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@@ -1,213 +0,0 @@
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-Taken from upstream PR: https://github.com/xbmc/xbmc/pull/3760
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-
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-Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
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-
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-
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-From 7388e8be7cd5e78100532ebf0dba15dccb7b03f8 Mon Sep 17 00:00:00 2001
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-From: Ben Avison <bavison@riscosopen.org>
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-Date: Tue, 3 Dec 2013 15:51:39 +0000
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-Subject: [PATCH] Faster and simpler portable implementation of
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- MathUtils::round_int().
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-
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-Much as I like a bit of inline assembler, I have also removed the ARM versions
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-of MathUtils::truncate_int() and MathUtils::round_int(). The former was just
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-how any sane compiler should have assembled a cast from double to signed int
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-anyway. The latter was a much too complicated way to achieve the desired
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-effect, and was switched out in most ARM builds anyway in favour of the old
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-portable implementation that used floor().
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-
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-Verified that MathUtils::test() still passes, and that GCC is now able to
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-inline MathUtils::round_int(), where it didn't previously.
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-
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-I tested on a Raspberry Pi with the default theme, displaying the front page
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-with the RSS ticker enabled. This saturates the CPU, so I'm measuring the
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-improvement using the debug window's FPS figure. This patch improves this from
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-~50.8 FPS to ~52.6 FPS.
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----
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- xbmc/utils/MathUtils.h | 129 +++++++++++++++++++++++--------------------------
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- 1 file changed, 61 insertions(+), 68 deletions(-)
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-
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-diff --git a/xbmc/utils/MathUtils.h b/xbmc/utils/MathUtils.h
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-index 96af9f4..0dae77d 100644
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---- a/xbmc/utils/MathUtils.h
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-+++ b/xbmc/utils/MathUtils.h
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-@@ -34,17 +34,13 @@
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-
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- #if defined(__ppc__) || \
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- defined(__powerpc__) || \
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-- (defined(TARGET_DARWIN_IOS) && defined(__llvm__)) || \
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-- (defined(TARGET_ANDROID) && defined(__arm__)) || \
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-- defined(TARGET_RASPBERRY_PI)
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-+ defined(__arm__)
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- #define DISABLE_MATHUTILS_ASM_ROUND_INT
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- #endif
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-
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- #if defined(__ppc__) || \
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- defined(__powerpc__) || \
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-- (defined(TARGET_DARWIN) && defined(__llvm__)) || \
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-- (defined(TARGET_ANDROID) && defined(__arm__)) || \
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-- defined(TARGET_RASPBERRY_PI)
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-+ defined(__arm__)
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- #define DISABLE_MATHUTILS_ASM_TRUNCATE_INT
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- #endif
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-
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-@@ -73,60 +69,63 @@
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- {
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- assert(x > static_cast<double>(INT_MIN / 2) - 1.0);
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- assert(x < static_cast<double>(INT_MAX / 2) + 1.0);
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-- const float round_to_nearest = 0.5f;
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-- int i;
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-
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- #if defined(DISABLE_MATHUTILS_ASM_ROUND_INT)
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-- i = floor(x + round_to_nearest);
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--
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--#elif defined(__arm__)
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-- // From 'ARM-v7-M Architecture Reference Manual' page A7-569:
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-- // "The floating-point to integer operation (vcvt) [normally] uses the Round towards Zero rounding mode"
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-- // Because of this...we must use some less-than-straightforward logic to perform this operation without
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-- // changing the rounding mode flags
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--
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-- /* The assembly below implements the following logic:
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-- if (x < 0)
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-- inc = -0.5f
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-- else
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-- inc = 0.5f
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-- int_val = trunc(x+inc);
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-- err = x - int_val;
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-- if (err == 0.5f)
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-- int_val++;
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-- return int_val;
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-- */
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-+ /* This implementation warrants some further explanation.
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-+ *
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-+ * First, a couple of notes on rounding:
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-+ * 1) C casts from float/double to integer round towards zero.
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-+ * 2) Float/double additions are rounded according to the normal rules,
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-+ * in other words: on some architectures, it's fixed at compile-time,
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-+ * and on others it can be set using fesetround()). The following
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-+ * analysis assumes round-to-nearest with ties rounding to even. This
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-+ * is a fairly sensible choice, and is the default with ARM VFP.
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-+ *
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-+ * What this function wants is round-to-nearest with ties rounding to
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-+ * +infinity. This isn't an IEEE rounding mode, even if we could guarantee
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-+ * that all architectures supported fesetround(), which they don't. Instead,
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-+ * this adds an offset of 2147483648.5 (= 0x80000000.8p0), then casts to
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-+ * an unsigned int (crucially, all possible inputs are now in a range where
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-+ * round to zero acts the same as round to -infinity) and then subtracts
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-+ * 0x80000000 in the integer domain. The 0.5 component of the offset
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-+ * converts what is effectively a round down into a round to nearest, with
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-+ * ties rounding up, as desired.
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-+ *
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-+ * There is a catch, that because there is a double rounding, there is a
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-+ * small region where the input falls just *below* a tie, where the addition
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-+ * of the offset causes a round *up* to an exact integer, due to the finite
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-+ * level of precision available in floating point. You need to be aware of
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-+ * this when calling this function, although at present it is not believed
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-+ * that XBMC ever attempts to round numbers in this window.
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-+ *
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-+ * It is worth proving the size of the affected window. Recall that double
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-+ * precision employs a mantissa of 52 bits.
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-+ * 1) For all inputs -0.5 <= x <= INT_MAX
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-+ * Once the offset is applied, the most significant binary digit in the
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-+ * floating-point representation is +2^31.
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-+ * At this magnitude, the smallest step representable in double precision
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-+ * is 2^31 / 2^52 = 0.000000476837158203125
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-+ * So the size of the range which is rounded up due to the addition is
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-+ * half the size of this step, or 0.0000002384185791015625
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-+ *
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-+ * 2) For all inputs INT_MIN/2 < x < -0.5
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-+ * Once the offset is applied, the most significant binary digit in the
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-+ * floating-point representation is +2^30.
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-+ * At this magnitude, the smallest step representable in double precision
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-+ * is 2^30 / 2^52 = 0.0000002384185791015625
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-+ * So the size of the range which is rounded up due to the addition is
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-+ * half the size of this step, or 0.00000011920928955078125
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-+ *
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-+ * 3) For all inputs INT_MIN <= x <= INT_MIN/2
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-+ * The representation once the offset is applied has equal or greater
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-+ * precision than the input, so the addition does not cause rounding.
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-+ */
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-+ return ((unsigned int) (x + 0x80000000.8p0)) - 0x80000000;
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-
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-- __asm__ __volatile__ (
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--#if defined(__ARM_PCS_VFP)
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-- "fconstd d1,#%G[rnd_val] \n\t" // Copy round_to_nearest into a working register (d1 = 0.5)
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- #else
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-- "vmov.F64 d1,%[rnd_val] \n\t"
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--#endif
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-- "fcmpezd %P[value] \n\t" // Check value against zero (value == 0?)
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-- "fmstat \n\t" // Copy the floating-point status flags into the general-purpose status flags
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-- "it mi \n\t"
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-- "vnegmi.F64 d1, d1 \n\t" // if N-flag is set, negate round_to_nearest (if (value < 0) d1 = -1 * d1)
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-- "vadd.F64 d1,%P[value],d1 \n\t" // Add round_to_nearest to value, store result in working register (d1 += value)
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-- "vcvt.S32.F64 s3,d1 \n\t" // Truncate(round towards zero) (s3 = (int)d1)
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-- "vmov %[result],s3 \n\t" // Store the integer result in a general-purpose register (result = s3)
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-- "vcvt.F64.S32 d1,s3 \n\t" // Convert back to floating-point (d1 = (double)s3)
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-- "vsub.F64 d1,%P[value],d1 \n\t" // Calculate the error (d1 = value - d1)
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--#if defined(__ARM_PCS_VFP)
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-- "fconstd d2,#%G[rnd_val] \n\t" // d2 = 0.5;
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--#else
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-- "vmov.F64 d2,%[rnd_val] \n\t"
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--#endif
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-- "fcmped d1, d2 \n\t" // (d1 == 0.5?)
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-- "fmstat \n\t" // Copy the floating-point status flags into the general-purpose status flags
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-- "it eq \n\t"
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-- "addeq %[result],#1 \n\t" // (if (d1 == d2) result++;)
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-- : [result] "=r"(i) // Outputs
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-- : [rnd_val] "Dv" (round_to_nearest), [value] "w"(x) // Inputs
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-- : "d1", "d2", "s3" // Clobbers
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-- );
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--
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--#elif defined(__SSE2__)
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-+ const float round_to_nearest = 0.5f;
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-+ int i;
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-+#if defined(__SSE2__)
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- const float round_dn_to_nearest = 0.4999999f;
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- i = (x > 0) ? _mm_cvttsd_si32(_mm_set_sd(x + round_to_nearest)) : _mm_cvttsd_si32(_mm_set_sd(x - round_dn_to_nearest));
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-
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-@@ -150,8 +149,8 @@
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- );
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-
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- #endif
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--
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- return i;
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-+#endif
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- }
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-
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- /*! \brief Truncate to nearest integer.
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-@@ -165,20 +164,13 @@
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- {
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- assert(x > static_cast<double>(INT_MIN / 2) - 1.0);
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- assert(x < static_cast<double>(INT_MAX / 2) + 1.0);
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-- int i;
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-
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- #if defined(DISABLE_MATHUTILS_ASM_TRUNCATE_INT)
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-- return i = (int)x;
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--
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--#elif defined(__arm__)
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-- __asm__ __volatile__ (
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-- "vcvt.S32.F64 %[result],%P[value] \n\t" // Truncate(round towards zero) and store the result
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-- : [result] "=w"(i) // Outputs
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-- : [value] "w"(x) // Inputs
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-- );
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-- return i;
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-+ return x;
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-
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--#elif defined(TARGET_WINDOWS)
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-+#else
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-+ int i;
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-+#if defined(TARGET_WINDOWS)
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- const float round_towards_m_i = -0.5f;
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- __asm
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- {
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-@@ -204,6 +196,7 @@
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- if (x < 0)
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- i = -i;
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- return (i);
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-+#endif
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- }
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-
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- inline int64_t abs(int64_t a)
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---
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-1.9.1
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-
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