[LLVMdev] Problem migrating from llvm 2.9 to 3.0

[Juan Manuel Martinez Caamaño]

Hello, I'm moving a compiler pass from llvm 2.9 to 3.0, and I'm getting
some strange extra store instructions when optimizing the code.

For example, in the code that is in the attachments (On block *for.body111* for
2.9 and block *for.body67 *for 3.0), the number of stores goes from 1 to
10. And since the compiler pass adds some verification code before each
store, this leads to some performance problems.

The resulting .ll is obtained in this way:
clang -O3 fir2dim.c -S -emit-llvm -o fir2dim.ll
llvm-as fir2dim.ll
opt -O3 fir2dim.bc > fir2dim.opt.bc
llvm-dis fir2dim.opt.bc

Any idea why this is happening ?

Thanks,

Juan
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