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-rw-r--r--src/cmd/compile/internal/ssa/_gen/RISCV64.rules12
-rw-r--r--src/cmd/compile/internal/ssa/rewriteRISCV64.go257
-rw-r--r--src/cmd/compile/internal/test/float_test.go59
3 files changed, 328 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/ssa/_gen/RISCV64.rules b/src/cmd/compile/internal/ssa/_gen/RISCV64.rules
index 31829a5eed..646948f2df 100644
--- a/src/cmd/compile/internal/ssa/_gen/RISCV64.rules
+++ b/src/cmd/compile/internal/ssa/_gen/RISCV64.rules
@@ -834,6 +834,18 @@
(FEQD x (FMOVDconst [math.Inf(1)])) => (SNEZ (ANDI <typ.Int64> [0b00_1000_0000] (FCLASSD x)))
(FNED x (FMOVDconst [math.Inf(1)])) => (SEQZ (ANDI <typ.Int64> [0b00_1000_0000] (FCLASSD x)))
+// Test for subnormal numbers using 64 bit classify instruction.
+(FLTD x (FMOVDconst [+0x1p-1022])) => (SNEZ (ANDI <typ.Int64> [0b00_0011_1111] (FCLASSD x)))
+(FLED (FMOVDconst [+0x1p-1022]) x) => (SNEZ (ANDI <typ.Int64> [0b00_1100_0000] (FCLASSD x)))
+(FLED x (FMOVDconst [-0x1p-1022])) => (SNEZ (ANDI <typ.Int64> [0b00_0000_0011] (FCLASSD x)))
+(FLTD (FMOVDconst [-0x1p-1022]) x) => (SNEZ (ANDI <typ.Int64> [0b00_1111_1100] (FCLASSD x)))
+
+// Absorb unary sign bit operations into 64 bit classify instruction.
+(S(EQ|NE)Z (ANDI [c] (FCLASSD (FNEGD x)))) => (S(EQ|NE)Z (ANDI <typ.Int64> [(c&0b11_0000_0000)|int64(bits.Reverse8(uint8(c))&0b1111_1111)] (FCLASSD x)))
+(S(EQ|NE)Z (ANDI [c] (FCLASSD (FABSD x)))) => (S(EQ|NE)Z (ANDI <typ.Int64> [(c&0b11_1111_0000)|int64(bits.Reverse8(uint8(c))&0b0000_1111)] (FCLASSD x)))
+(B(EQ|NE)Z (ANDI [c] (FCLASSD (FNEGD x))) yes no) => (B(EQ|NE)Z (ANDI <typ.Int64> [(c&0b11_0000_0000)|int64(bits.Reverse8(uint8(c))&0b1111_1111)] (FCLASSD x)) yes no)
+(B(EQ|NE)Z (ANDI [c] (FCLASSD (FABSD x))) yes no) => (B(EQ|NE)Z (ANDI <typ.Int64> [(c&0b11_1111_0000)|int64(bits.Reverse8(uint8(c))&0b0000_1111)] (FCLASSD x)) yes no)
+
//
// Optimisations for rva22u64 and above.
