[LLVMdev] Valid debug information being deleted by DAGCombiner

[Villmow, Micah]

Found another bitcode file where a debug symbol is being dropped.

In the attached bitcode file, the variable gid is not in the debug output.

From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On Behalf Of Villmow, Micah
Sent: Thursday, April 14, 2011 5:31 PM
To: llvmdev at cs.uiuc.edu
Subject: [LLVMdev] Valid debug information being deleted by DAGCombiner

I am working on some debug problems that we are seeing with the x86 backend and OpenCL.

The input is linked.bc. There are three debug values, ip, tid and gid.


llc -march=x86 linked.bc -o linked-x86.s <-- assembly file has all three values in the debug info section

However, if I attempt to optimize the bitcode with the following command:
opt -disable-opt -inline-all -mem2reg linked.bc -o optimized.bc
llc -march=x86 optimized.bc -o optimized-x86.s <-- Assembly file only has ip and gid in the debug info section.


Any idea on how to get this to work? I've attached the output, which is missing the 'tid' debug variable.

Thanks,
Micah

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