From db1a642cd213804ed1579a19c9f5db08407dad9b Mon Sep 17 00:00:00 2001
From: Ganesh Ajjanagadde <gajjanag@gmail.com>
Date: Mon, 14 Mar 2016 21:28:56 -0400
Subject: [PATCH] all: move ff_exp10, ff_exp10f, ff_fast_powf to lavu/ffmath.h

The idea is to use ffmath.h for internal implementations of math functions.
Currently, it is used for variants of libm functions, but is by no means
limited to such things.

Note that this is not exported; use lavu/mathematics for such purposes.

Reviewed-by: Ronald S. Bultje <rsbultje@gmail.com>
Signed-off-by: Ganesh Ajjanagadde <gajjanag@gmail.com>
---
 libavcodec/aacenc_utils.h       |  2 +-
 libavcodec/aacpsy.c             |  3 +-
 libavcodec/acelp_pitch_delay.c  |  3 +-
 libavcodec/cngdec.c             |  2 +-
 libavcodec/dcaenc.c             |  2 +-
 libavcodec/imc.c                |  2 +-
 libavcodec/on2avc.c             |  2 +-
 libavcodec/opus.c               |  2 +-
 libavcodec/wmadec.c             |  3 +-
 libavcodec/wmaenc.c             |  2 +-
 libavcodec/wmaprodec.c          |  2 +-
 libavfilter/af_anequalizer.c    |  1 +
 libavfilter/af_compand.c        |  1 +
 libavfilter/af_volume.c         |  1 +
 libavfilter/f_ebur128.c         |  1 +
 libavfilter/vaf_spectrumsynth.c |  1 +
 libavfilter/vsrc_testsrc.c      |  1 +
 libavutil/eval.c                |  1 +
 libavutil/ffmath.h              | 67 +++++++++++++++++++++++++++++++++
 libavutil/internal.h            | 36 ------------------
 20 files changed, 85 insertions(+), 50 deletions(-)
 create mode 100644 libavutil/ffmath.h

diff --git a/libavcodec/aacenc_utils.h b/libavcodec/aacenc_utils.h
index 07f733746bd..bb1dcb43616 100644
--- a/libavcodec/aacenc_utils.h
+++ b/libavcodec/aacenc_utils.h
@@ -28,7 +28,7 @@
 #ifndef AVCODEC_AACENC_UTILS_H
 #define AVCODEC_AACENC_UTILS_H
 
-#include "libavutil/internal.h"
+#include "libavutil/ffmath.h"
 #include "aac.h"
 #include "aacenctab.h"
 #include "aactab.h"
diff --git a/libavcodec/aacpsy.c b/libavcodec/aacpsy.c
index 8643fe70369..0898bafd241 100644
--- a/libavcodec/aacpsy.c
+++ b/libavcodec/aacpsy.c
@@ -25,8 +25,7 @@
  */
 
 #include "libavutil/attributes.h"
-#include "libavutil/internal.h"
-#include "libavutil/libm.h"
+#include "libavutil/ffmath.h"
 
 #include "avcodec.h"
 #include "aactab.h"
diff --git a/libavcodec/acelp_pitch_delay.c b/libavcodec/acelp_pitch_delay.c
index c2533b1eb1a..8ec1ba3a839 100644
--- a/libavcodec/acelp_pitch_delay.c
+++ b/libavcodec/acelp_pitch_delay.c
@@ -21,9 +21,8 @@
  */
 
 #include "libavutil/common.h"
+#include "libavutil/ffmath.h"
 #include "libavutil/float_dsp.h"
-#include "libavutil/internal.h"
-#include "libavutil/libm.h"
 #include "libavutil/mathematics.h"
 #include "avcodec.h"
 #include "acelp_pitch_delay.h"
diff --git a/libavcodec/cngdec.c b/libavcodec/cngdec.c
index 02510860429..34f881448de 100644
--- a/libavcodec/cngdec.c
+++ b/libavcodec/cngdec.c
@@ -22,7 +22,7 @@
 #include <math.h>
 
 #include "libavutil/common.h"
-#include "libavutil/internal.h"
+#include "libavutil/ffmath.h"
 #include "avcodec.h"
 #include "celp_filters.h"
 #include "internal.h"
diff --git a/libavcodec/dcaenc.c b/libavcodec/dcaenc.c
index 70e92300b68..ab40e37b320 100644
--- a/libavcodec/dcaenc.c
+++ b/libavcodec/dcaenc.c
@@ -24,7 +24,7 @@
 #include "libavutil/avassert.h"
 #include "libavutil/channel_layout.h"
 #include "libavutil/common.h"
-#include "libavutil/internal.h"
+#include "libavutil/ffmath.h"
 #include "avcodec.h"
 #include "dca.h"
 #include "dcadata.h"
diff --git a/libavcodec/imc.c b/libavcodec/imc.c
index 085ec095658..850bc9de9ab 100644
--- a/libavcodec/imc.c
+++ b/libavcodec/imc.c
@@ -35,9 +35,9 @@
 #include <stdio.h>
 
