cmd/compile: remove AuxCall.results, cleanup ssagen/ssa.go

More cleanup to remove unnecessary parts of AuxCall.
Passed testing on arm64 (a link-register architecture)
in addition to amd64 so very likely okay.

(Gratuitously updated commit message to see if it will
correctly this time.)

Updates #40724

Change-Id: Iaece952ceb5066149a5d32aaa14b36755f26bb8e
Reviewed-on: https://go-review.googlesource.com/c/go/+/303433
Trust: David Chase <drchase@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

6 files changed, 49 insertions, 76 deletions

diff --git a/src/cmd/compile/internal/ssa/expand_calls.go b/src/cmd/compile/internal/ssa/expand_calls.go
index 29a8f670b0..60eed37f1c 100644
--- a/src/cmd/compile/internal/ssa/expand_calls.go
+++ b/src/cmd/compile/internal/ssa/expand_calls.go
@@ -1058,14 +1058,14 @@ func expandCalls(f *Func) {
 			for j, a := range v.Args[:len(v.Args)-1] {
 				i := int64(j)
 				auxType := aux.TypeOfResult(i)
-				auxBase := b.NewValue2A(v.Pos, OpLocalAddr, types.NewPtr(auxType), aux.results[i].Name, x.sp, mem)
+				auxBase := b.NewValue2A(v.Pos, OpLocalAddr, types.NewPtr(auxType), aux.NameOfResult(i), x.sp, mem)
 				auxOffset := int64(0)
 				auxSize := aux.SizeOfResult(i)
 				aRegs := aux.RegsOfResult(int64(j))
 				if len(aRegs) == 0 && a.Op == OpDereference {
 					// Avoid a self-move, and if one is detected try to remove the already-inserted VarDef for the assignment that won't happen.
 					if dAddr, dMem := a.Args[0], a.Args[1]; dAddr.Op == OpLocalAddr && dAddr.Args[0].Op == OpSP &&
-						dAddr.Args[1] == dMem && dAddr.Aux == aux.results[i].Name {
+						dAddr.Args[1] == dMem && dAddr.Aux == aux.NameOfResult(i) {
 						if dMem.Op == OpVarDef && dMem.Aux == dAddr.Aux {
 							dMem.copyOf(dMem.MemoryArg()) // elide the VarDef
 						}
@@ -1075,7 +1075,7 @@ func expandCalls(f *Func) {
 				} else {
 					if a.Op == OpLoad && a.Args[0].Op == OpLocalAddr {
 						addr := a.Args[0] // This is a self-move. // TODO(register args) do what here for registers?
-						if addr.MemoryArg() == a.MemoryArg() && addr.Aux == aux.results[i].Name {
+						if addr.MemoryArg() == a.MemoryArg() && addr.Aux == aux.NameOfResult(i) {
 							continue
 						}
 					}
diff --git a/src/cmd/compile/internal/ssa/loopreschedchecks.go b/src/cmd/compile/internal/ssa/loopreschedchecks.go
index 2af6e8472c..738c62607a 100644
--- a/src/cmd/compile/internal/ssa/loopreschedchecks.go
+++ b/src/cmd/compile/internal/ssa/loopreschedchecks.go
@@ -247,7 +247,7 @@ func insertLoopReschedChecks(f *Func) {
 		//    goto header
 		resched := f.fe.Syslook("goschedguarded")
 		// TODO(register args) -- will need more details
-		mem1 := sched.NewValue1A(bb.Pos, OpStaticCall, types.TypeMem, StaticAuxCall(resched, nil, nil), mem0)
+		mem1 := sched.NewValue1A(bb.Pos, OpStaticCall, types.TypeMem, StaticAuxCall(resched, nil), mem0)
 		sched.AddEdgeTo(h)
 		headerMemPhi.AddArg(mem1)
 
diff --git a/src/cmd/compile/internal/ssa/op.go b/src/cmd/compile/internal/ssa/op.go
index 9e7e169137..e4721a1ba8 100644
--- a/src/cmd/compile/internal/ssa/op.go
+++ b/src/cmd/compile/internal/ssa/op.go
@@ -110,11 +110,9 @@ func (a *AuxNameOffset) String() string {
 }
 
 type AuxCall struct {
-	// TODO(register args) this information is largely redundant with ../abi information, needs cleanup once new ABI is in place.
 	Fn      *obj.LSym
-	results []Param
-	reg     *regInfo                // regInfo for this call // TODO for now nil means ignore
-	abiInfo *abi.ABIParamResultInfo // TODO remove fields above redundant with this information.
+	reg     *regInfo // regInfo for this call
+	abiInfo *abi.ABIParamResultInfo
 }
 
