[FFmpeg-devel] [PATCH v3 1/2] libavutil/common: clip nan value to amin

[mindmark at gmail.com]

From: Mark Reid <mindmark at gmail.com>

Changes av_clipf to return amin if a is nan.
Before if a is nan av_clipf_c returned nan and
av_clipf_sse would return amax. Now the both
should behave the same.

This works because nan > amin is false.
The max(nan, amin) will be amin.
---
 libavutil/common.h      | 12 ++++++------
 libavutil/x86/intmath.h |  8 ++++----
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/libavutil/common.h b/libavutil/common.h
index 3cc1f07566..9338bda7d5 100644
--- a/libavutil/common.h
+++ b/libavutil/common.h
@@ -379,6 +379,8 @@ static av_always_inline int64_t av_sat_sub64_c(int64_t a, int64_t b) {

 /**
  * Clip a float value into the amin-amax range.
+ * If a is nan or -inf amin will be returned.
+ * If a is +inf amax will be returned.
  * @param a value to clip
  * @param amin minimum value of the clip range
  * @param amax maximum value of the clip range
@@ -389,13 +391,13 @@ static av_always_inline av_const float av_clipf_c(float a, float amin, float ama
 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
     if (amin > amax) abort();
 #endif
-    if      (a < amin) return amin;
-    else if (a > amax) return amax;
-    else               return a;
+    return FFMIN(FFMAX(a, amin), amax);
 }

 /**
  * Clip a double value into the amin-amax range.
+ * If a is nan or -inf amin will be returned.
+ * If a is +inf amax will be returned.
  * @param a value to clip
  * @param amin minimum value of the clip range
  * @param amax maximum value of the clip range
@@ -406,9 +408,7 @@ static av_always_inline av_const double av_clipd_c(double a, double amin, double
 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
     if (amin > amax) abort();
 #endif
-    if      (a < amin) return amin;
-    else if (a > amax) return amax;
-    else               return a;
+    return FFMIN(FFMAX(a, amin), amax);
 }

 /** Compute ceil(log2(x)).
diff --git a/libavutil/x86/intmath.h b/libavutil/x86/intmath.h
index 40743fd13e..1520c25ec9 100644
--- a/libavutil/x86/intmath.h
+++ b/libavutil/x86/intmath.h
@@ -110,8 +110,8 @@ static av_always_inline av_const double av_clipd_sse2(double a, double amin, dou
 #if defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
     if (amin > amax) abort();
 #endif
-    __asm__ ("minsd %2, %0 \n\t"
-             "maxsd %1, %0 \n\t"
+    __asm__ ("maxsd %1, %0 \n\t"
+             "minsd %2, %0 \n\t"
              : "+&x"(a) : "xm"(amin), "xm"(amax));
     return a;
 }
@@ -126,8 +126,8 @@ static av_always_inline av_const float av_clipf_sse(float a, float amin, float a
 #if defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
     if (amin > amax) abort();
 #endif
-    __asm__ ("minss %2, %0 \n\t"
-             "maxss %1, %0 \n\t"
+    __asm__ ("maxss %1, %0 \n\t"
+             "minss %2, %0 \n\t"
              : "+&x"(a) : "xm"(amin), "xm"(amax));
     return a;
 }
--
2.31.1.windows.1