Add tanh method

Author: Atry

Expressions/src/main/scala/com/thoughtworks/compute/Expressions.scala

@@ -120,6 +120,7 @@ object Expressions {
       def exp(operand: FloatTerm): FloatTerm
       def abs(operand: FloatTerm): FloatTerm
       def sqrt(operand: FloatTerm): FloatTerm
+      def tanh(operand: FloatTerm): FloatTerm
     }
 
     /** @template */

OpenCLKernelBuilder/src/main/scala/com/thoughtworks/compute/OpenCLKernelBuilder.scala

@@ -265,6 +265,14 @@ trait OpenCLKernelBuilder extends AllExpressions {
       """
       float.termFactory.newInstance(valueTermName)
     }
+
+    def tanh(operand0: FloatTerm): FloatTerm = {
+      val valueTermName = freshName("")
+      localDefinitions += fastraw"""
+        const ${operand0.typeCode} $valueTermName = tanh(${operand0.termCode});
+      """
+      float.termFactory.newInstance(valueTermName)
+    }
   }
 
   type FloatType <: (ValueType with Any) with ClFloatType

Tensors/src/main/scala/com/thoughtworks/compute/Tensors.scala

@@ -502,6 +502,10 @@ trait Tensors extends OpenCL {
       leftHandSide.derivedTensor(trees.float.sqrt(leftHandSide.closure.asInstanceOf[FloatTerm]))
     }
 
+    def tanh(leftHandSide: Tensor): Tensor = {
+      leftHandSide.derivedTensor(trees.float.tanh(leftHandSide.closure.asInstanceOf[FloatTerm]))
+    }
+
     def exp(leftHandSide: Tensor): Tensor = {
       leftHandSide.derivedTensor(trees.float.exp(leftHandSide.closure.asInstanceOf[FloatTerm]))
     }

Trees/src/main/scala/com/thoughtworks/compute/Trees.scala

@@ -421,6 +421,21 @@ object Trees {
       }
     }
 
+    /** @group AST */
+    @(silent @companionObject)
+    final case class Tanh(operand0: FloatTree) extends FloatOperator {
+
+      protected def erasedExport(foreignCategory: Category, context: ExportContext) = {
+        context.asScala.getOrElseUpdate(this, foreignCategory.float.tanh(operand0.export(foreignCategory, context)))
+      }
+
+      protected def erasedAlphaConversion(context: AlphaConversionContext): Tree = {
+        def converted = copy(operand0 = operand0.alphaConversion(context))
+        context.asScala.getOrElseUpdate(this, converted)
+      }
+    }
+
+
     /** @group AST */
     @(silent @companionObject)
     final case class Sqrt(operand0: FloatTree) extends FloatOperator {
@@ -619,6 +634,11 @@ object Trees {
         term(Sqrt(operand.tree))
       }
 
+      @inline
+      def tanh(operand: FloatTerm): FloatTerm = {
+        term(Tanh(operand.tree))
+      }
+
     }
 
     type FloatType <: (ValueType with Any) with FloatTreeType