diff --git a/src/cmd/compile/internal/ssa/prove.go b/src/cmd/compile/internal/ssa/prove.go index 5ed5be47443..b4f91fd4fd1 100644 --- a/src/cmd/compile/internal/ssa/prove.go +++ b/src/cmd/compile/internal/ssa/prove.go @@ -2529,24 +2529,38 @@ func simplifyBlock(sdom SparseTree, ft *factsTable, b *Block) { switch v.Op { case OpSlicemask: // Replace OpSlicemask operations in b with constants where possible. - x, delta := isConstDelta(v.Args[0]) - if x == nil { + cap := v.Args[0] + x, delta := isConstDelta(cap) + if x != nil { + // slicemask(x + y) + // if x is larger than -y (y is negative), then slicemask is -1. + lim := ft.limits[x.ID] + if lim.umin > uint64(-delta) { + if cap.Op == OpAdd64 { + v.reset(OpConst64) + } else { + v.reset(OpConst32) + } + if b.Func.pass.debug > 0 { + b.Func.Warnl(v.Pos, "Proved slicemask not needed") + } + v.AuxInt = -1 + } break } - // slicemask(x + y) - // if x is larger than -y (y is negative), then slicemask is -1. - lim := ft.limits[x.ID] - if lim.umin > uint64(-delta) { - if v.Args[0].Op == OpAdd64 { + lim := ft.limits[cap.ID] + if lim.umin > 0 { + if cap.Type.Size() == 8 { v.reset(OpConst64) } else { v.reset(OpConst32) } if b.Func.pass.debug > 0 { - b.Func.Warnl(v.Pos, "Proved slicemask not needed") + b.Func.Warnl(v.Pos, "Proved slicemask not needed (by limit)") } v.AuxInt = -1 } + case OpCtz8, OpCtz16, OpCtz32, OpCtz64: // On some architectures, notably amd64, we can generate much better // code for CtzNN if we know that the argument is non-zero. diff --git a/test/loopbce.go b/test/loopbce.go index 8bc44ece945..8a58d942361 100644 --- a/test/loopbce.go +++ b/test/loopbce.go @@ -9,7 +9,7 @@ import "math" func f0a(a []int) int { x := 0 for i := range a { // ERROR "Induction variable: limits \[0,\?\), increment 1$" - x += a[i] // ERROR "(\([0-9]+\) )?Proved IsInBounds$" + x += a[i] // ERROR "Proved IsInBounds$" } return x } @@ -17,7 +17,7 @@ func f0a(a []int) int { func f0b(a []int) int { x := 0 for i := range a { // ERROR "Induction variable: limits \[0,\?\), increment 1$" - b := a[i:] // ERROR "(\([0-9]+\) )?Proved IsSliceInBounds$" + b := a[i:] // ERROR "Proved IsSliceInBounds$" x += b[0] } return x @@ -26,8 +26,8 @@ func f0b(a []int) int { func f0c(a []int) int { x := 0 for i := range a { // ERROR "Induction variable: limits \[0,\?\), increment 1$" - b := a[:i+1] // ERROR "(\([0-9]+\) )?Proved IsSliceInBounds$" - x += b[0] // ERROR "(\([0-9]+\) )?Proved IsInBounds$" + b := a[:i+1] // ERROR "Proved IsSliceInBounds$" + x += b[0] // ERROR "Proved IsInBounds$" } return x } @@ -43,7 +43,7 @@ func f1(a []int) int { func f2(a []int) int { x := 0 for i := 1; i < len(a); i++ { // ERROR "Induction variable: limits \[1,\?\), increment 1$" - x += a[i] // ERROR "(\([0-9]+\) )?Proved IsInBounds$" + x += a[i] // ERROR "Proved IsInBounds$" } return x } @@ -51,7 +51,7 @@ func f2(a []int) int { func f4(a [10]int) int { x := 0 for i := 0; i < len(a); i += 2 { // ERROR "Induction variable: limits \[0,8\], increment 2$" - x += a[i] // ERROR "(\([0-9]+\) )?Proved IsInBounds$" + x += a[i] // ERROR "Proved IsInBounds$" } return x } @@ -91,7 +91,7 @@ func f5_int8(a [10]int) int { //go:noinline func f6(a []int) { for i := range a { // ERROR "Induction variable: limits \[0,\?