cmd/compile: add single-precision FMA code generation for riscv64

This CL adds FMADDS,FMSUBS,FNMADDS,FNMSUBS SSA support for riscv

Change-Id: I1e7dd322b46b9e0f4923dbba256303d69ed12066
Reviewed-on: https://go-review.googlesource.com/c/go/+/506616
Reviewed-by: Joel Sing <joel@sing.id.au>
Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Run-TryBot: M Zhuo <mzh@golangcn.org>

src/cmd/compile/internal/riscv64/ssa.go

@@ -332,7 +332,8 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		p2.From.Reg = v.Reg1()
 		p2.To.Type = obj.TYPE_REG
 		p2.To.Reg = v.Reg1()
-	case ssa.OpRISCV64FMADDD, ssa.OpRISCV64FMSUBD, ssa.OpRISCV64FNMADDD, ssa.OpRISCV64FNMSUBD:
+	case ssa.OpRISCV64FMADDD, ssa.OpRISCV64FMSUBD, ssa.OpRISCV64FNMADDD, ssa.OpRISCV64FNMSUBD,
+		ssa.OpRISCV64FMADDS, ssa.OpRISCV64FMSUBS, ssa.OpRISCV64FNMADDS, ssa.OpRISCV64FNMSUBS:
 		r := v.Reg()
 		r1 := v.Args[0].Reg()
 		r2 := v.Args[1].Reg()

src/cmd/compile/internal/ssa/_gen/RISCV64.rules

@@ -780,9 +780,10 @@
 (Select0 m:(LoweredMuluhilo x y)) && m.Uses == 1 => (MULHU x y)
 (Select1 m:(LoweredMuluhilo x y)) && m.Uses == 1 => (MUL x y)
 
-(FADDD a (FMULD x y)) && a.Block.Func.useFMA(v) => (FMADDD x y a)
+(FADD(S|D) a (FMUL(S|D) x y)) && a.Block.Func.useFMA(v) => (FMADD(S|D) x y a)
-(FSUBD a (FMULD x y)) && a.Block.Func.useFMA(v) => (FNMSUBD x y a)
+(FSUB(S|D) a (FMUL(S|D) x y)) && a.Block.Func.useFMA(v) => (FNMSUB(S|D) x y a)
-(FSUBD (FMULD x y) a) && a.Block.Func.useFMA(v) => (FMSUBD x y a)
+(FSUB(S|D) (FMUL(S|D) x y) a) && a.Block.Func.useFMA(v) => (FMSUB(S|D) x y a)
+
 // Merge negation into fused multiply-add and multiply-subtract.
 //
 // Key:
@@ -793,5 +794,7 @@
 //                D B
 //
 // Note: multiplication commutativity handled by rule generator.
+(F(MADD|NMADD|MSUB|NMSUB)S neg:(FNEGS x) y z) && neg.Uses == 1 => (F(NMSUB|MSUB|NMADD|MADD)S x y z)
+(F(MADD|NMADD|MSUB|NMSUB)S x y neg:(FNEGS z)) && neg.Uses == 1 => (F(MSUB|NMSUB|MADD|NMADD)S x y z)
 (F(MADD|NMADD|MSUB|NMSUB)D neg:(FNEGD x) y z) && neg.Uses == 1 => (F(NMSUB|MSUB|NMADD|MADD)D x y z)
 (F(MADD|NMADD|MSUB|NMSUB)D x y neg:(FNEGD z)) && neg.Uses == 1 => (F(MSUB|NMSUB|MADD|NMADD)D x y z)

src/cmd/compile/internal/ssa/_gen/RISCV64Ops.go

@@ -411,6 +411,10 @@ func init() {
 		{name: "FSUBS", argLength: 2, reg: fp21, asm: "FSUBS", commutative: false, typ: "Float32"},                                          // arg0 - arg1
 		{name: "FMULS", argLength: 2, reg: fp21, asm: "FMULS", commutative: true, typ: "Float32"},                                           // arg0 * arg1
 		{name: "FDIVS", argLength: 2, reg: fp21, asm: "FDIVS", commutative: false, typ: "Float32"},                                          // arg0 / arg1
+		{name: "FMADDS", argLength: 3, reg: fp31, asm: "FMADDS", commutative: true, typ: "Float32"},                                         // (arg0 * arg1) + arg2
+		{name: "FMSUBS", argLength: 3, reg: fp31, asm: "FMSUBS", commutative: true, typ: "Float32"},                                         // (arg0 * arg1) - arg2
+		{name: "FNMADDS", argLength: 3, reg: fp31, asm: "FNMADDS", commutative: true, typ: "Float32"},                                       // -(arg0 * arg1) + arg2
+		{name: "FNMSUBS", argLength: 3, reg: fp31, asm: "FNMSUBS", commutative: true, typ: "Float32"},                                       // -(arg0 * arg1) - arg2
 		{name: "FSQRTS", argLength: 1, reg: fp11, asm: "FSQRTS", typ: "Float32"},                                                            // sqrt(arg0)
 		{name: "FNEGS", argLength: 1, reg: fp11, asm: "FNEGS", typ: "Float32"},                                                              // -arg0
 		{name: "FMVSX", argLength: 1, reg: gpfp, asm: "FMVSX", typ: "Float32"},                                                              // reinterpret arg0 as float

src/cmd/compile/internal/ssa/opGen.go

@@ -2436,6 +2436,10 @@ const (
 	OpRISCV64FSUBS
 	OpRISCV64FMULS
 	OpRISCV64FDIVS
+	OpRISCV64FMADDS
+	OpRISCV64FMSUBS
+	OpRISCV64FNMADDS
+	OpRISCV64FNMSUBS
 	OpRISCV64FSQRTS
 	OpRISCV64FNEGS
 	OpRISCV64FMVSX
@@ -32673,6 +32677,70 @@ var opcodeTable = [...]opInfo{
 			},
 		},
 	},
+	{
+		name:        "FMADDS",
+		argLen:      3,
+		commutative: true,
+		asm:         riscv.AFMADDS,
+		reg: regInfo{
+			inputs: []inputInfo{
+				{0, 9223372034707292160}, // F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 F14 F15 F16 F17 F18 F19 F20 F21 F22 F23 F24 F25 F26 F27 F28 F29 F30 F31
+				{1, 9223372034707292160}, // F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 F14 F15 F16 F17 F18 F19 F20 F21 F22 F23 F24 F25 F26 F27 F28 F29 F30 F31
+				{2, 9223372034707292160}, // F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 F14 F15 F16 F17 F18 F19 F20 F21 F22 F23 F24 F25 F26 F27 F28 F29 F30 F31
+			},
+			outputs: []outputInfo{
+				{0, 9223372034707292160}, // F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 F14 F15 F16 F17 F18 F19 F20 F21 F22 F23 F24 F25 F26 F27 F28 F29 F30 F31
+			},
+		},
+	},
+	{
+		name:        "FMSUBS",
+		argLen:      3,
+		commutative: true,
+		asm:         riscv.AFMSUBS,
+		reg: regInfo{
+			inputs: []inputInfo{
+				{0, 9223372034707292160}, // F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 F14 F15 F16 F17 F18 F19 F20 F21 F22 F23 F24 F25 F26 F27 F28 F29 F30 F31
+				{1, 9223372034707292160}, // F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 F14 F15 F16 F17 F18 F19 F20 F21 F22 F23 F24 F25 F26 F27 F28 F29 F30 F31
+				{2, 9223372034707292160}, // F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 F14 F15 F16 F17 F18 F19 F20 F21 F22 F23 F24 F25 F26 F27 F28 F29 F30 F31
+			},
+			outputs: []outputInfo{
+				{0, 9223372034707292160}, // F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 F14 F15 F16 F17 F18 F19 F20 F21 F22 F23 F24 F25 F26 F27 F28 F29 F30 F31
+			},
+		},
+	},
+	{
+		name:        "FNMADDS",
+		argLen:      3,
+		commutative: true,
+		asm:         riscv.AFNMADDS,
+		reg: regInfo{
+			inputs: []inputInfo{
+				{0, 9223372034707292160}, // F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 F14 F15 F16 F17 F18 F19 F20 F21 F22 F23 F24 F25 F26 F27 F28 F29 F30 F31
+				{1, 9223372034707292160}, // F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 F14 F15 F16 F17 F18 F19 F20 F21 F22 F23 F24 F25 F26 F27 F28 F29 F30 F31
+				{2, 9223372034707292160}, // F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 F14 F15 F16 F17 F18 F19 F20 F21 F22 F23 F24 F25 F26 F27 F28 F29 F30 F31
+			},
+			outputs: []outputInfo{
+				{0, 9223372034707292160}, // F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 F14 F15 F16 F17 F18 F19 F20 F21 F22 F23 F24 F25 F26 F27 F28 F29 F30 F31
+			},
+		},
+	},
+	{
+		name:        "FNMSUBS",
+		argLen:      3,
+		commutative: true,
+		asm:         riscv.AFNMSUBS,
+		reg: regInfo{
+			inputs: []inputInfo{
+				{0, 9223372034707292160}, // F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 F14 F15 F16 F17 F18 F19 F20 F21 F22 F23 F24 F25 F26 F27 F28 F29 F30 F31
+				{1, 9223372034707292160}, // F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 F14 F15 F16 F17 F18 F19 F20 F21 F22 F23 F24 F25 F26 F27 F28 F29 F30 F31
+				{2, 9223372034707292160}, // F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 F14 F15 F16 F17 F18 F19 F20 F21 F22 F23 F24 F25 F26 F27 F28 F29 F30 F31
+			},
+			outputs: []outputInfo{
+				{0, 9223372034707292160}, // F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 F14 F15 F16 F17 F18 F19 F20 F21 F22 F23 F24 F25 F26 F27 F28 F29 F30 F31
+			},
+		},
+	},
 	{
 		name:   "FSQRTS",
 		argLen: 1,

src/cmd/compile/internal/ssa/rewriteRISCV64.go

@@ -442,16 +442,28 @@ func rewriteValueRISCV64(v *Value) bool {
 		return rewriteValueRISCV64_OpRISCV64ANDI(v)
 	case OpRISCV64FADDD:
 		return rewriteValueRISCV64_OpRISCV64FADDD(v)
+	case OpRISCV64FADDS:
+		return rewriteValueRISCV64_OpRISCV64FADDS(v)
 	case OpRISCV64FMADDD:
 		return rewriteValueRISCV64_OpRISCV64FMADDD(v)
+	case OpRISCV64FMADDS:
+		return rewriteValueRISCV64_OpRISCV64FMADDS(v)
 	case OpRISCV64FMSUBD:
 		return rewriteValueRISCV64_OpRISCV64FMSUBD(v)
+	case OpRISCV64FMSUBS:
+		return rewriteValueRISCV64_OpRISCV64FMSUBS(v)
 	case OpRISCV64FNMADDD:
 		return rewriteValueRISCV64_OpRISCV64FNMADDD(v)
+	case OpRISCV64FNMADDS:
+		return rewriteValueRISCV64_OpRISCV64FNMADDS(v)
 	case OpRISCV64FNMSUBD:
 		return rewriteValueRISCV64_OpRISCV64FNMSUBD(v)
+	case OpRISCV64FNMSUBS:
+		return rewriteValueRISCV64_OpRISCV64FNMSUBS(v)
 	case OpRISCV64FSUBD:
 		return rewriteValueRISCV64_OpRISCV64FSUBD(v)
+	case OpRISCV64FSUBS:
+		return rewriteValueRISCV64_OpRISCV64FSUBS(v)
 	case OpRISCV64MOVBUload:
 		return rewriteValueRISCV64_OpRISCV64MOVBUload(v)
 	case OpRISCV64MOVBUreg:
@@ -3364,6 +3376,31 @@ func rewriteValueRISCV64_OpRISCV64FADDD(v *Value) bool {
 	}
 	return false
 }
+func rewriteValueRISCV64_OpRISCV64FADDS(v *Value) bool {
+	v_1 := v.Args[1]
+	v_0 := v.Args[0]
+	// match: (FADDS a (FMULS x y))
+	// cond: a.Block.Func.useFMA(v)
+	// result: (FMADDS x y a)
+	for {
+		for _i0 := 0; _i0 <= 1; _i0, v_0, v_1 = _i0+1, v_1, v_0 {
+			a := v_0
+			if v_1.Op != OpRISCV64FMULS {
+				continue
+			}
+			y := v_1.Args[1]
+			x := v_1.Args[0]
+			if !(a.Block.Func.useFMA(v)) {
+				continue
+			}
+			v.reset(OpRISCV64FMADDS)
+			v.AddArg3(x, y, a)
+			return true
+		}
+		break
+	}
+	return false
+}
 func rewriteValueRISCV64_OpRISCV64FMADDD(v *Value) bool {
 	v_2 := v.Args[2]
 	v_1 := v.Args[1]
@@ -3409,6 +3446,51 @@ func rewriteValueRISCV64_OpRISCV64FMADDD(v *Value) bool {
 	}
 	return false
 }
+func rewriteValueRISCV64_OpRISCV64FMADDS(v *Value) bool {
+	v_2 := v.Args[2]
+	v_1 := v.Args[1]
+	v_0 := v.Args[0]
+	// match: (FMADDS neg:(FNEGS x) y z)
+	// cond: neg.Uses == 1
+	// result: (FNMSUBS x y z)
+	for {
+		for _i0 := 0; _i0 <= 1; _i0, v_0, v_1 = _i0+1, v_1, v_0 {
+			neg := v_0
+			if neg.Op != OpRISCV64FNEGS {
+				continue
+			}
+			x := neg.Args[0]
+			y := v_1
+			z := v_2
+			if !(neg.Uses == 1) {
+				continue
+			}
+			v.reset(OpRISCV64FNMSUBS)
+			v.AddArg3(x, y, z)
+			return true
+		}
+		break
+	}
