Interop, backend: add bitsTo{Float,Double} intrinsics

Interop/Runtime/src/jvm/kotlin/kotlinx/cinterop/JvmUtils.kt

@@ -1,4 +1,7 @@
 package kotlinx.cinterop
 
 internal fun decodeFromUtf8(bytes: ByteArray) = String(bytes)
-internal fun encodeToUtf8(str: String) = str.toByteArray()
+internal fun encodeToUtf8(str: String) = str.toByteArray()
+
+fun bitsToFloat(bits: Int): Float = java.lang.Float.intBitsToFloat(bits)
+fun bitsToDouble(bits: Long): Double = java.lang.Double.longBitsToDouble(bits)

Interop/Runtime/src/native/kotlin/kotlinx/cinterop/NativeUtils.kt

@@ -1,5 +1,7 @@
 package kotlinx.cinterop
 
+import konan.internal.Intrinsic
+
 internal fun decodeFromUtf8(bytes: ByteArray): String = kotlin.text.fromUtf8Array(bytes, 0, bytes.size)
 
 fun encodeToUtf8(str: String): ByteArray {
@@ -13,4 +15,10 @@ fun encodeToUtf8(str: String): ByteArray {
         result[index] = char.toByte()
     }
     return result
-}
+}
+
+@Intrinsic
+external fun bitsToFloat(bits: Int): Float
+
+@Intrinsic
+external fun bitsToDouble(bits: Long): Double

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/InteropUtils.kt

@@ -93,6 +93,10 @@ internal class InteropBuiltIns(builtIns: KonanBuiltIns) {
 
     val nativePtrPlusLong = nativePtr.unsubstitutedMemberScope.getContributedFunctions("plus").single()
 
+    val bitsToFloat = packageScope.getContributedFunctions("bitsToFloat").single()
+
+    val bitsToDouble = packageScope.getContributedFunctions("bitsToDouble").single()
+
 }
 
 private fun MemberScope.getContributedVariables(name: String) =

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/lower/InteropLowering.kt

@@ -14,6 +14,7 @@ import org.jetbrains.kotlin.ir.builders.irCall
 import org.jetbrains.kotlin.ir.builders.irGet
 import org.jetbrains.kotlin.ir.declarations.IrFile
 import org.jetbrains.kotlin.ir.expressions.*
+import org.jetbrains.kotlin.ir.expressions.impl.IrConstImpl
 import org.jetbrains.kotlin.ir.expressions.impl.IrGetObjectValueImpl
 import org.jetbrains.kotlin.ir.visitors.transformChildrenVoid
 import org.jetbrains.kotlin.name.Name
@@ -186,6 +187,26 @@ private class InteropTransformer(val context: Context) : IrBuildingTransformer(c
                 builder.typeOf(type) ?: expression
             }
 
+            interop.bitsToFloat -> {
+                val argument = expression.getValueArgument(0)
+                if (argument is IrConst<*> && argument.kind == IrConstKind.Int) {
+                    val floatValue = kotlinx.cinterop.bitsToFloat(argument.value as Int)
+                    builder.irFloat(floatValue)
+                } else {
+                    expression
+                }
+            }
+
+            interop.bitsToDouble -> {
+                val argument = expression.getValueArgument(0)
+                if (argument is IrConst<*> && argument.kind == IrConstKind.Long) {
+                    val doubleValue = kotlinx.cinterop.bitsToDouble(argument.value as Long)
+                    builder.irDouble(doubleValue)
+                } else {
+                    expression
+                }
+            }
+
             else -> expression
         }
     }
@@ -194,4 +215,10 @@ private class InteropTransformer(val context: Context) : IrBuildingTransformer(c
         val typeParameter = descriptor.original.typeParameters.single()
         return getTypeArgument(typeParameter)!!
     }
-}
+}
+
+private fun IrBuilder.irFloat(value: Float) =
+        IrConstImpl.float(startOffset, endOffset, context.builtIns.floatType, value)
+
+private fun IrBuilder.irDouble(value: Double) =
+        IrConstImpl.double(startOffset, endOffset, context.builtIns.doubleType, value)