//
diff --git a/src/cmd/compile/internal/ssa/rewriteRISCV64.go b/src/cmd/compile/internal/ssa/rewriteRISCV64.go
index 52870fe199..191c7b3d48 100644
--- a/src/cmd/compile/internal/ssa/rewriteRISCV64.go
+++ b/src/cmd/compile/internal/ssa/rewriteRISCV64.go
@@ -4,6 +4,7 @@ package ssa
import "internal/buildcfg"
import "math"
+import "math/bits"
import "cmd/compile/internal/types"
func rewriteValueRISCV64(v *Value) bool {
@@ -3657,6 +3658,38 @@ func rewriteValueRISCV64_OpRISCV64FLED(v *Value) bool {
v.AddArg(v0)
return true
}
+ // match: (FLED (FMOVDconst [+0x1p-1022]) x)
+ // result: (SNEZ (ANDI <typ.Int64> [0b00_1100_0000] (FCLASSD x)))
+ for {
+ if v_0.Op != OpRISCV64FMOVDconst || auxIntToFloat64(v_0.AuxInt) != +0x1p-1022 {
+ break
+ }
+ x := v_1
+ v.reset(OpRISCV64SNEZ)
+ v0 := b.NewValue0(v.Pos, OpRISCV64ANDI, typ.Int64)
+ v0.AuxInt = int64ToAuxInt(0b00_1100_0000)
+ v1 := b.NewValue0(v.Pos, OpRISCV64FCLASSD, typ.Int64)
+ v1.AddArg(x)
+ v0.AddArg(v1)
+ v.AddArg(v0)
+ return true
+ }
+ // match: (FLED x (FMOVDconst [-0x1p-1022]))
+ // result: (SNEZ (ANDI <typ.Int64> [0b00_0000_0011] (FCLASSD x)))
+ for {
+ x := v_0
+ if v_1.Op != OpRISCV64FMOVDconst || auxIntToFloat64(v_1.AuxInt) != -0x1p-1022 {
+ break
+ }
+ v.reset(OpRISCV64SNEZ)
+ v0 := b.NewValue0(v.Pos, OpRISCV64ANDI, typ.Int64)
+ v0.AuxInt = int64ToAuxInt(0b00_0000_0011)
+ v1 := b.NewValue0(v.Pos, OpRISCV64FCLASSD, typ.Int64)
+ v1.AddArg(x)
+ v0.AddArg(v1)
+ v.AddArg(v0)
+ return true
+ }
return false
}
func rewriteValueRISCV64_OpRISCV64FLTD(v *Value) bool {
@@ -3694,6 +3727,38 @@ func rewriteValueRISCV64_OpRISCV64FLTD(v *Value) bool {
v.AddArg(v0)
return true
}
+ // match: (FLTD x (FMOVDconst [+0x1p-1022]))
+ // result: (SNEZ (ANDI <typ.Int64> [0b00_0011_1111] (FCLASSD x)))
+ for {
+ x := v_0
+ if v_1.Op != OpRISCV64FMOVDconst || auxIntToFloat64(v_1.AuxInt) != +0x1p-1022 {
+ break
+ }
+ v.reset(OpRISCV64SNEZ)
+ v0 := b.NewValue0(v.Pos, OpRISCV64ANDI, typ.Int64)
+ v0.AuxInt = int64ToAuxInt(0b00_0011_1111)
+ v1 := b.NewValue0(v.Pos, OpRISCV64FCLASSD, typ.Int64)
+ v1.AddArg(x)
+ v0.AddArg(v1)
+ v.AddArg(v0)
+ return true
+ }
+ // match: (FLTD (FMOVDconst [-0x1p-1022]) x)
+ // result: (SNEZ (ANDI <typ.Int64> [0b00_1111_1100] (FCLASSD x)))
+ for {
+ if v_0.Op != OpRISCV64FMOVDconst || auxIntToFloat64(v_0.AuxInt) != -0x1p-1022 {
+ break
+ }
+ x := v_1
+ v.reset(OpRISCV64SNEZ)
+ v0 := b.NewValue0(v.Pos, OpRISCV64ANDI, typ.Int64)
+ v0.AuxInt = int64ToAuxInt(0b00_1111_1100)
