core/fpu_ctrl.cpp

   1
   2 #include "config.h"
   3
   4 #include "fpu_ctrl.h"
   5
   6 #ifdef HAVE_INTRIN_H
   7 #include <intrin.h>
   8 #endif
   9 #ifdef HAVE_SSE_INTRINSICS
  10 #include <xmmintrin.h>
  11 #endif
  12
  13 #include "cpu_caps.h"
  14
  15
  16 void FPUCtl::enter() noexcept
  17 {
  18     if(this->in_mode) return;
  19
  20 #if defined(HAVE_SSE_INTRINSICS)
  21     this->sse_state = _mm_getcsr();
  22     unsigned int sseState{this->sse_state};
  23     sseState |= 0x8000; /* set flush-to-zero */
  24     sseState |= 0x0040; /* set denormals-are-zero */
  25     _mm_setcsr(sseState);
  26
  27 #elif defined(__GNUC__) && defined(HAVE_SSE)
  28
  29     if((CPUCapFlags&CPU_CAP_SSE))
  30     {
  31         __asm__ __volatile__("stmxcsr %0" : "=m" (*&this->sse_state));
  32         unsigned int sseState{this->sse_state};
  33         sseState |= 0x8000; /* set flush-to-zero */
  34         if((CPUCapFlags&CPU_CAP_SSE2))
  35             sseState |= 0x0040; /* set denormals-are-zero */
  36         __asm__ __volatile__("ldmxcsr %0" : : "m" (*&sseState));
  37     }
  38 #endif
  39
  40     this->in_mode = true;
  41 }
  42
  43 void FPUCtl::leave() noexcept
  44 {
  45     if(!this->in_mode) return;
  46
  47 #if defined(HAVE_SSE_INTRINSICS)
  48     _mm_setcsr(this->sse_state);
  49
  50 #elif defined(__GNUC__) && defined(HAVE_SSE)
  51
  52     if((CPUCapFlags&CPU_CAP_SSE))
  53         __asm__ __volatile__("ldmxcsr %0" : : "m" (*&this->sse_state));
  54 #endif
  55     this->in_mode = false;
  56 }