diff --git a/js/public/Id.h b/js/public/Id.h
index 7103df82d287..f2d89df5bd94 100644
--- a/js/public/Id.h
+++ b/js/public/Id.h
@@ -150,13 +150,13 @@ JSID_IS_VOID(const jsid id)
 {
     MOZ_ASSERT_IF(((size_t)JSID_BITS(id) & JSID_TYPE_MASK) == JSID_TYPE_VOID,
                  JSID_BITS(id) == JSID_TYPE_VOID);
-    return ((size_t)JSID_BITS(id) == JSID_TYPE_VOID);
+    return (size_t)JSID_BITS(id) == JSID_TYPE_VOID;
 }
 
 static MOZ_ALWAYS_INLINE bool
 JSID_IS_EMPTY(const jsid id)
 {
-    return ((size_t)JSID_BITS(id) == JSID_TYPE_SYMBOL);
+    return (size_t)JSID_BITS(id) == JSID_TYPE_SYMBOL;
 }
 
 extern JS_PUBLIC_DATA(const jsid) JSID_VOID;
diff --git a/js/public/Value.h b/js/public/Value.h
index 291b0fedc4ed..e0dd6c335b5f 100644
--- a/js/public/Value.h
+++ b/js/public/Value.h
@@ -1945,9 +1945,9 @@ DOUBLE_TO_JSVAL(double d)
 static inline JS_VALUE_CONSTEXPR jsval
 UINT_TO_JSVAL(uint32_t i)
 {
-    return (i <= JSVAL_INT_MAX
-            ? INT_TO_JSVAL((int32_t)i)
-            : DOUBLE_TO_JSVAL((double)i));
+    return i <= JSVAL_INT_MAX
+           ? INT_TO_JSVAL((int32_t)i)
+           : DOUBLE_TO_JSVAL((double)i);
 }
 
 static inline jsval
diff --git a/js/src/jit/BaselineDebugModeOSR.cpp b/js/src/jit/BaselineDebugModeOSR.cpp
index 6472f8f1bf6e..c69c6087e117 100644
--- a/js/src/jit/BaselineDebugModeOSR.cpp
+++ b/js/src/jit/BaselineDebugModeOSR.cpp
@@ -87,10 +87,10 @@ struct DebugModeOSREntry
     }
 
     bool needsRecompileInfo() const {
-        return (frameKind == ICEntry::Kind_CallVM ||
-                frameKind == ICEntry::Kind_DebugTrap ||
-                frameKind == ICEntry::Kind_DebugPrologue ||
-                frameKind == ICEntry::Kind_DebugEpilogue);
+        return frameKind == ICEntry::Kind_CallVM ||
+               frameKind == ICEntry::Kind_DebugTrap ||
+               frameKind == ICEntry::Kind_DebugPrologue ||
+               frameKind == ICEntry::Kind_DebugEpilogue;
     }
 
     bool recompiled() const {
@@ -805,9 +805,9 @@ JitRuntime::getBaselineDebugModeOSRHandlerAddress(JSContext *cx, bool popFrameRe
 {
     if (!getBaselineDebugModeOSRHandler(cx))
         return nullptr;
-    return (popFrameReg
-            ? baselineDebugModeOSRHandler_->raw()
-            : baselineDebugModeOSRHandlerNoFrameRegPopAddr_);
+    return popFrameReg
+           ? baselineDebugModeOSRHandler_->raw()
+           : baselineDebugModeOSRHandlerNoFrameRegPopAddr_;
 }
 
 JitCode *
diff --git a/js/src/jit/BaselineIC.cpp b/js/src/jit/BaselineIC.cpp
index 5e6c6871aabe..878fafa3202e 100644
--- a/js/src/jit/BaselineIC.cpp
+++ b/js/src/jit/BaselineIC.cpp
@@ -3890,9 +3890,9 @@ static bool
 TypedArrayRequiresFloatingPoint(TypedArrayObject *tarr)
 {
     uint32_t type = tarr->type();
-    return (type == Scalar::Uint32 ||
-            type == Scalar::Float32 ||
-            type == Scalar::Float64);
+    return type == Scalar::Uint32 ||
+           type == Scalar::Float32 ||
+           type == Scalar::Float64;
 }
 
 static bool
diff --git a/js/src/jit/BaselineIC.h b/js/src/jit/BaselineIC.h
index e3a545e52187..a95143421f7d 100644
--- a/js/src/jit/BaselineIC.h
+++ b/js/src/jit/BaselineIC.h
@@ -2255,8 +2255,8 @@ class ICCompare_Int32WithBoolean : public ICStub
         bool generateStubCode(MacroAssembler &masm);
 
         virtual int32_t getKey() const {
-            return (static_cast<int32_t>(kind) | (static_cast<int32_t>(op_) << 16) |
-                    (static_cast<int32_t>(lhsIsInt32_) << 24));
+            return static_cast<int32_t>(kind) | (static_cast<int32_t>(op_) << 16) |
+                   (static_cast<int32_t>(lhsIsInt32_) << 24);
         }
 
