Changeset 268506 in webkit

Timestamp:

Oct 14, 2020 7:29:30 PM (4 years ago)

Author:

Chris Dumez

Message:

Rename VectorMath::multiplyThenAddScalar() for clarity
​https://bugs.webkit.org/show_bug.cgi?id=217744

Reviewed by Darin Adler.

Rename VectorMath::multiplyThenAddScalar() to VectorMath::multiplyByScalarThenAddToOutput()
for clarity. The previous name was a bit confusing and hopefully the new name makes it
clearer what the function actually does. If not, I also improved the comment next to the
function.

• platform/audio/AudioBus.cpp:

(WebCore::AudioBus::speakersSumFromByDownMixing):

• platform/audio/VectorMath.cpp:

(WebCore::VectorMath::multiplyByScalarThenAddToOutput):

• platform/audio/VectorMath.h:

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• platform/audio/AudioBus.cpp (modified) (6 diffs)
• platform/audio/VectorMath.cpp (modified) (2 diffs)
• platform/audio/VectorMath.h (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2020-10-14  Chris Dumez  <cdumez@apple.com>
+
+        Rename VectorMath::multiplyThenAddScalar() for clarity
+        https://bugs.webkit.org/show_bug.cgi?id=217744
+
+        Reviewed by Darin Adler.
+
+        Rename VectorMath::multiplyThenAddScalar() to VectorMath::multiplyByScalarThenAddToOutput()
+        for clarity. The previous name was a bit confusing and hopefully the new name makes it
+        clearer what the function actually does. If not, I also improved the comment next to the
+        function.
+
+        * platform/audio/AudioBus.cpp:
+        (WebCore::AudioBus::speakersSumFromByDownMixing):
+        * platform/audio/VectorMath.cpp:
+        (WebCore::VectorMath::multiplyByScalarThenAddToOutput):
+        * platform/audio/VectorMath.h:
+
 2020-10-14  Chris Dumez  <cdumez@apple.com>
 

trunk/Source/WebCore/platform/audio/AudioBus.cpp

@@ -318 +318 @@
 
         float* destination = channelByType(ChannelLeft)->mutableData();
-        VectorMath::multiplyThenAddScalar(sourceL, 0.5, destination, length());
-        VectorMath::multiplyThenAddScalar(sourceR, 0.5, destination, length());
+        VectorMath::multiplyByScalarThenAddToOutput(sourceL, 0.5, destination, length());
+        VectorMath::multiplyByScalarThenAddToOutput(sourceR, 0.5, destination, length());
     } else if (numberOfSourceChannels == 4 && numberOfDestinationChannels == 1) {
         // Down-mixing: 4 -> 1
@@ -330 +330 @@
         auto* destination = channelByType(ChannelLeft)->mutableData();
 
-        VectorMath::multiplyThenAddScalar(sourceL, 0.25, destination, length());
-        VectorMath::multiplyThenAddScalar(sourceR, 0.25, destination, length());
-        VectorMath::multiplyThenAddScalar(sourceSL, 0.25, destination, length());
-        VectorMath::multiplyThenAddScalar(sourceSR, 0.25, destination, length());
+        VectorMath::multiplyByScalarThenAddToOutput(sourceL, 0.25, destination, length());
+        VectorMath::multiplyByScalarThenAddToOutput(sourceR, 0.25, destination, length());
+        VectorMath::multiplyByScalarThenAddToOutput(sourceSL, 0.25, destination, length());
+        VectorMath::multiplyByScalarThenAddToOutput(sourceSR, 0.25, destination, length());
     } else if (numberOfSourceChannels == 6 && numberOfDestinationChannels == 1) {
         // Down-mixing: 5.1 -> 1
@@ -346 +346 @@
         float scaleSqrtHalf = sqrtf(0.5);
 
-        VectorMath::multiplyThenAddScalar(sourceL, scaleSqrtHalf, destination, length());
-        VectorMath::multiplyThenAddScalar(sourceR, scaleSqrtHalf, destination, length());
+        VectorMath::multiplyByScalarThenAddToOutput(sourceL, scaleSqrtHalf, destination, length());
+        VectorMath::multiplyByScalarThenAddToOutput(sourceR, scaleSqrtHalf, destination, length());
         VectorMath::add(sourceC, destination, destination, length());
-        VectorMath::multiplyThenAddScalar(sourceSL, 0.5, destination, length());
-        VectorMath::multiplyThenAddScalar(sourceSR, 0.5, destination, length());
+        VectorMath::multiplyByScalarThenAddToOutput(sourceSL, 0.5, destination, length());
+        VectorMath::multiplyByScalarThenAddToOutput(sourceSR, 0.5, destination, length());
     } else if (numberOfSourceChannels == 4 && numberOfDestinationChannels == 2) {
         // Down-mixing: 4 -> 2
@@ -363 +363 @@
         auto* destinationR = channelByType(ChannelRight)->mutableData();
 