 // Reg returns the regInfo for a given call, combining the derived in/out register masks
@@ -229,6 +227,15 @@ func (a *AuxCall) RegsOfArg(which int64) []abi.RegIndex {
 	return a.abiInfo.InParam(int(which)).Registers
 }
 
+// NameOfResult returns the type of result which (indexed 0, 1, etc).
+func (a *AuxCall) NameOfResult(which int64) *ir.Name {
+	name := a.abiInfo.OutParam(int(which)).Name
+	if name == nil {
+		return nil
+	}
+	return name.(*ir.Name)
+}
+
 // TypeOfResult returns the type of result which (indexed 0, 1, etc).
 func (a *AuxCall) TypeOfResult(which int64) *types.Type {
 	return a.abiInfo.OutParam(int(which)).Type
@@ -272,10 +279,7 @@ func (a *AuxCall) NArgs() int64 {
 	return int64(len(a.abiInfo.InParams()))
 }
 
-// String returns
-// "AuxCall{<fn>(<args>)}"             if len(results) == 0;
-// "AuxCall{<fn>(<args>)<results[0]>}" if len(results) == 1;
-// "AuxCall{<fn>(<args>)(<results>)}"  otherwise.
+// String returns "AuxCall{<fn>}"
 func (a *AuxCall) String() string {
 	var fn string
 	if a.Fn == nil {
@@ -283,19 +287,7 @@ func (a *AuxCall) String() string {
 	} else {
 		fn = fmt.Sprintf("AuxCall{%v", a.Fn)
 	}
-
-	if len(a.results) > 0 { // usual is zero or one; only some RT calls have more than one.
-		if len(a.results) == 1 {
-			fn += fmt.Sprintf("[%v,%v]", a.results[0].Type, a.results[0].Offset)
-		} else {
-			s := "("
-			for _, result := range a.results {
-				fn += fmt.Sprintf("%s[%v,%v]", s, result.Type, result.Offset)
-				s = ","
-			}
-			fn += ")"
-		}
-	}
+	// TODO how much of the ABI should be printed?
 
 	return fn + "}"
 }
@@ -311,7 +303,7 @@ func ACParamsToTypes(ps []Param) (ts []*types.Type) {
 }
 
 // StaticAuxCall returns an AuxCall for a static call.
-func StaticAuxCall(sym *obj.LSym, results []Param, paramResultInfo *abi.ABIParamResultInfo) *AuxCall {
+func StaticAuxCall(sym *obj.LSym, paramResultInfo *abi.ABIParamResultInfo) *AuxCall {
 	if paramResultInfo == nil {
 		panic(fmt.Errorf("Nil paramResultInfo, sym=%v", sym))
 	}
@@ -319,37 +311,37 @@ func StaticAuxCall(sym *obj.LSym, results []Param, paramResultInfo *abi.ABIParam
 	if paramResultInfo.InRegistersUsed()+paramResultInfo.OutRegistersUsed() > 0 {
 		reg = &regInfo{}
 	}
-	return &AuxCall{Fn: sym, results: results, abiInfo: paramResultInfo, reg: reg}
+	return &AuxCall{Fn: sym, abiInfo: paramResultInfo, reg: reg}
 }
 