+	// match: (FMADDS x y neg:(FNEGS z))
+	// cond: neg.Uses == 1
+	// result: (FMSUBS x y z)
+	for {
+		x := v_0
+		y := v_1
+		neg := v_2
+		if neg.Op != OpRISCV64FNEGS {
+			break
+		}
+		z := neg.Args[0]
+		if !(neg.Uses == 1) {
+			break
+		}
+		v.reset(OpRISCV64FMSUBS)
+		v.AddArg3(x, y, z)
+		return true
+	}
+	return false
+}
 func rewriteValueRISCV64_OpRISCV64FMSUBD(v *Value) bool {
 	v_2 := v.Args[2]
 	v_1 := v.Args[1]
@@ -3454,6 +3536,51 @@ func rewriteValueRISCV64_OpRISCV64FMSUBD(v *Value) bool {
 	}
 	return false
 }
+func rewriteValueRISCV64_OpRISCV64FMSUBS(v *Value) bool {
+	v_2 := v.Args[2]
+	v_1 := v.Args[1]
+	v_0 := v.Args[0]
+	// match: (FMSUBS neg:(FNEGS x) y z)
+	// cond: neg.Uses == 1
+	// result: (FNMADDS x y z)
+	for {
+		for _i0 := 0; _i0 <= 1; _i0, v_0, v_1 = _i0+1, v_1, v_0 {
+			neg := v_0
+			if neg.Op != OpRISCV64FNEGS {
+				continue
+			}
+			x := neg.Args[0]
+			y := v_1
+			z := v_2
+			if !(neg.Uses == 1) {
+				continue
+			}
+			v.reset(OpRISCV64FNMADDS)
+			v.AddArg3(x, y, z)
+			return true
+		}
+		break
+	}
+	// match: (FMSUBS x y neg:(FNEGS z))
+	// cond: neg.Uses == 1
+	// result: (FMADDS x y z)
+	for {
+		x := v_0
+		y := v_1
+		neg := v_2
+		if neg.Op != OpRISCV64FNEGS {
+			break
+		}
+		z := neg.Args[0]
+		if !(neg.Uses == 1) {
+			break
+		}
+		v.reset(OpRISCV64FMADDS)
+		v.AddArg3(x, y, z)
+		return true
+	}
+	return false
+}
 func rewriteValueRISCV64_OpRISCV64FNMADDD(v *Value) bool {
 	v_2 := v.Args[2]
 	v_1 := v.Args[1]
@@ -3499,6 +3626,51 @@ func rewriteValueRISCV64_OpRISCV64FNMADDD(v *Value) bool {
 	}
 	return false
 }
+func rewriteValueRISCV64_OpRISCV64FNMADDS(v *Value) bool {
+	v_2 := v.Args[2]
+	v_1 := v.Args[1]
+	v_0 := v.Args[0]
+	// match: (FNMADDS neg:(FNEGS x) y z)
+	// cond: neg.Uses == 1
+	// result: (FMSUBS x y z)
+	for {
+		for _i0 := 0; _i0 <= 1; _i0, v_0, v_1 = _i0+1, v_1, v_0 {
+			neg := v_0
+			if neg.Op != OpRISCV64FNEGS {
+				continue
+			}
+			x := neg.Args[0]
+			y := v_1
+			z := v_2
+			if !(neg.Uses == 1) {
+				continue
+			}
+			v.reset(OpRISCV64FMSUBS)
+			v.AddArg3(x, y, z)
+			return true
+		}
+		break
+	}
+	// match: (FNMADDS x y neg:(FNEGS z))
+	// cond: neg.Uses == 1
+	// result: (FNMSUBS x y z)
+	for {
+		x := v_0
+		y := v_1
+		neg := v_2
+		if neg.Op != OpRISCV64FNEGS {
+			break
+		}
+		z := neg.Args[0]
+		if !(neg.Uses == 1) {
+			break
+		}
+		v.reset(OpRISCV64FNMSUBS)
+		v.AddArg3(x, y, z)
+		return true
+	}
+	return false
+}
 func rewriteValueRISCV64_OpRISCV64FNMSUBD(v *Value) bool {
