1 files changed, 65 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/alpha/setfpucw.c b/sysdeps/unix/sysv/linux/alpha/setfpucw.c
new file mode 100644
index 0000000000..43e8536b20
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/alpha/setfpucw.c
@@ -0,0 +1,65 @@
+#include <fpu_control.h>
+
+#include <asm/fpu.h>
+
+extern void		__ieee_set_fp_control (unsigned long);
+extern unsigned long	__ieee_get_fp_control (void);
+
+
+static inline unsigned long
+rdfpcr (void)
+{
+    unsigned long fpcr;
+
+    asm ("trapb; mf_fpcr $f0; trapb; stt $f0,%0" : "m="(fpcr));
+    return fpcr;
+}
+
+
+static inline void
+wrfpcr (unsigned long fpcr)
+{
+    asm volatile ("ldt $f0,%0; trapb; mt_fpcr $f0; trapb" :: "m"(fpcr));
+}
+
+
+void
+__setfpucw (unsigned short fpu_control)
+{
+    unsigned long fpcr = 0, fpcw = 0;
+
+    if (!fpu_control)
+	fpu_control = _FPU_DEFAULT;
+
+    /* first, set dynamic rounding mode: */
+
+    fpcr = rdfpcr();
+    fpcr &= ~FPCR_DYN_MASK;
+    switch (fpu_control & 0xc00) {
+      case _FPU_RC_NEAREST:	fpcr |= FPCR_DYN_NORMAL; break;
+      case _FPU_RC_DOWN:	fpcr |= FPCR_DYN_MINUS; break;
+      case _FPU_RC_UP:		fpcr |= FPCR_DYN_PLUS; break;
+      case _FPU_RC_ZERO:	fpcr |= FPCR_DYN_CHOPPED; break;
+    }
+    wrfpcr(fpcr);
+
+    /* now tell kernel about traps that we like to hear about: */
+
+    fpcw = __ieee_get_fp_control();
+    fpcw &= ~IEEE_TRAP_ENABLE_MASK;
+
+    if (!(fpu_control & _FPU_MASK_IM))
+	fpcw |= IEEE_TRAP_ENABLE_INV;
+    if (!(fpu_control & _FPU_MASK_DM))
+	fpcw |= IEEE_TRAP_ENABLE_UNF;
+    if (!(fpu_control & _FPU_MASK_ZM))
+	fpcw |= IEEE_TRAP_ENABLE_DZE;
+    if (!(fpu_control & _FPU_MASK_OM))
+	fpcw |= IEEE_TRAP_ENABLE_OVF;
+    if (!(fpu_control & _FPU_MASK_PM))
+	fpcw |= IEEE_TRAP_ENABLE_INE;
+
+    __ieee_set_fp_control(fpcw);
+
+    __fpu_control = fpu_control;	/* update global copy */
+}