diff --git a/src/cmd/internal/gc/syntax.go b/src/cmd/internal/gc/syntax.go
index 7c9fb8d2b88..70c6f3f5674 100644
--- a/src/cmd/internal/gc/syntax.go
+++ b/src/cmd/internal/gc/syntax.go
@@ -48,7 +48,6 @@ type Node struct {
 	Assigned    bool   // is the variable ever assigned to
 	Captured    bool   // is the variable captured by a closure
 	Byval       bool   // is the variable captured by value or by reference
-	Reslice     bool   // this is a reslice x = x[0:y] or x = append(x, ...)
 	Likely      int8   // likeliness of if statement
 	Hasbreak    bool   // has break statement
 	Needzero    bool   // if it contains pointers, needs to be zeroed on function entry
diff --git a/src/cmd/internal/gc/typecheck.go b/src/cmd/internal/gc/typecheck.go
index 6daf842474c..fdd393d0cf7 100644
--- a/src/cmd/internal/gc/typecheck.go
+++ b/src/cmd/internal/gc/typecheck.go
@@ -3360,29 +3360,6 @@ func typecheckas(n *Node) {
 	if n.Left.Typecheck == 0 {
 		typecheck(&n.Left, Erv|Easgn)
 	}
-
-	// Recognize slices being updated in place, for better code generation later.
-	// Don't rewrite if using race detector, to avoid needing to teach race detector
-	// about this optimization.
-	if n.Left != nil && n.Left.Op != OINDEXMAP && n.Right != nil && flag_race == 0 {
-		switch n.Right.Op {
-		// For x = x[0:y], x can be updated in place, without touching pointer.
-		// TODO(rsc): Reenable once it is actually updated in place without touching the pointer.
-		case OSLICE, OSLICE3, OSLICESTR:
-			if false && samesafeexpr(n.Left, n.Right.Left) && (n.Right.Right.Left == nil || iszero(n.Right.Right.Left)) {
-				n.Right.Reslice = true
-			}
-
-			// For x = append(x, ...), x can be updated in place when there is capacity,
-		// without touching the pointer; otherwise the emitted code to growslice
-		// can take care of updating the pointer, and only in that case.
-		// TODO(rsc): Reenable once the emitted code does update the pointer.
-		case OAPPEND:
-			if false && n.Right.List != nil && samesafeexpr(n.Left, n.Right.List.N) {
-				n.Right.Reslice = true
-			}
-		}
-	}
 }
 
 func checkassignto(src *Type, dst *Node) {
diff --git a/src/cmd/internal/gc/walk.go b/src/cmd/internal/gc/walk.go
index c32a8137d61..c8a5c7e2f3a 100644
--- a/src/cmd/internal/gc/walk.go
+++ b/src/cmd/internal/gc/walk.go
@@ -2185,26 +2185,6 @@ func needwritebarrier(l *Node, r *Node) bool {
 		return false
 	}
 
-	// No write barrier for reslice: x = x[0:y] or x = append(x, ...).
-	// Both are compiled to modify x directly.
-	// In the case of append, a write barrier may still be needed
-	// if the underlying array grows, but the append code can
-	// generate the write barrier directly in that case.
-	// (It does not yet, but the cost of the write barrier will be
-	// small compared to the cost of the allocation.)
-	if r.Reslice {
-		switch r.Op {
-		case OSLICE, OSLICE3, OSLICESTR, OAPPEND:
-			break
-
-		default:
-			Dump("bad reslice-l", l)
-			Dump("bad reslice-r", r)
-		}
-
-		return false
-	}
-
 	// Otherwise, be conservative and use write barrier.
 	return true
 }