sync/atomic: fix unimportant assembly errors found by go vet

None of these are real bugs.
The variable name in the reference is not semantically meaningful,
except that 'go vet' will double check the offset against the name for you.

The stack sizes being corrected really are incorrect but they are also
in NOSPLIT functions so they typically don't matter.

Found by vet.

GOOS=linux GOARCH=amd64 go vet sync/atomic
GOOS=linux GOARCH=amd64p32 go vet sync/atomic
GOOS=linux GOARCH=386 go vet sync/atomic
GOOS=linux GOARCH=arm go vet sync/atomic
GOOS=freebsd GOARCH=arm go vet sync/atomic
GOOS=netbsd GOARCH=arm go vet sync/atomic

LGTM=r
R=r, bradfitz
CC=golang-codereviews
https://golang.org/cl/100500043

src/pkg/sync/atomic/asm_386.s

@@ -13,7 +13,7 @@ TEXT ·SwapUint32(SB),NOSPLIT,$0-12
 	MOVL	addr+0(FP), BP
 	MOVL	new+4(FP), AX
 	XCHGL	AX, 0(BP)
-	MOVL	AX, new+8(FP)
+	MOVL	AX, old+8(FP)
 	RET
 
 TEXT ·SwapInt64(SB),NOSPLIT,$0-20
@@ -43,8 +43,8 @@ swaploop:
 
 	// success
 	// return DX:AX
-	MOVL	AX, new_lo+12(FP)
-	MOVL	DX, new_hi+16(FP)
+	MOVL	AX, old_lo+12(FP)
+	MOVL	DX, old_hi+16(FP)
 	RET
 
 TEXT ·SwapUintptr(SB),NOSPLIT,$0-12
@@ -155,10 +155,10 @@ TEXT ·LoadUint32(SB),NOSPLIT,$0-8
 	MOVL	AX, val+4(FP)
 	RET
 
-TEXT ·LoadInt64(SB),NOSPLIT,$0-16
+TEXT ·LoadInt64(SB),NOSPLIT,$0-12
 	JMP	·LoadUint64(SB)
 
-TEXT ·LoadUint64(SB),NOSPLIT,$0-16
+TEXT ·LoadUint64(SB),NOSPLIT,$0-12
 	MOVL	addr+0(FP), AX
 	TESTL	$7, AX
 	JZ	2(PC)
@@ -186,10 +186,10 @@ TEXT ·StoreUint32(SB),NOSPLIT,$0-8
 	XCHGL	AX, 0(BP)
 	RET
 
-TEXT ·StoreInt64(SB),NOSPLIT,$0-16
+TEXT ·StoreInt64(SB),NOSPLIT,$0-12
 	JMP	·StoreUint64(SB)
 
-TEXT ·StoreUint64(SB),NOSPLIT,$0-16
+TEXT ·StoreUint64(SB),NOSPLIT,$0-12
 	MOVL	addr+0(FP), AX
 	TESTL	$7, AX
 	JZ	2(PC)

src/pkg/sync/atomic/asm_amd64.s

@@ -13,7 +13,7 @@ TEXT ·SwapUint32(SB),NOSPLIT,$0-20
 	MOVQ	addr+0(FP), BP
 	MOVL	new+8(FP), AX
 	XCHGL	AX, 0(BP)
-	MOVL	AX, new+16(FP)
+	MOVL	AX, old+16(FP)
 	RET
 
 TEXT ·SwapInt64(SB),NOSPLIT,$0-24
@@ -23,7 +23,7 @@ TEXT ·SwapUint64(SB),NOSPLIT,$0-24
 	MOVQ	addr+0(FP), BP
 	MOVQ	new+8(FP), AX
 	XCHGQ	AX, 0(BP)
-	MOVQ	AX, new+16(FP)
+	MOVQ	AX, old+16(FP)
 	RET
 
 TEXT ·SwapUintptr(SB),NOSPLIT,$0-24

src/pkg/sync/atomic/asm_amd64p32.s

@@ -11,7 +11,7 @@ TEXT ·SwapUint32(SB),NOSPLIT,$0-12
 	MOVL	addr+0(FP), BX
 	MOVL	new+4(FP), AX
 	XCHGL	AX, 0(BX)
-	MOVL	AX, new+8(FP)
+	MOVL	AX, old+8(FP)
 	RET
 