\), increment 1$" - b := a[0:i] // ERROR "(\([0-9]+\) )?Proved IsSliceInBounds$" + b := a[0:i] // ERROR "Proved IsSliceInBounds$" f6(b) } } @@ -99,7 +99,7 @@ func f6(a []int) { func g0a(a string) int { x := 0 for i := 0; i < len(a); i++ { // ERROR "Induction variable: limits \[0,\?\), increment 1$" - x += int(a[i]) // ERROR "(\([0-9]+\) )?Proved IsInBounds$" + x += int(a[i]) // ERROR "Proved IsInBounds$" } return x } @@ -107,7 +107,7 @@ func g0a(a string) int { func g0b(a string) int { x := 0 for i := 0; len(a) > i; i++ { // ERROR "Induction variable: limits \[0,\?\), increment 1$" - x += int(a[i]) // ERROR "(\([0-9]+\) )?Proved IsInBounds$" + x += int(a[i]) // ERROR "Proved IsInBounds$" } return x } @@ -115,7 +115,7 @@ func g0b(a string) int { func g0c(a string) int { x := 0 for i := len(a); i > 0; i-- { // ERROR "Induction variable: limits \(0,\?\], increment 1$" - x += int(a[i-1]) // ERROR "(\([0-9]+\) )?Proved IsInBounds$" + x += int(a[i-1]) // ERROR "Proved IsInBounds$" } return x } @@ -123,7 +123,7 @@ func g0c(a string) int { func g0d(a string) int { x := 0 for i := len(a); 0 < i; i-- { // ERROR "Induction variable: limits \(0,\?\], increment 1$" - x += int(a[i-1]) // ERROR "(\([0-9]+\) )?Proved IsInBounds$" + x += int(a[i-1]) // ERROR "Proved IsInBounds$" } return x } @@ -131,7 +131,7 @@ func g0d(a string) int { func g0e(a string) int { x := 0 for i := len(a) - 1; i >= 0; i-- { // ERROR "Induction variable: limits \[0,\?\], increment 1$" - x += int(a[i]) // ERROR "(\([0-9]+\) )?Proved IsInBounds$" + x += int(a[i]) // ERROR "Proved IsInBounds$" } return x } @@ -139,7 +139,7 @@ func g0e(a string) int { func g0f(a string) int { x := 0 for i := len(a) - 1; 0 <= i; i-- { // ERROR "Induction variable: limits \[0,\?\], increment 1$" - x += int(a[i]) // ERROR "(\([0-9]+\) )?Proved IsInBounds$" + x += int(a[i]) // ERROR "Proved IsInBounds$" } return x } @@ -148,7 +148,7 @@ func g1() int { a := "evenlength" x := 0 for i := 0; i < len(a); i += 2 { // ERROR "Induction variable: limits \[0,8\], increment 2$" - x += int(a[i]) // ERROR "(\([0-9]+\) )?Proved IsInBounds$" + x += int(a[i]) // ERROR "Proved IsInBounds$" } return x } @@ -158,7 +158,7 @@ func g2() int { x := 0 for i := 0; i < len(a); i += 2 { // ERROR "Induction variable: limits \[0,8\], increment 2$" j := i - if a[i] == 'e' { // ERROR "(\([0-9]+\) )?Proved IsInBounds$" + if a[i] == 'e' { // ERROR "Proved IsInBounds$" j = j + 1 } x += int(a[j]) @@ -169,29 +169,29 @@ func g2() int { func g3a() { a := "this string has length 25" for i := 0; i < len(a); i += 5 { // ERROR "Induction variable: limits \[0,20\], increment 5$" - useString(a[i:]) // ERROR "(\([0-9]+\) )?Proved IsSliceInBounds$" - useString(a[:i+3]) // ERROR "(\([0-9]+\) )?Proved IsSliceInBounds$" - useString(a[:i+5]) // ERROR "(\([0-9]+\) )?Proved IsSliceInBounds$" + useString(a[i:]) // ERROR "Proved IsSliceInBounds$" "Proved slicemask not needed \(by limit\)$" + useString(a[:i+3]) // ERROR "Proved IsSliceInBounds$" + useString(a[:i+5]) // ERROR "Proved IsSliceInBounds$" useString(a[:i+6]) } } func g3b(a string) { for i := 0; i < len(a); i++ { // ERROR "Induction variable: limits \[0,\?