+ v1 := b.NewValue0(v.Pos, OpRISCV64FCLASSD, typ.Int64)
+ v1.AddArg(x)
+ v0.AddArg(v1)
+ v.AddArg(v0)
+ return true
+ }
return false
}
func rewriteValueRISCV64_OpRISCV64FMADDD(v *Value) bool {
@@ -7056,6 +7121,8 @@ func rewriteValueRISCV64_OpRISCV64RORW(v *Value) bool {
}
func rewriteValueRISCV64_OpRISCV64SEQZ(v *Value) bool {
v_0 := v.Args[0]
+ b := v.Block
+ typ := &b.Func.Config.Types
// match: (SEQZ (NEG x))
// result: (SEQZ x)
for {
@@ -7089,6 +7156,56 @@ func rewriteValueRISCV64_OpRISCV64SEQZ(v *Value) bool {
v.AddArg(x)
return true
}
+ // match: (SEQZ (ANDI [c] (FCLASSD (FNEGD x))))
+ // result: (SEQZ (ANDI <typ.Int64> [(c&0b11_0000_0000)|int64(bits.Reverse8(uint8(c))&0b1111_1111)] (FCLASSD x)))
+ for {
+ if v_0.Op != OpRISCV64ANDI {
+ break
+ }
+ c := auxIntToInt64(v_0.AuxInt)
+ v_0_0 := v_0.Args[0]
+ if v_0_0.Op != OpRISCV64FCLASSD {
+ break
+ }
+ v_0_0_0 := v_0_0.Args[0]
+ if v_0_0_0.Op != OpRISCV64FNEGD {
+ break
+ }
+ x := v_0_0_0.Args[0]
+ v.reset(OpRISCV64SEQZ)
+ v0 := b.NewValue0(v.Pos, OpRISCV64ANDI, typ.Int64)
+ v0.AuxInt = int64ToAuxInt((c & 0b11_0000_0000) | int64(bits.Reverse8(uint8(c))&0b1111_1111))
+ v1 := b.NewValue0(v.Pos, OpRISCV64FCLASSD, typ.Int64)
+ v1.AddArg(x)
+ v0.AddArg(v1)
+ v.AddArg(v0)
+ return true
+ }
+ // match: (SEQZ (ANDI [c] (FCLASSD (FABSD x))))
+ // result: (SEQZ (ANDI <typ.Int64> [(c&0b11_1111_0000)|int64(bits.Reverse8(uint8(c))&0b0000_1111)] (FCLASSD x)))
+ for {
+ if v_0.Op != OpRISCV64ANDI {
+ break
+ }
+ c := auxIntToInt64(v_0.AuxInt)
+ v_0_0 := v_0.Args[0]
+ if v_0_0.Op != OpRISCV64FCLASSD {
+ break
+ }
+ v_0_0_0 := v_0_0.Args[0]
+ if v_0_0_0.Op != OpRISCV64FABSD {
+ break
+ }
+ x := v_0_0_0.Args[0]
+ v.reset(OpRISCV64SEQZ)
+ v0 := b.NewValue0(v.Pos, OpRISCV64ANDI, typ.Int64)
+ v0.AuxInt = int64ToAuxInt((c & 0b11_1111_0000) | int64(bits.Reverse8(uint8(c))&0b0000_1111))
+ v1 := b.NewValue0(v.Pos, OpRISCV64FCLASSD, typ.Int64)
+ v1.AddArg(x)
+ v0.AddArg(v1)
+ v.AddArg(v0)
+ return true
+ }
return false
}
func rewriteValueRISCV64_OpRISCV64SLL(v *Value) bool {
@@ -7347,6 +7464,8 @@ func rewriteValueRISCV64_OpRISCV64SLTU(v *Value) bool {
}
func rewriteValueRISCV64_OpRISCV64SNEZ(v *Value) bool {
v_0 := v.Args[0]
+ b := v.Block
+ typ := &b.Func.Config.Types
// match: (SNEZ (NEG x))
// result: (SNEZ x)
for {
@@ -7380,6 +7499,56 @@ func rewriteValueRISCV64_OpRISCV64SNEZ(v *Value) bool {
v.AddArg(x)
return true
}
+ // match: (SNEZ (ANDI [c] (FCLASSD (FNEGD x))))
