[SCM] calf/master: More protections against denormals.

[js at users.alioth.debian.org]

The following commit has been merged in the master branch:
commit 23f14c9a0d01d2e461ba7e0eaf872880fab0c313
Author: Carl Hetherington <cth at carlh.net>
Date:   Sat Jan 7 09:56:36 2012 +0000

    More protections against denormals.
    
    Note from KF: I didn't apply the patch to configure.ac, as I'm not sure
    if it's safe for systems that don't support SSE (ARM etc.).

diff --git a/src/calf/biquad.h b/src/calf/biquad.h
index 99cf2a4..a6d5a95 100644
--- a/src/calf/biquad.h
+++ b/src/calf/biquad.h
@@ -429,6 +429,11 @@ struct biquad_d2: public biquad_coeffs<Coeff>
     /// direct II form with two state variables
     inline T process(T in)
     {
+        dsp::sanitize_denormal(in);
+        dsp::sanitize(in);
+        dsp::sanitize(w1);
+        dsp::sanitize(w2);
+
         T tmp = in - w1 * b1 - w2 * b2;
         T out = tmp * a0 + w1 * a1 + w2 * a2;
         w2 = w1;
diff --git a/src/calf/primitives.h b/src/calf/primitives.h
index efc820f..cbc7758 100644
--- a/src/calf/primitives.h
+++ b/src/calf/primitives.h
@@ -408,6 +408,16 @@ inline void sanitize(float &value)
 }
 
 /**
+ * Force already-denormal float value to zero
+ */
+inline void sanitize_denormal(float& value)
+{
+    if (((*(unsigned int *) &value) & 0x7f800000) == 0) {
+        value = 0;
+    }
+}
+	
+/**
  * Force "small enough" double value to zero
  */
 inline void sanitize(double &value)
diff --git a/src/modules_comp.cpp b/src/modules_comp.cpp
index 0a0d8ab..0ee6842 100644
--- a/src/modules_comp.cpp
+++ b/src/modules_comp.cpp
@@ -1715,7 +1715,9 @@ void gain_reduction_audio_module::process(float &left, float &right, const float
         
         float absample = average ? (fabs(*det_left) + fabs(*det_right)) * 0.5f : std::max(fabs(*det_left), fabs(*det_right));
         if(rms) absample *= absample;
-            
+
+        dsp::sanitize(linSlope);
+	
         linSlope += (absample - linSlope) * (absample > linSlope ? attack_coeff : release_coeff);
         float gain = 1.f;
         if(linSlope > 0.f) {
@@ -1963,7 +1965,9 @@ void expander_audio_module::process(float &left, float &right, const float *det_
         bool average = (stereo_link == 0);
         float absample = average ? (fabs(*det_left) + fabs(*det_right)) * 0.5f : std::max(fabs(*det_left), fabs(*det_right));
         if(rms) absample *= absample;
-            
+
+        dsp::sanitize(linSlope);
+	
         linSlope += (absample - linSlope) * (absample > linSlope ? attack_coeff : release_coeff);
         float gain = 1.f;
         if(linSlope > 0.f) {

-- 
calf audio plugins packaging