[tkreuzer] 45290: [CRT] - implement generic C version of cos(). On amd64 machines it will compile into very optimized SSE2 code. No need to use assembly.

Author: tkreuzer
Date: Thu Jan 28 00:42:34 2010
New Revision: 45290

URL: http://svn.reactos.org/svn/reactos?rev=45290&view=rev
Log:
[CRT]
- implement generic C version of cos(). On amd64 machines it will compile into very optimized SSE2 code. No need to use assembly.

Added:
    branches/ros-amd64-bringup/reactos/lib/sdk/crt/math/cos.c   (with props)
Removed:
    branches/ros-amd64-bringup/reactos/lib/sdk/crt/math/amd64/cos.S
Modified:
    branches/ros-amd64-bringup/reactos/lib/sdk/crt/crt.rbuild
    branches/ros-amd64-bringup/reactos/lib/sdk/crt/libcntpr.rbuild

Modified: branches/ros-amd64-bringup/reactos/lib/sdk/crt/crt.rbuild
URL: http://svn.reactos.org/svn/reactos/branches/ros-amd64-bringup/reactos/lib/sd...
==============================================================================
--- branches/ros-amd64-bringup/reactos/lib/sdk/crt/crt.rbuild [iso-8859-1] (original)
+++ branches/ros-amd64-bringup/reactos/lib/sdk/crt/crt.rbuild [iso-8859-1] Thu Jan 28 00:42:34 2010
@@ -161,13 +161,13 @@
    		<file>jn_yn.c</file>-->
    	</if>
    	<if property="ARCH" value="amd64">
+			<file>cos.c</file>
    		<directory name="amd64">
    			<file>alldiv.S</file>
    			<file>atan.S</file>
    			<file>atan2.S</file>
    			<file>ceil.S</file>
    			<file>ceilf.S</file>
-				<file>cos.S</file>
    			<file>exp.S</file>
    			<file>fabs.S</file>
    			<file>floor.S</file>

Modified: branches/ros-amd64-bringup/reactos/lib/sdk/crt/libcntpr.rbuild
URL: http://svn.reactos.org/svn/reactos/branches/ros-amd64-bringup/reactos/lib/sd...
==============================================================================
--- branches/ros-amd64-bringup/reactos/lib/sdk/crt/libcntpr.rbuild [iso-8859-1] (original)
+++ branches/ros-amd64-bringup/reactos/lib/sdk/crt/libcntpr.rbuild [iso-8859-1] Thu Jan 28 00:42:34 2010
@@ -64,7 +64,6 @@
    			<file>atan.S</file>
    			<file>atan2.S</file>
    			<file>ceil.S</file>
-				<file>cos.S</file>
    			<file>exp.S</file>
    			<file>fabs.S</file>
    			<file>floor.S</file>

Removed: branches/ros-amd64-bringup/reactos/lib/sdk/crt/math/amd64/cos.S
URL: http://svn.reactos.org/svn/reactos/branches/ros-amd64-bringup/reactos/lib/sd...
==============================================================================
--- branches/ros-amd64-bringup/reactos/lib/sdk/crt/math/amd64/cos.S [iso-8859-1] (original)
+++ branches/ros-amd64-bringup/reactos/lib/sdk/crt/math/amd64/cos.S (removed)
@@ -1,21 +1,0 @@
-/*
- * COPYRIGHT:         See COPYING in the top level directory
- * PROJECT:           ReactOS system libraries
- * PURPOSE:           Implementation of cos
- * FILE:              lib/sdk/crt/math/amd64/cos.S
- * PROGRAMMER:        Timo Kreuzer ([e-mail])
- */
-
-/* INCLUDES ******************************************************************/
-
-#include <ndk/amd64/asm.h>
-#include <ndk/amd64/asmmacro.S>
-
-.intel_syntax noprefix
-
-
-.proc cos
-    UNIMPLEMENTED cos
-    ret
-
-.endproc

Added: branches/ros-amd64-bringup/reactos/lib/sdk/crt/math/cos.c
URL: http://svn.reactos.org/svn/reactos/branches/ros-amd64-bringup/reactos/lib/sd...
==============================================================================
--- branches/ros-amd64-bringup/reactos/lib/sdk/crt/math/cos.c (added)
+++ branches/ros-amd64-bringup/reactos/lib/sdk/crt/math/cos.c [iso-8859-1] Thu Jan 28 00:42:34 2010
@@ -1,0 +1,89 @@
+/*
+ * COPYRIGHT:        See COPYING in the top level directory
+ * PROJECT:          ReactOS CRT
+ * FILE:             lib/crt/math/cos.c
+ * PURPOSE:          Generic C Implementation of cos
+ * PROGRAMMER:       Timo Kreuzer ([e-mail])
+ */
+
+#define PRECISION 9
+#define M_PI 3.141592653589793238462643
+
+static double cos_off_tbl[] = {0.0, -M_PI/2., 0, -M_PI/2.};
+static double cos_sign_tbl[] = {1,-1,-1,1};
+
+double
+cos(double x)
+{
+    int quadrant;
+    double x2, result;
+
+    /* Calculate the quadrant */
+    quadrant = x * (2./M_PI);
+
+    /* Get offset inside quadrant */
+    x = x - quadrant * (M_PI/2.);
+
+    /* Normalize quadrant to [0..3] */
+    quadrant = quadrant & 0x3;
+
+    /* Fixup value for the generic function */
+    x += cos_off_tbl[quadrant];
+
+    /* Calculate the negative of the square of x */
+    x2 = - (x * x);
+
+    /* This is an unrolled taylor series using <PRECISION> iterations 
+     * Example with 4 iterations:
+     * result = 1 - x^2/2! + x^4/4! - x^6/6! + x^8/8!
+     * To save multiplications and to keep the precision high, it's performed
+     * like this:
+     * result = 1 - x^2 * (1/2! - x^2 * (1/4! - x^2 * (1/6! - x^2 * (1/8!))))
+     */
+
+    /* Start with 0, compiler will optimize this away */
+    result = 0;
+
+#if (PRECISION >= 10)
+    result += 1./(1.*2*3*4*5*6*7*8*9*10*11*12*13*14*15*16*17*18*20);
+    result *= x2;
+#endif
+#if (PRECISION >= 9)
+    result += 1./(1.*2*3*4*5*6*7*8*9*10*11*12*13*14*15*16*17*18);
+    result *= x2;
+#endif
+#if (PRECISION >= 8)
+    result += 1./(1.*2*3*4*5*6*7*8*9*10*11*12*13*14*15*16);
+    result *= x2;
+#endif
+#if (PRECISION >= 7)
+    result += 1./(1.*2*3*4*5*6*7*8*9*10*11*12*13*14);
+    result *= x2;
+#endif
+#if (PRECISION >= 6)
+    result += 1./(1.*2*3*4*5*6*7*8*9*10*11*12);
+    result *= x2;
+#endif
+#if (PRECISION >= 5)
+    result += 1./(1.*2*3*4*5*6*7*8*9*10);
+    result *= x2;
+#endif
+    result += 1./(1.*2*3*4*5*6*7*8);
+    result *= x2;
+
+    result += 1./(1.*2*3*4*5*6);
+    result *= x2;
+
+    result += 1./(1.*2*3*4);
+    result *= x2;
+
+    result += 1./(1.*2);
+    result *= x2;
+
+    result += 1;
+
+    /* Apply correct sign */
+    result *= cos_sign_tbl[quadrant];
+
+    return result;
+}

Propchange: branches/ros-amd64-bringup/reactos/lib/sdk/crt/math/cos.c
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