       public:
@@ -2568,8 +2568,8 @@ class ICBinaryArith_Int32 : public ICStub
 
         // Stub keys shift-stubs need to encode the kind, the JSOp and if we allow doubles.
         virtual int32_t getKey() const {
-            return (static_cast<int32_t>(kind) | (static_cast<int32_t>(op_) << 16) |
-                    (static_cast<int32_t>(allowDouble_) << 24));
+            return static_cast<int32_t>(kind) | (static_cast<int32_t>(op_) << 16) |
+                   (static_cast<int32_t>(allowDouble_) << 24);
         }
 
       public:
diff --git a/js/src/jit/IonBuilder.cpp b/js/src/jit/IonBuilder.cpp
index a069b417b6a3..f5bf43c9d806 100644
--- a/js/src/jit/IonBuilder.cpp
+++ b/js/src/jit/IonBuilder.cpp
@@ -9250,8 +9250,8 @@ IonBuilder::needsToMonitorMissingProperties(types::TemporaryTypeSet *types)
     // TypeScript::Monitor to ensure that the observed type set contains
     // undefined. To account for possible missing properties, which property
     // types do not track, we must always insert a type barrier.
-    return (info().executionMode() == ParallelExecution &&
-            !types->hasType(types::Type::UndefinedType()));
+    return info().executionMode() == ParallelExecution &&
+           !types->hasType(types::Type::UndefinedType());
 }
 
 bool
diff --git a/js/src/jit/IonCaches.cpp b/js/src/jit/IonCaches.cpp
index a752ffccf1ba..83f9c5cf4cc5 100644
--- a/js/src/jit/IonCaches.cpp
+++ b/js/src/jit/IonCaches.cpp
@@ -2986,10 +2986,10 @@ const size_t GetElementIC::MAX_FAILED_UPDATES = 16;
 GetElementIC::canAttachGetProp(JSObject *obj, const Value &idval, jsid id)
 {
     uint32_t dummy;
-    return (obj->isNative() &&
-            idval.isString() &&
-            JSID_IS_ATOM(id) &&
-            !JSID_TO_ATOM(id)->isIndex(&dummy));
+    return obj->isNative() &&
+           idval.isString() &&
+           JSID_IS_ATOM(id) &&
+           !JSID_TO_ATOM(id)->isIndex(&dummy);
 }
 
 static bool
@@ -3562,8 +3562,8 @@ static bool
 IsTypedArrayElementSetInlineable(JSObject *obj, const Value &idval, const Value &value)
 {
     // Don't bother attaching stubs for assigning strings and objects.
-    return (obj->is<TypedArrayObject>() && idval.isInt32() &&
-            !value.isString() && !value.isObject());
+    return obj->is<TypedArrayObject>() && idval.isInt32() &&
+           !value.isString() && !value.isObject();
 }
 
 static void
diff --git a/js/src/jit/LiveRangeAllocator.h b/js/src/jit/LiveRangeAllocator.h
index e3e7753539ac..92eef0b8ace6 100644
--- a/js/src/jit/LiveRangeAllocator.h
+++ b/js/src/jit/LiveRangeAllocator.h
@@ -568,8 +568,8 @@ static inline bool
 IsNunbox(VirtualRegister *vreg)
 {
 #ifdef JS_NUNBOX32
-    return (vreg->type() == LDefinition::TYPE ||
-            vreg->type() == LDefinition::PAYLOAD);
+    return vreg->type() == LDefinition::TYPE ||
+           vreg->type() == LDefinition::PAYLOAD;
 #else
     return false;
 #endif
diff --git a/js/src/jit/MIR.h b/js/src/jit/MIR.h
index 36159bd4f9a2..8a729e6cc1ab 100644
--- a/js/src/jit/MIR.h
+++ b/js/src/jit/MIR.h
@@ -7559,13 +7559,13 @@ class MStoreTypedArrayElement
         return arrayType_;
     }
     bool isByteArray() const {
-        return (arrayType_ == Scalar::Int8 ||
-                arrayType_ == Scalar::Uint8 ||
-                arrayType_ == Scalar::Uint8Clamped);
+        return arrayType_ == Scalar::Int8 ||
+               arrayType_ == Scalar::Uint8 ||
+               arrayType_ == Scalar::Uint8Clamped;
     }
     bool isFloatArray() const {
-        return (arrayType_ == Scalar::Float32 ||
-                arrayType_ == Scalar::Float64);
+        return arrayType_ == Scalar::Float32 ||
+               arrayType_ == Scalar::Float64;
     }
     TypePolicy *typePolicy() {
         return this;
@@ -7632,13 +7632,13 @@ class MStoreTypedArrayElementHole
         return arrayType_;
     }
     bool isByteArray() const {
-        return (arrayType_ == Scalar::Int8 ||
-                arrayType_ == Scalar::Uint8 ||
-                arrayType_ == Scalar::Uint8Clamped);
+        return arrayType_ == Scalar::Int8 ||
+               arrayType_ == Scalar::Uint8 ||
+               arrayType_ == Scalar::Uint8Clamped;
     }
     bool isFloatArray() const {
-        return (arrayType_ == Scalar::Float32 ||
-                arrayType_ == Scalar::Float64);
+        return arrayType_ == Scalar::Float32 ||
+               arrayType_ == Scalar::Float64;
     }
     TypePolicy *typePolicy() {
         return this;
@@ -7695,8 +7695,8 @@ class MStoreTypedArrayElementStatic :
         return typedArray_->type();
     }
     bool isFloatArray() const {
-        return (viewType() == Scalar::Float32 ||
-                viewType() == Scalar::Float64);
+        return viewType() == Scalar::Float32 ||
+               viewType() == Scalar::Float64;
     }
 
