SSE2 rounding mode must be also set, not just FPU.

diff --git a/fpp.cpp b/fpp.cpp
index 6bb1171954a5dac31053f614ae33c1d73747bb50..4a96b201893a11796ab981951e2b71b4753443f9 100644 (file)
--- a/fpp.cpp
+++ b/fpp.cpp
@@ -581,6 +581,21 @@ static void init_fpucw_x87(void)
 
 static inline void set_fpucw_x87(uae_u32 m68k_cw)
 {
+#ifdef _MSC_VER
+       static int ex = 0;
+       // RN, RZ, RM, RP
+       static const unsigned int fp87_round[4] = { _RC_NEAR, _RC_CHOP, _RC_DOWN, _RC_UP };
+       // Extend X, Single S, Double D, Undefined
+       static const unsigned int fp87_prec[4] = { _PC_64, _PC_24, _PC_53, 0 };
+#ifdef WIN64
+       // x64 only sets SSE2, must also call x87_fldcw_code() to set FPU rounding mode.
+       _controlfp(ex | fp87_round[(m68k_cw >> 4) & 3], _MCW_RC);
+#else
+       // x86 sets both FPU and SSE2 rounding mode, don't need x87_fldcw_code()
+       _control87(ex | fp87_round[(m68k_cw >> 4) & 3] | fp87_prec[(m68k_cw >> 6) & 3], _MCW_RC | _MCW_PC);
+       return;
+#endif
+#endif
        static const uae_u16 x87_cw_tab[] = {
                0x137f, 0x1f7f, 0x177f, 0x1b7f, /* Extended */
                0x107f, 0x1c7f, 0x147f, 0x187f, /* Single */