 TEXT ·SwapInt64(SB),NOSPLIT,$0-24
@@ -24,13 +24,13 @@ TEXT ·SwapUint64(SB),NOSPLIT,$0-24
 	MOVL	0, BX // crash with nil ptr deref
 	MOVQ	new+8(FP), AX
 	XCHGQ	AX, 0(BX)
-	MOVQ	AX, new+16(FP)
+	MOVQ	AX, old+16(FP)
 	RET
 
-TEXT ·SwapUintptr(SB),NOSPLIT,$0-24
+TEXT ·SwapUintptr(SB),NOSPLIT,$0-12
 	JMP	·SwapUint32(SB)
 
-TEXT ·SwapPointer(SB),NOSPLIT,$0-24
+TEXT ·SwapPointer(SB),NOSPLIT,$0-12
 	JMP	·SwapUint32(SB)
 
 TEXT ·CompareAndSwapInt32(SB),NOSPLIT,$0-17
@@ -45,10 +45,10 @@ TEXT ·CompareAndSwapUint32(SB),NOSPLIT,$0-17
 	SETEQ	swapped+16(FP)
 	RET
 
-TEXT ·CompareAndSwapUintptr(SB),NOSPLIT,$0-25
+TEXT ·CompareAndSwapUintptr(SB),NOSPLIT,$0-17
 	JMP	·CompareAndSwapUint32(SB)
 
-TEXT ·CompareAndSwapPointer(SB),NOSPLIT,$0-25
+TEXT ·CompareAndSwapPointer(SB),NOSPLIT,$0-17
 	JMP	·CompareAndSwapUint32(SB)
 
 TEXT ·CompareAndSwapInt64(SB),NOSPLIT,$0-25
@@ -82,7 +82,7 @@ TEXT ·AddUint32(SB),NOSPLIT,$0-12
 TEXT ·AddUintptr(SB),NOSPLIT,$0-12
 	JMP	·AddUint32(SB)
 
-TEXT ·AddInt64(SB),NOSPLIT,$0-12
+TEXT ·AddInt64(SB),NOSPLIT,$0-24
 	JMP	·AddUint64(SB)
 
 TEXT ·AddUint64(SB),NOSPLIT,$0-24

src/pkg/sync/atomic/asm_linux_arm.s

@@ -42,7 +42,7 @@ casagain:
 	BCC	cascheck
 	MOVW	$1, R0
 casret:
-	MOVW	R0, ret+12(FP)
+	MOVB	R0, swapped+12(FP)
 	RET
 cascheck:
 	// Kernel lies; double-check.
@@ -73,7 +73,7 @@ addloop1:
 	ADD	R4, R1
 	BL	cas<>(SB)
 	BCC	addloop1
-	MOVW	R1, ret+8(FP)
+	MOVW	R1, new+8(FP)
 	RET
 
 TEXT ·AddUintptr(SB),NOSPLIT,$0
@@ -132,13 +132,13 @@ TEXT ·generalCAS64(SB),NOSPLIT,$20-21
 	BEQ 	2(PC)
 	MOVW	R1, (R1)
 	MOVW	R0, 4(R13)
-	MOVW	oldlo+4(FP), R1
+	MOVW	old_lo+4(FP), R1
 	MOVW	R1, 8(R13)
-	MOVW	oldhi+8(FP), R1
+	MOVW	old_hi+8(FP), R1
 	MOVW	R1, 12(R13)
-	MOVW	newlo+12(FP), R2
+	MOVW	new_lo+12(FP), R2
 	MOVW	R2, 16(R13)
-	MOVW	newhi+16(FP), R3
+	MOVW	new_hi+16(FP), R3
 	MOVW	R3, 20(R13)
 	BL  	runtime·cas64(SB)
 	MOVB	R0, ret+20(FP)

src/pkg/sync/atomic/export_linux_arm_test.go

@@ -4,6 +4,6 @@
 
 package atomic
 
-func generalCAS64(*uint64, uint64, uint64) bool
+func generalCAS64(addr *uint64, old uint64, new uint64) bool
 
 var GeneralCAS64 = generalCAS64