+ // result: (SNEZ (ANDI <typ.Int64> [(c&0b11_0000_0000)|int64(bits.Reverse8(uint8(c))&0b1111_1111)] (FCLASSD x)))
+ for {
+ if v_0.Op != OpRISCV64ANDI {
+ break
+ }
+ c := auxIntToInt64(v_0.AuxInt)
+ v_0_0 := v_0.Args[0]
+ if v_0_0.Op != OpRISCV64FCLASSD {
+ break
+ }
+ v_0_0_0 := v_0_0.Args[0]
+ if v_0_0_0.Op != OpRISCV64FNEGD {
+ break
+ }
+ x := v_0_0_0.Args[0]
+ v.reset(OpRISCV64SNEZ)
+ v0 := b.NewValue0(v.Pos, OpRISCV64ANDI, typ.Int64)
+ v0.AuxInt = int64ToAuxInt((c & 0b11_0000_0000) | int64(bits.Reverse8(uint8(c))&0b1111_1111))
+ v1 := b.NewValue0(v.Pos, OpRISCV64FCLASSD, typ.Int64)
+ v1.AddArg(x)
+ v0.AddArg(v1)
+ v.AddArg(v0)
+ return true
+ }
+ // match: (SNEZ (ANDI [c] (FCLASSD (FABSD x))))
+ // result: (SNEZ (ANDI <typ.Int64> [(c&0b11_1111_0000)|int64(bits.Reverse8(uint8(c))&0b0000_1111)] (FCLASSD x)))
+ for {
+ if v_0.Op != OpRISCV64ANDI {
+ break
+ }
+ c := auxIntToInt64(v_0.AuxInt)
+ v_0_0 := v_0.Args[0]
+ if v_0_0.Op != OpRISCV64FCLASSD {
+ break
+ }
+ v_0_0_0 := v_0_0.Args[0]
+ if v_0_0_0.Op != OpRISCV64FABSD {
+ break
+ }
+ x := v_0_0_0.Args[0]
+ v.reset(OpRISCV64SNEZ)
+ v0 := b.NewValue0(v.Pos, OpRISCV64ANDI, typ.Int64)
+ v0.AuxInt = int64ToAuxInt((c & 0b11_1111_0000) | int64(bits.Reverse8(uint8(c))&0b0000_1111))
+ v1 := b.NewValue0(v.Pos, OpRISCV64FCLASSD, typ.Int64)
+ v1.AddArg(x)
+ v0.AddArg(v1)
+ v.AddArg(v0)
+ return true
+ }
return false
}
func rewriteValueRISCV64_OpRISCV64SRA(v *Value) bool {
@@ -9940,6 +10109,50 @@ func rewriteBlockRISCV64(b *Block) bool {
b.resetWithControl2(BlockRISCV64BGEU, y, v0)
return true
}
+ // match: (BEQZ (ANDI [c] (FCLASSD (FNEGD x))) yes no)
+ // result: (BEQZ (ANDI <typ.Int64> [(c&0b11_0000_0000)|int64(bits.Reverse8(uint8(c))&0b1111_1111)] (FCLASSD x)) yes no)
+ for b.Controls[0].Op == OpRISCV64ANDI {
+ v_0 := b.Controls[0]
+ c := auxIntToInt64(v_0.AuxInt)
+ v_0_0 := v_0.Args[0]
+ if v_0_0.Op != OpRISCV64FCLASSD {
+ break
+ }
+ v_0_0_0 := v_0_0.Args[0]
+ if v_0_0_0.Op != OpRISCV64FNEGD {
+ break
+ }
+ x := v_0_0_0.Args[0]
+ v0 := b.NewValue0(v_0.Pos, OpRISCV64ANDI, typ.Int64)
+ v0.AuxInt = int64ToAuxInt((c & 0b11_0000_0000) | int64(bits.Reverse8(uint8(c))&0b1111_1111))
+ v1 := b.NewValue0(v_0.Pos, OpRISCV64FCLASSD, typ.Int64)
+ v1.AddArg(x)
+ v0.AddArg(v1)
+ b.resetWithControl(BlockRISCV64BEQZ, v0)
+ return true
+ }
+ // match: (BEQZ (ANDI [c] (FCLASSD (FABSD x))) yes no)
