Bug 989344 part 2 - Share LRecoverInfo between LSnapshots. r=jandem

js/src/jit/shared/Lowering-shared.cpp

@@ -57,17 +57,21 @@ LIRGeneratorShared::lowerTypedPhiInput(MPhi *phi, uint32_t inputPosition, LBlock
 }
 
 LRecoverInfo *
-LIRGeneratorShared::buildRecover(MResumePoint *rp)
+LIRGeneratorShared::getRecoverInfo(MResumePoint *rp)
 {
-    LRecoverInfo *recover = LRecoverInfo::New(gen, rp);
-    return recover;
+    if (cachedRecoverInfo_ && cachedRecoverInfo_->mir() == rp)
+        return cachedRecoverInfo_;
+
+    LRecoverInfo *recoverInfo = LRecoverInfo::New(gen, rp);
+    cachedRecoverInfo_ = recoverInfo;
+    return recoverInfo;
 }
 
 #ifdef JS_NUNBOX32
 LSnapshot *
 LIRGeneratorShared::buildSnapshot(LInstruction *ins, MResumePoint *rp, BailoutKind kind)
 {
-    LRecoverInfo *recover = buildRecover(rp);
+    LRecoverInfo *recover = getRecoverInfo(rp);
     if (!recover)
         return nullptr;
 
@@ -125,7 +129,7 @@ LIRGeneratorShared::buildSnapshot(LInstruction *ins, MResumePoint *rp, BailoutKi
 LSnapshot *
 LIRGeneratorShared::buildSnapshot(LInstruction *ins, MResumePoint *rp, BailoutKind kind)
 {
-    LRecoverInfo *recover = buildRecover(rp);
+    LRecoverInfo *recover = getRecoverInfo(rp);
     if (!recover)
         return nullptr;
 

js/src/jit/shared/Lowering-shared.h

@@ -31,6 +31,7 @@ class LIRGeneratorShared : public MInstructionVisitorWithDefaults
     LIRGraph &lirGraph_;
     LBlock *current;
     MResumePoint *lastResumePoint_;
+    LRecoverInfo *cachedRecoverInfo_;
     LOsiPoint *osiPoint_;
 
   public:
@@ -39,6 +40,7 @@ class LIRGeneratorShared : public MInstructionVisitorWithDefaults
         graph(graph),
         lirGraph_(lirGraph),
         lastResumePoint_(nullptr),
+        cachedRecoverInfo_(nullptr),
         osiPoint_(nullptr)
     { }
 
@@ -160,7 +162,7 @@ class LIRGeneratorShared : public MInstructionVisitorWithDefaults
         return tmp;
     }
 
-    LRecoverInfo *buildRecover(MResumePoint *rp);
+    LRecoverInfo *getRecoverInfo(MResumePoint *rp);
     LSnapshot *buildSnapshot(LInstruction *ins, MResumePoint *rp, BailoutKind kind);
     bool assignPostSnapshot(MInstruction *mir, LInstruction *ins);