[LV] Use BB::instructionsWithoutDebug to skip DbgInfo (NFC).

[fhahn]

Summary

This patch updates some code responsible the skip debug info to use
BasicBlock::instructionsWithoutDebug. I think this makes things
slightly simpler and more direct.

[rengolin]

makes sense. thanks!

[mattd]

I like this, clean.

[dcaballe]

Thanks for the cleanup, Florian!

[hsaito]

Thanks, Florian. This is loosely related to D46199. See comments there. We need to consciously try using (or even creating) generically reusable code like this, instead of each file having it's own "skip this, skip that".

[rengolin]

In D46254#1083185, @hsaito wrote:

We need to consciously try using (or even creating) generically reusable code like this, instead of each file having it's own "skip this, skip that".

+1!

[fhahn]

In D46254#1083185, @hsaito wrote:

Thanks, Florian. This is loosely related to D46199. See comments there. We need to consciously try using (or even creating) generically reusable code like this, instead of each file having it's own "skip this, skip that".

That was the intention behind adding BB::instructionsWithoutDebug. It should be applicable to a wide range of cases and I will try to move existing code slowly towards using it. I think there might be a case for having a generic utility function that skips lifetime/assume intrinisics. But at least the few passes I had a look at so far seemed to have problems dealing with those intrinsics in the first place.

[davide]

LGTM, thanks.

llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp

 LoopVectorizationCostModel::expectedCost(unsigned VF) {
   VectorizationCostTy Cost;
 
   // For each block.
   for (BasicBlock *BB : TheLoop->blocks()) {
     VectorizationCostTy BlockCost;
 
     // For each instruction in the old loop.
-    for (Instruction &I : *BB) {
-      // Skip dbg intrinsics.
-      if (isa<DbgInfoIntrinsic>(I))
-        continue;
-
+    for (Instruction &I : BB->instructionsWithoutDebug()) {
       // Skip ignored values.
       if (ValuesToIgnore.count(&I) ||
           (VF > 1 && VecValuesToIgnore.count(&I)))
         continue;
 
       VectorizationCostTy C = getInstructionCost(&I, VF);
 
       // Check if we should override the cost.
for (BasicBlock *BB : make_range(DFS.beginRPO(), DFS.endRPO())) {
     VPBB->setOneSuccessor(FirstVPBBForBB);
     VPBB = FirstVPBBForBB;
     Builder.setInsertPoint(VPBB);
 
     std::vector<Instruction *> Ingredients;
 
     // Organize the ingredients to vectorize from current basic block in the
     // right order.
-    for (Instruction &I : *BB) {
+    for (Instruction &I : BB->instructionsWithoutDebug()) {
       Instruction *Instr = &I;
 
       // First filter out irrelevant instructions, to ensure no recipes are
       // built for them.
-      if (isa<BranchInst>(Instr) || isa<DbgInfoIntrinsic>(Instr) ||
-          DeadInstructions.count(Instr))
+      if (isa<BranchInst>(Instr) || DeadInstructions.count(Instr))
         continue;
 
       // I is a member of an InterleaveGroup for Range.Start. If it's an adjunct
       // member of the IG, do not construct any Recipe for it.
       const InterleaveGroup *IG = CM.getInterleavedAccessGroup(Instr);
       if (IG && Instr != IG->getInsertPos() &&
           Range.Start >= 2 && // Query is illegal for VF == 1
           CM.getWideningDecision(Instr, Range.Start) ==