step

Author: fhahn

llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp

@@ -3226,42 +3226,6 @@ Instruction *InstCombinerImpl::visitCallInst(CallInst &CI) {
         MaybeSimplifyHint(OBU.Inputs[0]);
         MaybeSimplifyHint(OBU.Inputs[1]);
       }
-
-      if (OBU.getTagName() == "align" && OBU.Inputs.size() == 2) {
-        RetainedKnowledge RK = getKnowledgeFromBundle(
-            *cast<AssumeInst>(II), II->bundle_op_info_begin()[Idx]);
-        if (!RK || RK.AttrKind != Attribute::Alignment ||
-            !isPowerOf2_64(RK.ArgValue))
-          continue;
-        SetVector<const Instruction *> WorkList;
-        bool AlignNeeded = false;
-        WorkList.insert(II);
-        for (unsigned I = 0; I != WorkList.size(); ++I) {
-          if (auto *LI = dyn_cast<LoadInst>(WorkList[I])) {
-            if (auto *AlignMD = LI->getMetadata(LLVMContext::MD_align)) {
-              auto *A = mdconst::extract<ConstantInt>(AlignMD->getOperand(0));
-
-              if (A->getZExtValue() % RK.ArgValue != 0) {
-                AlignNeeded = true;
-                break;
-              }
-            }
-          }
-          if (isa<ICmpInst>(WorkList[I])) {
-            AlignNeeded = true;
-            break;
-          }
-          if (WorkList.size() > 16) {
-            AlignNeeded = true;
-            break;
-          }
-
-          for (const User *U : WorkList[I]->users())
-            WorkList.insert(cast<Instruction>(U));
-        }
-        auto *New = CallBase::removeOperandBundle(II, OBU.getTagID());
-        return New;
-      }
     }
 
     // Convert nonnull assume like:

llvm/lib/Transforms/Scalar/EarlyCSE.cpp

@@ -1606,15 +1606,58 @@ bool EarlyCSE::processNode(DomTreeNode *Node) {
         // alignment assumption. Note that this doesn't use salavageKnowledge,
         // as we need to create the assumption for the value we replaced the
         // load with.
-        if (Inst.hasMetadata(LLVMContext::MD_noundef)) {
-          if (auto *AlignMD = Inst.getMetadata(LLVMContext::MD_align)) {
+        if (auto *AlignMD = Inst.getMetadata(LLVMContext::MD_align)) {
+          if (Inst.hasMetadata(LLVMContext::MD_noundef) ||
+              programUndefinedIfPoison(&Inst)) {
             Inst.setMetadata(LLVMContext::MD_align, nullptr);
-            auto *A = mdconst::extract<ConstantInt>(AlignMD->getOperand(0));
+            auto *B = mdconst::extract<ConstantInt>(AlignMD->getOperand(0));
             auto KB = computeKnownBits(Op, SQ.DL);
             unsigned AlignFromKB = 1 << KB.countMinTrailingZeros();
-            if (AlignFromKB < A->getZExtValue()) {
-              IRBuilder B(&Inst);
-              B.CreateAlignmentAssumption(SQ.DL, Op, A);
+            if (AlignFromKB < B->getZExtValue()) {
+              SetVector<const Value *> WorkList;
+              bool AlignNeeded = false;
+              for (const User *U : Inst.users())
+                if (auto *I = dyn_cast<Instruction>(U))
+                  WorkList.insert(I);
+
+              for (unsigned I = 0; I != WorkList.size(); ++I) {
+                auto *Curr = WorkList[I];
+                if (auto *LI = dyn_cast<LoadInst>(Curr)) {
+                  if (LI->getAlign().value() < B->getZExtValue()) {
+                    AlignNeeded = true;
+                    break;
+                  }
+                  continue;
+                }
+                if (auto *SI = dyn_cast<StoreInst>(Curr)) {
+                  if (SI->getAlign().value() < B->getZExtValue()) {
+                    AlignNeeded = true;
+                    break;
+                  }
+                  continue;
+                }
+                if (isa<ReturnInst>(Curr)) {
+                  AlignNeeded = true;
+                  break;
+                }
+                if (isa<ICmpInst>(Curr) &&
+                    !isa<Constant>(cast<Instruction>(Curr)->getOperand(0)) &&
+                    !isa<Constant>(cast<Instruction>(Curr)->getOperand(1))) {
+                  AlignNeeded = true;
+                  break;
+                }
+                if (WorkList.size() > 16) {
+                  AlignNeeded = true;
+                  break;
+                }
+
+                for (const User *U : Curr->users())
+                  WorkList.insert(cast<Instruction>(U));
+              }
+              if (AlignNeeded) {
+                IRBuilder Builder(&Inst);
+                Builder.CreateAlignmentAssumption(SQ.DL, Op, B);
+              }
             }
           }
         }