gallium: document PK2H/UP2H

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-by: Roland Scheidegger <sroland@vmware.com>

diff --git a/src/gallium/docs/source/tgsi.rst b/src/gallium/docs/source/tgsi.rst
index 955ece89da5202acc2d48f026675f6181178373f..2149d08419a024b1dc9f45ae64e2cd0d006a381b 100644 (file)
--- a/src/gallium/docs/source/tgsi.rst
+++ b/src/gallium/docs/source/tgsi.rst
@@ -458,7 +458,11 @@ while DDY is allowed to be the same for the entire 2x2 quad.
 
 .. opcode:: PK2H - Pack Two 16-bit Floats
 
-  TBD
+This instruction replicates its result.
+
+.. math::
+
+  dst = f32\_to\_f16(src.x) | f32\_to\_f16(src.y) << 16
 
 
 .. opcode:: PK2US - Pack Two Unsigned 16-bit Scalars
@@ -615,7 +619,15 @@ This instruction replicates its result.
 
 .. opcode:: UP2H - Unpack Two 16-Bit Floats
 
-  TBD
+.. math::
+
+  dst.x = f16\_to\_f32(src0.x \& 0xffff)
+
+  dst.y = f16\_to\_f32(src0.x >> 16)
+
+  dst.z = f16\_to\_f32(src0.x \& 0xffff)
+
+  dst.w = f16\_to\_f32(src0.x >> 16)
 
 .. note::