\), increment 1$" - useString(a[i+1:]) // ERROR "(\([0-9]+\) )?Proved IsSliceInBounds$" + useString(a[i+1:]) // ERROR "Proved IsSliceInBounds$" } } func g3c(a string) { for i := 0; i < len(a); i++ { // ERROR "Induction variable: limits \[0,\?\), increment 1$" - useString(a[:i+1]) // ERROR "(\([0-9]+\) )?Proved IsSliceInBounds$" + useString(a[:i+1]) // ERROR "Proved IsSliceInBounds$" } } func h1(a []byte) { c := a[:128] for i := range c { // ERROR "Induction variable: limits \[0,128\), increment 1$" - c[i] = byte(i) // ERROR "(\([0-9]+\) )?Proved IsInBounds$" + c[i] = byte(i) // ERROR "Proved IsInBounds$" } } @@ -208,11 +208,11 @@ func k0(a [100]int) [100]int { continue } a[i-11] = i - a[i-10] = i // ERROR "(\([0-9]+\) )?Proved IsInBounds$" - a[i-5] = i // ERROR "(\([0-9]+\) )?Proved IsInBounds$" - a[i] = i // ERROR "(\([0-9]+\) )?Proved IsInBounds$" - a[i+5] = i // ERROR "(\([0-9]+\) )?Proved IsInBounds$" - a[i+10] = i // ERROR "(\([0-9]+\) )?Proved IsInBounds$" + a[i-10] = i // ERROR "Proved IsInBounds$" + a[i-5] = i // ERROR "Proved IsInBounds$" + a[i] = i // ERROR "Proved IsInBounds$" + a[i+5] = i // ERROR "Proved IsInBounds$" + a[i+10] = i // ERROR "Proved IsInBounds$" a[i+11] = i } return a @@ -225,12 +225,12 @@ func k1(a [100]int) [100]int { continue } useSlice(a[:i-11]) - useSlice(a[:i-10]) // ERROR "(\([0-9]+\) )?Proved IsSliceInBounds$" - useSlice(a[:i-5]) // ERROR "(\([0-9]+\) )?Proved IsSliceInBounds$" - useSlice(a[:i]) // ERROR "(\([0-9]+\) )?Proved IsSliceInBounds$" - useSlice(a[:i+5]) // ERROR "(\([0-9]+\) )?Proved IsSliceInBounds$" - useSlice(a[:i+10]) // ERROR "(\([0-9]+\) )?Proved IsSliceInBounds$" - useSlice(a[:i+11]) // ERROR "(\([0-9]+\) )?Proved IsSliceInBounds$" + useSlice(a[:i-10]) // ERROR "Proved IsSliceInBounds$" + useSlice(a[:i-5]) // ERROR "Proved IsSliceInBounds$" + useSlice(a[:i]) // ERROR "Proved IsSliceInBounds$" + useSlice(a[:i+5]) // ERROR "Proved IsSliceInBounds$" + useSlice(a[:i+10]) // ERROR "Proved IsSliceInBounds$" + useSlice(a[:i+11]) // ERROR "Proved IsSliceInBounds$" useSlice(a[:i+12]) } @@ -243,13 +243,13 @@ func k2(a [100]int) [100]int { // This is a trick to prohibit sccp to optimize out the following out of bound check continue } - useSlice(a[i-11:]) - useSlice(a[i-10:]) // ERROR "(\([0-9]+\) )?Proved IsSliceInBounds$" - useSlice(a[i-5:]) // ERROR "(\([0-9]+\) )?Proved IsSliceInBounds$" - useSlice(a[i:]) // ERROR "(\([0-9]+\) )?Proved IsSliceInBounds$" - useSlice(a[i+5:]) // ERROR "(\([0-9]+\) )?Proved IsSliceInBounds$" - useSlice(a[i+10:]) // ERROR "(\([0-9]+\) )?Proved IsSliceInBounds$" - useSlice(a[i+11:]) // ERROR "(\([0-9]+\) )?Proved IsSliceInBounds$" + useSlice(a[i-11:]) // ERROR "Proved slicemask not needed \(by limit\)$" + useSlice(a[i-10:]) // ERROR "Proved IsSliceInBounds$" "Proved