If the size of memory access is unknown, do not use it to analysis. One example of unknown size memory access is to load/store scalable vector objects on the stack.
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| Time | Test | |
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| 390 ms | linux > HWAddressSanitizer-x86_64.TestCases::sizes.cpp Script:
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: 'RUN: at line 3'; /mnt/disks/ssd0/agent/llvm-project/build/./bin/clang --driver-mode=g++ -m64 -gline-tables-only -fsanitize=hwaddress -fuse-ld=lld -mcmodel=large -mllvm -hwasan-globals -mllvm -hwasan-use-short-granules -mllvm -hwasan-instrument-landing-pads=0 -mllvm -hwasan-instrument-personality-functions /mnt/disks/ssd0/agent/llvm-project/compiler-rt/test/hwasan/TestCases/sizes.cpp -nostdlib++ -lstdc++ -o /mnt/disks/ssd0/agent/llvm-project/build/projects/compiler-rt/test/hwasan/X86_64/TestCases/Output/sizes.cpp.tmp
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| 70 ms | linux > LLVM.Transforms/LowerMatrixIntrinsics::multiply-minimal.ll Script:
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: 'RUN: at line 2'; /mnt/disks/ssd0/agent/llvm-project/build/bin/opt -lower-matrix-intrinsics-minimal -fuse-matrix-tile-size=2 -matrix-allow-contract -force-fuse-matrix -instcombine -verify-dom-info /mnt/disks/ssd0/agent/llvm-project/llvm/test/Transforms/LowerMatrixIntrinsics/multiply-minimal.ll -S | /mnt/disks/ssd0/agent/llvm-project/build/bin/FileCheck /mnt/disks/ssd0/agent/llvm-project/llvm/test/Transforms/LowerMatrixIntrinsics/multiply-minimal.ll
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| 140 ms | windows > LLVM.Transforms/LowerMatrixIntrinsics::multiply-minimal.ll Script:
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: 'RUN: at line 2'; c:\ws\w16n2-1\llvm-project\premerge-checks\build\bin\opt.exe -lower-matrix-intrinsics-minimal -fuse-matrix-tile-size=2 -matrix-allow-contract -force-fuse-matrix -instcombine -verify-dom-info C:\ws\w16n2-1\llvm-project\premerge-checks\llvm\test\Transforms\LowerMatrixIntrinsics\multiply-minimal.ll -S | c:\ws\w16n2-1\llvm-project\premerge-checks\build\bin\filecheck.exe C:\ws\w16n2-1\llvm-project\premerge-checks\llvm\test\Transforms\LowerMatrixIntrinsics\multiply-minimal.ll
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Event Timeline
| llvm/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp | ||
|---|---|---|
| 103 | This is too aggressive. We can still determine that a two addresses are non-aliasing even if one is unknown size. (e.g. FrameIndex vs. Global) | |
| llvm/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp | ||
|---|---|---|
| 103 | The checking is under the condition that BasePtr0.equalBaseIndex(BasePtr1, ...) equals true. It would not be the case you considered. | |
| llvm/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp | ||
|---|---|---|
| 103 | What about the case where equalBaseIndex returns true, and the lowered addressed access has a known size smaller than the difference? In that case, we should be able to determine that they are do not alias. | |
| llvm/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp | ||
|---|---|---|
| 103 | I doubt there is a such scenario to share the same base between fixed and scalable types. I could add an assertion here. | |
| llvm/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp | ||
|---|---|---|
| 103 | I could not exclude the case that one fixed object is fixed length type and another fixed object is scalable vector type. Sorry for that. I will update the patch. | |
Comment Actions
LGTM modulo minor nit. Thanks!
| llvm/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp | ||
|---|---|---|
| 105 | nit: These bools are single use and can be inlined. | |