 #include "libavutil/channel_layout.h"
+#include "libavutil/ffmath.h"
 #include "libavutil/float_dsp.h"
 #include "libavutil/internal.h"
-#include "libavutil/libm.h"
 #include "avcodec.h"
 #include "bswapdsp.h"
 #include "get_bits.h"
diff --git a/libavcodec/on2avc.c b/libavcodec/on2avc.c
index 62c71ccea53..3064c6fc6ae 100644
--- a/libavcodec/on2avc.c
+++ b/libavcodec/on2avc.c
@@ -21,8 +21,8 @@
  */
 
 #include "libavutil/channel_layout.h"
+#include "libavutil/ffmath.h"
 #include "libavutil/float_dsp.h"
-#include "libavutil/internal.h"
 #include "avcodec.h"
 #include "bytestream.h"
 #include "fft.h"
diff --git a/libavcodec/opus.c b/libavcodec/opus.c
index f2b8ecc4112..47f26572048 100644
--- a/libavcodec/opus.c
+++ b/libavcodec/opus.c
@@ -27,7 +27,7 @@
 #include <stdint.h>
 
 #include "libavutil/error.h"
-#include "libavutil/internal.h"
+#include "libavutil/ffmath.h"
 
 #include "opus.h"
 #include "vorbis.h"
diff --git a/libavcodec/wmadec.c b/libavcodec/wmadec.c
index 1a8432376bb..7130bf62cc3 100644
--- a/libavcodec/wmadec.c
+++ b/libavcodec/wmadec.c
@@ -34,8 +34,7 @@
  */
 
 #include "libavutil/attributes.h"
-#include "libavutil/internal.h"
-#include "libavutil/libm.h"
+#include "libavutil/ffmath.h"
 
 #include "avcodec.h"
 #include "internal.h"
diff --git a/libavcodec/wmaenc.c b/libavcodec/wmaenc.c
index d0727e69b20..418e9586f68 100644
--- a/libavcodec/wmaenc.c
+++ b/libavcodec/wmaenc.c
@@ -20,7 +20,7 @@
  */
 
 #include "libavutil/attributes.h"
-#include "libavutil/internal.h"
+#include "libavutil/ffmath.h"
 
 #include "avcodec.h"
 #include "internal.h"
diff --git a/libavcodec/wmaprodec.c b/libavcodec/wmaprodec.c
index 2ea59e9251e..2cc1b093fbf 100644
--- a/libavcodec/wmaprodec.c
+++ b/libavcodec/wmaprodec.c
@@ -88,8 +88,8 @@
 
 #include <inttypes.h>
 
+#include "libavutil/ffmath.h"
 #include "libavutil/float_dsp.h"
-#include "libavutil/internal.h"
 #include "libavutil/intfloat.h"
 #include "libavutil/intreadwrite.h"
 #include "avcodec.h"
diff --git a/libavfilter/af_anequalizer.c b/libavfilter/af_anequalizer.c
index a344c77535c..24034602fd0 100644
--- a/libavfilter/af_anequalizer.c
+++ b/libavfilter/af_anequalizer.c
@@ -21,6 +21,7 @@
 
 #include "libavutil/intreadwrite.h"
 #include "libavutil/avstring.h"
+#include "libavutil/ffmath.h"
 #include "libavutil/opt.h"
 #include "libavutil/parseutils.h"
 #include "avfilter.h"
diff --git a/libavfilter/af_compand.c b/libavfilter/af_compand.c
index b74636409c3..0bb719fae5a 100644
--- a/libavfilter/af_compand.c
+++ b/libavfilter/af_compand.c
@@ -29,6 +29,7 @@
 
 #include "libavutil/avassert.h"
 #include "libavutil/avstring.h"
+#include "libavutil/ffmath.h"
 #include "libavutil/opt.h"
 #include "libavutil/samplefmt.h"
 #include "audio.h"
diff --git a/libavfilter/af_volume.c b/libavfilter/af_volume.c
index 3913e7b261a..4d6b91645a1 100644
--- a/libavfilter/af_volume.c
+++ b/libavfilter/af_volume.c
@@ -27,6 +27,7 @@
 #include "libavutil/channel_layout.h"
 #include "libavutil/common.h"
 #include "libavutil/eval.h"
+#include "libavutil/ffmath.h"
 #include "libavutil/float_dsp.h"
 #include "libavutil/intreadwrite.h"
 #include "libavutil/opt.h"
diff --git a/libavfilter/f_ebur128.c b/libavfilter/f_ebur128.c
index c4b30b4926b..59eaedd9269 100644
--- a/libavfilter/f_ebur128.c
+++ b/libavfilter/f_ebur128.c
@@ -33,6 +33,7 @@
 #include "libavutil/avstring.h"
 #include "libavutil/channel_layout.h"
 #include "libavutil/dict.h"
+#include "libavutil/ffmath.h"
 #include "libavutil/xga_font_data.h"
 #include "libavutil/opt.h"
 #include "libavutil/timestamp.h"
diff --git a/libavfilter/vaf_spectrumsynth.c b/libavfilter/vaf_spectrumsynth.c
index 8d4014eae89..ee394b49e3d 100644
--- a/libavfilter/vaf_spectrumsynth.c
+++ b/libavfilter/vaf_spectrumsynth.c
@@ -27,6 +27,7 @@
 #include "libavcodec/avfft.h"
 #include "libavutil/avassert.h"
 #include "libavutil/channel_layout.h"
+#include "libavutil/ffmath.h"
 #include "libavutil/opt.h"
 #include "libavutil/parseutils.h"
 #include "avfilter.h"
diff --git a/libavfilter/vsrc_testsrc.c b/libavfilter/vsrc_testsrc.c
index a75dd4c37e2..f0c09859649 100644
--- a/libavfilter/vsrc_testsrc.c
+++ b/libavfilter/vsrc_testsrc.c
@@ -37,6 +37,7 @@
 
