[PATCH] D79205: [SROA] Clean up some uses of MaybeAlign in SROA.

[Eli Friedman via Phabricator via llvm-commits]

efriedma created this revision.
efriedma added a reviewer: jdoerfert.
Herald added a subscriber: hiraditya.
Herald added a project: LLVM.
efriedma added a child revision: D77454: LoadInst should store Align, not MaybeAlign..

Use Align instead of using MaybeAlign; all the operations in question have known alignment.

For getSliceAlign() in particular, in the cases where we used to return None, it would be converted back to an Align by IRBuilder, so there's no functional change there.

Split off from D77454 <https://reviews.llvm.org/D77454>.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D79205

Files:
  llvm/lib/Transforms/Scalar/SROA.cpp


Index: llvm/lib/Transforms/Scalar/SROA.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/SROA.cpp
+++ llvm/lib/Transforms/Scalar/SROA.cpp
@@ -1267,6 +1267,7 @@
 
   LoadInst *SomeLoad = cast<LoadInst>(PN.user_back());
   Type *LoadTy = SomeLoad->getType();
+  const DataLayout &DL = PN.getModule()->getDataLayout();
   IRBuilderTy PHIBuilder(&PN);
   PHINode *NewPN = PHIBuilder.CreatePHI(LoadTy, PN.getNumIncomingValues(),
                                         PN.getName() + ".sroa.speculated");
@@ -1275,7 +1276,8 @@
   // matter which one we get and if any differ.
   AAMDNodes AATags;
   SomeLoad->getAAMetadata(AATags);
-  const MaybeAlign Align = MaybeAlign(SomeLoad->getAlignment());
+  llvm::Align Align =
+      DL.getValueOrABITypeAlignment(SomeLoad->getAlign(), SomeLoad->getType());
 
   // Rewrite all loads of the PN to use the new PHI.
   while (!PN.use_empty()) {
@@ -2445,14 +2447,10 @@
   ///
   /// You can optionally pass a type to this routine and if that type's ABI
   /// alignment is itself suitable, this will return zero.
-  MaybeAlign getSliceAlign(Type *Ty = nullptr) {
-    const MaybeAlign NewAIAlign = DL.getValueOrABITypeAlignment(
+  Align getSliceAlign() {
+    Align NewAIAlign = DL.getValueOrABITypeAlignment(
         MaybeAlign(NewAI.getAlignment()), NewAI.getAllocatedType());
-    const MaybeAlign Align =
-        commonAlignment(NewAIAlign, NewBeginOffset - NewAllocaBeginOffset);
-    return (Ty && Align && Align->value() == DL.getABITypeAlignment(Ty))
-               ? None
-               : Align;
+    return commonAlignment(NewAIAlign, NewBeginOffset - NewAllocaBeginOffset);
   }
 
   unsigned getIndex(uint64_t Offset) {
@@ -2568,9 +2566,9 @@
           }
     } else {
       Type *LTy = TargetTy->getPointerTo(AS);
-      LoadInst *NewLI = IRB.CreateAlignedLoad(
-          TargetTy, getNewAllocaSlicePtr(IRB, LTy), getSliceAlign(TargetTy),
-          LI.isVolatile(), LI.getName());
+      LoadInst *NewLI =
+          IRB.CreateAlignedLoad(TargetTy, getNewAllocaSlicePtr(IRB, LTy),
+                                getSliceAlign(), LI.isVolatile(), LI.getName());
       if (AATags)
         NewLI->setAAMetadata(AATags);
       if (LI.isVolatile())
@@ -2596,7 +2594,8 @@
       // the computed value, and then replace the placeholder with LI, leaving
       // LI only used for this computation.
       Value *Placeholder = new LoadInst(
-          LI.getType(), UndefValue::get(LI.getType()->getPointerTo(AS)));
+          LI.getType(), UndefValue::get(LI.getType()->getPointerTo(AS)), "",
+          false, Align(1));
       V = insertInteger(DL, IRB, Placeholder, V, NewBeginOffset - BeginOffset,
                         "insert");
       LI.replaceAllUsesWith(V);
@@ -2721,8 +2720,8 @@
     } else {
       unsigned AS = SI.getPointerAddressSpace();
       Value *NewPtr = getNewAllocaSlicePtr(IRB, V->getType()->getPointerTo(AS));
-      NewSI = IRB.CreateAlignedStore(V, NewPtr, getSliceAlign(V->getType()),
-                                     SI.isVolatile());
+      NewSI =
+          IRB.CreateAlignedStore(V, NewPtr, getSliceAlign(), SI.isVolatile());
     }
     NewSI->copyMetadata(SI, {LLVMContext::MD_mem_parallel_loop_access,
                              LLVMContext::MD_access_group});
@@ -3140,14 +3139,14 @@
       Instruction *I = Uses.pop_back_val();
 
       if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
-        MaybeAlign LoadAlign = DL.getValueOrABITypeAlignment(
-            MaybeAlign(LI->getAlignment()), LI->getType());
+        Align LoadAlign =
+            DL.getValueOrABITypeAlignment(LI->getAlign(), LI->getType());
         LI->setAlignment(std::min(LoadAlign, getSliceAlign()));
         continue;
       }
       if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
           Value *Op = SI->getOperand(0);
-          MaybeAlign StoreAlign = DL.getValueOrABITypeAlignment(
+          Align StoreAlign = DL.getValueOrABITypeAlignment(
               MaybeAlign(SI->getAlignment()), Op->getType());
           SI->setAlignment(std::min(StoreAlign, getSliceAlign()));
           continue;


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