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[AMDGPU] Uses SExt on indices in isInterestingPHIIncomingValue #85717

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DataCorrupted opened this issue Mar 18, 2024 · 1 comment · Fixed by #85718
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[AMDGPU] Uses SExt on indices in isInterestingPHIIncomingValue #85717

DataCorrupted opened this issue Mar 18, 2024 · 1 comment · Fixed by #85718
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backend:AMDGPU crash Prefer [crash-on-valid] or [crash-on-invalid]

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Reproduction

https://godbolt.org/z/P97TT7fEs

Cause

When i1 true is used as an index, SExt extends it to i32 -1. This would cause BitVector to overflow.
This can be a quick fix by using ZExt over SExt, as we have specified in the language manual that the index shall be treated as an unsigned number. (https://llvm.org/docs/LangRef.html#insertelement-instruction)
@DataCorrupted DataCorrupted added backend:AMDGPU crash Prefer [crash-on-valid] or [crash-on-invalid] labels Mar 18, 2024
@DataCorrupted DataCorrupted self-assigned this Mar 18, 2024
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llvmbot commented Mar 18, 2024

@llvm/issue-subscribers-backend-amdgpu

Author: Peter Rong (DataCorrupted)

## Reproduction

https://godbolt.org/z/P97TT7fEs

Cause

When i1 true is used as an index, SExt extends it to i32 -1. This would cause BitVector to overflow.
This can be a quick fix by using ZExt over SExt, as we have specified in the language manual that the index shall be treated as an unsigned number. (https://llvm.org/docs/LangRef.html#insertelement-instruction)

DataCorrupted added a commit to SecurityLab-UCD/llvm-project that referenced this issue Mar 18, 2024
@DataCorrupted
[AMDGCN] Use ZExt when handling indices in insertment element instruc…
fe2d2aa 
…tion.

This patch fixes llvm#85717

Signed-off-by: Peter Rong <PeterRong96@gmail.com>
@DataCorrupted DataCorrupted mentioned this issue Mar 18, 2024
Merged
DataCorrupted added a commit that referenced this issue Mar 20, 2024
@DataCorrupted
[AMDGCN] Use ZExt when handling indices in insertment element (#85718)
4a026b5 
When i1 true is used as an index, SExt extends it to i32 -1. This would
cause BitVector to overflow.
The language manual have specified that the index shall be treated as an
unsigned number, this patch fixes that.
(https://llvm.org/docs/LangRef.html#insertelement-instruction)

This patch fixes #85717

---------

Signed-off-by: Peter Rong <PeterRong96@gmail.com>
chencha3 pushed a commit to chencha3/llvm-project that referenced this issue Mar 23, 2024
@DataCorrupted @chencha3
[AMDGCN] Use ZExt when handling indices in insertment element (llvm#8…
e4650d1 
…5718)

When i1 true is used as an index, SExt extends it to i32 -1. This would
cause BitVector to overflow.
The language manual have specified that the index shall be treated as an
unsigned number, this patch fixes that.
(https://llvm.org/docs/LangRef.html#insertelement-instruction)

This patch fixes llvm#85717

---------

Signed-off-by: Peter Rong <PeterRong96@gmail.com>
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[AMDGCN] Use ZExt when handling indices in insertment element SecurityLab-UCD/llvm-project
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