#pragma once
/*
- * Copyright (C) 2005-2008 Team XBMC
- * http://www.xbmc.org
+ * Copyright (C) 2005-2013 Team XBMC
+ * http://xbmc.org
*
* This Program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
- * along with XBMC; see the file COPYING. If not, write to
- * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
- * http://www.gnu.org/copyleft/gpl.html
+ * along with XBMC; see the file COPYING. If not, see
+ * <http://www.gnu.org/licenses/>.
*
*/
#include <climits>
#include <cmath>
+#ifdef __SSE2__
+#include <emmintrin.h>
+#endif
+
+// use real compiler defines in here as we want to
+// avoid including system.h or other magic includes.
+// use 'gcc -dM -E - < /dev/null' or similar to find them.
+
+#if defined(__ppc__) || \
+ defined(__powerpc__) || \
+ (defined(TARGET_DARWIN_IOS) && defined(__llvm__)) || \
+ (defined(TARGET_ANDROID) && defined(__arm__)) || \
+ defined(TARGET_RASPBERRY_PI) || defined(TARGET_DVBBOX) // oskwon
+ #define DISABLE_MATHUTILS_ASM_ROUND_INT
+#endif
+
+#if defined(__ppc__) || \
+ defined(__powerpc__) || \
+ (defined(TARGET_DARWIN) && defined(__llvm__)) || \
+ (defined(TARGET_ANDROID) && defined(__arm__)) || \
+ defined(TARGET_RASPBERRY_PI) || defined(TARGET_DVBBOX) // oskwon
+ #define DISABLE_MATHUTILS_ASM_TRUNCATE_INT
+#endif
+
+/*! \brief Math utility class.
+ Note that the test() routine should return true for all implementations
+
+ See http://ldesoras.free.fr/doc/articles/rounding_en.pdf for an explanation
+ of the technique used on x86.
+ */
namespace MathUtils
{
// GCC does something stupid with optimization on release builds if we try
// to assert in these functions
- inline int round_int (double x)
+
+ /*! \brief Round to nearest integer.
+ This routine does fast rounding to the nearest integer.
+ In the case (k + 0.5 for any integer k) we round up to k+1, and in all other
+ instances we should return the nearest integer.
+ Thus, { -1.5, -0.5, 0.5, 1.5 } is rounded to { -1, 0, 1, 2 }.
+ It preserves the property that round(k) - round(k-1) = 1 for all doubles k.
+
+ Make sure MathUtils::test() returns true for each implementation.
+ \sa truncate_int, test
+ */
+ inline int round_int(double x)
{
assert(x > static_cast<double>(INT_MIN / 2) - 1.0);
- assert(x < static_cast <double>(INT_MAX / 2) + 1.0);
+ assert(x < static_cast<double>(INT_MAX / 2) + 1.0);
const float round_to_nearest = 0.5f;
int i;
-
-#ifndef _LINUX
- __asm
- {
- fld x
- fadd st, st (0)
- fadd round_to_nearest
- fistp i
- sar i, 1
- }
-#else
-#if defined(__powerpc__) || defined(__ppc__)
+
+#if defined(DISABLE_MATHUTILS_ASM_ROUND_INT)
i = floor(x + round_to_nearest);
+
#elif defined(__arm__)
+ // From 'ARM-v7-M Architecture Reference Manual' page A7-569:
+ // "The floating-point to integer operation (vcvt) [normally] uses the Round towards Zero rounding mode"
+ // Because of this...we must use some less-than-straightforward logic to perform this operation without
+ // changing the rounding mode flags
+
+ /* The assembly below implements the following logic:
+ if (x < 0)
+ inc = -0.5f
+ else
+ inc = 0.5f
+ int_val = trunc(x+inc);
+ err = x - int_val;
+ if (err == 0.5f)
+ int_val++;
+ return int_val;
+ */
+
__asm__ __volatile__ (
- "vmov.F64 d1,%[rnd_val] \n\t" // Copy round_to_nearest into a working register
- "vadd.F64 %P[value],%P[value],d1 \n\t" // Add round_to_nearest to value
- "vcvt.S32.F64 %[result],%P[value] \n\t" // Truncate(round towards zero) and store the result
- : [result] "=w"(i), [value] "+w"(x) // Outputs
- : [rnd_val] "Dv" (round_to_nearest) // Inputs
- : "d1"); // Clobbers
+#if defined(__ARM_PCS_VFP)
+ "fconstd d1,#%G[rnd_val] \n\t" // Copy round_to_nearest into a working register (d1 = 0.5)
#else
- __asm__ __volatile__ (
- "fadd %%st\n\t"
- "fadd %%st(1)\n\t"
- "fistpl %0\n\t"
- "sarl $1, %0\n"
- : "=m"(i) : "u"(round_to_nearest), "t"(x) : "st"
- );
+ "vmov.F64 d1,%[rnd_val] \n\t"
#endif
+ "fcmpezd %P[value] \n\t" // Check value against zero (value == 0?)