slicemask not needed \(by limit\)$" + useSlice(a[i-5:]) // ERROR "Proved IsSliceInBounds$" "Proved slicemask not needed \(by limit\)$" + useSlice(a[i:]) // ERROR "Proved IsSliceInBounds$" "Proved slicemask not needed \(by limit\)$" + useSlice(a[i+5:]) // ERROR "Proved IsSliceInBounds$" "Proved slicemask not needed \(by limit\)$" + useSlice(a[i+10:]) // ERROR "Proved IsSliceInBounds$" "Proved slicemask not needed \(by limit\)$" + useSlice(a[i+11:]) // ERROR "Proved IsSliceInBounds$" useSlice(a[i+12:]) } return a @@ -262,7 +262,7 @@ func k3(a [100]int) [100]int { continue } a[i+9] = i - a[i+10] = i // ERROR "(\([0-9]+\) )?Proved IsInBounds$" + a[i+10] = i // ERROR "Proved IsInBounds$" a[i+11] = i } return a @@ -275,7 +275,7 @@ func k3neg(a [100]int) [100]int { continue } a[i+9] = i - a[i+10] = i // ERROR "(\([0-9]+\) )?Proved IsInBounds$" + a[i+10] = i // ERROR "Proved IsInBounds$" a[i+11] = i } return a @@ -288,7 +288,7 @@ func k3neg2(a [100]int) [100]int { continue } a[i+9] = i - a[i+10] = i // ERROR "(\([0-9]+\) )?Proved IsInBounds$" + a[i+10] = i // ERROR "Proved IsInBounds$" a[i+11] = i } return a @@ -299,7 +299,7 @@ func k4(a [100]int) [100]int { // and it isn't worth adding that special case to prove. min := (-1)<<63 + 1 for i := min; i < min+50; i++ { // ERROR "Induction variable: limits \[-9223372036854775807,-9223372036854775757\), increment 1$" - a[i-min] = i // ERROR "(\([0-9]+\) )?Proved IsInBounds$" + a[i-min] = i // ERROR "Proved IsInBounds$" } return a } @@ -307,8 +307,8 @@ func k4(a [100]int) [100]int { func k5(a [100]int) [100]int { max := (1 << 63) - 1 for i := max - 50; i < max; i++ { // ERROR "Induction variable: limits \[9223372036854775757,9223372036854775807\), increment 1$" - a[i-max+50] = i // ERROR "(\([0-9]+\) )?Proved IsInBounds$" - a[i-(max-70)] = i // ERROR "(\([0-9]+\) )?Proved IsInBounds$" + a[i-max+50] = i // ERROR "Proved IsInBounds$" + a[i-(max-70)] = i // ERROR "Proved IsInBounds$" } return a } @@ -374,22 +374,22 @@ func d4() { } func d5() { - for i := int64(math.MinInt64 + 9); i > math.MinInt64+2; i -= 4 { // ERROR "Induction variable: limits \[-9223372036854775803,-9223372036854775799\], increment 4" + for i := int64(math.MinInt64 + 9); i > math.MinInt64+2; i -= 4 { // ERROR "Induction variable: limits \[-9223372036854775803,-9223372036854775799\], increment 4$" useString("foo") } - for i := int64(math.MinInt64 + 8); i > math.MinInt64+2; i -= 4 { // ERROR "Induction variable: limits \[-9223372036854775804,-9223372036854775800\], increment 4" + for i := int64(math.MinInt64 + 8); i > math.MinInt64+2; i -= 4 { // ERROR "Induction variable: limits \[-9223372036854775804,-9223372036854775800\], increment 4$" useString("foo") } for i := int64(math.MinInt64 + 7); i > math.MinInt64+2; i -= 4 { useString("foo") } - for i := int64(math.MinInt64 + 6); i > math.MinInt64+2; i -= 4 { // ERROR "Induction variable: limits \[-9223372036854775802,-9223372036854775802\], increment 4" + for i := int64(math.MinInt64 + 6); i > math.MinInt64+2; i -= 4 { // ERROR "Induction variable: limits \[-9223372036854775802,-9223372036854775802\], increment 4$" useString("foo") } - for i := int64(math.MinInt64 + 9); i >= math.MinInt64+2; i -= 4 { // ERROR "Induction variable: limits \[-9223372036854775803,-9223372036854775799\], increment 4" + for i := int64(math.MinInt64 + 9); i >= math.MinInt64+2; i -= 4 { // ERROR "Induction variable: limits \[-9223372036854775803,-9223372036854775799\], increment 4$" useString("foo") } - for i := int64(math.MinInt64 + 8); i >= math.MinInt64+2; i -= 4 { // ERROR "Induction variable: limits \[-9223372036854775804,-9223372036854775800\], increment 4" + for i := int64(math.MinInt64 + 8); i >= math.MinInt64+2; i -= 4 { // ERROR "Induction variable: limits \[-9223372036854775804,-9223372036854775800\], increment 4$" useString("foo") } for i := int64(math.MinInt64 + 7); i >= math.MinInt64+2; i -= 4 { @@ -410,23 +410,23 @@ func bce1() { panic("invalid test: modulos should differ") } - for i := b; i < a; i += z { // ERROR "Induction variable: limits \[-1547,9223372036854772720\], increment 1337" + for i := b; i < a; i += z { // ERROR "Induction variable: limits \[-1547,9223372036854772720\], increment 1337$" useString("foobar") } } func nobce2(a string) { for i := int64(0); i < int64(len(a)); i++ { // ERROR "Induction variable: limits \[0,\?\), increment 1$" - useString(a[i:]) // ERROR "(\([0-9]+\) )?Proved IsSliceInBounds$" + useString(a[i:]) // ERROR "Proved IsSliceInBounds$" } for i := int64(0); i < int64(len(a))-31337; i++ { // ERROR "Induction variable: limits \[0,\?\), increment 1$" - useString(a[i:]) // ERROR "(\([0-9]+\) )?Proved IsSliceInBounds$" + useString(a[i:]) // ERROR "Proved IsSliceInBounds$" } - for i := int64(0); i < int64(len(a))+int64(-1<<63); i++ { // ERROR "Induction variable: limits \[0,\?\), increment 1$" "Disproved Less64" + for i := int64(0); i < int64(len(a))+int64(-1<<63); i++ { // ERROR "Disproved Less64$" "Induction variable: limits \[0,\?\), increment 1$" useString(a[i:]) } j := int64(len(a)) - 123 - for i := int64(0); i < j+123+int64(-1<<63); i++ { // ERROR "Induction variable: limits \[0,\?\), increment 1$" "Disproved Less64" + for i := int64(0); i < j+123+int64(-1<<63); i++ { // ERROR "Disproved Less64$" "Induction variable: limits \[0,\?\), increment 1$" useString(a[i:]) } for i := int64(0); i < j+122+int64(-1<<63); i++ { // ERROR "Induction variable: limits \[0,\?\), increment 1$" @@ -455,16 +455,16 @@ func issue26116a(a []int) { func stride1(x *[7]int) int { s := 0 - for i := 0; i <= 8; i += 3 { // ERROR "Induction variable: limits \[0,6\], increment 3" - s += x[i] // ERROR "Proved IsInBounds" + for i := 0; i <= 8; i += 3 { // ERROR "Induction variable: limits \[0,6\], increment 3$" + s += x[i] // ERROR "Proved IsInBounds$" } return s } func stride2(x *[7]int) int { s := 0 - for i := 0; i < 9; i += 3 { // ERROR "Induction variable: limits \[0,6\], increment 3" - s += x[i] // ERROR "Proved IsInBounds" + for i := 0; i < 9; i += 3 { // ERROR "Induction variable: limits \[0,6\], increment 3$" + s += x[i] // ERROR "Proved IsInBounds$" } return s }