diff --git a/src/cmd/go/internal/base/path.go b/src/cmd/go/internal/base/path.go
index 4f12fa8c28..7a51181c97 100644
--- a/src/cmd/go/internal/base/path.go
+++ b/src/cmd/go/internal/base/path.go
@@ -44,28 +44,6 @@ func RelPaths(paths []string) []string {
 	return out
 }
 
-// FilterDotUnderscoreFiles returns a slice containing all elements
-// of path whose base name doesn't begin with "." or "_".
-func FilterDotUnderscoreFiles(path []string) []string {
-	var out []string // lazily initialized
-	for i, p := range path {
-		base := filepath.Base(p)
-		if strings.HasPrefix(base, ".") || strings.HasPrefix(base, "_") {
-			if out == nil {
-				out = append(make([]string, 0, len(path)), path[:i]...)
-			}
-			continue
-		}
-		if out != nil {
-			out = append(out, p)
-		}
-	}
-	if out == nil {
-		return path
-	}
-	return out
-}
-
 // IsTestFile reports whether the source file is a set of tests and should therefore
 // be excluded from coverage analysis.
 func IsTestFile(file string) bool {
diff --git a/src/cmd/go/internal/fix/fix.go b/src/cmd/go/internal/fix/fix.go
index 788d49bcb6..81cf869a65 100644
--- a/src/cmd/go/internal/fix/fix.go
+++ b/src/cmd/go/internal/fix/fix.go
@@ -33,7 +33,7 @@ func runFix(cmd *base.Command, args []string) {
 		// Use pkg.gofiles instead of pkg.Dir so that
 		// the command only applies to this package,
 		// not to packages in subdirectories.
-		files := base.FilterDotUnderscoreFiles(base.RelPaths(pkg.Internal.AllGoFiles))
+		files := base.RelPaths(pkg.InternalAllGoFiles())
 		base.Run(str.StringList(cfg.BuildToolexec, base.Tool("fix"), files))
 	}
 }
diff --git a/src/cmd/go/internal/fmtcmd/fmt.go b/src/cmd/go/internal/fmtcmd/fmt.go
index 5839028b07..75e2fe39ce 100644
--- a/src/cmd/go/internal/fmtcmd/fmt.go
+++ b/src/cmd/go/internal/fmtcmd/fmt.go
@@ -59,7 +59,7 @@ func runFmt(cmd *base.Command, args []string) {
 		// Use pkg.gofiles instead of pkg.Dir so that
 		// the command only applies to this package,
 		// not to packages in subdirectories.
-		files := base.FilterDotUnderscoreFiles(base.RelPaths(pkg.Internal.AllGoFiles))
+		files := base.RelPaths(pkg.InternalAllGoFiles())
 		for _, file := range files {
 			fileC <- file
 		}
diff --git a/src/cmd/go/internal/generate/generate.go b/src/cmd/go/internal/generate/generate.go
index d47c9b7323..017d0e2ee2 100644
--- a/src/cmd/go/internal/generate/generate.go
+++ b/src/cmd/go/internal/generate/generate.go
@@ -153,7 +153,7 @@ func runGenerate(cmd *base.Command, args []string) {
 	}
 	// Even if the arguments are .go files, this loop suffices.
 	for _, pkg := range load.Packages(args) {
-		for _, file := range pkg.Internal.GoFiles {
+		for _, file := range pkg.InternalGoFiles() {
 			if !generate(pkg.Name, file) {
 				break
 			}
diff --git a/src/cmd/go/internal/get/get.go b/src/cmd/go/internal/get/get.go
index 7acba46db3..e1c90181fe 100644
--- a/src/cmd/go/internal/get/get.go
+++ b/src/cmd/go/internal/get/get.go
@@ -301,7 +301,7 @@ func download(arg string, parent *load.Package, stk *load.ImportStack, mode int)
 	// due to wildcard expansion.
 	for _, p := range pkgs {
 		if *getFix {
-			files := base.FilterDotUnderscoreFiles(base.RelPaths(p.Internal.AllGoFiles))
+			files := base.RelPaths(p.InternalAllGoFiles())
 			base.Run(cfg.BuildToolexec, str.StringList(base.Tool("fix"), files))
 
