CodeGenPrepare: Reorder check for cold and shouldOptimizeForSize

[arsenm]

Summary

shouldOptimizeForSize is showing up in a profile, spending around 10%
of the pass time in one function. This should probably not be so slow,
but the much cheaper attribute check should be done first anyway.

[hjyamauchi]

LGTM.

[arsenm]

23b76096b7d9b3a81ebfb1579471329a7d6b9c03

llvm/lib/CodeGen/CodeGenPrepare.cpp

if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(CI)) {
       }
     }
   }
 
   // If we have a cold call site, try to sink addressing computation into the
   // cold block.  This interacts with our handling for loads and stores to
   // ensure that we can fold all uses of a potential addressing computation
   // into their uses.  TODO: generalize this to work over profiling data
-  bool OptForSize = OptSize || llvm::shouldOptimizeForSize(BB, PSI, BFI.get());
-  if (!OptForSize && CI->hasFnAttr(Attribute::Cold))
+  if (CI->hasFnAttr(Attribute::Cold) &&
+      !OptSize && !llvm::shouldOptimizeForSize(BB, PSI, BFI.get()))
     for (auto &Arg : CI->arg_operands()) {
       if (!Arg->getType()->isPointerTy())
         continue;
       unsigned AS = Arg->getType()->getPointerAddressSpace();
       return optimizeMemoryInst(CI, Arg, Arg->getType(), AS);
     }
 
   IntrinsicInst *II = dyn_cast<IntrinsicInst>(CI);
if (AtomicCmpXchgInst *CmpX = dyn_cast<AtomicCmpXchgInst>(UserI)) {
       unsigned opNo = U.getOperandNo();
       if (opNo != AtomicCmpXchgInst::getPointerOperandIndex())
         return true; // Storing addr, not into addr.
       MemoryUses.push_back(std::make_pair(CmpX, opNo));
       continue;
     }
 
     if (CallInst *CI = dyn_cast<CallInst>(UserI)) {
+      if (CI->hasFnAttr(Attribute::Cold)) {
         // If this is a cold call, we can sink the addressing calculation into
         // the cold path.  See optimizeCallInst
         bool OptForSize = OptSize ||
           llvm::shouldOptimizeForSize(CI->getParent(), PSI, BFI);
-      if (!OptForSize && CI->hasFnAttr(Attribute::Cold))
+        if (!OptForSize)
           continue;
+      }
 
       InlineAsm *IA = dyn_cast<InlineAsm>(CI->getCalledValue());
       if (!IA) return true;
 
       // If this is a memory operand, we're cool, otherwise bail out.
       if (!IsOperandAMemoryOperand(CI, IA, I, TLI, TRI))
         return true;
       continue;