diff --git a/src/cmd/compile/internal/gc/noder.go b/src/cmd/compile/internal/gc/noder.go
index e911ac6e42..a4cf3a14f5 100644
--- a/src/cmd/compile/internal/gc/noder.go
+++ b/src/cmd/compile/internal/gc/noder.go
@@ -128,6 +128,12 @@ type noder struct {
 	pragcgobuf string
 	err        chan syntax.Error
 	scope      ScopeID
+
+	// scopeVars is a stack tracking the number of variables declared in the
+	// current function at the moment each open scope was opened.
+	scopeVars []int
+
+	lastCloseScopePos syntax.Pos
 }
 
 func (p *noder) funchdr(n *Node) ScopeID {
@@ -147,6 +153,7 @@ func (p *noder) openScope(pos syntax.Pos) {
 
 	if trackScopes {
 		Curfn.Func.Parents = append(Curfn.Func.Parents, p.scope)
+		p.scopeVars = append(p.scopeVars, len(Curfn.Func.Dcl))
 		p.scope = ScopeID(len(Curfn.Func.Parents))
 
 		p.markScope(pos)
@@ -154,9 +161,34 @@ func (p *noder) openScope(pos syntax.Pos) {
 }
 
 func (p *noder) closeScope(pos syntax.Pos) {
+	p.lastCloseScopePos = pos
 	types.Popdcl()
 
 	if trackScopes {
+		scopeVars := p.scopeVars[len(p.scopeVars)-1]
+		p.scopeVars = p.scopeVars[:len(p.scopeVars)-1]
+		if scopeVars == len(Curfn.Func.Dcl) {
+			// no variables were declared in this scope, so we can retract it.
+
+			if int(p.scope) != len(Curfn.Func.Parents) {
+				Fatalf("scope tracking inconsistency, no variables declared but scopes were not retracted")
+			}
+
+			p.scope = Curfn.Func.Parents[p.scope-1]
+			Curfn.Func.Parents = Curfn.Func.Parents[:len(Curfn.Func.Parents)-1]
+
+			nmarks := len(Curfn.Func.Marks)
+			Curfn.Func.Marks[nmarks-1].Scope = p.scope
+			prevScope := ScopeID(0)
+			if nmarks >= 2 {
+				prevScope = Curfn.Func.Marks[nmarks-2].Scope
+			}
+			if Curfn.Func.Marks[nmarks-1].Scope == prevScope {
+				Curfn.Func.Marks = Curfn.Func.Marks[:nmarks-1]
+			}
+			return
+		}
+
 		p.scope = Curfn.Func.Parents[p.scope-1]
 
 		p.markScope(pos)
@@ -177,12 +209,7 @@ func (p *noder) markScope(pos syntax.Pos) {
 // "if" statements, as their implicit blocks always end at the same
 // position as an explicit block.
 func (p *noder) closeAnotherScope() {
-	types.Popdcl()
-
-	if trackScopes {
-		p.scope = Curfn.Func.Parents[p.scope-1]
-		Curfn.Func.Marks[len(Curfn.Func.Marks)-1].Scope = p.scope
-	}
+	p.closeScope(p.lastCloseScopePos)
 }
 
 // linkname records a //go:linkname directive.
diff --git a/src/cmd/compile/internal/gc/scope.go b/src/cmd/compile/internal/gc/scope.go
index ebdaa19994..b019329067 100644
--- a/src/cmd/compile/internal/gc/scope.go
+++ b/src/cmd/compile/internal/gc/scope.go
@@ -87,21 +87,12 @@ func scopePCs(fnsym *obj.LSym, marks []Mark, dwarfScopes []dwarf.Scope) {
 		pcs = append(pcs, scopedPCs{start: p0.Pc, end: fnsym.Size, pos: p0.Pos})
 	}
 
-	// Sort PCs by source position, and walk in parallel with
-	// scope marks to assign a lexical scope to each PC interval.
-	sort.Sort(pcsByPos(pcs))
-	var marki int
-	var scope ScopeID
+	// Assign scopes to each chunk of instructions.
 	for i := range pcs {
-		for marki < len(marks) && !xposBefore(pcs[i].pos, marks[marki].Pos) {
-			scope = marks[marki].Scope
-			marki++
-		}
-		pcs[i].scope = scope
+		pcs[i].scope = findScope(marks, pcs[i].pos)
 	}
 
-	// Re-sort to create sorted PC ranges for each DWARF scope.
-	sort.Sort(pcsByPC(pcs))
+	// Create sorted PC ranges for each DWARF scope.
 	for _, pc := range pcs {
 		r := &dwarfScopes[pc.scope].Ranges
 		if i := len(*r); i > 0 && (*r)[i-1].End == pc.start {
@@ -113,23 +104,6 @@ func scopePCs(fnsym *obj.LSym, marks []Mark, dwarfScopes []dwarf.Scope) {
 }
 
 func compactScopes(dwarfScopes []dwarf.Scope) []dwarf.Scope {
-	// Forward pass to collapse empty scopes into parents.
-	remap := make([]int32, len(dwarfScopes))
-	j := int32(1)
-	for i := 1; i < len(dwarfScopes); i++ {
-		s := &dwarfScopes[i]
-		s.Parent = remap[s.Parent]
-		if len(s.Vars) == 0 {
-			dwarfScopes[s.Parent].UnifyRanges(s)
-			remap[i] = s.Parent
-			continue
-		}
-		remap[i] = j
-		dwarfScopes[j] = *s
-		j++
-	}
-	dwarfScopes = dwarfScopes[:j]
-
 	// Reverse pass to propagate PC ranges to parent scopes.
 	for i := len(dwarfScopes) - 1; i > 0; i-- {
 		s := &dwarfScopes[i]
@@ -147,14 +121,6 @@ func (s pcsByPC) Less(i, j int) bool {
 	return s[i].start < s[j].start
 }
 
-type pcsByPos []scopedPCs
-
-func (s pcsByPos) Len() int      { return len(s) }
-func (s pcsByPos) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
-func (s pcsByPos) Less(i, j int) bool {
-	return xposBefore(s[i].pos, s[j].pos)
-}
-
 type varsByScopeAndOffset struct {
 	vars   []*dwarf.Var
 	scopes []ScopeID
diff --git a/src/cmd/internal/dwarf/dwarf.go b/src/cmd/internal/dwarf/dwarf.go
index b9cf95bf75..3b352aa5aa 100644
--- a/src/cmd/internal/dwarf/dwarf.go
+++ b/src/cmd/internal/dwarf/dwarf.go
@@ -1304,6 +1304,11 @@ func putscope(ctxt Context, s *FnState, scopes []Scope, curscope int32, fnabbrev
 			return curscope
 		}
 
+		if len(scopes[curscope].Vars) == 0 {
+			curscope = putscope(ctxt, s, scopes, curscope, fnabbrev, encbuf)
+			continue
+		}
+
 		if len(scope.Ranges) == 1 {
 			Uleb128put(ctxt, s.Info, DW_ABRV_LEXICAL_BLOCK_SIMPLE)
 			putattr(ctxt, s.Info, DW_ABRV_LEXICAL_BLOCK_SIMPLE, DW_FORM_addr, DW_CLS_ADDRESS, scope.Ranges[0].Start, s.StartPC)
@@ -1316,6 +1321,7 @@ func putscope(ctxt Context, s *FnState, scopes []Scope, curscope int32, fnabbrev
 		}
 
 		curscope = putscope(ctxt, s, scopes, curscope, fnabbrev, encbuf)
+
 		Uleb128put(ctxt, s.Info, 0)
 	}
 	return curscope