 	v_2 := v.Args[2]
 	v_1 := v.Args[1]
@@ -3544,6 +3716,51 @@ func rewriteValueRISCV64_OpRISCV64FNMSUBD(v *Value) bool {
 	}
 	return false
 }
+func rewriteValueRISCV64_OpRISCV64FNMSUBS(v *Value) bool {
+	v_2 := v.Args[2]
+	v_1 := v.Args[1]
+	v_0 := v.Args[0]
+	// match: (FNMSUBS neg:(FNEGS x) y z)
+	// cond: neg.Uses == 1
+	// result: (FMADDS x y z)
+	for {
+		for _i0 := 0; _i0 <= 1; _i0, v_0, v_1 = _i0+1, v_1, v_0 {
+			neg := v_0
+			if neg.Op != OpRISCV64FNEGS {
+				continue
+			}
+			x := neg.Args[0]
+			y := v_1
+			z := v_2
+			if !(neg.Uses == 1) {
+				continue
+			}
+			v.reset(OpRISCV64FMADDS)
+			v.AddArg3(x, y, z)
+			return true
+		}
+		break
+	}
+	// match: (FNMSUBS x y neg:(FNEGS z))
+	// cond: neg.Uses == 1
+	// result: (FNMADDS x y z)
+	for {
+		x := v_0
+		y := v_1
+		neg := v_2
+		if neg.Op != OpRISCV64FNEGS {
+			break
+		}
+		z := neg.Args[0]
+		if !(neg.Uses == 1) {
+			break
+		}
+		v.reset(OpRISCV64FNMADDS)
+		v.AddArg3(x, y, z)
+		return true
+	}
+	return false
+}
 func rewriteValueRISCV64_OpRISCV64FSUBD(v *Value) bool {
 	v_1 := v.Args[1]
 	v_0 := v.Args[0]
@@ -3583,6 +3800,45 @@ func rewriteValueRISCV64_OpRISCV64FSUBD(v *Value) bool {
 	}
 	return false
 }
+func rewriteValueRISCV64_OpRISCV64FSUBS(v *Value) bool {
+	v_1 := v.Args[1]
+	v_0 := v.Args[0]
+	// match: (FSUBS a (FMULS x y))
+	// cond: a.Block.Func.useFMA(v)
+	// result: (FNMSUBS x y a)
+	for {
+		a := v_0
+		if v_1.Op != OpRISCV64FMULS {
+			break
+		}
+		y := v_1.Args[1]
+		x := v_1.Args[0]
+		if !(a.Block.Func.useFMA(v)) {
+			break
+		}
+		v.reset(OpRISCV64FNMSUBS)
+		v.AddArg3(x, y, a)
+		return true
+	}
+	// match: (FSUBS (FMULS x y) a)
+	// cond: a.Block.Func.useFMA(v)
+	// result: (FMSUBS x y a)
+	for {
+		if v_0.Op != OpRISCV64FMULS {
+			break
+		}
+		y := v_0.Args[1]
+		x := v_0.Args[0]
+		a := v_1
+		if !(a.Block.Func.useFMA(v)) {
+			break
+		}
+		v.reset(OpRISCV64FMSUBS)
+		v.AddArg3(x, y, a)
+		return true
+	}
+	return false
+}
 func rewriteValueRISCV64_OpRISCV64MOVBUload(v *Value) bool {
 	v_1 := v.Args[1]
 	v_0 := v.Args[0]

test/codegen/floats.go

@@ -70,17 +70,20 @@ func FusedAdd32(x, y, z float32) float32 {
 	// s390x:"FMADDS\t"
 	// ppc64x:"FMADDS\t"
 	// arm64:"FMADDS"
+	// riscv64:"FMADDS\t"
 	return x*y + z
 }
 
 func FusedSub32_a(x, y, z float32) float32 {
 	// s390x:"FMSUBS\t"
 	// ppc64x:"FMSUBS\t"
+	// riscv64:"FMSUBS\t"
 	return x*y - z
 }
 
 func FusedSub32_b(x, y, z float32) float32 {
 	// arm64:"FMSUBS"
+	// riscv64:"FNMSUBS\t"
 	return z - x*y
 }