Initial work

1 files changed, 47 insertions, 0 deletions

diff --git a/Ryujinx.Graphics.Shader/Translation/Optimizations/HalfConversion.cs b/Ryujinx.Graphics.Shader/Translation/Optimizations/HalfConversion.cs
new file mode 100644
index 00000000..96060272
--- /dev/null
+++ b/Ryujinx.Graphics.Shader/Translation/Optimizations/HalfConversion.cs
@@ -0,0 +1,47 @@
+using System;
+
+namespace Ryujinx.Graphics.Shader.Translation.Optimizations
+{
+    static class HalfConversion
+    {
+        public static float HalfToSingle(int value)
+        {
+            int mantissa = (value >> 0)  & 0x3ff;
+            int exponent = (value >> 10) & 0x1f;
+            int sign     = (value >> 15) & 0x1;
+
+            if (exponent == 0x1f)
+            {
+                // NaN or Infinity.
+                mantissa <<= 13;
+                exponent   = 0xff;
+            }
+            else if (exponent != 0 || mantissa != 0 )
+            {
+                if (exponent == 0)
+                {
+                    // Denormal.
+                    int e = -1;
+                    int m = mantissa;
+
+                    do
+                    {
+                        e++;
+                        m <<= 1;
+                    }
+                    while ((m & 0x400) == 0);
+
+                    mantissa = m & 0x3ff;
+                    exponent = e;
+                }
+
+                mantissa <<= 13;
+                exponent   = 127 - 15 + exponent;
+            }
+
+            int output = (sign << 31) | (exponent << 23) | mantissa;
+
+            return BitConverter.Int32BitsToSingle(output);
+        }
+    }
+}
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