[PATCH] D76454: [ValueTracking] Fix usage of DataLayout::getTypeStoreSize()

[Huihui Zhang via Phabricator via llvm-commits]

huihuiz created this revision.
huihuiz added reviewers: sdesmalen, efriedma, apazos, reames.
huihuiz added a project: LLVM.
Herald added a subscriber: hiraditya.

DataLayout::getTypeStoreSize() returns TypeSize.
For cases where it can not be scalable vector (GlobalVariable),
explicitly call TypeSize::getFixedSize().
For cases where scalable property doesn't matter (check for zero-sized),
explicitly call TypeSize::getKnownMinSize(), to avoid implicit type
conversion to uint64_t, which is invalid for scalable vector.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D76454

Files:
  llvm/lib/Analysis/ValueTracking.cpp
  llvm/test/Transforms/MemCpyOpt/vscale.ll


Index: llvm/test/Transforms/MemCpyOpt/vscale.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/MemCpyOpt/vscale.ll
@@ -0,0 +1,18 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -S -memcpyopt | FileCheck %s
+
+; Check that this test doesn't cause compier warning
+; warning: Compiler has made implicit assumption that TypeSize is not scalable. This may or may not lead to broken code.
+
+define <vscale x 4 x i32> @test_isBytewiseValue(<vscale x 4 x i32> %z) {
+; CHECK-LABEL: @test_isBytewiseValue(
+; CHECK-NEXT:    [[A:%.*]] = alloca <vscale x 4 x i32>
+; CHECK-NEXT:    store <vscale x 4 x i32> [[Z:%.*]], <vscale x 4 x i32>* [[A]]
+; CHECK-NEXT:    [[LOAD:%.*]] = load <vscale x 4 x i32>, <vscale x 4 x i32>* [[A]]
+; CHECK-NEXT:    ret <vscale x 4 x i32> [[LOAD]]
+;
+  %a = alloca <vscale x 4 x i32>
+  store <vscale x 4 x i32> %z, <vscale x 4 x i32>* %a
+  %load = load <vscale x 4 x i32>, <vscale x 4 x i32>* %a
+  ret <vscale x 4 x i32> %load
+}
Index: llvm/lib/Analysis/ValueTracking.cpp
===================================================================
--- llvm/lib/Analysis/ValueTracking.cpp
+++ llvm/lib/Analysis/ValueTracking.cpp
@@ -3497,7 +3497,7 @@
   if (isa<UndefValue>(V))
     return UndefInt8;
 
-  const uint64_t Size = DL.getTypeStoreSize(V->getType());
+  const uint64_t Size = DL.getTypeStoreSize(V->getType()).getKnownMinSize();
   if (!Size)
     return UndefInt8;
 
@@ -3816,7 +3816,7 @@
       Array = nullptr;
     } else {
       const DataLayout &DL = GV->getParent()->getDataLayout();
-      uint64_t SizeInBytes = DL.getTypeStoreSize(GVTy);
+      uint64_t SizeInBytes = DL.getTypeStoreSize(GVTy).getFixedSize();
       uint64_t Length = SizeInBytes / (ElementSize / 8);
       if (Length <= Offset)
         return false;


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