]> Cypherpunks repositories - gostls13.git/commitdiff
[dev.ssa] cmd/compile: added floating point to [u]int conversions
authorDavid Chase <drchase@google.com>
Wed, 26 Aug 2015 18:25:40 +0000 (14:25 -0400)
committerDavid Chase <drchase@google.com>
Fri, 28 Aug 2015 21:46:39 +0000 (21:46 +0000)
Change-Id: I8dee400aef07165f911750de2615b8757f826000
Reviewed-on: https://go-review.googlesource.com/13945
Reviewed-by: Keith Randall <khr@golang.org>
src/cmd/compile/internal/gc/ssa.go
src/cmd/compile/internal/gc/testdata/fp_ssa.go

index 0194a52c2bd34aa3c378afcb499498e397a53946..5614a6c3b9024214d6cad48ff86a3a468d48a086 100644 (file)
@@ -1253,7 +1253,6 @@ func (s *state) expr(n *Node) *ssa.Value {
                        return s.newValue1(op, n.Type, x)
                }
 
-               var op1, op2 ssa.Op
                if ft.IsInteger() && tt.IsFloat() {
                        // signed 1, 2, 4, 8, unsigned 6, 7, 9, 13
                        signedSize := ft.Size()
@@ -1261,6 +1260,7 @@ func (s *state) expr(n *Node) *ssa.Value {
                        if !ft.IsSigned() {
                                signedSize += 5
                        }
+                       var op1, op2 ssa.Op
                        switch signedSize {
                        case 1:
                                op1 = ssa.OpSignExt8to32
@@ -1315,6 +1315,72 @@ func (s *state) expr(n *Node) *ssa.Value {
                        }
                        return s.newValue1(op2, n.Type, s.newValue1(op1, Types[it], x))
                }
+
+               if tt.IsInteger() && ft.IsFloat() {
+                       // signed 1, 2, 4, 8, unsigned 6, 7, 9, 13
+                       signedSize := tt.Size()
+                       it := TINT32 // intermediate type in conversion, int32 or int64
+                       if !tt.IsSigned() {
+                               signedSize += 5
+                       }
+                       var op1, op2 ssa.Op
+                       switch signedSize {
+                       case 1:
+                               op2 = ssa.OpTrunc32to8
+                       case 2:
+                               op2 = ssa.OpTrunc32to16
+                       case 4:
+                               op2 = ssa.OpCopy
+                       case 8:
+                               op2 = ssa.OpCopy
+                               it = TINT64
+                       case 6:
+                               op2 = ssa.OpTrunc32to8
+                       case 7:
+                               op2 = ssa.OpTrunc32to16
+                       case 9:
+                               // Go wide to dodge the unsignedness correction
+                               op2 = ssa.OpTrunc64to32
+                               it = TINT64
+                       case 13:
+                               // unsigned 64, branchy correction code is needed
+                               // because there is only FP to signed-integer
+                               // conversion in the (AMD64) instructions set.
+                               // Branchy correction code *may* be amenable to
+                               // optimization, and it can be cleanly expressed
+                               // in generic SSA, so do it here.
+                               if ft.Size() == 4 {
+                                       return s.float32ToUint64(n, x, ft, tt)
+                               }
+                               if ft.Size() == 8 {
+                                       return s.float64ToUint64(n, x, ft, tt)
+                               }
+                               // unrecognized size is also "weird", hence fatal.
+                               fallthrough
+
+                       default:
+                               s.Fatalf("weird float to integer conversion %s -> %s", ft, tt)
+
+                       }
+                       if ft.Size() == 4 {
+                               if it == TINT64 {
+                                       op1 = ssa.OpCvt32Fto64
+                               } else {
+                                       op1 = ssa.OpCvt32Fto32
+                               }
+                       } else {
+                               if it == TINT64 {
+                                       op1 = ssa.OpCvt64Fto64
+                               } else {
+                                       op1 = ssa.OpCvt64Fto32
+                               }
+                       }
+                       if op2 == ssa.OpCopy {
+                               return s.newValue1(op1, n.Type, x)
+                       }
+                       return s.newValue1(op2, n.Type, s.newValue1(op1, Types[it], x))
+               }
+
                if ft.IsFloat() && tt.IsFloat() {
                        var op ssa.Op
                        if ft.Size() == tt.Size() {
@@ -1328,7 +1394,7 @@ func (s *state) expr(n *Node) *ssa.Value {
                        }
                        return s.newValue1(op, n.Type, x)
                }
-               // TODO: Still lack float-to-int
+               // TODO: Still lack complex conversions.
 
