func oforuntil(b []int) {
+ i := 0
+ if len(b) > i {
+ top:
+ println(b[i]) // ERROR "Induction variable: limits \[0,\?\), increment 1$" "Proved IsInBounds$"
+ i++
+ if i < len(b) {
+ goto top
+ }
+ }
+}
+
+func atexit(foobar []func()) {
+ for i := len(foobar) - 1; i >= 0; i-- { // ERROR "Induction variable: limits \[0,\?\], increment 1"
+ f := foobar[i]
+ foobar = foobar[:i] // ERROR "IsSliceInBounds"
+ f()
+ }
+}
+
+func make1(n int) []int {
+ s := make([]int, n)
+ for i := 0; i < n; i++ { // ERROR "Induction variable: limits \[0,\?\), increment 1"
+ s[i] = 1 // ERROR "Proved IsInBounds$"
+ }
+ return s
+}
+
+func make2(n int) []int {
+ s := make([]int, n)
+ for i := range s { // ERROR "Induction variable: limits \[0,\?\), increment 1"
+ s[i] = 1 // ERROR "Proved IsInBounds$"
+ }
+ return s
+}
+
+// The range tests below test the index variable of range loops.
+
+// range1 compiles to the "efficiently indexable" form of a range loop.
+func range1(b []int) {
+ for i, v := range b { // ERROR "Induction variable: limits \[0,\?\), increment 1$"
+ b[i] = v + 1 // ERROR "Proved IsInBounds$"
+ if i < len(b) { // ERROR "Proved Less64$"
+ println("x")
+ }
+ if i >= 0 { // ERROR "Proved Leq64$"
+ println("x")
+ }
+ }
+}
+
+// range2 elements are larger, so they use the general form of a range loop.
+func range2(b [][32]int) {
+ for i, v := range b {
+ b[i][0] = v[0] + 1 // ERROR "Induction variable: limits \[0,\?\), increment 1$" "Proved IsInBounds$"
+ if i < len(b) { // ERROR "Proved Less64$"
+ println("x")
+ }
+ if i >= 0 { // ERROR "Proved Leq64$"
+ println("x")
+ }
+ }
+}
+
+// signhint1-2 test whether the hint (int >= 0) is propagated into the loop.
+func signHint1(i int, data []byte) {
+ if i >= 0 {
+ for i < len(data) { // ERROR "Induction variable: limits \[\?,\?\), increment 1$"
+ _ = data[i] // ERROR "Proved IsInBounds$"
+ i++
+ }
+ }
+}
+
+func signHint2(b []byte, n int) {
+ if n < 0 {
+ panic("")
+ }
+ _ = b[25]
+ for i := n; i <= 25; i++ { // ERROR "Induction variable: limits \[\?,25\], increment 1$"
+ b[i] = 123 // ERROR "Proved IsInBounds$"
+ }
+}
+
+// indexGT0 tests whether prove learns int index >= 0 from bounds check.
+func indexGT0(b []byte, n int) {
+ _ = b[n]
+ _ = b[25]
+
+ for i := n; i <= 25; i++ { // ERROR "Induction variable: limits \[\?,25\], increment 1$"
+ b[i] = 123 // ERROR "Proved IsInBounds$"
+ }
+}
+
+// Induction variable in unrolled loop.
+func unrollUpExcl(a []int) int {
+ var i, x int
+ for i = 0; i < len(a)-1; i += 2 { // ERROR "Induction variable: limits \[0,\?\), increment 2$"
+ x += a[i] // ERROR "Proved IsInBounds$"
+ x += a[i+1]
+ }
+ if i == len(a)-1 {
+ x += a[i]
+ }
+ return x
+}
+
+// Induction variable in unrolled loop.
+func unrollUpIncl(a []int) int {
+ var i, x int
+ for i = 0; i <= len(a)-2; i += 2 { // ERROR "Induction variable: limits \[0,\?\], increment 2$"
+ x += a[i]
+ x += a[i+1]
+ }
+ if i == len(a)-1 {
+ x += a[i]
+ }
+ return x
+}
+
+// Induction variable in unrolled loop.