 #include "libavutil/avassert.h"
 #include "libavutil/common.h"
+#include "libavutil/ffmath.h"
 #include "libavutil/opt.h"
 #include "libavutil/imgutils.h"
 #include "libavutil/intreadwrite.h"
diff --git a/libavutil/eval.c b/libavutil/eval.c
index 2acbbb47d16..37b8511845b 100644
--- a/libavutil/eval.c
+++ b/libavutil/eval.c
@@ -31,6 +31,7 @@
 #include "avutil.h"
 #include "common.h"
 #include "eval.h"
+#include "ffmath.h"
 #include "internal.h"
 #include "log.h"
 #include "mathematics.h"
diff --git a/libavutil/ffmath.h b/libavutil/ffmath.h
new file mode 100644
index 00000000000..aad1347f26d
--- /dev/null
+++ b/libavutil/ffmath.h
@@ -0,0 +1,67 @@
+/*
+ * copyright (c) 2016 Ganesh Ajjanagadde <gajjanag@gmail.com>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * internal math functions header
+ */
+
+#ifndef AVUTIL_FFMATH_H
+#define AVUTIL_FFMATH_H
+
+#include "attributes.h"
+#include "libm.h"
+
+/**
+ * Compute 10^x for floating point values. Note: this function is by no means
+ * "correctly rounded", and is meant as a fast, reasonably accurate approximation.
+ * For instance, maximum relative error for the double precision variant is
+ * ~ 1e-13 for very small and very large values.
+ * This is ~2x faster than GNU libm's approach, which is still off by 2ulp on
+ * some inputs.
+ * @param x exponent
+ * @return 10^x
+ */
+static av_always_inline double ff_exp10(double x)
+{
+    return exp2(M_LOG2_10 * x);
+}
+
+static av_always_inline float ff_exp10f(float x)
+{
+    return exp2f(M_LOG2_10 * x);
+}
+
+/**
+ * Compute x^y for floating point x, y. Note: this function is faster than the
+ * libm variant due to mainly 2 reasons:
+ * 1. It does not handle any edge cases. In particular, this is only guaranteed
+ * to work correctly for x > 0.
+ * 2. It is not as accurate as a standard nearly "correctly rounded" libm variant.
+ * @param x base
+ * @param y exponent
+ * @return x^y
+ */
+static av_always_inline float ff_fast_powf(float x, float y)
+{
+    return expf(logf(x) * y);
+}
+
+#endif /* AVUTIL_FFMATH_H */
diff --git a/libavutil/internal.h b/libavutil/internal.h
index 340e18bc5dd..61784b5128f 100644
--- a/libavutil/internal.h
+++ b/libavutil/internal.h
@@ -294,42 +294,6 @@ static av_always_inline av_const int64_t ff_rint64_clip(double a, int64_t amin,
     return res;
 }
 
-/**
- * Compute 10^x for floating point values. Note: this function is by no means
- * "correctly rounded", and is meant as a fast, reasonably accurate approximation.
- * For instance, maximum relative error for the double precision variant is
- * ~ 1e-13 for very small and very large values.
- * This is ~2x faster than GNU libm's approach, which is still off by 2ulp on
- * some inputs.
- * @param x exponent
- * @return 10^x
- */
-static av_always_inline double ff_exp10(double x)
-{
-    return exp2(M_LOG2_10 * x);
-}
-
-static av_always_inline float ff_exp10f(float x)
-{
-    return exp2f(M_LOG2_10 * x);
-}
-
-/**
- * Compute x^y for floating point x, y. Note: this function is faster than the
- * libm variant due to mainly 2 reasons:
- * 1. It does not handle any edge cases. In particular, this is only guaranteed
- * to work correctly for x > 0.
- * 2. It is not as accurate as a standard nearly "correctly rounded" libm variant.
- * @param x base
- * @param y exponent
- * @return x^y
- */
-static av_always_inline float ff_fast_powf(float x, float y)
-{
-    return expf(logf(x) * y);
-}
-
-
 /**
  * A wrapper for open() setting O_CLOEXEC.
  */
-- 
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