[LLVMdev] Performance regression on ARM

Anton Korobeynikov anton at korobeynikov.info
Fri Oct 17 07:51:38 PDT 2014

> Chandler’s complex arithmetic changes are also in the range: r219557 in clang.  We saw it change the code in mandel-2 significantly.
mandel-2 is broken on hard FP ABI systems, btw. The reason is simply:
we're emitting a call to __muldc3 with AAPCS VFP calling convention,
however, the function expects softfp (AAPCS) calling conv and reads
garbage from GP registers.

I'm working on fix.

With best regards, Anton Korobeynikov
Faculty of Mathematics and Mechanics, Saint Petersburg State University

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