Mark setjmp as "returns twice" and turn off SimpleCoalescing when called.

src/IceTargetLowering.h

 //===- subzero/src/IceTargetLowering.h - Lowering interface -----*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file declares the TargetLowering and LoweringContext
@@ skipping 123 matching lines @@
   // Returns a printable name for the register.
   virtual IceString getRegName(SizeT RegNum, Type Ty) const = 0;
 
   virtual bool hasFramePointer() const { return false; }
   virtual SizeT getFrameOrStackReg() const = 0;
   virtual size_t typeWidthInBytesOnStack(Type Ty) const = 0;
   virtual SizeT getBundleAlignLog2Bytes() const = 0;
   virtual llvm::ArrayRef<uint8_t> getNonExecBundlePadding() const = 0;
   bool hasComputedFrame() const { return HasComputedFrame; }
   bool shouldDoNopInsertion() const;
+  // Returns true if this function calls a function that has the
+  // "returns twice" attribute.
+  bool callsReturnsTwice() const { return CallsReturnsTwice; }
+  void setCallsReturnsTwice(bool RetTwice) {
+    CallsReturnsTwice = RetTwice;
+  }
   int32_t getStackAdjustment() const { return StackAdjustment; }
   void updateStackAdjustment(int32_t Offset) { StackAdjustment += Offset; }
   void resetStackAdjustment() { StackAdjustment = 0; }
   LoweringContext &getContext() { return Context; }
 
   enum RegSet {
     RegSet_None = 0,
     RegSet_CallerSave = 1 << 0,
     RegSet_CalleeSave = 1 << 1,
     RegSet_StackPointer = 1 << 2,
@@ skipping 15 matching lines @@
   virtual void addProlog(CfgNode *Node) = 0;
   virtual void addEpilog(CfgNode *Node) = 0;
 
   virtual void emitConstants() const = 0;
 
   virtual ~TargetLowering() {}
 
 protected:
   TargetLowering(Cfg *Func)
       : Func(Func), Ctx(Func->getContext()), HasComputedFrame(false),
-        StackAdjustment(0) {}
+        CallsReturnsTwice(false), StackAdjustment(0) {}
   virtual void lowerAlloca(const InstAlloca *Inst) = 0;
   virtual void lowerArithmetic(const InstArithmetic *Inst) = 0;
   virtual void lowerAssign(const InstAssign *Inst) = 0;
   virtual void lowerBr(const InstBr *Inst) = 0;
   virtual void lowerCall(const InstCall *Inst) = 0;
   virtual void lowerCast(const InstCast *Inst) = 0;
   virtual void lowerFcmp(const InstFcmp *Inst) = 0;
   virtual void lowerExtractElement(const InstExtractElement *Inst) = 0;
   virtual void lowerIcmp(const InstIcmp *Inst) = 0;
   virtual void lowerInsertElement(const InstInsertElement *Inst) = 0;
@@ skipping 13 matching lines @@
   // expansion before returning.  The primary intention is to do some
   // Register Manager activity as necessary, specifically to eagerly
   // allocate registers based on affinity and other factors.  The
   // simplest lowering does nothing here and leaves it all to a
   // subsequent global register allocation pass.
   virtual void postLower() {}
 
   Cfg *Func;
   GlobalContext *Ctx;
   bool HasComputedFrame;
+  bool CallsReturnsTwice;
   // StackAdjustment keeps track of the current stack offset from its
   // natural location, as arguments are pushed for a function call.
   int32_t StackAdjustment;
   LoweringContext Context;
 
 private:
   TargetLowering(const TargetLowering &) LLVM_DELETED_FUNCTION;
   TargetLowering &operator=(const TargetLowering &) LLVM_DELETED_FUNCTION;
 };
 
@@ skipping 18 matching lines @@
 private:
   TargetGlobalInitLowering(const TargetGlobalInitLowering &)
   LLVM_DELETED_FUNCTION;
   TargetGlobalInitLowering &
   operator=(const TargetGlobalInitLowering &) LLVM_DELETED_FUNCTION;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICETARGETLOWERING_H