 // InterfaceAuxCall returns an AuxCall for an interface call.
-func InterfaceAuxCall(args []Param, results []Param, paramResultInfo *abi.ABIParamResultInfo) *AuxCall {
+func InterfaceAuxCall(paramResultInfo *abi.ABIParamResultInfo) *AuxCall {
 	var reg *regInfo
 	if paramResultInfo.InRegistersUsed()+paramResultInfo.OutRegistersUsed() > 0 {
 		reg = &regInfo{}
 	}
-	return &AuxCall{Fn: nil, results: results, abiInfo: paramResultInfo, reg: reg}
+	return &AuxCall{Fn: nil, abiInfo: paramResultInfo, reg: reg}
 }
 
 // ClosureAuxCall returns an AuxCall for a closure call.
-func ClosureAuxCall(args []Param, results []Param, paramResultInfo *abi.ABIParamResultInfo) *AuxCall {
+func ClosureAuxCall(paramResultInfo *abi.ABIParamResultInfo) *AuxCall {
 	var reg *regInfo
 	if paramResultInfo.InRegistersUsed()+paramResultInfo.OutRegistersUsed() > 0 {
 		reg = &regInfo{}
 	}
-	return &AuxCall{Fn: nil, results: results, abiInfo: paramResultInfo, reg: reg}
+	return &AuxCall{Fn: nil, abiInfo: paramResultInfo, reg: reg}
 }
 
 func (*AuxCall) CanBeAnSSAAux() {}
 
 // OwnAuxCall returns a function's own AuxCall
-func OwnAuxCall(fn *obj.LSym, args []Param, results []Param, paramResultInfo *abi.ABIParamResultInfo) *AuxCall {
+func OwnAuxCall(fn *obj.LSym, paramResultInfo *abi.ABIParamResultInfo) *AuxCall {
 	// TODO if this remains identical to ClosureAuxCall above after new ABI is done, should deduplicate.
 	var reg *regInfo
 	if paramResultInfo.InRegistersUsed()+paramResultInfo.OutRegistersUsed() > 0 {
 		reg = &regInfo{}
 	}
-	return &AuxCall{Fn: fn, results: results, abiInfo: paramResultInfo, reg: reg}
+	return &AuxCall{Fn: fn, abiInfo: paramResultInfo, reg: reg}
 }
 
 const (
diff --git a/src/cmd/compile/internal/ssa/rewrite.go b/src/cmd/compile/internal/ssa/rewrite.go
index 9e67c3482c..f9ad980172 100644
--- a/src/cmd/compile/internal/ssa/rewrite.go
+++ b/src/cmd/compile/internal/ssa/rewrite.go
@@ -765,7 +765,7 @@ func devirt(v *Value, aux Aux, sym Sym, offset int64) *AuxCall {
 		return nil
 	}
 	va := aux.(*AuxCall)
-	return StaticAuxCall(lsym, va.results, va.abiInfo)
+	return StaticAuxCall(lsym, va.abiInfo)
 }
 
 // de-virtualize an InterLECall
diff --git a/src/cmd/compile/internal/ssa/writebarrier.go b/src/cmd/compile/internal/ssa/writebarrier.go
index 9b956a4577..ddcafe461c 100644
--- a/src/cmd/compile/internal/ssa/writebarrier.go
+++ b/src/cmd/compile/internal/ssa/writebarrier.go
@@ -516,7 +516,7 @@ func wbcall(pos src.XPos, b *Block, fn, typ *obj.LSym, ptr, val, mem, sp, sb *Va
 	off = round(off, config.PtrSize)
 
 	// issue call
-	mem = b.NewValue1A(pos, OpStaticCall, types.TypeResultMem, StaticAuxCall(fn, nil, b.Func.ABIDefault.ABIAnalyzeTypes(nil, argTypes, nil)), mem)
+	mem = b.NewValue1A(pos, OpStaticCall, types.TypeResultMem, StaticAuxCall(fn, b.Func.ABIDefault.ABIAnalyzeTypes(nil, argTypes, nil)), mem)
 	mem.AuxInt = off - config.ctxt.FixedFrameSize()
 	return b.NewValue1I(pos, OpSelectN, types.TypeMem, 0, mem)
 }
diff --git a/src/cmd/compile/internal/ssagen/ssa.go b/src/cmd/compile/internal/ssagen/ssa.go
index f142810cf3..45952482fb 100644
--- a/src/cmd/compile/internal/ssagen/ssa.go
+++ b/src/cmd/compile/internal/ssagen/ssa.go
@@ -566,7 +566,7 @@ func buildssa(fn *ir.Func, worker int) *ssa.Func {
 		results[i].Reg = r
 	}
 
