[cfe-commits] r154204 - /cfe/trunk/lib/Basic/SourceManager.cpp

Jonathan Sauer jonathan.sauer at gmx.de
Fri Apr 6 23:26:55 PDT 2012


> The speedup from vectorization isn't very large, as we fall back to bytewise
> scanning when we hit a newline. There might be a way to avoid leaving the sse
> loop but everything I tried didn't work out because a call to push_back
> clobbers xmm registers.

Wouldn't that indicate a codegen bug? Judging from <http://www.agner.org/optimize/calling_conventions.pdf>,
most calling conventions specify that at least some xmm registers are scratch registers, i.e. must be
saved on the stack before calling a function and restored afterwards, if they should keep their value.
If that doesn't happen, it seems to me to be a bug in the compiler you used to compile clang.


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