Replace isTrapping with a new, similar method called

isSafeToSpeculativelyExecute. The new method is a bit closer to what 
the callers actually care about in that it rejects more things callers 
don't want.  It also adds more precise handling for integer 
division, and unifies code for analyzing the legality of a speculative 
load.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76150 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Scalar/TailDuplication.cpp

@@ -258,7 +258,8 @@ void TailDup::eliminateUnconditionalBranch(BranchInst *Branch) {
     while (!isa<TerminatorInst>(BBI)) {
       Instruction *I = BBI++;
 
-      bool CanHoist = !I->isTrapping() && !I->mayHaveSideEffects();
+      bool CanHoist = I->isSafeToSpeculativelyExecute() &&
+                      !I->mayReadFromMemory();
       if (CanHoist) {
         for (unsigned op = 0, e = I->getNumOperands(); op != e; ++op)
           if (Instruction *OpI = dyn_cast<Instruction>(I->getOperand(op)))