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diff src/build-msvctools/math/trunc.c @ 3061:f8299bb6c872

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Initial support for native MSVC compilation. * add MSVC support files: compiler wrappers and support libraries * adapt libiconv to work with MSVC * adapt gettext to work with MSVC
author Michael Goffioul <michael.goffioul@gmail.com>
date Mon, 17 Jun 2013 22:43:11 -0400
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/build-msvctools/math/trunc.c	Mon Jun 17 22:43:11 2013 -0400
@@ -0,0 +1,16 @@
+#include <fenv.h>
+#include <math.h>
+
+double
+trunc (double _x){
+  double retval;
+  unsigned short saved_cw;
+  unsigned short tmp_cw;
+  __asm__ ("fnstcw %0;" : "=m" (saved_cw)); /* save FPU control word */
+  tmp_cw = (saved_cw & ~(FE_TONEAREST | FE_DOWNWARD | FE_UPWARD | FE_TOWARDZERO))
+	    | FE_TOWARDZERO;
+  __asm__ ("fldcw %0;" : : "m" (tmp_cw));
+  __asm__ ("frndint;" : "=t" (retval)  : "0" (_x)); /* round towards zero */
+  __asm__ ("fldcw %0;" : : "m" (saved_cw) ); /* restore saved control word */
+  return retval;
+}