diff --git a/src/cmd/compile/internal/gc/alg.go b/src/cmd/compile/internal/gc/alg.go
index 8bdb7fc349..0b4c9c7b3f 100644
--- a/src/cmd/compile/internal/gc/alg.go
+++ b/src/cmd/compile/internal/gc/alg.go
@@ -311,9 +311,8 @@ func genhash(sym *types.Sym, t *types.Type) {
 	old_safemode := safemode
 	safemode = false
 
-	disable_checknil++
+	fn.Func.SetNilCheckDisabled(true)
 	funccompile(fn)
-	disable_checknil--
 
 	safemode = old_safemode
 }
@@ -500,12 +499,10 @@ func geneq(sym *types.Sym, t *types.Type) {
 	// We are comparing a struct or an array,
 	// neither of which can be nil, and our comparisons
 	// are shallow.
-	disable_checknil++
-
+	fn.Func.SetNilCheckDisabled(true)
 	funccompile(fn)
 
 	safemode = old_safemode
-	disable_checknil--
 }
 
 // eqfield returns the node
diff --git a/src/cmd/compile/internal/gc/main.go b/src/cmd/compile/internal/gc/main.go
index ce84024174..058c08ec4f 100644
--- a/src/cmd/compile/internal/gc/main.go
+++ b/src/cmd/compile/internal/gc/main.go
@@ -1087,6 +1087,8 @@ var concurrentFlagOK = [256]bool{
 	'I': true, // add `directory` to import search path
 	'N': true, // disable optimizations
 	'l': true, // disable inlining
+	'w': true, // all printing happens before compilation
+	'W': true, // all printing happens before compilation
 }
 
 func concurrentBackendAllowed() bool {
diff --git a/src/cmd/compile/internal/gc/ssa.go b/src/cmd/compile/internal/gc/ssa.go
index 926bc9d724..d058118f27 100644
--- a/src/cmd/compile/internal/gc/ssa.go
+++ b/src/cmd/compile/internal/gc/ssa.go
@@ -3399,7 +3399,7 @@ func (s *state) exprPtr(n *Node, bounded bool, lineno src.XPos) *ssa.Value {
 // Used only for automatically inserted nil checks,
 // not for user code like 'x != nil'.
 func (s *state) nilCheck(ptr *ssa.Value) {
-	if disable_checknil != 0 {
+	if disable_checknil != 0 || s.curfn.Func.NilCheckDisabled() {
 		return
 	}
 	s.newValue2(ssa.OpNilCheck, ssa.TypeVoid, ptr, s.mem())
diff --git a/src/cmd/compile/internal/gc/syntax.go b/src/cmd/compile/internal/gc/syntax.go
index 234ebad41c..9b1eeaf43e 100644
--- a/src/cmd/compile/internal/gc/syntax.go
+++ b/src/cmd/compile/internal/gc/syntax.go
@@ -386,25 +386,28 @@ const (
 	funcNeedctxt                  // function uses context register (has closure variables)
 	funcReflectMethod             // function calls reflect.Type.Method or MethodByName
 	funcIsHiddenClosure
-	funcNoFramePointer // Must not use a frame pointer for this function
-	funcHasDefer       // contains a defer statement
+	funcNoFramePointer   // Must not use a frame pointer for this function
+	funcHasDefer         // contains a defer statement
+	funcNilCheckDisabled // disable nil checks when compiling this function
 )
 
-func (f *Func) Dupok() bool           { return f.flags&funcDupok != 0 }
-func (f *Func) Wrapper() bool         { return f.flags&funcWrapper != 0 }
-func (f *Func) Needctxt() bool        { return f.flags&funcNeedctxt != 0 }
-func (f *Func) ReflectMethod() bool   { return f.flags&funcReflectMethod != 0 }
-func (f *Func) IsHiddenClosure() bool { return f.flags&funcIsHiddenClosure != 0 }
-func (f *Func) NoFramePointer() bool  { return f.flags&funcNoFramePointer != 0 }
-func (f *Func) HasDefer() bool        { return f.flags&funcHasDefer != 0 }
+func (f *Func) Dupok() bool            { return f.flags&funcDupok != 0 }
+func (f *Func) Wrapper() bool          { return f.flags&funcWrapper != 0 }
+func (f *Func) Needctxt() bool         { return f.flags&funcNeedctxt != 0 }
+func (f *Func) ReflectMethod() bool    { return f.flags&funcReflectMethod != 0 }
+func (f *Func) IsHiddenClosure() bool  { return f.flags&funcIsHiddenClosure != 0 }
+func (f *Func) NoFramePointer() bool   { return f.flags&funcNoFramePointer != 0 }
+func (f *Func) HasDefer() bool         { return f.flags&funcHasDefer != 0 }
+func (f *Func) NilCheckDisabled() bool { return f.flags&funcNilCheckDisabled != 0 }
 
-func (f *Func) SetDupok(b bool)           { f.flags.set(funcDupok, b) }
-func (f *Func) SetWrapper(b bool)         { f.flags.set(funcWrapper, b) }
-func (f *Func) SetNeedctxt(b bool)        { f.flags.set(funcNeedctxt, b) }
-func (f *Func) SetReflectMethod(b bool)   { f.flags.set(funcReflectMethod, b) }
-func (f *Func) SetIsHiddenClosure(b bool) { f.flags.set(funcIsHiddenClosure, b) }
-func (f *Func) SetNoFramePointer(b bool)  { f.flags.set(funcNoFramePointer, b) }
-func (f *Func) SetHasDefer(b bool)        { f.flags.set(funcHasDefer, b) }
+func (f *Func) SetDupok(b bool)            { f.flags.set(funcDupok, b) }
+func (f *Func) SetWrapper(b bool)          { f.flags.set(funcWrapper, b) }
+func (f *Func) SetNeedctxt(b bool)         { f.flags.set(funcNeedctxt, b) }
+func (f *Func) SetReflectMethod(b bool)    { f.flags.set(funcReflectMethod, b) }
+func (f *Func) SetIsHiddenClosure(b bool)  { f.flags.set(funcIsHiddenClosure, b) }
+func (f *Func) SetNoFramePointer(b bool)   { f.flags.set(funcNoFramePointer, b) }
+func (f *Func) SetHasDefer(b bool)         { f.flags.set(funcHasDefer, b) }
+func (f *Func) SetNilCheckDisabled(b bool) { f.flags.set(funcNilCheckDisabled, b) }
 
 type Op uint8