+ // result: (BEQZ (ANDI <typ.Int64> [(c&0b11_1111_0000)|int64(bits.Reverse8(uint8(c))&0b0000_1111)] (FCLASSD x)) yes no)
+ for b.Controls[0].Op == OpRISCV64ANDI {
+ v_0 := b.Controls[0]
+ c := auxIntToInt64(v_0.AuxInt)
+ v_0_0 := v_0.Args[0]
+ if v_0_0.Op != OpRISCV64FCLASSD {
+ break
+ }
+ v_0_0_0 := v_0_0.Args[0]
+ if v_0_0_0.Op != OpRISCV64FABSD {
+ break
+ }
+ x := v_0_0_0.Args[0]
+ v0 := b.NewValue0(v_0.Pos, OpRISCV64ANDI, typ.Int64)
+ v0.AuxInt = int64ToAuxInt((c & 0b11_1111_0000) | int64(bits.Reverse8(uint8(c))&0b0000_1111))
+ v1 := b.NewValue0(v_0.Pos, OpRISCV64FCLASSD, typ.Int64)
+ v1.AddArg(x)
+ v0.AddArg(v1)
+ b.resetWithControl(BlockRISCV64BEQZ, v0)
+ return true
+ }
case BlockRISCV64BGE:
// match: (BGE (MOVDconst [0]) cond yes no)
// result: (BLEZ cond yes no)
@@ -10141,6 +10354,50 @@ func rewriteBlockRISCV64(b *Block) bool {
b.resetWithControl2(BlockRISCV64BLTU, y, v0)
return true
}
+ // match: (BNEZ (ANDI [c] (FCLASSD (FNEGD x))) yes no)
+ // result: (BNEZ (ANDI <typ.Int64> [(c&0b11_0000_0000)|int64(bits.Reverse8(uint8(c))&0b1111_1111)] (FCLASSD x)) yes no)
+ for b.Controls[0].Op == OpRISCV64ANDI {
+ v_0 := b.Controls[0]
+ c := auxIntToInt64(v_0.AuxInt)
+ v_0_0 := v_0.Args[0]
+ if v_0_0.Op != OpRISCV64FCLASSD {
+ break
+ }
+ v_0_0_0 := v_0_0.Args[0]
+ if v_0_0_0.Op != OpRISCV64FNEGD {
+ break
+ }
+ x := v_0_0_0.Args[0]
+ v0 := b.NewValue0(v_0.Pos, OpRISCV64ANDI, typ.Int64)
+ v0.AuxInt = int64ToAuxInt((c & 0b11_0000_0000) | int64(bits.Reverse8(uint8(c))&0b1111_1111))
+ v1 := b.NewValue0(v_0.Pos, OpRISCV64FCLASSD, typ.Int64)
+ v1.AddArg(x)
+ v0.AddArg(v1)
+ b.resetWithControl(BlockRISCV64BNEZ, v0)
+ return true
+ }
+ // match: (BNEZ (ANDI [c] (FCLASSD (FABSD x))) yes no)
+ // result: (BNEZ (ANDI <typ.Int64> [(c&0b11_1111_0000)|int64(bits.Reverse8(uint8(c))&0b0000_1111)] (FCLASSD x)) yes no)
+ for b.Controls[0].Op == OpRISCV64ANDI {
+ v_0 := b.Controls[0]
+ c := auxIntToInt64(v_0.AuxInt)
+ v_0_0 := v_0.Args[0]
+ if v_0_0.Op != OpRISCV64FCLASSD {
+ break
+ }
+ v_0_0_0 := v_0_0.Args[0]
+ if v_0_0_0.Op != OpRISCV64FABSD {
+ break
+ }
+ x := v_0_0_0.Args[0]
+ v0 := b.NewValue0(v_0.Pos, OpRISCV64ANDI, typ.Int64)
+ v0.AuxInt = int64ToAuxInt((c & 0b11_1111_0000) | int64(bits.Reverse8(uint8(c))&0b0000_1111))
+ v1 := b.NewValue0(v_0.Pos, OpRISCV64FCLASSD, typ.Int64)
+ v1.AddArg(x)
+ v0.AddArg(v1)
+ b.resetWithControl(BlockRISCV64BNEZ, v0)
+ return true
+ }
case BlockIf:
// match: (If cond yes no)
// result: (BNEZ (MOVBUreg <typ.UInt64> cond) yes no)