                s.Unimplementedf("unhandled OCONV %s -> %s", Econv(int(n.Left.Type.Etype), 0), Econv(int(n.Type.Etype), 0))
                return nil
@@ -1981,8 +2047,8 @@ func (s *state) uintTofloat(cvttab *u2fcvtTab, n *Node, x *ssa.Value, ft, tt *Ty
        //        z = uintX(x) ; z = z >> 1
        //        z = z >> 1
        //        z = z | y
-       //        result = (floatY) z
-       //        z = z + z
+       //        result = floatY(z)
+       //        result = result + result
        // }
        //
        // Code borrowed from old code generator.
@@ -2068,6 +2134,72 @@ func (s *state) lenMap(n *Node, x *ssa.Value) *ssa.Value {
        return s.variable(n, lenType)
 }
 
+type f2uCvtTab struct {
+       ltf, cvt2U, subf ssa.Op
+       value            func(*state, ssa.Type, float64) *ssa.Value
+}
+
+var f32_u64 f2uCvtTab = f2uCvtTab{
+       ltf:   ssa.OpLess32F,
+       cvt2U: ssa.OpCvt32Fto64,
+       subf:  ssa.OpSub32F,
+       value: (*state).constFloat32,
+}
+
+var f64_u64 f2uCvtTab = f2uCvtTab{
+       ltf:   ssa.OpLess64F,
+       cvt2U: ssa.OpCvt64Fto64,
+       subf:  ssa.OpSub64F,
+       value: (*state).constFloat64,
+}
+
+func (s *state) float32ToUint64(n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value {
+       return s.floatToUint(&f32_u64, n, x, ft, tt)
+}
+func (s *state) float64ToUint64(n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value {
+       return s.floatToUint(&f64_u64, n, x, ft, tt)
+}
+
+func (s *state) floatToUint(cvttab *f2uCvtTab, n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value {
+       // if x < 9223372036854775808.0 {
+       //      result = uintY(x)
+       // } else {
+       //      y = x - 9223372036854775808.0
+       //      z = uintY(y)
+       //      result = z | -9223372036854775808
+       // }
+       twoToThe63 := cvttab.value(s, ft, 9223372036854775808.0)
+       cmp := s.newValue2(cvttab.ltf, Types[TBOOL], x, twoToThe63)
+       b := s.endBlock()
+       b.Kind = ssa.BlockIf
+       b.Control = cmp
+       b.Likely = ssa.BranchLikely
+
+       bThen := s.f.NewBlock(ssa.BlockPlain)
+       bElse := s.f.NewBlock(ssa.BlockPlain)
+       bAfter := s.f.NewBlock(ssa.BlockPlain)
+
+       addEdge(b, bThen)
+       s.startBlock(bThen)
+       a0 := s.newValue1(cvttab.cvt2U, tt, x)
+       s.vars[n] = a0
+       s.endBlock()
+       addEdge(bThen, bAfter)
+
+       addEdge(b, bElse)
+       s.startBlock(bElse)
+       y := s.newValue2(cvttab.subf, ft, x, twoToThe63)
+       y = s.newValue1(cvttab.cvt2U, tt, y)
+       z := s.constInt64(tt, -9223372036854775808)
+       a1 := s.newValue2(ssa.OpOr64, tt, y, z)
+       s.vars[n] = a1
+       s.endBlock()
+       addEdge(bElse, bAfter)
+
+       s.startBlock(bAfter)
+       return s.variable(n, n.Type)
+}
+
 // checkgoto checks that a goto from from to to does not
 // jump into a block or jump over variable declarations.
 // It is a copy of checkgoto in the pre-SSA backend,
index 5eb65035d4954185bcc4a335795356ef41fdc8c3..c9eb23d371f92c96993dcb17ccd47fa824e77189 100644 (file)
@@ -1052,6 +1052,222 @@ func gtbr32_ssa(x, y float32) float32 {
        return 42
 }
 
