diff --git a/src/cmd/compile/internal/amd64/ssa.go b/src/cmd/compile/internal/amd64/ssa.go
index 38d2d43e279..6a478de2a0c 100644
--- a/src/cmd/compile/internal/amd64/ssa.go
+++ b/src/cmd/compile/internal/amd64/ssa.go
@@ -1370,5 +1370,6 @@ func spillArgReg(pp *objw.Progs, p *obj.Prog, f *ssa.Func, t *types.Type, reg in
 	p = pp.Append(p, storeByType(t), obj.TYPE_REG, reg, 0, obj.TYPE_MEM, 0, n.FrameOffset()+off)
 	p.To.Name = obj.NAME_PARAM
 	p.To.Sym = n.Linksym()
+	p.Pos = p.Pos.WithNotStmt()
 	return p
 }
diff --git a/src/cmd/compile/internal/ssa/numberlines.go b/src/cmd/compile/internal/ssa/numberlines.go
index 54a158ff876..9d6aeca9c0d 100644
--- a/src/cmd/compile/internal/ssa/numberlines.go
+++ b/src/cmd/compile/internal/ssa/numberlines.go
@@ -16,7 +16,8 @@ func isPoorStatementOp(op Op) bool {
 	// so that a debugger-user sees the stop before the panic, and can examine the value.
 	case OpAddr, OpLocalAddr, OpOffPtr, OpStructSelect, OpPhi, OpITab, OpIData,
 		OpIMake, OpStringMake, OpSliceMake, OpStructMake0, OpStructMake1, OpStructMake2, OpStructMake3, OpStructMake4,
-		OpConstBool, OpConst8, OpConst16, OpConst32, OpConst64, OpConst32F, OpConst64F, OpSB, OpSP:
+		OpConstBool, OpConst8, OpConst16, OpConst32, OpConst64, OpConst32F, OpConst64F, OpSB, OpSP,
+		OpArgIntReg, OpArgFloatReg:
 		return true
 	}
 	return false
@@ -61,7 +62,7 @@ func nextGoodStatementIndex(v *Value, i int, b *Block) int {
 // statement boundary.
 func notStmtBoundary(op Op) bool {
 	switch op {
-	case OpCopy, OpPhi, OpVarKill, OpVarDef, OpVarLive, OpUnknown, OpFwdRef, OpArg:
+	case OpCopy, OpPhi, OpVarKill, OpVarDef, OpVarLive, OpUnknown, OpFwdRef, OpArg, OpArgIntReg, OpArgFloatReg:
 		return true
 	}
 	return false
diff --git a/src/cmd/compile/internal/ssa/rewrite.go b/src/cmd/compile/internal/ssa/rewrite.go
index bdc4f799aa2..375c4d5a560 100644
--- a/src/cmd/compile/internal/ssa/rewrite.go
+++ b/src/cmd/compile/internal/ssa/rewrite.go
@@ -159,7 +159,7 @@ func applyRewrite(f *Func, rb blockRewriter, rv valueRewriter, deadcode deadValu
 				f.freeValue(v)
 				continue
 			}
-			if v.Pos.IsStmt() != src.PosNotStmt && pendingLines.get(vl) == int32(b.ID) {
+			if v.Pos.IsStmt() != src.PosNotStmt && !notStmtBoundary(v.Op) && pendingLines.get(vl) == int32(b.ID) {
 				pendingLines.remove(vl)
 				v.Pos = v.Pos.WithIsStmt()
 			}
diff --git a/src/cmd/compile/internal/ssagen/ssa.go b/src/cmd/compile/internal/ssagen/ssa.go
index 800d6a0b635..891047f56d9 100644
--- a/src/cmd/compile/internal/ssagen/ssa.go
+++ b/src/cmd/compile/internal/ssagen/ssa.go
@@ -7071,8 +7071,10 @@ func defframe(s *State, e *ssafn, f *ssa.Func) {
 	// slot. This can only happen with aggregate-typed arguments that are SSA-able
 	// and not address-taken (for non-SSA-able or address-taken arguments we always
 	// spill upfront).
+	// Note: spilling is unnecessary in the -N/no-optimize case, since all values
+	// will be considered non-SSAable and spilled up front.
 	// TODO(register args) Make liveness more fine-grained to that partial spilling is okay.
-	if f.OwnAux.ABIInfo().InRegistersUsed() != 0 {
+	if f.OwnAux.ABIInfo().InRegistersUsed() != 0 && base.Flag.N == 0 {
 		// First, see if it is already spilled before it may be live. Look for a spill
 		// in the entry block up to the first safepoint.
 		type nameOff struct {