+func unrollDownExcl0(a []int) int {
+ var i, x int
+ for i = len(a) - 1; i > 0; i -= 2 { // ERROR "Induction variable: limits \(0,\?\], increment 2$"
+ x += a[i] // ERROR "Proved IsInBounds$"
+ x += a[i-1] // ERROR "Proved IsInBounds$"
+ }
+ if i == 0 {
+ x += a[i]
+ }
+ return x
+}
+
+// Induction variable in unrolled loop.
+func unrollDownExcl1(a []int) int {
+ var i, x int
+ for i = len(a) - 1; i >= 1; i -= 2 { // ERROR "Induction variable: limits \[1,\?\], increment 2$"
+ x += a[i] // ERROR "Proved IsInBounds$"
+ x += a[i-1] // ERROR "Proved IsInBounds$"
+ }
+ if i == 0 {
+ x += a[i]
+ }
+ return x
+}
+
+// Induction variable in unrolled loop.
+func unrollDownInclStep(a []int) int {
+ var i, x int
+ for i = len(a); i >= 2; i -= 2 { // ERROR "Induction variable: limits \[2,\?\], increment 2$"
+ x += a[i-1] // ERROR "Proved IsInBounds$"
+ x += a[i-2]
+ }
+ if i == 1 {
+ x += a[i-1]
+ }
+ return x
+}
+
+// Not an induction variable (step too large)
+func unrollExclStepTooLarge(a []int) int {
+ var i, x int
+ for i = 0; i < len(a)-1; i += 3 {
+ x += a[i]
+ x += a[i+1]
+ }
+ if i == len(a)-1 {
+ x += a[i]
+ }
+ return x
+}
+
+// Not an induction variable (step too large)
+func unrollInclStepTooLarge(a []int) int {
+ var i, x int
+ for i = 0; i <= len(a)-2; i += 3 {
+ x += a[i]
+ x += a[i+1]
+ }
+ if i == len(a)-1 {
+ x += a[i]
+ }
+ return x
+}
+
+// Not an induction variable (min too small, iterating down)
+func unrollDecMin(a []int) int {
+ var i, x int
+ for i = len(a); i >= math.MinInt64; i -= 2 {
+ x += a[i-1]
+ x += a[i-2]
+ }
+ if i == 1 { // ERROR "Disproved Eq64$"
+ x += a[i-1]
+ }
+ return x
+}
+
+// Not an induction variable (min too small, iterating up -- perhaps could allow, but why bother?)
+func unrollIncMin(a []int) int {
+ var i, x int
+ for i = len(a); i >= math.MinInt64; i += 2 {
+ x += a[i-1]
+ x += a[i-2]
+ }
+ if i == 1 { // ERROR "Disproved Eq64$"
+ x += a[i-1]
+ }
+ return x
+}
+
+// The 4 xxxxExtNto64 functions below test whether prove is looking
+// through value-preserving sign/zero extensions of index values (issue #26292).
