[dev.ssa] cmd/compile: added floating point to [u]int conversions
Change-Id: I8dee400aef07165f911750de2615b8757f826000
Reviewed-on: https://go-review.googlesource.com/13945
Reviewed-by: Keith Randall <khr@golang.org>
diff --git a/src/cmd/compile/internal/gc/ssa.go b/src/cmd/compile/internal/gc/ssa.go
index 0194a52..5614a6c 100644
--- a/src/cmd/compile/internal/gc/ssa.go
+++ b/src/cmd/compile/internal/gc/ssa.go
@@ -1253,7 +1253,6 @@
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 @@
if !ft.IsSigned() {
signedSize += 5
}
+ var op1, op2 ssa.Op
switch signedSize {
case 1:
op1 = ssa.OpSignExt8to32
@@ -1315,6 +1315,72 @@
}
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 @@
}
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 @@
// 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 @@
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,
diff --git a/src/cmd/compile/internal/gc/testdata/fp_ssa.go b/src/cmd/compile/internal/gc/testdata/fp_ssa.go
index 5eb6503..c9eb23d 100644
--- a/src/cmd/compile/internal/gc/testdata/fp_ssa.go
+++ b/src/cmd/compile/internal/gc/testdata/fp_ssa.go
@@ -1052,6 +1052,222 @@
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 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 @@
fails += expectUint64("gt", gt, 0x0000100011000000)
}
+ fails += floatingToIntegerConversionsTest()
+
if fails > 0 {
fmt.Printf("Saw %v failures\n", fails)
panic("Failed.")
