all: remove some double spaces from comments

Went mainly for the ones that make no sense, such as the ones
mid-sentence or after commas.

Change-Id: Ie245d2c19cc7428a06295635cf6a9482ade25ff0
Reviewed-on: https://go-review.googlesource.com/57293
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/cmd/asm/internal/asm/asm.go

@@ -666,7 +666,7 @@ func (p *Parser) asmInstruction(op obj.As, cond string, a []obj.Addr) {
 			}
 		}
 		if p.arch.Family == sys.AMD64 {
-			// 4 operand instruction have form  ymm1, ymm2, ymm3/m256, imm8
+			// 4 operand instruction have form ymm1, ymm2, ymm3/m256, imm8
 			// So From3 is always just a register, so we store imm8 in Offset field,
 			// to avoid increasing size of Prog.
 			prog.From = a[1]

src/cmd/compile/fmt_test.go

@@ -419,7 +419,7 @@ func stringVal(tv types.TypeAndValue) (string, bool) {
 // formatIter iterates through the string s in increasing
 // index order and calls f for each format specifier '%..v'.
 // The arguments for f describe the specifier's index range.
-// If a format specifier contains a  "*", f is called with
+// If a format specifier contains a "*", f is called with
 // the index range for "*" alone, before being called for
 // the entire specifier. The result of f is the index of
 // the rune at which iteration continues.

src/cmd/compile/internal/amd64/ssa.go

@@ -878,7 +878,7 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
 	case ssa.OpAMD64LoweredNilCheck:
 		// Issue a load which will fault if the input is nil.
 		// TODO: We currently use the 2-byte instruction TESTB AX, (reg).
-		// Should we use the 3-byte TESTB $0, (reg) instead?  It is larger
+		// Should we use the 3-byte TESTB $0, (reg) instead? It is larger
 		// but it doesn't have false dependency on AX.
 		// Or maybe allocate an output register and use MOVL (reg),reg2 ?
 		// That trades clobbering flags for clobbering a register.

src/cmd/compile/internal/gc/builtin/runtime.go

@@ -77,7 +77,7 @@ func convT2Istring(tab *byte, elem *any) (ret any)
 func convT2Islice(tab *byte, elem *any) (ret any)
 func convT2Inoptr(tab *byte, elem *any) (ret any)
 
-// interface type assertions  x.(T)
+// interface type assertions x.(T)
 func assertE2I(typ *byte, iface any) (ret any)
 func assertE2I2(typ *byte, iface any) (ret any, b bool)
 func assertI2I(typ *byte, iface any) (ret any)

src/cmd/compile/internal/gc/const.go

@@ -247,7 +247,7 @@ func convlit1(n *Node, t *types.Type, explicit bool, reuse canReuseNode) *Node {
 
 		return n
 
-		// target is invalid type for a constant?  leave alone.
+		// target is invalid type for a constant? leave alone.
 	case OLITERAL:
 		if !okforconst[t.Etype] && n.Type.Etype != TNIL {
 			return defaultlitreuse(n, nil, reuse)

src/cmd/compile/internal/gc/main.go

@@ -769,7 +769,7 @@ func isDriveLetter(b byte) bool {
 	return 'a' <= b && b <= 'z' || 'A' <= b && b <= 'Z'
 }
 
-// is this path a local name?  begins with ./ or ../ or /
+// is this path a local name? begins with ./ or ../ or /
 func islocalname(name string) bool {
 	return strings.HasPrefix(name, "/") ||
 		runtime.GOOS == "windows" && len(name) >= 3 && isDriveLetter(name[0]) && name[1] == ':' && name[2] == '/' ||

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

@@ -3373,7 +3373,7 @@ func (s *state) canSSA(n *Node) bool {
 		return false
 	case PPARAMOUT:
 		if s.hasdefer {
-			// TODO: handle this case?  Named return values must be
+			// TODO: handle this case? Named return values must be
 			// in memory so that the deferred function can see them.
 			// Maybe do: if !strings.HasPrefix(n.String(), "~") { return false }
 			// Or maybe not, see issue 18860.  Even unnamed return values

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

@@ -45,7 +45,7 @@ func copySource(v *Value) *Value {
 	// but we take some extra care to make sure we
 	// don't get stuck in an infinite loop.
 	// Infinite copy loops may happen in unreachable code.
-	// (TODO: or can they?  Needs a test.)
+	// (TODO: or can they? Needs a test.)
 	slow := w
 	var advance bool
 	for w.Op == OpCopy {

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

@@ -884,7 +884,7 @@ func (s *regAllocState) regalloc(f *Func) {
 			// Decide on registers for phi ops. Use the registers determined
 			// by the primary predecessor if we can.
 			// TODO: pick best of (already processed) predecessors?
-			// Majority vote?  Deepest nesting level?
+			// Majority vote? Deepest nesting level?
 			phiRegs = phiRegs[:0]
 			var phiUsed regMask
 			for _, v := range phis {

src/cmd/compile/internal/x86/ssa.go

@@ -728,7 +728,7 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
 	case ssa.Op386LoweredNilCheck:
 		// Issue a load which will fault if the input is nil.
 		// TODO: We currently use the 2-byte instruction TESTB AX, (reg).
-		// Should we use the 3-byte TESTB $0, (reg) instead?  It is larger
+		// Should we use the 3-byte TESTB $0, (reg) instead? It is larger
 		// but it doesn't have false dependency on AX.
 		// Or maybe allocate an output register and use MOVL (reg),reg2 ?
 		// That trades clobbering flags for clobbering a register.

