OS#15659337: Try to allocate JIT code in PreReservedSegment even if CFG is not enabled

agarwal-sandeep · agarwal-sandeep · commit d8b60d1b1e41 · 2018-02-07T09:33:36.000-08:00
This speeds up stack walking IsNativeAddress checks when CFG is not enabled.
diff --git a/lib/Backend/Func.cpp b/lib/Backend/Func.cpp
@@ -1140,12 +1140,11 @@ Func::IsAggressiveIntTypeSpecDisabled() const
     return (HasProfileInfo() && GetReadOnlyProfileInfo()->IsAggressiveIntTypeSpecDisabled(IsLoopBody())) || m_output.IsAggressiveIntTypeSpecDisabled();
 }
 
-bool Func::CanAllocInPreReservedHeapPageSegment ()
+bool Func::CanAllocInPreReservedHeapPageSegment()
 {
 #ifdef _CONTROL_FLOW_GUARD
     return PHASE_FORCE1(Js::PreReservedHeapAllocPhase) || (!PHASE_OFF1(Js::PreReservedHeapAllocPhase) &&
-        !IsJitInDebugMode() && GetThreadContextInfo()->IsCFGEnabled()
-        //&& !GetScriptContext()->IsScriptContextInDebugMode()
+        !IsJitInDebugMode()
 #if _M_IX86
         && m_workItem->GetJitMode() == ExecutionMode::FullJit
 

Original file line number	Diff line number	Diff line change
`@@ -1140,12 +1140,11 @@ Func::IsAggressiveIntTypeSpecDisabled() const`
`1140`	`1140`	`return (HasProfileInfo() && GetReadOnlyProfileInfo()->IsAggressiveIntTypeSpecDisabled(IsLoopBody())) \|\| m_output.IsAggressiveIntTypeSpecDisabled();`
`1141`	`1141`	`}`
`1142`	`1142`
`1143`		`-bool Func::CanAllocInPreReservedHeapPageSegment ()`
	`1143`	`+bool Func::CanAllocInPreReservedHeapPageSegment()`
`1144`	`1144`	`{`
`1145`	`1145`	`#ifdef _CONTROL_FLOW_GUARD`
`1146`	`1146`	`return PHASE_FORCE1(Js::PreReservedHeapAllocPhase) \|\| (!PHASE_OFF1(Js::PreReservedHeapAllocPhase) &&`
`1147`		`- !IsJitInDebugMode() && GetThreadContextInfo()->IsCFGEnabled()`
`1148`		`- //&& !GetScriptContext()->IsScriptContextInDebugMode()`
	`1147`	`+ !IsJitInDebugMode()`
`1149`	`1148`	`#if _M_IX86`
`1150`	`1149`	`&& m_workItem->GetJitMode() == ExecutionMode::FullJit`
`1151`	`1150`