-	s.f.OwnAux = ssa.OwnAuxCall(fn.LSym, args, results, params)
+	s.f.OwnAux = ssa.OwnAuxCall(fn.LSym, params)
 
 	// Populate SSAable arguments.
 	for _, n := range fn.Dcl {
@@ -4783,21 +4783,20 @@ func (s *state) openDeferExit() {
 		// Generate code to call the function call of the defer, using the
 		// closure/receiver/args that were stored in argtmps at the point
 		// of the defer statement.
-		argStart := base.Ctxt.FixedFrameSize()
 		fn := r.n.X
 		stksize := fn.Type().ArgWidth()
-		var ACArgs []ssa.Param
-		var ACResults []ssa.Param
+		var ACArgs []*types.Type
+		var ACResults []*types.Type
 		var callArgs []*ssa.Value
 		if r.rcvr != nil {
 			// rcvr in case of OCALLINTER
 			v := s.load(r.rcvr.Type.Elem(), r.rcvr)
-			ACArgs = append(ACArgs, ssa.Param{Type: types.Types[types.TUINTPTR], Offset: int32(argStart)})
+			ACArgs = append(ACArgs, types.Types[types.TUINTPTR])
 			callArgs = append(callArgs, v)
 		}
 		for j, argAddrVal := range r.argVals {
 			f := getParam(r.n, j)
-			ACArgs = append(ACArgs, ssa.Param{Type: f.Type, Offset: int32(argStart + abi.FieldOffsetOf(f))})
+			ACArgs = append(ACArgs, f.Type)
 			var a *ssa.Value
 			if !TypeOK(f.Type) {
 				a = s.newValue2(ssa.OpDereference, f.Type, argAddrVal, s.mem())
@@ -4811,10 +4810,10 @@ func (s *state) openDeferExit() {
 			v := s.load(r.closure.Type.Elem(), r.closure)
 			s.maybeNilCheckClosure(v, callDefer)
 			codeptr := s.rawLoad(types.Types[types.TUINTPTR], v)
-			aux := ssa.ClosureAuxCall(ACArgs, ACResults, s.f.ABIDefault.ABIAnalyzeTypes(nil, ssa.ACParamsToTypes(ACArgs), ssa.ACParamsToTypes(ACResults)))
+			aux := ssa.ClosureAuxCall(s.f.ABIDefault.ABIAnalyzeTypes(nil, ACArgs, ACResults))
 			call = s.newValue2A(ssa.OpClosureLECall, aux.LateExpansionResultType(), aux, codeptr, v)
 		} else {
-			aux := ssa.StaticAuxCall(fn.(*ir.Name).Linksym(), ACResults, s.f.ABIDefault.ABIAnalyzeTypes(nil, ssa.ACParamsToTypes(ACArgs), ssa.ACParamsToTypes(ACResults)))
+			aux := ssa.StaticAuxCall(fn.(*ir.Name).Linksym(), s.f.ABIDefault.ABIAnalyzeTypes(nil, ACArgs, ACResults))
 			call = s.newValue0A(ssa.OpStaticLECall, aux.LateExpansionResultType(), aux)
 		}
 		callArgs = append(callArgs, s.mem())
@@ -4861,9 +4860,9 @@ func (s *state) call(n *ir.CallExpr, k callKind, returnResultAddr bool) *ssa.Val
 	var codeptr *ssa.Value // ptr to target code (if dynamic)
 	var rcvr *ssa.Value    // receiver to set
 	fn := n.X
-	var ACArgs []ssa.Param    // AuxCall args
-	var ACResults []ssa.Param // AuxCall results
-	var callArgs []*ssa.Value // For late-expansion, the args themselves (not stored, args to the call instead).
+	var ACArgs []*types.Type    // AuxCall args
+	var ACResults []*types.Type // AuxCall results
+	var callArgs []*ssa.Value   // For late-expansion, the args themselves (not stored, args to the call instead).
 	inRegisters := false
 
