cmd/compile: intrinsify math.Sqrt on mips64

Fixes #24006

Change-Id: Ic1438b121fe705f9a6e3ed8340882e9dfd26ecf7
Reviewed-on: https://go-review.googlesource.com/95916Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>

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

@@ -2913,7 +2913,7 @@ func init() {
 		func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
 			return s.newValue1(ssa.OpSqrt, types.Types[TFLOAT64], args[0])
 		},
-		sys.AMD64, sys.ARM, sys.ARM64, sys.MIPS, sys.PPC64, sys.S390X)
+		sys.AMD64, sys.ARM, sys.ARM64, sys.MIPS, sys.MIPS64, sys.PPC64, sys.S390X)
 	addF("math", "Trunc",
 		func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
 			return s.newValue1(ssa.OpTrunc, types.Types[TFLOAT64], args[0])

src/cmd/compile/internal/mips64/ssa.go

@@ -354,7 +354,8 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
 		ssa.OpMIPS64MOVFD,
 		ssa.OpMIPS64MOVDF,
 		ssa.OpMIPS64NEGF,
-		ssa.OpMIPS64NEGD:
+		ssa.OpMIPS64NEGD,
+		ssa.OpMIPS64SQRTD:
 		p := s.Prog(v.Op.Asm())
 		p.From.Type = obj.TYPE_REG
 		p.From.Reg = v.Args[0].Reg()

src/cmd/compile/internal/ssa/gen/MIPS64.rules

@@ -111,6 +111,8 @@
 
 (Com(64|32|16|8) x) -> (NOR (MOVVconst [0]) x)
 
+(Sqrt x) -> (SQRTD x)
+
 // boolean ops -- booleans are represented with 0=false, 1=true
 (AndB x y) -> (AND x y)
 (OrB x y) -> (OR x y)

src/cmd/compile/internal/ssa/gen/MIPS64Ops.go

@@ -189,9 +189,10 @@ func init() {
 		{name: "NOR", argLength: 2, reg: gp21, asm: "NOR", commutative: true},                // ^(arg0 | arg1)
 		{name: "NORconst", argLength: 1, reg: gp11, asm: "NOR", aux: "Int64"},                // ^(arg0 | auxInt)
 
-		{name: "NEGV", argLength: 1, reg: gp11},              // -arg0
-		{name: "NEGF", argLength: 1, reg: fp11, asm: "NEGF"}, // -arg0, float32
-		{name: "NEGD", argLength: 1, reg: fp11, asm: "NEGD"}, // -arg0, float64
+		{name: "NEGV", argLength: 1, reg: gp11},                // -arg0
+		{name: "NEGF", argLength: 1, reg: fp11, asm: "NEGF"},   // -arg0, float32
+		{name: "NEGD", argLength: 1, reg: fp11, asm: "NEGD"},   // -arg0, float64
+		{name: "SQRTD", argLength: 1, reg: fp11, asm: "SQRTD"}, // sqrt(arg0), float64
 
 		// shifts
 		{name: "SLLV", argLength: 2, reg: gp21, asm: "SLLV"},                    // arg0 << arg1, shift amount is mod 64

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

@@ -1272,6 +1272,7 @@ const (
 	OpMIPS64NEGV
 	OpMIPS64NEGF
 	OpMIPS64NEGD
+	OpMIPS64SQRTD
 	OpMIPS64SLLV
 	OpMIPS64SLLVconst
 	OpMIPS64SRLV
@@ -16320,6 +16321,19 @@ var opcodeTable = [...]opInfo{
 			},
 		},
 	},
+	{
+		name:   "SQRTD",
+		argLen: 1,
+		asm:    mips.ASQRTD,
+		reg: regInfo{
+			inputs: []inputInfo{
+				{0, 1152921504338411520}, // 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, 1152921504338411520}, // 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:   "SLLV",
 		argLen: 2,

src/cmd/compile/internal/ssa/rewriteMIPS64.go

@@ -551,6 +551,8 @@ func rewriteValueMIPS64(v *Value) bool {
 		return rewriteValueMIPS64_OpSignExt8to64_0(v)
 	case OpSlicemask:
 		return rewriteValueMIPS64_OpSlicemask_0(v)
+	case OpSqrt:
+		return rewriteValueMIPS64_OpSqrt_0(v)
 	case OpStaticCall:
 		return rewriteValueMIPS64_OpStaticCall_0(v)
 	case OpStore:
@@ -9578,6 +9580,17 @@ func rewriteValueMIPS64_OpSlicemask_0(v *Value) bool {
 		return true
 	}
 }
+func rewriteValueMIPS64_OpSqrt_0(v *Value) bool {
+	// match: (Sqrt x)
+	// cond:
+	// result: (SQRTD x)
+	for {
+		x := v.Args[0]
+		v.reset(OpMIPS64SQRTD)
+		v.AddArg(x)
+		return true
+	}
+}
 func rewriteValueMIPS64_OpStaticCall_0(v *Value) bool {
 	// match: (StaticCall [argwid] {target} mem)
 	// cond: