diff --git a/src/cmd/internal/gc/cplx.go b/src/cmd/internal/gc/cplx.go
index 5351d2b0c3..0097571390 100644
--- a/src/cmd/internal/gc/cplx.go
+++ b/src/cmd/internal/gc/cplx.go
@@ -238,9 +238,6 @@ func nodfconst(n *Node, t *Type, fval *Mpflt) {
 	}
 }
 
-/*
- * cplx.c
- */
 func Complexop(n *Node, res *Node) bool {
 	if n != nil && n.Type != nil {
 		if Iscomplex[n.Type.Etype] {
diff --git a/src/cmd/internal/gc/gsubr.go b/src/cmd/internal/gc/gsubr.go
index 44e0d22a87..8540b920b5 100644
--- a/src/cmd/internal/gc/gsubr.go
+++ b/src/cmd/internal/gc/gsubr.go
@@ -76,9 +76,6 @@ func Samereg(a *Node, b *Node) bool {
 	return true
 }
 
-/*
- * gsubr.c
- */
 func Gbranch(as int, t *Type, likely int) *obj.Prog {
 	p := Prog(as)
 	p.To.Type = obj.TYPE_BRANCH
diff --git a/src/cmd/internal/gc/obj.go b/src/cmd/internal/gc/obj.go
index cb5b914803..d59898f286 100644
--- a/src/cmd/internal/gc/obj.go
+++ b/src/cmd/internal/gc/obj.go
@@ -294,9 +294,6 @@ func dstringptr(s *Sym, off int, str string) int {
 	return off
 }
 
-/*
- * gobj.c
- */
 func Datastring(s string, a *obj.Addr) {
 	sym := stringsym(s)
 	a.Type = obj.TYPE_MEM
diff --git a/src/cmd/internal/gc/pgen.go b/src/cmd/internal/gc/pgen.go
index 81b02e1e1b..208ecb80ff 100644
--- a/src/cmd/internal/gc/pgen.go
+++ b/src/cmd/internal/gc/pgen.go
@@ -12,10 +12,6 @@ import (
 )
 
 // "Portable" code generation.
-// Compiled separately for 5g, 6g, and 8g, so allowed to use gg.h, opt.h.
-// Must code to the intersection of the three back ends.
-
-//#include	"opt.h"
 
 var makefuncdatasym_nsym int32
 
@@ -350,9 +346,6 @@ func Cgen_checknil(n *Node) {
 	Thearch.Gins(obj.ACHECKNIL, n, nil)
 }
 
-/*
- * ggen.c
- */
 func compile(fn *Node) {
 	if Newproc == nil {
 		Newproc = Sysfunc("newproc")
diff --git a/src/cmd/internal/gc/popt.go b/src/cmd/internal/gc/popt.go
index 46f844e08c..d4cb4b676a 100644
--- a/src/cmd/internal/gc/popt.go
+++ b/src/cmd/internal/gc/popt.go
@@ -38,8 +38,6 @@ import (
 )
 
 // "Portable" optimizations.
-// Compiled separately for 5g, 6g, and 8g, so allowed to use gg.h, opt.h.
-// Must code to the intersection of the three back ends.
 
 // Derived from Inferno utils/6c/gc.h
 // http://code.google.com/p/inferno-os/source/browse/utils/6c/gc.h
@@ -168,26 +166,9 @@ type OptStats struct {
 
 var Ostats OptStats
 
-/*
- * reg.c
- */
-
-/*
- * peep.c
-void	peep(Prog*);
-void	excise(Flow*);
-int	copyu(Prog*, Adr*, Adr*);
-*/
-
-/*
- * prog.c
-
-void proginfo(ProgInfo*, Prog*);
-*/
-// p is a call instruction. Does the call fail to return?
-
 var noreturn_symlist [10]*Sym
 
+// p is a call instruction. Does the call fail to return?
 func Noreturn(p *obj.Prog) bool {
 	if noreturn_symlist[0] == nil {
 		noreturn_symlist[0] = Pkglookup("panicindex", Runtimepkg)
diff --git a/src/cmd/internal/gc/racewalk.go b/src/cmd/internal/gc/racewalk.go
index 3fd2c268f3..2b3fc306f9 100644
--- a/src/cmd/internal/gc/racewalk.go
+++ b/src/cmd/internal/gc/racewalk.go
@@ -629,7 +629,7 @@ func hascallspred(n *Node, c interface{}) {
 	}
 }
 
-// appendinit is like addinit in subr.c
+// appendinit is like addinit in subr.go
 // but appends rather than prepends.
 func appendinit(np **Node, init *NodeList) {
 	if init == nil {
diff --git a/src/cmd/internal/gc/range.go b/src/cmd/internal/gc/range.go
index 8dbb002b24..ca901d2bb3 100644
--- a/src/cmd/internal/gc/range.go
+++ b/src/cmd/internal/gc/range.go
@@ -306,7 +306,7 @@ func walkrange(n *Node) {
 		hit := n.Alloc
 		hit.Type = th
 		n.Left = nil
-		keyname := newname(th.Type.Sym)      // depends on layout of iterator struct.  See reflect.c:hiter
+		keyname := newname(th.Type.Sym)      // depends on layout of iterator struct.  See reflect.go:hiter
 		valname := newname(th.Type.Down.Sym) // ditto
 
 		fn := syslook("mapiterinit", 1)
diff --git a/src/cmd/internal/gc/reflect.go b/src/cmd/internal/gc/reflect.go
index 19694ad3d8..60d6ea510f 100644
--- a/src/cmd/internal/gc/reflect.go
+++ b/src/cmd/internal/gc/reflect.go
@@ -107,7 +107,7 @@ func lsort(l *Sig, f func(*Sig, *Sig) int) *Sig {
 // the given map type.  This type is not visible to users -
 // we include only enough information to generate a correct GC
 // program for it.
-// Make sure this stays in sync with ../../runtime/hashmap.c!
+// Make sure this stays in sync with ../../runtime/hashmap.go!
 const (
 	BUCKETSIZE = 8
 	MAXKEYSIZE = 128
@@ -236,7 +236,7 @@ func hiter(t *Type) *Type {
 	//    bucket uintptr
 	//    checkBucket uintptr
 	// }
-	// must match ../../runtime/hashmap.c:hash_iter.
+	// must match ../../runtime/hashmap.go:hash_iter.
 	var field [12]*Type
 	field[0] = makefield("key", Ptrto(t.Down))
 
diff --git a/src/cmd/internal/gc/select.go b/src/cmd/internal/gc/select.go
index 5816428deb..e3c92947bc 100644
--- a/src/cmd/internal/gc/select.go
+++ b/src/cmd/internal/gc/select.go
@@ -324,7 +324,7 @@ out:
 	lineno = int32(lno)
 }
 
-// Keep in sync with src/runtime/chan.h.
+// Keep in sync with src/runtime/runtime2.go and src/runtime/select.go.
 func selecttype(size int32) *Type {
 	// TODO(dvyukov): it's possible to generate SudoG and Scase only once
 	// and then cache; and also cache Select per size.
diff --git a/src/cmd/internal/gc/walk.go b/src/cmd/internal/gc/walk.go
index af45015ccb..e88b4c28b0 100644
--- a/src/cmd/internal/gc/walk.go
+++ b/src/cmd/internal/gc/walk.go
@@ -2636,7 +2636,7 @@ func vmatch2(l *Node, r *Node) bool {
 
 /*
  * is any name mentioned in l also mentioned in r?
- * called by sinit.c
+ * called by sinit.go
  */
 func vmatch1(l *Node, r *Node) bool {
 	/*
diff --git a/src/reflect/type.go b/src/reflect/type.go
index 1752dddd8d..bf1148fd07 100644
--- a/src/reflect/type.go
+++ b/src/reflect/type.go
@@ -201,9 +201,9 @@ type Type interface {
 // See golang.org/issue/4876 for more details.
 
 /*
- * These data structures are known to the compiler (../../cmd/gc/reflect.c).
+ * These data structures are known to the compiler (../../cmd/internal/gc/reflect.go).
  * A few are known to ../runtime/type.go to convey to debuggers.
- * They are also known to ../runtime/type.h.
+ * They are also known to ../runtime/type.go.
  */
 
 // A Kind represents the specific kind of type that a Type represents.
@@ -1143,7 +1143,7 @@ func implements(T, V *rtype) bool {
 	// methods along the way, or else V does not implement T.
 	// This lets us run the scan in overall linear time instead of
 	// the quadratic time  a naive search would require.
-	// See also ../runtime/iface.c.
+	// See also ../runtime/iface.go.
 	if V.Kind() == Interface {
 		v := (*interfaceType)(unsafe.Pointer(V))
 		i := 0
@@ -1637,13 +1637,10 @@ func (gc *gcProg) align(a uintptr) {
 	gc.size = align(gc.size, a)
 }
 
-// These constants must stay in sync with ../runtime/mgc0.h.
+// These constants must stay in sync with ../runtime/mbitmap.go.
 const (
 	bitsScalar  = 1
 	bitsPointer = 2
-
-	bitsIface = 2
-	bitsEface = 3
 )
 
 // Make sure these routines stay in sync with ../../runtime/hashmap.go!
diff --git a/src/reflect/value.go b/src/reflect/value.go
index ad48152730..ad106f53dd 100644
--- a/src/reflect/value.go
+++ b/src/reflect/value.go
@@ -176,7 +176,7 @@ type emptyInterface struct {
 
 // nonEmptyInterface is the header for a interface value with methods.
 type nonEmptyInterface struct {
-	// see ../runtime/iface.c:/Itab
+	// see ../runtime/iface.go:/Itab
 	itab *struct {
 		ityp   *rtype // static interface type
 		typ    *rtype // dynamic concrete type
diff --git a/src/runtime/cgocallback.go b/src/runtime/cgocallback.go
index 2c89143208..20ce87d4ca 100644
--- a/src/runtime/cgocallback.go
+++ b/src/runtime/cgocallback.go
@@ -6,7 +6,7 @@ package runtime
 
 import "unsafe"
 
-// These functions are called from C code via cgo/callbacks.c.
+// These functions are called from C code via cgo/callbacks.go.
 
 // Allocate memory.  This allocates the requested number of bytes in
 // memory controlled by the Go runtime.  The allocated memory will be
diff --git a/src/runtime/chan_test.go b/src/runtime/chan_test.go
index 8a357c1f23..66dfd6f8d8 100644
--- a/src/runtime/chan_test.go
+++ b/src/runtime/chan_test.go
@@ -453,7 +453,7 @@ func TestMultiConsumer(t *testing.T) {
 func TestShrinkStackDuringBlockedSend(t *testing.T) {
 	// make sure that channel operations still work when we are
 	// blocked on a channel send and we shrink the stack.
-	// NOTE: this test probably won't fail unless stack.c:StackDebug
+	// NOTE: this test probably won't fail unless stack1.go:StackDebug
 	// is set to >= 1.
 	const n = 10
 	c := make(chan int)
diff --git a/src/runtime/hashmap.go b/src/runtime/hashmap.go
index ca049dd632..aaaef48381 100644
--- a/src/runtime/hashmap.go
+++ b/src/runtime/hashmap.go
@@ -68,7 +68,7 @@ const (
 	// Maximum key or value size to keep inline (instead of mallocing per element).
 	// Must fit in a uint8.
 	// Fast versions cannot handle big values - the cutoff size for
-	// fast versions in ../../cmd/gc/walk.c must be at most this value.
+	// fast versions in ../../cmd/internal/gc/walk.go must be at most this value.
 	maxKeySize   = 128
 	maxValueSize = 128
 
@@ -103,7 +103,7 @@ const (
 
 // A header for a Go map.
 type hmap struct {
-	// Note: the format of the Hmap is encoded in ../../cmd/gc/reflect.c and
+	// Note: the format of the Hmap is encoded in ../../cmd/internal/gc/reflect.go and
 	// ../reflect/type.go.  Don't change this structure without also changing that code!
 	count int // # live cells == size of map.  Must be first (used by len() builtin)
 	flags uint8
@@ -137,11 +137,11 @@ type bmap struct {
 }
 
 // A hash iteration structure.
-// If you modify hiter, also change cmd/gc/reflect.c to indicate
+// If you modify hiter, also change cmd/internal/gc/reflect.go to indicate
 // the layout of this structure.
 type hiter struct {
-	key         unsafe.Pointer // Must be in first position.  Write nil to indicate iteration end (see cmd/gc/range.c).
-	value       unsafe.Pointer // Must be in second position (see cmd/gc/range.c).
+	key         unsafe.Pointer // Must be in first position.  Write nil to indicate iteration end (see cmd/internal/gc/range.go).
+	value       unsafe.Pointer // Must be in second position (see cmd/internal/gc/range.go).
 	t           *maptype
 	h           *hmap
 	buckets     unsafe.Pointer // bucket ptr at hash_iter initialization time
@@ -597,7 +597,7 @@ func mapiterinit(t *maptype, h *hmap, it *hiter) {
 	}
 
 	if unsafe.Sizeof(hiter{})/ptrSize != 12 {
-		throw("hash_iter size incorrect") // see ../../cmd/gc/reflect.c
+		throw("hash_iter size incorrect") // see ../../cmd/internal/gc/reflect.go
 	}
 	it.t = t
 	it.h = h
diff --git a/src/runtime/malloc.go b/src/runtime/malloc.go
index 87ccc13df9..c33456258f 100644
--- a/src/runtime/malloc.go
+++ b/src/runtime/malloc.go
@@ -114,7 +114,7 @@ const (
 	_64bit = 1 << (^uintptr(0) >> 63) / 2
 
 	// Computed constant.  The definition of MaxSmallSize and the
-	// algorithm in msize.c produce some number of different allocation
+	// algorithm in msize.go produces some number of different allocation
 	// size classes.  NumSizeClasses is that number.  It's needed here
 	// because there are static arrays of this length; when msize runs its
 	// size choosing algorithm it double-checks that NumSizeClasses agrees.
diff --git a/src/runtime/mcentral.go b/src/runtime/mcentral.go
index a6dbe45ba1..8aab903ab9 100644
--- a/src/runtime/mcentral.go
+++ b/src/runtime/mcentral.go
@@ -4,7 +4,7 @@
 
 // Central free lists.
 //
-// See malloc.h for an overview.
+// See malloc.go for an overview.
 //
 // The MCentral doesn't actually contain the list of free objects; the MSpan does.
 // Each MCentral is two lists of MSpans: those with free objects (c->nonempty)
diff --git a/src/runtime/mfixalloc.go b/src/runtime/mfixalloc.go
index c1106b6281..bb2f4e7e24 100644
--- a/src/runtime/mfixalloc.go
+++ b/src/runtime/mfixalloc.go
@@ -4,7 +4,7 @@
 
 // Fixed-size object allocator.  Returned memory is not zeroed.
 //
-// See malloc.h for overview.
+// See malloc.go for overview.
 
 package runtime
 
diff --git a/src/runtime/mgcmark.go b/src/runtime/mgcmark.go
index 3276ab8344..b17be92875 100644
--- a/src/runtime/mgcmark.go
+++ b/src/runtime/mgcmark.go
@@ -58,7 +58,7 @@ func markroot(desc *parfor, i uint32) {
 	var gcw gcWorkProducer
 	gcw.initFromCache()
 
-	// Note: if you add a case here, please also update heapdump.c:dumproots.
+	// Note: if you add a case here, please also update heapdump.go:dumproots.
 	switch i {
 	case _RootData:
 		scanblock(uintptr(unsafe.Pointer(&data)), uintptr(unsafe.Pointer(&edata))-uintptr(unsafe.Pointer(&data)), gcdatamask.bytedata, &gcw)
diff --git a/src/runtime/mheap.go b/src/runtime/mheap.go
index fc4dfeea97..e94b79fb8f 100644
--- a/src/runtime/mheap.go
+++ b/src/runtime/mheap.go
@@ -158,7 +158,7 @@ func recordspan(vh unsafe.Pointer, p unsafe.Pointer) {
 		if len(h_allspans) > 0 {
 			copy(new, h_allspans)
 			// Don't free the old array if it's referenced by sweep.
-			// See the comment in mgc0.c.
+			// See the comment in mgc.go.
 			if h.allspans != mheap_.gcspans {
 				sysFree(unsafe.Pointer(h.allspans), uintptr(cap(h_allspans))*ptrSize, &memstats.other_sys)
 			}
diff --git a/src/runtime/msize.go b/src/runtime/msize.go
index f2a7cb9ddd..9ba145dbf6 100644
--- a/src/runtime/msize.go
+++ b/src/runtime/msize.go
@@ -4,7 +4,7 @@
 
 // Malloc small size classes.
 //
-// See malloc.h for overview.
+// See malloc.go for overview.
 //
 // The size classes are chosen so that rounding an allocation
 // request up to the next size class wastes at most 12.5% (1.125x).
diff --git a/src/runtime/mstats.go b/src/runtime/mstats.go
index 19b6833a32..88cf42fe41 100644
--- a/src/runtime/mstats.go
+++ b/src/runtime/mstats.go
@@ -64,9 +64,6 @@ type mstats struct {
 
 var memstats mstats
 
-// Note: the MemStats struct should be kept in sync with
-// struct MStats in malloc.h
-
 // A MemStats records statistics about the memory allocator.
 type MemStats struct {
 	// General statistics.
diff --git a/src/runtime/os1_freebsd.go b/src/runtime/os1_freebsd.go
index f49f28edff..ae9f78c27b 100644
--- a/src/runtime/os1_freebsd.go
+++ b/src/runtime/os1_freebsd.go
@@ -28,7 +28,7 @@ func getncpu() int32 {
 
 // FreeBSD's umtx_op syscall is effectively the same as Linux's futex, and
 // thus the code is largely similar. See Linux implementation
-// and lock_futex.c for comments.
+// and lock_futex.go for comments.
 
 //go:nosplit
 func futexsleep(addr *uint32, val uint32, ns int64) {
diff --git a/src/runtime/rune.go b/src/runtime/rune.go
index a9f6835818..99c38e0bd9 100644
--- a/src/runtime/rune.go
+++ b/src/runtime/rune.go
@@ -15,7 +15,7 @@
 
 /*
  * This code is copied, with slight editing due to type differences,
- * from a subset of ../lib9/utf/rune.c
+ * from a subset of ../lib9/utf/rune.c [which no longer exists]
  */
 
 package runtime
diff --git a/src/runtime/runtime1.go b/src/runtime/runtime1.go
index f0d26c8edc..ae30adb2fc 100644
--- a/src/runtime/runtime1.go
+++ b/src/runtime/runtime1.go
@@ -435,7 +435,7 @@ func reflect_typelinks() []*_type {
 	return ret
 }
 
-// TODO: move back into mgc0.c when converted to Go
+// TODO: move back into mgc.go
 func readgogc() int32 {
 	p := gogetenv("GOGC")
 	if p == "" {
diff --git a/src/runtime/runtime2.go b/src/runtime/runtime2.go
index abd12544ae..13c5dee078 100644
--- a/src/runtime/runtime2.go
+++ b/src/runtime/runtime2.go
@@ -14,7 +14,7 @@ const (
 	//
 	// If you add to this list, add to the list
 	// of "okay during garbage collection" status
-	// in mgc0.c too.
+	// in mgcmark.go too.
 	_Gidle            = iota // 0
 	_Grunnable               // 1 runnable and on a run queue
 	_Grunning                // 2
@@ -129,7 +129,7 @@ type gobuf struct {
 }
 
 // Known to compiler.
-// Changes here must also be made in src/cmd/gc/select.c's selecttype.
+// Changes here must also be made in src/cmd/internal/gc/select.go's selecttype.
 type sudog struct {
 	g           *g
 	selectdone  *uint32
@@ -316,7 +316,7 @@ type p struct {
 	m           *m     // back-link to associated m (nil if idle)
 	mcache      *mcache
 
-	deferpool    [5][]*_defer // pool of available defer structs of different sizes (see panic.c)
+	deferpool    [5][]*_defer // pool of available defer structs of different sizes (see panic.go)
 	deferpoolbuf [5][32]*_defer
 
 	// Cache of goroutine ids, amortizes accesses to runtime·sched.goidgen.
@@ -420,7 +420,7 @@ const (
 
 // Layout of in-memory per-function information prepared by linker
 // See http://golang.org/s/go12symtab.
-// Keep in sync with linker and with ../../libmach/sym.c
+// Keep in sync with linker
 // and with package debug/gosym and with symtab.go in package runtime.
 type _func struct {
 	entry   uintptr // start pc
diff --git a/src/runtime/select.go b/src/runtime/select.go
index 8a4ff68197..73fcb439f1 100644
--- a/src/runtime/select.go
+++ b/src/runtime/select.go
@@ -371,7 +371,7 @@ loop:
 		c = cas.c
 		sg := acquireSudog()
 		sg.g = gp
-		// Note: selectdone is adjusted for stack copies in stack.c:adjustsudogs
+		// Note: selectdone is adjusted for stack copies in stack1.go:adjustsudogs
 		sg.selectdone = (*uint32)(noescape(unsafe.Pointer(&done)))
 		sg.elem = cas.elem
 		sg.releasetime = 0
diff --git a/src/runtime/type.go b/src/runtime/type.go
index 64d7c30056..70ed24cd87 100644
--- a/src/runtime/type.go
+++ b/src/runtime/type.go
@@ -8,7 +8,7 @@ package runtime
 
 import "unsafe"
 
-// Needs to be in sync with ../../cmd/ld/decodesym.c:/^commonsize and pkg/reflect/type.go:/type.
+// Needs to be in sync with ../../cmd/internal/ld/decodesym.go:/^commonsize and pkg/reflect/type.go:/type.
 type _type struct {
 	size       uintptr
 	hash       uint32