From bc3e0f7fe6920076f584507a62221214b1ce1e55 Mon Sep 17 00:00:00 2001
From: Sam Hocevar <sam@hocevar.net>
Date: Tue, 21 Mar 2006 09:48:02 +0000
Subject: [PATCH]   * Use the asm versions of sin and cos when available.

---
 configure.ac    |  5 +++++
 kernel/kernel.c | 10 ++++++++--
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/configure.ac b/configure.ac
index 9cdd782..845d563 100644
--- a/configure.ac
+++ b/configure.ac
@@ -59,6 +59,11 @@ AC_TRY_COMPILE([#include <windows.h>],[Sleep(42);],
  [AC_MSG_RESULT(yes)
   AC_DEFINE(HAVE_SLEEP, 1, [Define to 1 if you have the `Sleep' function.])],
  [AC_MSG_RESULT(no)])
+AC_MSG_CHECKING(for fsin/fcos)
+AC_TRY_COMPILE([],[asm("fsin\n\tfcos");],
+ [AC_MSG_RESULT(yes)
+  AC_DEFINE(HAVE_FSIN_FCOS, 1, [Define to 1 if you have the `fsin' and `fcos' operands.])],
+ [AC_MSG_RESULT(no)])
 AC_CHECK_LIB(m, sin, MATH_LIBS="${MATH_LIBS} -lm")
 
 CACA_DRIVERS="" 
diff --git a/kernel/kernel.c b/kernel/kernel.c
index 780dcc8..1c3d7c1 100644
--- a/kernel/kernel.c
+++ b/kernel/kernel.c
@@ -227,6 +227,9 @@ int gettimeofday(struct timeval *tv, struct timezone *tz)
 double cos(double x)
 {
     double ret = 0.0;
+#ifdef HAVE_FSIN_FCOS
+    asm volatile("fcos" : "=t" (ret) : "0" (x));
+#else
     double x2;
     double num = 1.0;
     double fact = 1.0;
@@ -242,13 +245,16 @@ double cos(double x)
         num *= - x2;
         fact *= (2 * i + 1) * (2 * i + 2);
     }
-
+#endif
     return ret;
 }
 
 double sin(double x)
 {
     double ret = 0.0;
+#ifdef HAVE_FSIN_FCOS
+    asm volatile("fsin" : "=t" (ret) : "0" (x));
+#else
     double x2;
     double num;
     double fact = 1.0;
@@ -265,7 +271,7 @@ double sin(double x)
         num *= - x2;
         fact *= (2 * i + 2) * (2 * i + 3);
     }
-
+#endif
     return ret;
 }