[llvm] 3c51b9e - Fix incorrect GEP bitwidth in areNonOverlapSameBaseLoadAndStore()

[Alex Richardson via llvm-commits]

Author: Alex Richardson
Date: 2021-09-28T17:57:36+01:00
New Revision: 3c51b9e270bac26fdec1b06ae8dd72960a2353a3

URL: https://github.com/llvm/llvm-project/commit/3c51b9e270bac26fdec1b06ae8dd72960a2353a3
DIFF: https://github.com/llvm/llvm-project/commit/3c51b9e270bac26fdec1b06ae8dd72960a2353a3.diff

LOG: Fix incorrect GEP bitwidth in areNonOverlapSameBaseLoadAndStore()

When using a datalayout that has pointer index width != pointer size this
code triggers an assertion in Value::stripAndAccumulateConstantOffsets().
I encountered this this while compiling FreeBSD for CHERI-RISC-V.
Also update LoadsTest.cpp to use a DataLayout with index width != pointer
width to ensure this case is tested.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D110406

Added: 
    

Modified: 
    llvm/lib/Analysis/Loads.cpp
    llvm/unittests/Analysis/LoadsTest.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Analysis/Loads.cpp b/llvm/lib/Analysis/Loads.cpp
index 1c55f485aa763..2e5f80d800156 100644
--- a/llvm/lib/Analysis/Loads.cpp
+++ b/llvm/lib/Analysis/Loads.cpp
@@ -451,8 +451,8 @@ static bool areNonOverlapSameBaseLoadAndStore(const Value *LoadPtr,
                                               const Value *StorePtr,
                                               Type *StoreTy,
                                               const DataLayout &DL) {
-  APInt LoadOffset(DL.getTypeSizeInBits(LoadPtr->getType()), 0);
-  APInt StoreOffset(DL.getTypeSizeInBits(StorePtr->getType()), 0);
+  APInt LoadOffset(DL.getIndexTypeSizeInBits(LoadPtr->getType()), 0);
+  APInt StoreOffset(DL.getIndexTypeSizeInBits(StorePtr->getType()), 0);
   const Value *LoadBase = LoadPtr->stripAndAccumulateConstantOffsets(
       DL, LoadOffset, /* AllowNonInbounds */ false);
   const Value *StoreBase = StorePtr->stripAndAccumulateConstantOffsets(

diff  --git a/llvm/unittests/Analysis/LoadsTest.cpp b/llvm/unittests/Analysis/LoadsTest.cpp
index 0ee1a5fa08a32..5570b747a4464 100644
--- a/llvm/unittests/Analysis/LoadsTest.cpp
+++ b/llvm/unittests/Analysis/LoadsTest.cpp
@@ -28,6 +28,7 @@ TEST(LoadsTest, FindAvailableLoadedValueSameBasePtrConstantOffsetsNullAA) {
   LLVMContext C;
   std::unique_ptr<Module> M = parseIR(C,
                                       R"IR(
+target datalayout = "p:64:64:64:32"
 %class = type <{ i32, i32 }>
 
 define i32 @f() {