     void *base() const;
diff --git a/js/src/jit/ParallelFunctions.cpp b/js/src/jit/ParallelFunctions.cpp
index 4fbae4fccb68..87b326515813 100644
--- a/js/src/jit/ParallelFunctions.cpp
+++ b/js/src/jit/ParallelFunctions.cpp
@@ -123,8 +123,8 @@ jit::IsInTargetRegion(ForkJoinContext *cx, TypedObject *typedObj)
 {
     JS_ASSERT(typedObj->is<TypedObject>()); // in case JIT supplies something bogus
     uint8_t *typedMem = typedObj->typedMem();
-    return (typedMem >= cx->targetRegionStart &&
-            typedMem <  cx->targetRegionEnd);
+    return typedMem >= cx->targetRegionStart &&
+           typedMem <  cx->targetRegionEnd;
 }
 
 bool
diff --git a/js/src/jsapi.cpp b/js/src/jsapi.cpp
index 60d14ca22b04..55d12fdb555e 100644
--- a/js/src/jsapi.cpp
+++ b/js/src/jsapi.cpp
@@ -4332,9 +4332,9 @@ JS::OwningCompileOptions::copy(JSContext *cx, const ReadOnlyCompileOptions &rhs)
     setElementAttributeName(rhs.elementAttributeName());
     setIntroductionScript(rhs.introductionScript());
 
-    return (setFileAndLine(cx, rhs.filename(), rhs.lineno) &&
-            setSourceMapURL(cx, rhs.sourceMapURL()) &&
-            setIntroducerFilename(cx, rhs.introducerFilename()));
+    return setFileAndLine(cx, rhs.filename(), rhs.lineno) &&
+           setSourceMapURL(cx, rhs.sourceMapURL()) &&
+           setIntroducerFilename(cx, rhs.introducerFilename());
 }
 
 bool
diff --git a/js/src/vm/Probes-inl.h b/js/src/vm/Probes-inl.h
index c828a37bb9af..453abaa1cdd2 100644
--- a/js/src/vm/Probes-inl.h
+++ b/js/src/vm/Probes-inl.h
@@ -35,8 +35,8 @@ probes::CallTrackingActive(JSContext *cx)
 inline bool
 probes::WantNativeAddressInfo(JSContext *cx)
 {
-    return (cx->reportGranularity >= JITREPORT_GRANULARITY_FUNCTION &&
-            JITGranularityRequested(cx) >= JITREPORT_GRANULARITY_FUNCTION);
+    return cx->reportGranularity >= JITREPORT_GRANULARITY_FUNCTION &&
+           JITGranularityRequested(cx) >= JITREPORT_GRANULARITY_FUNCTION;
 }
 
 inline bool
diff --git a/js/xpconnect/src/XPCMaps.cpp b/js/xpconnect/src/XPCMaps.cpp
index 695bac411334..5fc5a8bbf582 100644
--- a/js/xpconnect/src/XPCMaps.cpp
+++ b/js/xpconnect/src/XPCMaps.cpp
@@ -375,10 +375,10 @@ NativeSetMap::Entry::Match(PLDHashTable *table,
         // it would end up really being a set with two interfaces (except for
         // the case where the one interface happened to be nsISupports).
 
-        return ((SetInTable->GetInterfaceCount() == 1 &&
-                 SetInTable->GetInterfaceAt(0) == Addition) ||
-                (SetInTable->GetInterfaceCount() == 2 &&
-                 SetInTable->GetInterfaceAt(1) == Addition));
+        return (SetInTable->GetInterfaceCount() == 1 &&
+                SetInTable->GetInterfaceAt(0) == Addition) ||
+               (SetInTable->GetInterfaceCount() == 2 &&
+                SetInTable->GetInterfaceAt(1) == Addition);
     }
 
     if (!Addition && Set == SetInTable)