+
+// Look through all extensions
+func signExtNto64(x []int, j8 int8, j16 int16, j32 int32) int {
+ if len(x) < 22 {
+ return 0
+ }
+ if j8 >= 0 && j8 < 22 {
+ return x[j8] // ERROR "Proved IsInBounds$"
+ }
+ if j16 >= 0 && j16 < 22 {
+ return x[j16] // ERROR "Proved IsInBounds$"
+ }
+ if j32 >= 0 && j32 < 22 {
+ return x[j32] // ERROR "Proved IsInBounds$"
+ }
+ return 0
+}
+
+func zeroExtNto64(x []int, j8 uint8, j16 uint16, j32 uint32) int {
+ if len(x) < 22 {
+ return 0
+ }
+ if j8 >= 0 && j8 < 22 {
+ return x[j8] // ERROR "Proved IsInBounds$"
+ }
+ if j16 >= 0 && j16 < 22 {
+ return x[j16] // ERROR "Proved IsInBounds$"
+ }
+ if j32 >= 0 && j32 < 22 {
+ return x[j32] // ERROR "Proved IsInBounds$"
+ }
+ return 0
+}
+
+// Process fence-post implications through 32to64 extensions (issue #29964)
+func signExt32to64Fence(x []int, j int32) int {
+ if x[j] != 0 {
+ return 1
+ }
+ if j > 0 && x[j-1] != 0 { // ERROR "Proved IsInBounds$"
+ return 1
+ }
+ return 0
+}
+
+func zeroExt32to64Fence(x []int, j uint32) int {
+ if x[j] != 0 {
+ return 1
+ }
+ if j > 0 && x[j-1] != 0 { // ERROR "Proved IsInBounds$"
+ return 1
+ }
+ return 0
+}
+
+// Ensure that bounds checks with negative indexes are not incorrectly removed.
+func negIndex() {
+ n := make([]int, 1)
+ for i := -1; i <= 0; i++ { // ERROR "Induction variable: limits \[-1,0\], increment 1$"
+ n[i] = 1
+ }
+}
+func negIndex2(n int) {
+ a := make([]int, 5)
+ b := make([]int, 5)
+ c := make([]int, 5)
+ for i := -1; i <= 0; i-- {
+ b[i] = i
+ n++
+ if n > 10 {
+ break
+ }
+ }
+ useSlice(a)
+ useSlice(c)
+}
+
+// Check that prove is zeroing these right shifts of positive ints by bit-width - 1.
+// e.g (Rsh64x64 <t> n (Const64 <typ.UInt64> [63])) && ft.isNonNegative(n) -> 0
+func sh64(n int64) int64 {
+ if n < 0 {
+ return n
+ }
+ return n >> 63 // ERROR "Proved Rsh64x64 shifts to zero"
+}
+
+func sh32(n int32) int32 {
+ if n < 0 {
+ return n
+ }
+ return n >> 31 // ERROR "Proved Rsh32x64 shifts to zero"
+}
+
+func sh32x64(n int32) int32 {
+ if n < 0 {
+ return n
+ }
+ return n >> uint64(31) // ERROR "Proved Rsh32x64 shifts to zero"
+}
+
+func sh16(n int16) int16 {
+ if n < 0 {
+ return n
+ }
+ return n >> 15 // ERROR "Proved Rsh16x64 shifts to zero"
+}
+
+func sh64noopt(n int64) int64 {
+ return n >> 63 // not optimized; n could be negative
+}
+
+// These cases are division of a positive signed integer by a power of 2.
+// The opt pass doesnt have sufficient information to see that n is positive.
+// So, instead, opt rewrites the division with a less-than-optimal replacement.
+// Prove, which can see that n is nonnegative, cannot see the division because
+// opt, an earlier pass, has already replaced it.
+// The fix for this issue allows prove to zero a right shift that was added as
+// part of the less-than-optimal reqwrite. That change by prove then allows
+// lateopt to clean up all the unneccesary parts of the original division
+// replacement. See issue #36159.
+func divShiftClean(n int) int {
+ if n < 0 {
+ return n
+ }
+ return n / int(8) // ERROR "Proved Rsh64x64 shifts to zero"
+}
+
+func divShiftClean64(n int64) int64 {
+ if n < 0 {
+ return n
+ }
+ return n / int64(16) // ERROR "Proved Rsh64x64 shifts to zero"
+}
+
+func divShiftClean32(n int32) int32 {
+ if n < 0 {
+ return n
+ }
+ return n / int32(16) // ERROR "Proved Rsh32x64 shifts to zero"
+}
+
+//go:noinline
+func useInt(a int) {
+}
+
+//go:noinline
+func useSlice(a []int) {
+}
+
+func main() {
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-12 16:22:51 +0000