Automerge.

1 files changed, 35 insertions, 1 deletions

diff --git a/sql/mysqld.cc b/sql/mysqld.cc
index 3664f46995f..3ffc1a21e9c 100644
--- a/sql/mysqld.cc
+++ b/sql/mysqld.cc
@@ -183,6 +183,21 @@ typedef fp_except fp_except_t;
 /* for IRIX to use set_fpc_csr() */
 #include <sys/fpu.h>
 #endif
+#ifdef HAVE_FPU_CONTROL_H
+#include <fpu_control.h>
+#endif
+#if defined(__i386__) && !defined(HAVE_FPU_CONTROL_H)
+# define fpu_control_t unsigned int
+# define _FPU_EXTENDED 0x300
+# define _FPU_DOUBLE 0x200
+# ifdef __GNUC__
+#  define _FPU_GETCW(cw) __asm__ __volatile__("fnstcw %0" : "=m" (*&cw))
+#  define _FPU_SETCW(cw) __asm__ __volatile__("fldcw %0" : : "m" (*&cw))
+# else
+#  define _FPU_GETCW(cw) (cw= 0)
+#  define _FPU_SETCW(cw)
+# endif
+#endif
 
 inline void setup_fpu()
 {
@@ -204,7 +219,26 @@ inline void setup_fpu()
     /* Set FPU rounding mode to "round-to-nearest" */
   fesetround(FE_TONEAREST);
 #endif /* HAVE_FESETROUND */
-    
+
+  /*
+    x86 (32-bit) requires FPU precision to be explicitly set to 64 bit
+    (double precision) for portable results of floating point operations.
+    However, there is no need to do so if compiler is using SSE2 for floating
+    point, double values will be stored and processed in 64 bits anyway.
+  */
+#if defined(__i386__) && !defined(__SSE2_MATH__)
+#if defined(_WIN32)
+#if !defined(_WIN64)
+  _control87(_PC_53, MCW_PC);
+#endif /* !_WIN64 */
+#else /* !_WIN32 */
+  fpu_control_t cw;
+  _FPU_GETCW(cw);
+  cw= (cw & ~_FPU_EXTENDED) | _FPU_DOUBLE;
+  _FPU_SETCW(cw);
+#endif /* _WIN32 && */
+#endif /* __i386__ */
+
 #if defined(__sgi) && defined(HAVE_SYS_FPU_H)
   /* Enable denormalized DOUBLE values support for IRIX */
   union fpc_csr n;