Use exact-at-power-of-two reciprocal for texture projection.

Change-Id: I1b3a4bb977ea5d311be6af9b6b8f04235b002dbe
Reviewed-on: https://swiftshader-review.googlesource.com/16028
Tested-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
diff --git a/src/Shader/ShaderCore.cpp b/src/Shader/ShaderCore.cpp
index 58e535c..559208c 100644
--- a/src/Shader/ShaderCore.cpp
+++ b/src/Shader/ShaderCore.cpp
@@ -727,7 +727,7 @@
 
 	void ShaderCore::rcpx(Vector4f &dst, const Vector4f &src, bool pp)
 	{
-		Float4 rcp = reciprocal(src.x, pp, true);
+		Float4 rcp = reciprocal(src.x, pp, true, true);
 
 		dst.x = rcp;
 		dst.y = rcp;