[llvm] r366470 - [LAA] Re-check bit-width of pointers after stripping.

[Michael Liao via llvm-commits]

Author: hliao
Date: Thu Jul 18 10:30:27 2019
New Revision: 366470

URL: http://llvm.org/viewvc/llvm-project?rev=366470&view=rev
Log:
[LAA] Re-check bit-width of pointers after stripping.

Summary:
- As the pointer stripping now tracks through `addrspacecast`, prepare
  to handle the bit-width difference from the result pointer.

Reviewers: jdoerfert

Subscribers: jvesely, nhaehnle, hiraditya, arphaman, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64928

Modified:
    llvm/trunk/lib/Analysis/LoopAccessAnalysis.cpp
    llvm/trunk/test/Transforms/SLPVectorizer/AMDGPU/address-space-ptr-sze-gep-index-assert.ll

Modified: llvm/trunk/lib/Analysis/LoopAccessAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/LoopAccessAnalysis.cpp?rev=366470&r1=366469&r2=366470&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/LoopAccessAnalysis.cpp (original)
+++ llvm/trunk/lib/Analysis/LoopAccessAnalysis.cpp Thu Jul 18 10:30:27 2019
@@ -1189,12 +1189,25 @@ bool llvm::isConsecutiveAccess(Value *A,
 
   unsigned IdxWidth = DL.getIndexSizeInBits(ASA);
   Type *Ty = cast<PointerType>(PtrA->getType())->getElementType();
-  APInt Size(IdxWidth, DL.getTypeStoreSize(Ty));
 
   APInt OffsetA(IdxWidth, 0), OffsetB(IdxWidth, 0);
   PtrA = PtrA->stripAndAccumulateInBoundsConstantOffsets(DL, OffsetA);
   PtrB = PtrB->stripAndAccumulateInBoundsConstantOffsets(DL, OffsetB);
 
+  // Retrieve the address space again as pointer stripping now tracks through
+  // `addrspacecast`.
+  ASA = cast<PointerType>(PtrA->getType())->getAddressSpace();
+  ASB = cast<PointerType>(PtrB->getType())->getAddressSpace();
+  // Check that the address spaces match and that the pointers are valid.
+  if (ASA != ASB)
+    return false;
+
+  IdxWidth = DL.getIndexSizeInBits(ASA);
+  OffsetA = OffsetA.sextOrTrunc(IdxWidth);
+  OffsetB = OffsetB.sextOrTrunc(IdxWidth);
+
+  APInt Size(IdxWidth, DL.getTypeStoreSize(Ty));
+
   //  OffsetDelta = OffsetB - OffsetA;
   const SCEV *OffsetSCEVA = SE.getConstant(OffsetA);
   const SCEV *OffsetSCEVB = SE.getConstant(OffsetB);

Modified: llvm/trunk/test/Transforms/SLPVectorizer/AMDGPU/address-space-ptr-sze-gep-index-assert.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SLPVectorizer/AMDGPU/address-space-ptr-sze-gep-index-assert.ll?rev=366470&r1=366469&r2=366470&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/SLPVectorizer/AMDGPU/address-space-ptr-sze-gep-index-assert.ll (original)
+++ llvm/trunk/test/Transforms/SLPVectorizer/AMDGPU/address-space-ptr-sze-gep-index-assert.ll Thu Jul 18 10:30:27 2019
@@ -147,3 +147,16 @@ bb:
   store i32 %sub1, i32* undef
   ret void
 }
+
+; CHECK-LABEL: slp_crash_on_addrspacecast
+; CHECK: ret void
+define void @slp_crash_on_addrspacecast() {
+entry:
+  %0 = getelementptr inbounds i64, i64 addrspace(3)* undef, i32 undef
+  %p0 = addrspacecast i64 addrspace(3)* %0 to i64*
+  store i64 undef, i64* %p0, align 8
+  %1 = getelementptr inbounds i64, i64 addrspace(3)* undef, i32 undef
+  %p1 = addrspacecast i64 addrspace(3)* %1 to i64*
+  store i64 undef, i64* %p1, align 8
+  ret void
+}