diff --git a/src/cmd/compile/internal/test/float_test.go b/src/cmd/compile/internal/test/float_test.go
index 7a5e27870f..00735e3cb1 100644
--- a/src/cmd/compile/internal/test/float_test.go
+++ b/src/cmd/compile/internal/test/float_test.go
@@ -727,6 +727,65 @@ func TestFusedNaNChecks32(t *testing.T) {
}
}
+// minNormal64 is the smallest float64 value that is not subnormal.
+const minNormal64 = 2.2250738585072014e-308
+
+//go:noinline
+func isAbsLessThanMinNormal64(x float64) bool {
+ return math.Abs(x) < minNormal64
+}
+
+//go:noinline
+func isLessThanMinNormal64(x float64) bool {
+ return x < minNormal64
+}
+
+//go:noinline
+func isGreaterThanNegMinNormal64(x float64) bool {
+ return x > -minNormal64
+}
+
+//go:noinline
+func isGreaterThanOrEqualToMinNormal64(x float64) bool {
+ return math.Abs(x) >= minNormal64
+}
+
+func TestSubnormalComparisons(t *testing.T) {
+ tests := []struct {
+ value float64
+ isAbsLessThanMinNormal bool
+ isPositive bool
+ isNegative bool
+ isNaN bool
+ }{
+ {value: math.Inf(1), isPositive: true},
+ {value: math.MaxFloat64, isPositive: true},
+ {value: math.Inf(-1), isNegative: true},
+ {value: -math.MaxFloat64, isNegative: true},
+ {value: math.NaN(), isNaN: true},
+ {value: minNormal64, isPositive: true},
+ {value: minNormal64 / 2, isAbsLessThanMinNormal: true, isPositive: true},
+ {value: -minNormal64, isNegative: true},
+ {value: -minNormal64 / 2, isAbsLessThanMinNormal: true, isNegative: true},
+ {value: 0, isAbsLessThanMinNormal: true, isPositive: true},
+ {value: math.Copysign(0, -1), isAbsLessThanMinNormal: true, isNegative: true},
+ }
+
+ check := func(name string, f func(x float64) bool, value float64, want bool) {
+ got := f(value)
+ if got != want {
+ t.Errorf("%v(%g): want %v, got %v", name, value, want, got)
+ }
+ }
+
+ for _, test := range tests {
+ check("isAbsLessThanMinNormal64", isAbsLessThanMinNormal64, test.value, test.isAbsLessThanMinNormal)
+ check("isLessThanMinNormal64", isLessThanMinNormal64, test.value, test.isAbsLessThanMinNormal || test.isNegative)
+ check("isGreaterThanNegMinNormal64", isGreaterThanNegMinNormal64, test.value, test.isAbsLessThanMinNormal || test.isPositive)
+ check("isGreaterThanOrEqualToMinNormal64", isGreaterThanOrEqualToMinNormal64, test.value, !test.isAbsLessThanMinNormal && !test.isNaN)
+ }
+}
+
var sinkFloat float64
func BenchmarkMul2(b *testing.B) {
generated by cgit v1.3-5-g9baa (git 2.53.0) at 2026-04-17 08:36:54 +0000