 			// The imports might have changed, so reload again.
diff --git a/src/cmd/go/internal/load/pkg.go b/src/cmd/go/internal/load/pkg.go
index 41aaf30f05..57048d076c 100644
--- a/src/cmd/go/internal/load/pkg.go
+++ b/src/cmd/go/internal/load/pkg.go
@@ -95,8 +95,6 @@ type PackageInternal struct {
 	Build        *build.Package
 	Pkgdir       string               // overrides build.PkgDir
 	Imports      []*Package           // this package's direct imports
-	GoFiles      []string             // GoFiles+CgoFiles+TestGoFiles+XTestGoFiles files, absolute paths
-	AllGoFiles   []string             // gofiles + IgnoredGoFiles, absolute paths
 	Target       string               // installed file for this package (may be executable)
 	Pkgfile      string               // where package will be (or is already) built or installed
 	ForceLibrary bool                 // this package is a library (even if named "main")
@@ -980,21 +978,6 @@ func (p *Package) load(stk *ImportStack, bp *build.Package, err error) {
 		importPaths = append(importPaths, "runtime/internal/sys")
 	}
 
-	// Build list of full paths to all Go files in the package,
-	// for use by commands like go fmt.
-	p.Internal.GoFiles = str.StringList(p.GoFiles, p.CgoFiles, p.TestGoFiles, p.XTestGoFiles)
-	for i := range p.Internal.GoFiles {
-		p.Internal.GoFiles[i] = filepath.Join(p.Dir, p.Internal.GoFiles[i])
-	}
-	sort.Strings(p.Internal.GoFiles)
-
-	p.Internal.AllGoFiles = str.StringList(p.IgnoredGoFiles)
-	for i := range p.Internal.AllGoFiles {
-		p.Internal.AllGoFiles[i] = filepath.Join(p.Dir, p.Internal.AllGoFiles[i])
-	}
-	p.Internal.AllGoFiles = append(p.Internal.AllGoFiles, p.Internal.GoFiles...)
-	sort.Strings(p.Internal.AllGoFiles)
-
 	// Check for case-insensitive collision of input files.
 	// To avoid problems on case-insensitive files, we reject any package
 	// where two different input files have equal names under a case-insensitive
@@ -1141,6 +1124,36 @@ func (p *Package) load(stk *ImportStack, bp *build.Package, err error) {
 	}
 }
 
+// mkAbs rewrites list, which must be paths relative to p.Dir,
+// into a sorted list of absolute paths. It edits list in place but for
+// convenience also returns list back to its caller.
+func (p *Package) mkAbs(list []string) []string {
+	for i, f := range list {
+		list[i] = filepath.Join(p.Dir, f)
+	}
+	sort.Strings(list)
+	return list
+}
+
+// InternalGoFiles returns the list of Go files being built for the package,
+// using absolute paths.
+func (p *Package) InternalGoFiles() []string {
+	return p.mkAbs(str.StringList(p.GoFiles, p.CgoFiles, p.TestGoFiles, p.XTestGoFiles))
+}
+
+// InternalGoFiles returns the list of all Go files possibly relevant for the package,
+// using absolute paths. "Possibly relevant" means that files are not excluded
+// due to build tags, but files with names beginning with . or _ are still excluded.
+func (p *Package) InternalAllGoFiles() []string {
+	var extra []string
+	for _, f := range p.IgnoredGoFiles {
+		if f != "" && f[0] != '.' || f[0] != '_' {
+			extra = append(extra, f)
+		}
+	}
+	return p.mkAbs(str.StringList(extra, p.GoFiles, p.CgoFiles, p.TestGoFiles, p.XTestGoFiles))
+}
+
 // InternalDeps returns the full dependency list for p,
 // built by traversing p.Internal.Imports, their .Internal.Imports, and so on.
 // It guarantees that the returned list has only one package per ImportPath