diff options
Diffstat (limited to 'package/kodi/0002-mathutil.patch')
| -rw-r--r-- | package/kodi/0002-mathutil.patch | 213 |
1 files changed, 0 insertions, 213 deletions
diff --git a/package/kodi/0002-mathutil.patch b/package/kodi/0002-mathutil.patch deleted file mode 100644 index 33f91eb38a..0000000000 --- a/package/kodi/0002-mathutil.patch +++ /dev/null @@ -1,213 +0,0 @@ -Taken from upstream PR: https://github.com/xbmc/xbmc/pull/3760 - -Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de> - - -From 7388e8be7cd5e78100532ebf0dba15dccb7b03f8 Mon Sep 17 00:00:00 2001 -From: Ben Avison <bavison@riscosopen.org> -Date: Tue, 3 Dec 2013 15:51:39 +0000 -Subject: [PATCH] Faster and simpler portable implementation of - MathUtils::round_int(). - -Much as I like a bit of inline assembler, I have also removed the ARM versions -of MathUtils::truncate_int() and MathUtils::round_int(). The former was just -how any sane compiler should have assembled a cast from double to signed int -anyway. The latter was a much too complicated way to achieve the desired -effect, and was switched out in most ARM builds anyway in favour of the old -portable implementation that used floor(). - -Verified that MathUtils::test() still passes, and that GCC is now able to -inline MathUtils::round_int(), where it didn't previously. - -I tested on a Raspberry Pi with the default theme, displaying the front page -with the RSS ticker enabled. This saturates the CPU, so I'm measuring the -improvement using the debug window's FPS figure. This patch improves this from -~50.8 FPS to ~52.6 FPS. ---- - xbmc/utils/MathUtils.h | 129 +++++++++++++++++++++++-------------------------- - 1 file changed, 61 insertions(+), 68 deletions(-) - -diff --git a/xbmc/utils/MathUtils.h b/xbmc/utils/MathUtils.h -index 96af9f4..0dae77d 100644 ---- a/xbmc/utils/MathUtils.h -+++ b/xbmc/utils/MathUtils.h -@@ -34,17 +34,13 @@ - - #if defined(__ppc__) || \ - defined(__powerpc__) || \ -- (defined(TARGET_DARWIN_IOS) && defined(__llvm__)) || \ -- (defined(TARGET_ANDROID) && defined(__arm__)) || \ -- defined(TARGET_RASPBERRY_PI) -+ defined(__arm__) - #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(__arm__) - #define DISABLE_MATHUTILS_ASM_TRUNCATE_INT - #endif - -@@ -73,60 +69,63 @@ - { - assert(x > static_cast<double>(INT_MIN / 2) - 1.0); - assert(x < static_cast<double>(INT_MAX / 2) + 1.0); -- const float round_to_nearest = 0.5f; -- int i; - - #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; -- */ -+ /* This implementation warrants some further explanation. -+ * -+ * First, a couple of notes on rounding: -+ * 1) C casts from float/double to integer round towards zero. -+ * 2) Float/double additions are rounded according to the normal rules, -+ * in other words: on some architectures, it's fixed at compile-time, -+ * and on others it can be set using fesetround()). The following -+ * analysis assumes round-to-nearest with ties rounding to even. This -+ * is a fairly sensible choice, and is the default with ARM VFP. -+ * -+ * What this function wants is round-to-nearest with ties rounding to -+ * +infinity. This isn't an IEEE rounding mode, even if we could guarantee -+ * that all architectures supported fesetround(), which they don't. Instead, -+ * this adds an offset of 2147483648.5 (= 0x80000000.8p0), then casts to -+ * an unsigned int (crucially, all possible inputs are now in a range where -+ * round to zero acts the same as round to -infinity) and then subtracts -+ * 0x80000000 in the integer domain. The 0.5 component of the offset -+ * converts what is effectively a round down into a round to nearest, with -+ * ties rounding up, as desired. -+ * -+ * There is a catch, that because there is a double rounding, there is a -+ * small region where the input falls just *below* a tie, where the addition -+ * of the offset causes a round *up* to an exact integer, due to the finite -+ * level of precision available in floating point. You need to be aware of -+ * this when calling this function, although at present it is not believed -+ * that XBMC ever attempts to round numbers in this window. -+ * -+ * It is worth proving the size of the affected window. Recall that double -+ * precision employs a mantissa of 52 bits. -+ * 1) For all inputs -0.5 <= x <= INT_MAX -+ * Once the offset is applied, the most significant binary digit in the -+ * floating-point representation is +2^31. -+ * At this magnitude, the smallest step representable in double precision -+ * is 2^31 / 2^52 = 0.000000476837158203125 -+ * So the size of the range which is rounded up due to the addition is -+ * half the size of this step, or 0.0000002384185791015625 -+ * -+ * 2) For all inputs INT_MIN/2 < x < -0.5 -+ * Once the offset is applied, the most significant binary digit in the -+ * floating-point representation is +2^30. -+ * At this magnitude, the smallest step representable in double precision -+ * is 2^30 / 2^52 = 0.0000002384185791015625 -+ * So the size of the range which is rounded up due to the addition is -+ * half the size of this step, or 0.00000011920928955078125 -+ * -+ * 3) For all inputs INT_MIN <= x <= INT_MIN/2 -+ * The representation once the offset is applied has equal or greater -+ * precision than the input, so the addition does not cause rounding. -+ */ -+ return ((unsigned int) (x + 0x80000000.8p0)) - 0x80000000; - -- __asm__ __volatile__ ( --#if defined(__ARM_PCS_VFP) -- "fconstd d1,#%G[rnd_val] \n\t" // Copy round_to_nearest into a working register (d1 = 0.5) - #else -- "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 -- "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_to_nearest = 0.5f; -+ int i; -+#if 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)); - -@@ -150,8 +149,8 @@ - ); - - #endif -- - return i; -+#endif - } - - /*! \brief Truncate to nearest integer. -@@ -165,20 +164,13 @@ - { - assert(x > static_cast<double>(INT_MIN / 2) - 1.0); - assert(x < static_cast<double>(INT_MAX / 2) + 1.0); -- int i; - - #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; -+ return x; - --#elif defined(TARGET_WINDOWS) -+#else -+ int i; -+#if defined(TARGET_WINDOWS) - const float round_towards_m_i = -0.5f; - __asm - { -@@ -204,6 +196,7 @@ - if (x < 0) - i = -i; - return (i); -+#endif - } - - inline int64_t abs(int64_t a) --- -1.9.1 - |
