cmd/compile: make modified Aux type for OpArgXXXX pass ssa/check

For #40724.

Change-Id: I7d1e76139d187cd15a6e0df9d19542b7200589f6
Reviewed-on: https://go-review.googlesource.com/c/go/+/297911
Trust: David Chase <drchase@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

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

@@ -182,6 +182,12 @@ func checkFunc(f *Func) {
 					f.Fatalf("value %v has Aux type %T, want *AuxCall", v, v.Aux)
 				}
 				canHaveAux = true
+			case auxNameOffsetInt8:
+				if _, ok := v.Aux.(*AuxNameOffset); !ok {
+					f.Fatalf("value %v has Aux type %T, want *AuxNameOffset", v, v.Aux)
+				}
+				canHaveAux = true
+				canHaveAuxInt = true
 			case auxSym, auxTyp:
 				canHaveAux = true
 			case auxSymOff, auxSymValAndOff, auxTypSize:

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

@@ -336,8 +336,8 @@ var genericOps = []opData{
 
 	// Like Arg, these are generic ops that survive lowering. AuxInt is a register index, and the actual output register for each index is defined by the architecture.
 	// AuxInt = integer argument index (not a register number). ABI-specified spill loc obtained from function
-	{name: "ArgIntReg", aux: "Int8", zeroWidth: true},   // argument to the function in an int reg.
-	{name: "ArgFloatReg", aux: "Int8", zeroWidth: true}, // argument to the function in a float reg.
+	{name: "ArgIntReg", aux: "NameOffsetInt8", zeroWidth: true},   // argument to the function in an int reg.
+	{name: "ArgFloatReg", aux: "NameOffsetInt8", zeroWidth: true}, // argument to the function in a float reg.
 
 	// The address of a variable.  arg0 is the base pointer.
 	// If the variable is a global, the base pointer will be SB and

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

@@ -251,6 +251,7 @@ const (
 	auxFloat32                // auxInt is a float32 (encoded with math.Float64bits)
 	auxFloat64                // auxInt is a float64 (encoded with math.Float64bits)
 	auxFlagConstant           // auxInt is a flagConstant
+	auxNameOffsetInt8         // aux is a &struct{Name ir.Name, Offset int64}; auxInt is index in parameter registers array
 	auxString                 // aux is a string
 	auxSym                    // aux is a symbol (a *gc.Node for locals, an *obj.LSym for globals, or nil for none)
 	auxSymOff                 // aux is a symbol, auxInt is an offset

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

@@ -35445,14 +35445,14 @@ var opcodeTable = [...]opInfo{
 	},
 	{
 		name:      "ArgIntReg",
-		auxType:   auxInt8,
+		auxType:   auxNameOffsetInt8,
 		argLen:    0,
 		zeroWidth: true,
 		generic:   true,
 	},
 	{
 		name:      "ArgFloatReg",
-		auxType:   auxInt8,
+		auxType:   auxNameOffsetInt8,
 		argLen:    0,
 		zeroWidth: true,
 		generic:   true,

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

@@ -78,7 +78,7 @@ func (v *Value) String() string {
 }
 
 func (v *Value) AuxInt8() int8 {
-	if opcodeTable[v.Op].auxType != auxInt8 {
+	if opcodeTable[v.Op].auxType != auxInt8 && opcodeTable[v.Op].auxType != auxNameOffsetInt8 {
 		v.Fatalf("op %s doesn't have an int8 aux field", v.Op)
 	}
 	return int8(v.AuxInt)