+func F32toU8_ssa(x float32) uint8 {
+       switch {
+       }
+       return uint8(x)
+}
+
+func F32toI8_ssa(x float32) int8 {
+       switch {
+       }
+       return int8(x)
+}
+
+func F32toU16_ssa(x float32) uint16 {
+       switch {
+       }
+       return uint16(x)
+}
+
+func F32toI16_ssa(x float32) int16 {
+       switch {
+       }
+       return int16(x)
+}
+
+func F32toU32_ssa(x float32) uint32 {
+       switch {
+       }
+       return uint32(x)
+}
+
+func F32toI32_ssa(x float32) int32 {
+       switch {
+       }
+       return int32(x)
+}
+
+func F32toU64_ssa(x float32) uint64 {
+       switch {
+       }
+       return uint64(x)
+}
+
+func F32toI64_ssa(x float32) int64 {
+       switch {
+       }
+       return int64(x)
+}
+
+func F64toU8_ssa(x float64) uint8 {
+       switch {
+       }
+       return uint8(x)
+}
+
+func F64toI8_ssa(x float64) int8 {
+       switch {
+       }
+       return int8(x)
+}
+
+func F64toU16_ssa(x float64) uint16 {
+       switch {
+       }
+       return uint16(x)
+}
+
+func F64toI16_ssa(x float64) int16 {
+       switch {
+       }
+       return int16(x)
+}
+
+func F64toU32_ssa(x float64) uint32 {
+       switch {
+       }
+       return uint32(x)
+}
+
+func F64toI32_ssa(x float64) int32 {
+       switch {
+       }
+       return int32(x)
+}
+
+func F64toU64_ssa(x float64) uint64 {
+       switch {
+       }
+       return uint64(x)
+}
+
+func F64toI64_ssa(x float64) int64 {
+       switch {
+       }
+       return int64(x)
+}
+
+func floatsToInts(x float64, expected int64) int {
+       y := float32(x)
+       fails := 0
+       fails += expectInt64("F64toI8", int64(F64toI8_ssa(x)), expected)
+       fails += expectInt64("F64toI16", int64(F64toI16_ssa(x)), expected)
+       fails += expectInt64("F64toI32", int64(F64toI32_ssa(x)), expected)
+       fails += expectInt64("F64toI64", int64(F64toI64_ssa(x)), expected)
+       fails += expectInt64("F32toI8", int64(F32toI8_ssa(y)), expected)
+       fails += expectInt64("F32toI16", int64(F32toI16_ssa(y)), expected)
+       fails += expectInt64("F32toI32", int64(F32toI32_ssa(y)), expected)
+       fails += expectInt64("F32toI64", int64(F32toI64_ssa(y)), expected)
+       return fails
+}
+
+func floatsToUints(x float64, expected uint64) int {
+       y := float32(x)
+       fails := 0
+       fails += expectUint64("F64toU8", uint64(F64toU8_ssa(x)), expected)
+       fails += expectUint64("F64toU16", uint64(F64toU16_ssa(x)), expected)
+       fails += expectUint64("F64toU32", uint64(F64toU32_ssa(x)), expected)
+       fails += expectUint64("F64toU64", uint64(F64toU64_ssa(x)), expected)
+       fails += expectUint64("F32toU8", uint64(F32toU8_ssa(y)), expected)
+       fails += expectUint64("F32toU16", uint64(F32toU16_ssa(y)), expected)
+       fails += expectUint64("F32toU32", uint64(F32toU32_ssa(y)), expected)
+       fails += expectUint64("F32toU64", uint64(F32toU64_ssa(y)), expected)
+       return fails
+}
+
+func floatingToIntegerConversionsTest() int {
+       fails := 0
+       fails += floatsToInts(0.0, 0)
+       fails += floatsToInts(1.0, 1)
+       fails += floatsToInts(127.0, 127)
+       fails += floatsToInts(-1.0, -1)
+       fails += floatsToInts(-128.0, -128)
+
+       fails += floatsToUints(0.0, 0)
+       fails += floatsToUints(1.0, 1)
+       fails += floatsToUints(255.0, 255)
+
+       for j := uint(0); j < 24; j++ {
+               // Avoid hard cases in the construction
+               // of the test inputs.
+               v := int64(1<<62) | int64(1<<(62-j))
+               w := uint64(v)
+               f := float32(v)
+               d := float64(v)
+               fails += expectUint64("2**62...", F32toU64_ssa(f), w)
+               fails += expectUint64("2**62...", F64toU64_ssa(d), w)
+               fails += expectInt64("2**62...", F32toI64_ssa(f), v)
+               fails += expectInt64("2**62...", F64toI64_ssa(d), v)
+               fails += expectInt64("2**62...", F32toI64_ssa(-f), -v)
+               fails += expectInt64("2**62...", F64toI64_ssa(-d), -v)
+               w += w
+               f += f
+               d += d
+               fails += expectUint64("2**63...", F32toU64_ssa(f), w)
+               fails += expectUint64("2**63...", F64toU64_ssa(d), w)
+       }
+
+       for j := uint(0); j < 16; j++ {
+               // Avoid hard cases in the construction
+               // of the test inputs.
+               v := int32(1<<30) | int32(1<<(30-j))
+               w := uint32(v)
+               f := float32(v)
+               d := float64(v)
+               fails += expectUint32("2**30...", F32toU32_ssa(f), w)
+               fails += expectUint32("2**30...", F64toU32_ssa(d), w)
+               fails += expectInt32("2**30...", F32toI32_ssa(f), v)
+               fails += expectInt32("2**30...", F64toI32_ssa(d), v)
+               fails += expectInt32("2**30...", F32toI32_ssa(-f), -v)
+               fails += expectInt32("2**30...", F64toI32_ssa(-d), -v)
+               w += w
+               f += f
+               d += d
+               fails += expectUint32("2**31...", F32toU32_ssa(f), w)
+               fails += expectUint32("2**31...", F64toU32_ssa(d), w)
+       }
+
+       for j := uint(0); j < 15; j++ {
+               // Avoid hard cases in the construction
+               // of the test inputs.
+               v := int16(1<<14) | int16(1<<(14-j))
+               w := uint16(v)
+               f := float32(v)
+               d := float64(v)
+               fails += expectUint16("2**14...", F32toU16_ssa(f), w)
+               fails += expectUint16("2**14...", F64toU16_ssa(d), w)
+               fails += expectInt16("2**14...", F32toI16_ssa(f), v)
+               fails += expectInt16("2**14...", F64toI16_ssa(d), v)
+               fails += expectInt16("2**14...", F32toI16_ssa(-f), -v)
+               fails += expectInt16("2**14...", F64toI16_ssa(-d), -v)
+               w += w
+               f += f
+               d += d
+               fails += expectUint16("2**15...", F32toU16_ssa(f), w)
+               fails += expectUint16("2**15...", F64toU16_ssa(d), w)
+       }
+
+       fails += expectInt32("-2147483648", F32toI32_ssa(-2147483648), -2147483648)
+
+       fails += expectInt32("-2147483648", F64toI32_ssa(-2147483648), -2147483648)
+       fails += expectInt32("-2147483647", F64toI32_ssa(-2147483647), -2147483647)
+       fails += expectUint32("4294967295", F64toU32_ssa(4294967295), 4294967295)
+
+       fails += expectInt16("-32768", F64toI16_ssa(-32768), -32768)
+       fails += expectInt16("-32768", F32toI16_ssa(-32768), -32768)
+
+       // NB more of a pain to do these for 32-bit because of lost bits in Float32 mantissa
+       fails += expectInt16("32767", F64toI16_ssa(32767), 32767)
+       fails += expectInt16("32767", F32toI16_ssa(32767), 32767)
+       fails += expectUint16("32767", F64toU16_ssa(32767), 32767)
+       fails += expectUint16("32767", F32toU16_ssa(32767), 32767)
+       fails += expectUint16("65535", F64toU16_ssa(65535), 65535)
+       fails += expectUint16("65535", F32toU16_ssa(65535), 65535)
+
+       return fails
+}
+
 func fail64(s string, f func(a, b float64) float64, a, b, e float64) int {
        d := f(a, b)
        if d != e {
@@ -1106,7 +1322,47 @@ func expect32(s string, x, expected float32) int {
 
 func expectUint64(s string, x, expected uint64) int {
        if x != expected {
-               fmt.Printf("Expected 0x%016x for %s, got 0x%016x\n", expected, s, x)
+               fmt.Printf("%s: Expected 0x%016x, got 0x%016x\n", s, expected, x)
+               return 1
+       }
+       return 0
+}
+
+func expectInt64(s string, x, expected int64) int {
+       if x != expected {
+               fmt.Printf("%s: Expected 0x%016x, got 0x%016x\n", s, expected, x)
+               return 1
+       }
+       return 0
+}
+
+func expectUint32(s string, x, expected uint32) int {
+       if x != expected {
+               fmt.Printf("U32 %s: Expected 0x%08x, got 0x%08x\n", s, expected, x)
+               return 1
+       }
+       return 0
+}
+
+func expectInt32(s string, x, expected int32) int {
+       if x != expected {
+               fmt.Printf("I32 %s: Expected 0x%08x, got 0x%08x\n", s, expected, x)
+               return 1
+       }
+       return 0
+}
+
+func expectUint16(s string, x, expected uint16) int {
+       if x != expected {
+               fmt.Printf("U16 %s: Expected 0x%04x, got 0x%04x\n", s, expected, x)
+               return 1
+       }
+       return 0
+}
+
+func expectInt16(s string, x, expected int16) int {
+       if x != expected {
+               fmt.Printf("I16 %s: Expected 0x%04x, got 0x%04x\n", s, expected, x)
                return 1
        }
        return 0
@@ -1266,6 +1522,8 @@ func main() {
                fails += expectUint64("gt", gt, 0x0000100011000000)
        }
 
+       fails += floatingToIntegerConversionsTest()
+
        if fails > 0 {
                fmt.Printf("Saw %v failures\n", fails)
                panic("Failed.")