32 lines
873 B
C
32 lines
873 B
C
#include <fenv.h>
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#include "cpu_features.h"
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/* 7.6.3.2
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The fesetround function establishes the rounding direction
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represented by its argument round. If the argument is not equal
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to the value of a rounding direction macro, the rounding direction
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is not changed. */
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int fesetround (int mode)
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{
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unsigned short _cw;
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if ((mode & ~(FE_TONEAREST | FE_DOWNWARD | FE_UPWARD | FE_TOWARDZERO))
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!= 0)
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return -1;
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__asm__ volatile ("fnstcw %0;": "=m" (_cw));
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_cw &= ~(FE_TONEAREST | FE_DOWNWARD | FE_UPWARD | FE_TOWARDZERO);
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_cw |= mode;
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__asm__ volatile ("fldcw %0;" : : "m" (_cw));
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if (__HAS_SSE)
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{
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unsigned int _mxcsr;
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__asm__ volatile ("stmxcsr %0" : "=m" (_mxcsr));
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_mxcsr &= ~ 0x6000;
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_mxcsr |= (mode << __MXCSR_ROUND_FLAG_SHIFT);
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__asm__ volatile ("ldmxcsr %0" : : "m" (_mxcsr));
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}
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return 0;
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}
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