[llvm-commits] [llvm] r144399 - in /llvm/trunk: include/llvm/CodeGen/GCStrategy.h lib/CodeGen/GCStrategy.cpp

[Nicolas Geoffray]

Author: geoffray
Date: Fri Nov 11 12:32:52 2011
New Revision: 144399

URL: http://llvm.org/viewvc/llvm-project?rev=144399&view=rev
Log:
Add a custom safepoint method, in order for language implementers to decide which machine instruction gets to be a safepoint.


Modified:
    llvm/trunk/include/llvm/CodeGen/GCStrategy.h
    llvm/trunk/lib/CodeGen/GCStrategy.cpp

Modified: llvm/trunk/include/llvm/CodeGen/GCStrategy.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/GCStrategy.h?rev=144399&r1=144398&r2=144399&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/GCStrategy.h (original)
+++ llvm/trunk/include/llvm/CodeGen/GCStrategy.h Fri Nov 11 12:32:52 2011
@@ -37,6 +37,7 @@
 #define LLVM_CODEGEN_GCSTRATEGY_H
 
 #include "llvm/CodeGen/GCMetadata.h"
+#include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/Support/Registry.h"
 #include <string>
 
@@ -68,6 +69,8 @@
     bool CustomReadBarriers;   //< Default is to insert loads.
     bool CustomWriteBarriers;  //< Default is to insert stores.
     bool CustomRoots;          //< Default is to pass through to backend.
+    bool CustomSafePoints;     //< Default is to use NeededSafePoints
+                               //  to find safe points.
     bool InitRoots;            //< If set, roots are nulled during lowering.
     bool UsesMetadata;         //< If set, backend must emit metadata tables.
     
@@ -87,7 +90,9 @@
 
     /// needsSafePoitns - True if safe points of any kind are required. By
     //                    default, none are recorded.
-    bool needsSafePoints() const { return NeededSafePoints != 0; }
+    bool needsSafePoints() const {
+      return CustomSafePoints || NeededSafePoints != 0;
+    }
     
     /// needsSafePoint(Kind) - True if the given kind of safe point is
     //                          required. By default, none are recorded.
@@ -109,6 +114,11 @@
     ///               can generate a stack map. If true, then
     //                performCustomLowering must delete them.
     bool customRoots() const { return CustomRoots; }
+
+    /// customSafePoints - By default, the GC analysis will find safe
+    ///                    points according to NeededSafePoints. If true,
+    ///                    then findCustomSafePoints must create them.
+    bool customSafePoints() const { return CustomSafePoints; }
     
     /// initializeRoots - If set, gcroot intrinsics should initialize their
     //                    allocas to null before the first use. This is
@@ -135,6 +145,7 @@
     /// which the LLVM IR can be modified.
     virtual bool initializeCustomLowering(Module &F);
     virtual bool performCustomLowering(Function &F);
+    virtual bool findCustomSafePoints(GCFunctionInfo& FI, MachineFunction& MF);
   };
   
 }

Modified: llvm/trunk/lib/CodeGen/GCStrategy.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/GCStrategy.cpp?rev=144399&r1=144398&r2=144399&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/GCStrategy.cpp (original)
+++ llvm/trunk/lib/CodeGen/GCStrategy.cpp Fri Nov 11 12:32:52 2011
@@ -97,6 +97,7 @@
   CustomReadBarriers(false),
   CustomWriteBarriers(false),
   CustomRoots(false),
+  CustomSafePoints(false),
   InitRoots(true),
   UsesMetadata(false)
 {}
@@ -116,6 +117,14 @@
   return 0;
 }
 
+
+bool GCStrategy::findCustomSafePoints(GCFunctionInfo& FI, MachineFunction &F) {
+  dbgs() << "gc " << getName() << " must override findCustomSafePoints.\n";
+  llvm_unreachable(0);
+  return 0;
+}
+
+
 GCFunctionInfo *GCStrategy::insertFunctionInfo(const Function &F) {
   GCFunctionInfo *FI = new GCFunctionInfo(F, *this);
   Functions.push_back(FI);
@@ -405,9 +414,13 @@
   
   // Find the size of the stack frame.
   FI->setFrameSize(MF.getFrameInfo()->getStackSize());
-  
+
   // Find all safe points.
-  FindSafePoints(MF);
+  if (FI->getStrategy().customSafePoints()) {
+    FI->getStrategy().findCustomSafePoints(*FI, MF);
+  } else {
+    FindSafePoints(MF);
+  }
   
   // Find the stack offsets for all roots.
   FindStackOffsets(MF);