 	var magicFnNameSym *types.Sym
@@ -4932,14 +4931,7 @@ func (s *state) call(n *ir.CallExpr, k callKind, returnResultAddr bool) *ssa.Val
 	res := n.X.Type().Results()
 	if k == callNormal {
 		for _, p := range params.OutParams() {
-			r := p.Registers
-			var o int32
-			if len(r) == 0 {
-				o = p.Offset()
-			} else {
-				o = p.SpillOffset() + int32(params.SpillAreaOffset())
-			}
-			ACResults = append(ACResults, ssa.Param{Type: p.Type, Offset: o, Reg: r})
+			ACResults = append(ACResults, p.Type)
 		}
 	}
 
@@ -4993,8 +4985,8 @@ func (s *state) call(n *ir.CallExpr, k callKind, returnResultAddr bool) *ssa.Val
 		}
 
 		// Call runtime.deferprocStack with pointer to _defer record.
-		ACArgs = append(ACArgs, ssa.Param{Type: types.Types[types.TUINTPTR], Offset: int32(base.Ctxt.FixedFrameSize())})
-		aux := ssa.StaticAuxCall(ir.Syms.DeferprocStack, ACResults, s.f.ABIDefault.ABIAnalyzeTypes(nil, ssa.ACParamsToTypes(ACArgs), ssa.ACParamsToTypes(ACResults)))
+		ACArgs = append(ACArgs, types.Types[types.TUINTPTR])
+		aux := ssa.StaticAuxCall(ir.Syms.DeferprocStack, s.f.ABIDefault.ABIAnalyzeTypes(nil, ACArgs, ACResults))
 		callArgs = append(callArgs, addr, s.mem())
 		call = s.newValue0A(ssa.OpStaticLECall, aux.LateExpansionResultType(), aux)
 		call.AddArgs(callArgs...)
@@ -5009,19 +5001,16 @@ func (s *state) call(n *ir.CallExpr, k callKind, returnResultAddr bool) *ssa.Val
 		// Store arguments to stack, including defer/go arguments and receiver for method calls.
 		// These are written in SP-offset order.
 		argStart := base.Ctxt.FixedFrameSize()
-		// argExtra is for combining with ABI-derived offsets; argStart is for old ABI0 code (defer, go).
-		argExtra := int32(0) // TODO(register args) untangle this mess when fully transition to abiutils, defer/go sanitized.
 		// Defer/go args.
 		if k != callNormal {
 			// Write argsize and closure (args to newproc/deferproc).
 			argsize := s.constInt32(types.Types[types.TUINT32], int32(stksize))
-			ACArgs = append(ACArgs, ssa.Param{Type: types.Types[types.TUINT32], Offset: int32(argStart)}) // not argExtra
+			ACArgs = append(ACArgs, types.Types[types.TUINT32]) // not argExtra
 			callArgs = append(callArgs, argsize)
-			ACArgs = append(ACArgs, ssa.Param{Type: types.Types[types.TUINTPTR], Offset: int32(argStart) + int32(types.PtrSize)})
+			ACArgs = append(ACArgs, types.Types[types.TUINTPTR])
 			callArgs = append(callArgs, closure)
 			stksize += 2 * int64(types.PtrSize)
 			argStart += 2 * int64(types.PtrSize)
-			argExtra = 2 * int32(types.PtrSize)
 		}
 
 		// Set receiver (for interface calls).
@@ -5037,15 +5026,7 @@ func (s *state) call(n *ir.CallExpr, k callKind, returnResultAddr bool) *ssa.Val
 		}
 
