[PATCH] D48330: [GVN] Avoid casting a vector of size less than 8 bits to i8

[Matthew Voss via Phabricator via llvm-commits]

ormris updated this revision to Diff 152364.
ormris added a comment.

Add load-load case and sanity checks


Repository:
  rL LLVM

https://reviews.llvm.org/D48330

Files:
  lib/Transforms/Utils/VNCoercion.cpp
  test/Transforms/GVN/load-load-odd-vector.ll
  test/Transforms/GVN/pr28879.ll


Index: test/Transforms/GVN/pr28879.ll
===================================================================
--- /dev/null
+++ test/Transforms/GVN/pr28879.ll
@@ -0,0 +1,18 @@
+; RUN: opt -gvn <%s -S -o - | FileCheck %s
+
+define void @f() {
+entry:
+  %a = alloca <7 x i1>, align 2
+  store <7 x i1> undef, <7 x i1>* %a, align 2
+; CHECK: store <7 x i1> undef, <7 x i1>*
+  %0 = getelementptr inbounds <7 x i1>, <7 x i1>* %a, i64 0, i64 0
+  %val = load i1, i1* %0, align 2
+; CHECK: load i1, i1* 
+  br i1 %val, label %cond.true, label %cond.false
+
+cond.true:
+  ret void
+
+cond.false:
+  ret void
+}
Index: test/Transforms/GVN/load-load-odd-vector.ll
===================================================================
--- /dev/null
+++ test/Transforms/GVN/load-load-odd-vector.ll
@@ -0,0 +1,17 @@
+; RUN: opt -gvn <%s -S -o - | FileCheck %s
+
+define <7 x i1> @f(<7 x i1>* %a) {
+entry:
+  %vec = load <7 x i1>, <7 x i1>* %a
+; CHECK: load <7 x i1>, <7 x i1>*
+  %0 = getelementptr inbounds <7 x i1>, <7 x i1>* %a, i64 0, i64 0
+  %val = load i1, i1* %0, align 2
+; CHECK: load i1, i1*
+  br i1 %val, label %cond.true, label %cond.false
+
+cond.true:
+  ret <7 x i1> %vec
+
+cond.false:
+  ret <7 x i1> <i1 false, i1 false, i1 false, i1 false, i1 false, i1 false, i1 false>
+}
Index: lib/Transforms/Utils/VNCoercion.cpp
===================================================================
--- lib/Transforms/Utils/VNCoercion.cpp
+++ lib/Transforms/Utils/VNCoercion.cpp
@@ -20,8 +20,13 @@
       StoredVal->getType()->isStructTy() || StoredVal->getType()->isArrayTy())
     return false;
 
+  uint64_t StoreSize = DL.getTypeSizeInBits(StoredVal->getType());
+
+  if (llvm::alignTo(StoreSize, 8) != StoreSize)
+    return false;
+
   // The store has to be at least as big as the load.
-  if (DL.getTypeSizeInBits(StoredVal->getType()) < DL.getTypeSizeInBits(LoadTy))
+  if (StoreSize < DL.getTypeSizeInBits(LoadTy))
     return false;
 
   // Don't coerce non-integral pointers to integers or vice versa.


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D48330.152364.patch
Type: text/x-patch
Size: 2006 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20180621/11e4c50b/attachment.bin>