From d2395180af89f163dd308bc69deeb82d341acb3f Mon Sep 17 00:00:00 2001
From: Philip Rebohle <philip.rebohle@tu-dortmund.de>
Date: Thu, 4 Apr 2019 05:48:42 +0200
Subject: [PATCH] [util] Add helpers to pack/unpack data to/from larger units

---
 src/util/util_bit.h | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/src/util/util_bit.h b/src/util/util_bit.h
index 23b8cc655..9d9cdfc36 100644
--- a/src/util/util_bit.h
+++ b/src/util/util_bit.h
@@ -6,6 +6,8 @@
 #include <intrin.h>
 #endif
 
+#include "util_likely.h"
+
 namespace dxvk::bit {
   
   template<typename T>
@@ -46,5 +48,23 @@ namespace dxvk::bit {
     return n != 0 ? r : 32;
     #endif
   }
+
+  template<typename T>
+  uint32_t pack(T& dst, uint32_t& shift, T src, uint32_t count) {
+    constexpr uint32_t Bits = 8 * sizeof(T);
+    if (likely(shift < Bits))
+      dst |= src << shift;
+    shift += count;
+    return shift > Bits ? shift - Bits : 0;
+  }
+
+  template<typename T>
+  uint32_t unpack(T& dst, T src, uint32_t& shift, uint32_t count) {
+    constexpr uint32_t Bits = 8 * sizeof(T);
+    if (likely(shift < Bits))
+      dst = (src >> shift) & ((T(1) << count) - 1);
+    shift += count;
+    return shift > Bits ? shift - Bits : 0;
+  }
   
 }
\ No newline at end of file