 		for _, p := range params.InParams() { // includes receiver for interface calls
-			r := p.Registers
-			var o int32
-			if len(r) == 0 {
-				o = p.Offset()
-			} else {
-				o = p.SpillOffset() + int32(params.SpillAreaOffset())
-			}
-			ACArg := ssa.Param{Type: p.Type, Offset: argExtra + o, Reg: r} // o from ABI includes any architecture-dependent offsets.
-			ACArgs = append(ACArgs, ACArg)
+			ACArgs = append(ACArgs, p.Type)
 		}
 		for i, n := range args {
 			callArgs = append(callArgs, s.putArg(n, t.Params().Field(i).Type))
@@ -5056,10 +5037,10 @@ func (s *state) call(n *ir.CallExpr, k callKind, returnResultAddr bool) *ssa.Val
 		// call target
 		switch {
 		case k == callDefer:
-			aux := ssa.StaticAuxCall(ir.Syms.Deferproc, ACResults, s.f.ABIDefault.ABIAnalyzeTypes(nil, ssa.ACParamsToTypes(ACArgs), ssa.ACParamsToTypes(ACResults))) // TODO paramResultInfo for DeferProc
+			aux := ssa.StaticAuxCall(ir.Syms.Deferproc, s.f.ABIDefault.ABIAnalyzeTypes(nil, ACArgs, ACResults)) // TODO paramResultInfo for DeferProc
 			call = s.newValue0A(ssa.OpStaticLECall, aux.LateExpansionResultType(), aux)
 		case k == callGo:
-			aux := ssa.StaticAuxCall(ir.Syms.Newproc, ACResults, s.f.ABIDefault.ABIAnalyzeTypes(nil, ssa.ACParamsToTypes(ACArgs), ssa.ACParamsToTypes(ACResults)))
+			aux := ssa.StaticAuxCall(ir.Syms.Newproc, s.f.ABIDefault.ABIAnalyzeTypes(nil, ACArgs, ACResults))
 			call = s.newValue0A(ssa.OpStaticLECall, aux.LateExpansionResultType(), aux) // TODO paramResultInfo for NewProc
 		case closure != nil:
 			// rawLoad because loading the code pointer from a
@@ -5068,14 +5049,14 @@ func (s *state) call(n *ir.CallExpr, k callKind, returnResultAddr bool) *ssa.Val
 			// critical that we not clobber any arguments already
 			// stored onto the stack.
 			codeptr = s.rawLoad(types.Types[types.TUINTPTR], closure)
-			aux := ssa.ClosureAuxCall(ACArgs, ACResults, callABI.ABIAnalyzeTypes(nil, ssa.ACParamsToTypes(ACArgs), ssa.ACParamsToTypes(ACResults)))
+			aux := ssa.ClosureAuxCall(callABI.ABIAnalyzeTypes(nil, ACArgs, ACResults))
 			call = s.newValue2A(ssa.OpClosureLECall, aux.LateExpansionResultType(), aux, codeptr, closure)
 		case codeptr != nil:
 			// Note that the "receiver" parameter is nil because the actual receiver is the first input parameter.
-			aux := ssa.InterfaceAuxCall(ACArgs, ACResults, params)
+			aux := ssa.InterfaceAuxCall(params)
 			call = s.newValue1A(ssa.OpInterLECall, aux.LateExpansionResultType(), aux, codeptr)
 		case callee != nil:
-			aux := ssa.StaticAuxCall(callTargetLSym(callee, s.curfn.LSym), ACResults, params)
+			aux := ssa.StaticAuxCall(callTargetLSym(callee, s.curfn.LSym), params)
 			call = s.newValue0A(ssa.OpStaticLECall, aux.LateExpansionResultType(), aux)
 		default:
 			s.Fatalf("bad call type %v %v", n.Op(), n)
@@ -5542,7 +5523,7 @@ func (s *state) rtcall(fn *obj.LSym, returns bool, results []*types.Type, args .
 
 	// Issue call
 	var call *ssa.Value
-	aux := ssa.StaticAuxCall(fn, ACResults, s.f.ABIDefault.ABIAnalyzeTypes(nil, callArgTypes, results))
+	aux := ssa.StaticAuxCall(fn, s.f.ABIDefault.ABIAnalyzeTypes(nil, callArgTypes, results))
 	callArgs = append(callArgs, s.mem())
 	call = s.newValue0A(ssa.OpStaticLECall, aux.LateExpansionResultType(), aux)
 	call.AddArgs(callArgs...)