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Add CC clobber to cpuid call 

This should not be needed, but it does not hurt. According to Ian Lance Taylor (http://gcc.gnu.org/ml/gcc-help/2014-02/msg00023.html), the CC clobber causes GCC to forget its internal representation of flag state. It should not be needed for cpuid. However, Clang has some odd behave in a couple of versions of its compiler when using cpuid. Both JW and UB experienced it on separate occassions.
pull/339/head
Jeffrey Walton 2016-11-13 11:14:03 -05:00
parent 61aa62bd8f
commit 5be05bce07
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cpu.cpp
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@ -113,6 +113,7 @@ bool CpuId(word32 input, word32 output[4])
# endif # endif
: "=a" (output[0]), "=D" (output[1]), "=c" (output[2]), "=d" (output[3]) : "=a" (output[0]), "=D" (output[1]), "=c" (output[2]), "=d" (output[3])
: "a" (input), "c" (0) : "a" (input), "c" (0)
: "cc"
); );
} }