src/cmd/internal/obj/x86/obj6.go

@@ -528,7 +528,7 @@ func rewriteToPcrel(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) {
 	var dst int16 = REG_CX
 	if (p.As == ALEAL || p.As == AMOVL) && p.To.Reg != p.From.Reg && p.To.Reg != p.From.Index {
 		dst = p.To.Reg
-		// Why?  See the comment near the top of rewriteToUseGot above.
+		// Why? See the comment near the top of rewriteToUseGot above.
 		// AMOVLs might be introduced by the GOT rewrites.
 	}
 	q := obj.Appendp(p, newprog)

src/cmd/internal/objfile/goobj.go

@@ -81,7 +81,7 @@ func (f *goobjFile) symbols() ([]Sym, error) {
 }
 
 func (f *goobjFile) pcln() (textStart uint64, symtab, pclntab []byte, err error) {
-	// Should never be called.  We implement Liner below, callers
+	// Should never be called. We implement Liner below, callers
 	// should use that instead.
 	return 0, nil, nil, fmt.Errorf("pcln not available in go object file")
 }
@@ -90,7 +90,7 @@ func (f *goobjFile) pcln() (textStart uint64, symtab, pclntab []byte, err error)
 // Returns "",0,nil if unknown.
 // This function implements the Liner interface in preference to pcln() above.
 func (f *goobjFile) PCToLine(pc uint64) (string, int, *gosym.Func) {
-	// TODO: this is really inefficient.  Binary search?  Memoize last result?
+	// TODO: this is really inefficient. Binary search? Memoize last result?
 	var arch *sys.Arch
 	for _, a := range sys.Archs {
 		if a.Name == f.goobj.Arch {

src/encoding/gob/decoder.go

@@ -55,7 +55,7 @@ func NewDecoder(r io.Reader) *Decoder {
 
 // recvType loads the definition of a type.
 func (dec *Decoder) recvType(id typeId) {
-	// Have we already seen this type?  That's an error
+	// Have we already seen this type? That's an error
 	if id < firstUserId || dec.wireType[id] != nil {
 		dec.err = errors.New("gob: duplicate type received")
 		return

src/encoding/json/decode.go

@@ -508,7 +508,7 @@ func (d *decodeState) array(v reflect.Value) {
 	switch v.Kind() {
 	case reflect.Interface:
 		if v.NumMethod() == 0 {
-			// Decoding into nil interface?  Switch to non-reflect code.
+			// Decoding into nil interface? Switch to non-reflect code.
 			v.Set(reflect.ValueOf(d.arrayInterface()))
 			return
 		}
@@ -612,7 +612,7 @@ func (d *decodeState) object(v reflect.Value) {
 	}
 	v = pv
 
-	// Decoding into nil interface?  Switch to non-reflect code.
+	// Decoding into nil interface? Switch to non-reflect code.
 	if v.Kind() == reflect.Interface && v.NumMethod() == 0 {
 		v.Set(reflect.ValueOf(d.objectInterface()))
 		return
@@ -1190,7 +1190,7 @@ func unquoteBytes(s []byte) (t []byte, ok bool) {
 	b := make([]byte, len(s)+2*utf8.UTFMax)
 	w := copy(b, s[0:r])
 	for r < len(s) {
-		// Out of room?  Can only happen if s is full of
+		// Out of room? Can only happen if s is full of
 		// malformed UTF-8 and we're replacing each
 		// byte with RuneError.
 		if w >= len(b)-2*utf8.UTFMax {

src/encoding/xml/read.go

@@ -160,7 +160,7 @@ func (e UnmarshalError) Error() string { return string(e) }
 // UnmarshalXML must consume exactly one XML element.
 // One common implementation strategy is to unmarshal into
 // a separate value with a layout matching the expected XML
-// using d.DecodeElement,  and then to copy the data from
+// using d.DecodeElement, and then to copy the data from
 // that value into the receiver.
 // Another common strategy is to use d.Token to process the
 // XML object one token at a time.

src/flag/flag.go

@@ -646,13 +646,13 @@ func (f *FlagSet) UintVar(p *uint, name string, value uint, usage string) {
 }
 
 // UintVar defines a uint flag with specified name, default value, and usage string.
-// The argument p points to a uint  variable in which to store the value of the flag.
+// The argument p points to a uint variable in which to store the value of the flag.
 func UintVar(p *uint, name string, value uint, usage string) {
 	CommandLine.Var(newUintValue(value, p), name, usage)
 }
 
