printer: cleaner output

examples/add/add.s

@@ -7,4 +7,4 @@ TEXT ·Add(SB),0,$0-24
 	MOVQ	y+8(FP), CX
 	ADDQ	AX, CX
 	MOVQ	CX, ret+16(FP)
-	RET	
+	RET

examples/complex/complex.s

@@ -5,12 +5,14 @@
 TEXT ·Real(SB),0,$0-24
 	MOVSD	x_real(FP), X0
 	MOVSD	X0, ret+16(FP)
-	RET	
+	RET
+
 // func Imag(x complex128) float64
 TEXT ·Imag(SB),0,$0-24
 	MOVSD	x_imag+8(FP), X0
 	MOVSD	X0, ret+16(FP)
-	RET	
+	RET
+
 // func Norm(x complex128) float64
 TEXT ·Norm(SB),0,$0-24
 	MOVSD	x_real(FP), X0
@@ -20,4 +22,4 @@ TEXT ·Norm(SB),0,$0-24
 	ADDSD	X1, X0
 	SQRTSD	X0, X2
 	MOVSD	X2, ret+16(FP)
-	RET	
+	RET

examples/components/components.s

@@ -5,64 +5,76 @@
 TEXT ·FieldByte(SB),0,$0-184
 	MOVB	s_Byte(FP), AL
 	MOVB	AL, ret+176(FP)
-	RET	
+	RET
+
 // func FieldInt8(s Struct) int8
 TEXT ·FieldInt8(SB),0,$0-184
 	MOVB	s_Int8+1(FP), AL
 	MOVB	AL, ret+176(FP)
-	RET	
+	RET
+
 // func FieldUint16(s Struct) uint16
 TEXT ·FieldUint16(SB),0,$0-184
 	MOVW	s_Uint16+2(FP), AX
 	MOVW	AX, ret+176(FP)
-	RET	
+	RET
+
 // func FieldInt32(s Struct) int32
 TEXT ·FieldInt32(SB),0,$0-184
 	MOVL	s_Int32+4(FP), AX
 	MOVL	AX, ret+176(FP)
-	RET	
+	RET
+
 // func FieldUint64(s Struct) uint64
 TEXT ·FieldUint64(SB),0,$0-184
 	MOVQ	s_Uint64+8(FP), AX
 	MOVQ	AX, ret+176(FP)
-	RET	
+	RET
+
 // func FieldFloat32(s Struct) float32
 TEXT ·FieldFloat32(SB),0,$0-184
 	MOVSS	s_Float32+16(FP), X0
 	MOVSS	X0, ret+176(FP)
-	RET	
+	RET
+
 // func FieldFloat64(s Struct) float64
 TEXT ·FieldFloat64(SB),0,$0-184
 	MOVSD	s_Float64+24(FP), X0
 	MOVSD	X0, ret+176(FP)
-	RET	
+	RET
+
 // func FieldStringLen(s Struct) int
 TEXT ·FieldStringLen(SB),0,$0-184
 	MOVQ	s_String_len+40(FP), AX
 	MOVQ	AX, ret+176(FP)
-	RET	
+	RET
+
 // func FieldSliceCap(s Struct) int
 TEXT ·FieldSliceCap(SB),0,$0-184
 	MOVQ	s_Slice_cap+64(FP), AX
 	MOVQ	AX, ret+176(FP)
-	RET	
+	RET
+
 // func FieldArrayTwoBTwo(s Struct) byte
 TEXT ·FieldArrayTwoBTwo(SB),0,$0-184
 	MOVB	s_Array_2_B_2+114(FP), AL
 	MOVB	AL, ret+176(FP)
-	RET	
+	RET
+
 // func FieldArrayOneC(s Struct) uint16
 TEXT ·FieldArrayOneC(SB),0,$0-184
 	MOVW	s_Array_1_C+100(FP), AX
 	MOVW	AX, ret+176(FP)
-	RET	
+	RET
+
 // func FieldComplex64Imag(s Struct) float32
 TEXT ·FieldComplex64Imag(SB),0,$0-184
 	MOVSS	s_Complex64_imag+156(FP), X0
 	MOVSS	X0, ret+176(FP)
-	RET	
+	RET
+
 // func FieldComplex128Real(s Struct) float64
 TEXT ·FieldComplex128Real(SB),0,$0-184
 	MOVSD	s_Complex128_real+160(FP), X0
 	MOVSD	X0, ret+176(FP)
-	RET	
+	RET

examples/fnv1a/fnv1a.s

@@ -18,4 +18,4 @@ loop:
 	JMP	loop
 done:
 	MOVQ	AX, ret+24(FP)
-	RET	
+	RET

examples/sum/sum.s

@@ -15,4 +15,4 @@ loop:
 	JMP	loop
 done:
 	MOVQ	DX, ret+24(FP)
-	RET	
+	RET

printer/goasm.go

@@ -31,21 +31,25 @@ func (p *goasm) Print(f *avo.File) ([]byte, error) {
 func (p *goasm) header() {
 	p.NL()
 	p.include("textflag.h")
-	p.NL()
 }
 
 func (p *goasm) include(path string) {
 	p.Printf("#include \"%s\"\n", path)
 }
 
 func (p *goasm) function(f *avo.Function) {
+	p.NL()
 	p.Comment(f.Stub())
 	p.Printf("TEXT %s%s(SB),0,$%d-%d\n", dot, f.Name, f.FrameBytes(), f.ArgumentBytes())
 
 	for _, node := range f.Nodes {
 		switch n := node.(type) {
 		case *avo.Instruction:
-			p.Printf("\t%s\t%s\n", n.Opcode, joinOperands(n.Operands))
+			if len(n.Operands) > 0 {
+				p.Printf("\t%s\t%s\n", n.Opcode, joinOperands(n.Operands))
+			} else {
+				p.Printf("\t%s\n", n.Opcode)
+			}
 		case avo.Label:
 			p.Printf("%s:\n", n)
 		default: