[llvm] 5350a48 - [ConstantFold][SVE] Fix constant fold for FoldReinterpretLoadFromConstPtr.

[Huihui Zhang via llvm-commits]

Author: Huihui Zhang
Date: 2020-02-12T10:24:50-08:00
New Revision: 5350a48931d035900ac90bc56620eaa2baeb5c09

URL: https://github.com/llvm/llvm-project/commit/5350a48931d035900ac90bc56620eaa2baeb5c09
DIFF: https://github.com/llvm/llvm-project/commit/5350a48931d035900ac90bc56620eaa2baeb5c09.diff

LOG: [ConstantFold][SVE] Fix constant fold for FoldReinterpretLoadFromConstPtr.

Summary:
Bail out early for scalable vectors. As global variables are not expected
to be scalable.

Use explicit call of getFixedSize() to assert on places where scalable size
doesn't make sense.

Reviewers: sdesmalen, efriedma, apazos, huntergr, willlovett

Reviewed By: sdesmalen

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74424

Added: 
    

Modified: 
    llvm/lib/Analysis/ConstantFolding.cpp
    llvm/test/Analysis/ConstantFolding/vscale.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Analysis/ConstantFolding.cpp b/llvm/lib/Analysis/ConstantFolding.cpp
index 33d82c6527f4..0e4828d912dc 100644
--- a/llvm/lib/Analysis/ConstantFolding.cpp
+++ b/llvm/lib/Analysis/ConstantFolding.cpp
@@ -501,6 +501,10 @@ bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset, unsigned char *CurPtr,
 
 Constant *FoldReinterpretLoadFromConstPtr(Constant *C, Type *LoadTy,
                                           const DataLayout &DL) {
+  // Bail out early. Not expect to load from scalable global variable.
+  if (LoadTy->isVectorTy() && LoadTy->getVectorIsScalable())
+    return nullptr;
+
   auto *PTy = cast<PointerType>(C->getType());
   auto *IntType = dyn_cast<IntegerType>(LoadTy);
 
@@ -520,8 +524,8 @@ Constant *FoldReinterpretLoadFromConstPtr(Constant *C, Type *LoadTy,
     else if (LoadTy->isDoubleTy())
       MapTy = Type::getInt64Ty(C->getContext());
     else if (LoadTy->isVectorTy()) {
-      MapTy = PointerType::getIntNTy(C->getContext(),
-                                     DL.getTypeSizeInBits(LoadTy));
+      MapTy = PointerType::getIntNTy(
+          C->getContext(), DL.getTypeSizeInBits(LoadTy).getFixedSize());
     } else
       return nullptr;
 
@@ -561,7 +565,8 @@ Constant *FoldReinterpretLoadFromConstPtr(Constant *C, Type *LoadTy,
     return nullptr;
 
   int64_t Offset = OffsetAI.getSExtValue();
-  int64_t InitializerSize = DL.getTypeAllocSize(GV->getInitializer()->getType());
+  int64_t InitializerSize =
+      DL.getTypeAllocSize(GV->getInitializer()->getType()).getFixedSize();
 
   // If we're not accessing anything in this constant, the result is undefined.
   if (Offset <= -1 * static_cast<int64_t>(BytesLoaded))

diff  --git a/llvm/test/Analysis/ConstantFolding/vscale.ll b/llvm/test/Analysis/ConstantFolding/vscale.ll
index 3a3d6a16c7d6..1616c70f200c 100644
--- a/llvm/test/Analysis/ConstantFolding/vscale.ll
+++ b/llvm/test/Analysis/ConstantFolding/vscale.ll
@@ -185,6 +185,20 @@ define <vscale x 4 x i32> @shufflevector() {
   %i2 = shufflevector <vscale x 4 x i32> %i, <vscale x 4 x i32> undef, <vscale x 4 x i32> zeroinitializer
   ret <vscale x 4 x i32> %i2
 }
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Memory Access and Addressing Operations
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+define <vscale x 2 x double> @load() {
+; CHECK-LABEL: @load(
+; CHECK-NEXT:    [[R:%.*]] = load <vscale x 2 x double>, <vscale x 2 x double>* getelementptr (<vscale x 2 x double>, <vscale x 2 x double>* null, i64 1)
+; CHECK-NEXT:    ret <vscale x 2 x double> [[R]]
+;
+  %r = load <vscale x 2 x double>, <vscale x 2 x double>* getelementptr (<vscale x 2 x double>, <vscale x 2 x double>* null, i64 1)
+  ret <vscale x 2 x double> %r
+}
+
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; Conversion Operations
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;