+ "fmstat \n\t" // Copy the floating-point status flags into the general-purpose status flags
+ "it mi \n\t"
+ "vnegmi.F64 d1, d1 \n\t" // if N-flag is set, negate round_to_nearest (if (value < 0) d1 = -1 * d1)
+ "vadd.F64 d1,%P[value],d1 \n\t" // Add round_to_nearest to value, store result in working register (d1 += value)
+ "vcvt.S32.F64 s3,d1 \n\t" // Truncate(round towards zero) (s3 = (int)d1)
+ "vmov %[result],s3 \n\t" // Store the integer result in a general-purpose register (result = s3)
+ "vcvt.F64.S32 d1,s3 \n\t" // Convert back to floating-point (d1 = (double)s3)
+ "vsub.F64 d1,%P[value],d1 \n\t" // Calculate the error (d1 = value - d1)
+#if defined(__ARM_PCS_VFP)
+ "fconstd d2,#%G[rnd_val] \n\t" // d2 = 0.5;
+#else
+ "vmov.F64 d2,%[rnd_val] \n\t"
#endif
- return (i);
- }
-
- inline int ceil_int (double x)
- {
- assert(x > static_cast<double>(INT_MIN / 2) - 1.0);
- assert(x < static_cast <double>(INT_MAX / 2) + 1.0);
-
-#if !defined(__powerpc__) && !defined(__ppc__) && !defined(__arm__)
- const float round_towards_p_i = -0.5f;
-#endif
- int i;
-
-#ifndef _LINUX
+ "fcmped d1, d2 \n\t" // (d1 == 0.5?)
+ "fmstat \n\t" // Copy the floating-point status flags into the general-purpose status flags
+ "it eq \n\t"
+ "addeq %[result],#1 \n\t" // (if (d1 == d2) result++;)
+ : [result] "=r"(i) // Outputs
+ : [rnd_val] "Dv" (round_to_nearest), [value] "w"(x) // Inputs
+ : "d1", "d2", "s3" // Clobbers
+ );
+
+#elif defined(__SSE2__)
+ const float round_dn_to_nearest = 0.4999999f;
+ i = (x > 0) ? _mm_cvttsd_si32(_mm_set_sd(x + round_to_nearest)) : _mm_cvttsd_si32(_mm_set_sd(x - round_dn_to_nearest));
+
+#elif defined(TARGET_WINDOWS)
__asm
{
fld x
fadd st, st (0)
- fsubr round_towards_p_i
+ fadd round_to_nearest
fistp i
sar i, 1
}
-#else
-#if defined(__powerpc__) || defined(__ppc__) || defined(__arm__)
- return (int)ceil(x);
+
#else
__asm__ __volatile__ (
- "fadd %%st\n\t"
- "fsubr %%st(1)\n\t"
- "fistpl %0\n\t"
- "sarl $1, %0\n"
- : "=m"(i) : "u"(round_towards_p_i), "t"(x) : "st"
- );
-#endif
+ "fadd %%st\n\t"
+ "fadd %%st(1)\n\t"
+ "fistpl %0\n\t"
+ "sarl $1, %0\n"
+ : "=m"(i) : "u"(round_to_nearest), "t"(x) : "st"
+ );
+
#endif
- return (-i);
+
+ return i;
}
-
+
+ /*! \brief Truncate to nearest integer.
+ This routine does fast truncation to an integer.
+ It should simply drop the fractional portion of the floating point number.
+
+ Make sure MathUtils::test() returns true for each implementation.
+ \sa round_int, test
+ */
inline int truncate_int(double x)
{
assert(x > static_cast<double>(INT_MIN / 2) - 1.0);
- assert(x < static_cast <double>(INT_MAX / 2) + 1.0);
-
-#if !defined(__powerpc__) && !defined(__ppc__) && !defined(__arm__)
- const float round_towards_m_i = -0.5f;
-#endif
+ assert(x < static_cast<double>(INT_MAX / 2) + 1.0);
int i;
-
-#ifndef _LINUX
+
+#if defined(DISABLE_MATHUTILS_ASM_TRUNCATE_INT)
+ return i = (int)x;
+
+#elif defined(__arm__)
+ __asm__ __volatile__ (
+ "vcvt.S32.F64 %[result],%P[value] \n\t" // Truncate(round towards zero) and store the result
+ : [result] "=w"(i) // Outputs
+ : [value] "w"(x) // Inputs
+ );
+ return i;
+
+#elif defined(TARGET_WINDOWS)
+ const float round_towards_m_i = -0.5f;
__asm
{
fld x
fistp i
sar i, 1
}
+
#else
-#if defined(__powerpc__) || defined(__ppc__) || defined(__arm__)
- return (int)x;
-#else
+ const float round_towards_m_i = -0.5f;
__asm__ __volatile__ (
- "fadd %%st\n\t"
- "fabs\n\t"
- "fadd %%st(1)\n\t"
- "fistpl %0\n\t"
- "sarl $1, %0\n"
- : "=m"(i) : "u"(round_towards_m_i), "t"(x) : "st"
- );
-#endif
+ "fadd %%st\n\t"
+ "fabs\n\t"
+ "fadd %%st(1)\n\t"
+ "fistpl %0\n\t"
+ "sarl $1, %0\n"
+ : "=m"(i) : "u"(round_towards_m_i), "t"(x) : "st"
+ );
#endif
if (x < 0)
i = -i;
return (i);
}
-
+
inline int64_t abs(int64_t a)
{
return (a < 0) ? -a : a;
}
-
+
+ inline unsigned bitcount(unsigned v)
+ {
+ unsigned c = 0;
+ for (c = 0; v; c++)
+ v &= v - 1; // clear the least significant bit set
+ return c;
+ }
+
inline void hack()
{
// stupid hack to keep compiler from dropping these
// functions as unused
MathUtils::round_int(0.0);
MathUtils::truncate_int(0.0);
- MathUtils::ceil_int(0.0);
MathUtils::abs(0);
}
+
+#if 0
+ /*! \brief test routine for round_int and truncate_int
+ Must return true on all platforms.
+ */
+ inline bool test()
+ {
+ for (int i = -8; i < 8; ++i)
+ {
+ double d = 0.25*i;
+ int r = (i < 0) ? (i - 1) / 4 : (i + 2) / 4;
+ int t = i / 4;
+ if (round_int(d) != r || truncate_int(d) != t)
+ return false;
+ }
+ return true;
+ }
+#endif
} // namespace MathUtils
projects / vuplus_xbmc / blobdiff