 // Uint defines a uint flag with specified name, default value, and usage string.
-// The return value is the address of a uint  variable that stores the value of the flag.
+// The return value is the address of a uint variable that stores the value of the flag.
 func (f *FlagSet) Uint(name string, value uint, usage string) *uint {
 	p := new(uint)
 	f.UintVar(p, name, value, usage)
@@ -660,7 +660,7 @@ func (f *FlagSet) Uint(name string, value uint, usage string) *uint {
 }
 
 // Uint defines a uint flag with specified name, default value, and usage string.
-// The return value is the address of a uint  variable that stores the value of the flag.
+// The return value is the address of a uint variable that stores the value of the flag.
 func Uint(name string, value uint, usage string) *uint {
 	return CommandLine.Uint(name, value, usage)
 }
@@ -935,7 +935,7 @@ func (f *FlagSet) Parsed() bool {
 	return f.parsed
 }
 
-// Parse parses the command-line flags from os.Args[1:].  Must be called
+// Parse parses the command-line flags from os.Args[1:]. Must be called
 // after all flags are defined and before flags are accessed by the program.
 func Parse() {
 	// Ignore errors; CommandLine is set for ExitOnError.

src/fmt/print.go

@@ -837,7 +837,7 @@ func (p *pp) printValue(value reflect.Value, verb rune, depth int) {
 			p.buf.WriteByte(']')
 		}
 	case reflect.Ptr:
-		// pointer to array or slice or struct?  ok at top level
+		// pointer to array or slice or struct? ok at top level
 		// but not embedded (avoid loops)
 		if depth == 0 && f.Pointer() != 0 {
 			switch a := f.Elem(); a.Kind() {

src/net/http/server.go

@@ -1337,7 +1337,7 @@ func (cw *chunkWriter) writeHeader(p []byte) {
 	} else if hasCL {
 		delHeader("Transfer-Encoding")
 	} else if w.req.ProtoAtLeast(1, 1) {
-		// HTTP/1.1 or greater: Transfer-Encoding has been set to identity,  and no
+		// HTTP/1.1 or greater: Transfer-Encoding has been set to identity, and no
 		// content-length has been provided. The connection must be closed after the
 		// reply is written, and no chunking is to be done. This is the setup
 		// recommended in the Server-Sent Events candidate recommendation 11,

src/runtime/cputicks.go

@@ -11,6 +11,6 @@
 
 package runtime
 
-// careful: cputicks is not guaranteed to be monotonic!  In particular, we have
+// careful: cputicks is not guaranteed to be monotonic! In particular, we have
 // noticed drift between cpus on certain os/arch combinations. See issue 8976.
 func cputicks() int64

src/runtime/lock_sema.go

@@ -140,7 +140,7 @@ func notewakeup(n *note) {
 	case v == 0:
 		// Nothing was waiting. Done.
 	case v == locked:
-		// Two notewakeups!  Not allowed.
+		// Two notewakeups! Not allowed.
 		throw("notewakeup - double wakeup")
 	default:
 		// Must be the waiting m. Wake it up.

src/runtime/mgc.go

@@ -1235,7 +1235,7 @@ func gcStart(mode gcMode, trigger gcTrigger) {
 		}
 	}
 
-	// Ok, we're doing it!  Stop everybody else
+	// Ok, we're doing it! Stop everybody else
 	semacquire(&worldsema)
 
 	if trace.enabled {

src/runtime/panic.go

@@ -680,7 +680,7 @@ func startpanic_m() {
 		exit(4)
 		fallthrough
 	default:
-		// Can't even print!  Just exit.
+		// Can't even print! Just exit.
 		exit(5)
 	}
 }

src/strconv/quote.go

@@ -381,7 +381,7 @@ func Unquote(s string) (string, error) {
 		return "", ErrSyntax
 	}
 
-	// Is it trivial?  Avoid allocation.
+	// Is it trivial? Avoid allocation.
 	if !contains(s, '\\') && !contains(s, quote) {
 		switch quote {
 		case '"':

src/sync/atomic/atomic_test.go

@@ -30,7 +30,7 @@ const (
 	magic64 = 0xdeddeadbeefbeef
 )
 
-// Do the 64-bit functions panic?  If so, don't bother testing.
+// Do the 64-bit functions panic? If so, don't bother testing.
 var test64err = func() (err interface{}) {
 	defer func() {
 		err = recover()

src/syscall/mksyscall_windows.go

@@ -614,7 +614,7 @@ func (src *Source) ExternalImport(pkg string) {
 }
 
 // ParseFiles parses files listed in fs and extracts all syscall
-// functions listed in  sys comments. It returns source files
+// functions listed in sys comments. It returns source files
 // and functions collection *Source if successful.
 func ParseFiles(fs []string) (*Source, error) {
 	src := &Source{

src/unsafe/unsafe.go

@@ -176,7 +176,7 @@ type Pointer *ArbitraryType
 // Sizeof takes an expression x of any type and returns the size in bytes
 // of a hypothetical variable v as if v was declared via var v = x.
 // The size does not include any memory possibly referenced by x.
-// For instance, if x is a slice,  Sizeof returns the size of the slice
+// For instance, if x is a slice, Sizeof returns the size of the slice
 // descriptor, not the size of the memory referenced by the slice.
 func Sizeof(x ArbitraryType) uintptr