-        VectorMath::multiplyThenAddScalar(sourceL, 0.5, destinationL, length());
-        VectorMath::multiplyThenAddScalar(sourceSL, 0.5, destinationL, length());
-        VectorMath::multiplyThenAddScalar(sourceR, 0.5, destinationR, length());
-        VectorMath::multiplyThenAddScalar(sourceSR, 0.5, destinationR, length());
+        VectorMath::multiplyByScalarThenAddToOutput(sourceL, 0.5, destinationL, length());
+        VectorMath::multiplyByScalarThenAddToOutput(sourceSL, 0.5, destinationL, length());
+        VectorMath::multiplyByScalarThenAddToOutput(sourceR, 0.5, destinationR, length());
+        VectorMath::multiplyByScalarThenAddToOutput(sourceSR, 0.5, destinationR, length());
     } else if (numberOfSourceChannels == 6 && numberOfDestinationChannels == 2) {
         // Down-mixing: 5.1 -> 2
@@ -382 +382 @@
 
         VectorMath::add(sourceL, destinationL, destinationL, length());
-        VectorMath::multiplyThenAddScalar(sourceC, scaleSqrtHalf, destinationL, length());
-        VectorMath::multiplyThenAddScalar(sourceSL, scaleSqrtHalf, destinationL, length());
+        VectorMath::multiplyByScalarThenAddToOutput(sourceC, scaleSqrtHalf, destinationL, length());
+        VectorMath::multiplyByScalarThenAddToOutput(sourceSL, scaleSqrtHalf, destinationL, length());
         VectorMath::add(sourceR, destinationR, destinationR, length());
-        VectorMath::multiplyThenAddScalar(sourceC, scaleSqrtHalf, destinationR, length());
-        VectorMath::multiplyThenAddScalar(sourceSR, scaleSqrtHalf, destinationR, length());
+        VectorMath::multiplyByScalarThenAddToOutput(sourceC, scaleSqrtHalf, destinationR, length());
+        VectorMath::multiplyByScalarThenAddToOutput(sourceSR, scaleSqrtHalf, destinationR, length());
     } else if (numberOfSourceChannels == 6 && numberOfDestinationChannels == 4) {
         // Down-mixing: 5.1 -> 4
@@ -402 +402 @@
 
         VectorMath::add(sourceL, destinationL, destinationL, length());
-        VectorMath::multiplyThenAddScalar(sourceC, scaleSqrtHalf, destinationL, length());
+        VectorMath::multiplyByScalarThenAddToOutput(sourceC, scaleSqrtHalf, destinationL, length());
         VectorMath::add(sourceR, destinationR, destinationR, length());
-        VectorMath::multiplyThenAddScalar(sourceC, scaleSqrtHalf, destinationR, length());
+        VectorMath::multiplyByScalarThenAddToOutput(sourceC, scaleSqrtHalf, destinationR, length());
         channel(2)->sumFrom(sourceBus.channel(4));
         channel(3)->sumFrom(sourceBus.channel(5));

trunk/Source/WebCore/platform/audio/VectorMath.cpp

@@ -87 +87 @@
 }
 
-void multiplyThenAddScalar(const float* inputVector, float scale, float* outputVector, size_t numberOfElementsToProcess)
+void multiplyByScalarThenAddToOutput(const float* inputVector, float scale, float* outputVector, size_t numberOfElementsToProcess)
 {
     vDSP_vsma(inputVector, 1, &scale, outputVector, 1, outputVector, 1, numberOfElementsToProcess);
@@ -129 +129 @@
 }
 
-void multiplyThenAddScalar(const float* inputVector, float scale, float* outputVector, size_t numberOfElementsToProcess)
+void multiplyByScalarThenAddToOutput(const float* inputVector, float scale, float* outputVector, size_t numberOfElementsToProcess)
 {
     size_t n = numberOfElementsToProcess;

trunk/Source/WebCore/platform/audio/VectorMath.h

@@ -32 +32 @@
 namespace VectorMath {
 
-// Vector scalar multiply and then add (vsma).
-void multiplyThenAddScalar(const float* inputVector, float scale, float* outputVector, size_t numberOfElementsToProcess);
+// Multiples inputVector by scalar then adds the result to outputVector (vsma).
+// for (n = 0; n < numberOfElementsToProcess; ++n)
+//     outputVector[n] += inputVector[n] * scale;
+void multiplyByScalarThenAddToOutput(const float* inputVector, float scale, float* outputVector, size_t numberOfElementsToProcess);
 
 // Multiplies the sum of two vectors by a scalar value (vasm).