diff --git a/renderdoc/driver/shaders/dxbc/dxbc_debug.cpp b/renderdoc/driver/shaders/dxbc/dxbc_debug.cpp
index bc950882a..e21bcfad9 100644
--- a/renderdoc/driver/shaders/dxbc/dxbc_debug.cpp
+++ b/renderdoc/driver/shaders/dxbc/dxbc_debug.cpp
@@ -1093,6 +1093,25 @@ ShaderVariable State::GetSrc(const ASMOperand &oper, const ASMOperation &op) con
   return v;
 }
 
+static uint32_t BitwiseReverseLSB16(uint32_t x)
+{
+  // Reverse the bits in x, then discard the lower half
+  // https://graphics.stanford.edu/~seander/bithacks.html#ReverseParallel
+  x = ((x >> 1) & 0x55555555) | ((x & 0x55555555) << 1);
+  x = ((x >> 2) & 0x33333333) | ((x & 0x33333333) << 2);
+  x = ((x >> 4) & 0x0F0F0F0F) | ((x & 0x0F0F0F0F) << 4);
+  x = ((x >> 8) & 0x00FF00FF) | ((x & 0x00FF00FF) << 8);
+  return x << 16;
+}
+
+static uint32_t PopCount(uint32_t x)
+{
+  // https://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetParallel
+  x = x - ((x >> 1) & 0x55555555);
+  x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
+  return (((x + (x >> 4)) & 0x0F0F0F0F) * 0x01010101) >> 24;
+}
+
 State State::GetNext(GlobalState &global, State quad[4]) const
 {
   State s = *this;
@@ -1156,13 +1175,9 @@ State State::GetNext(GlobalState &global, State quad[4]) const
     {
       ShaderVariable ret("", 0U, 0U, 0U, 0U);
 
-      // do a bitwise reverse
       for(size_t i = 0; i < 4; i++)
       {
-        for(size_t b = 0; b < 32; b++)
-        {
-          ret.value.uv[i] |= (srcOpers[0].value.uv[i] & (1 << b)) << (31 - 2 * b);
-        }
+        ret.value.uv[i] = BitwiseReverseLSB16(srcOpers[0].value.uv[i]);
       }
 
       s.SetDst(op.operands[0], op, ret);
@@ -1173,13 +1188,9 @@ State State::GetNext(GlobalState &global, State quad[4]) const
     {
       ShaderVariable ret("", 0U, 0U, 0U, 0U);
 
-      // do a bitwise reverse
       for(size_t i = 0; i < 4; i++)
       {
-        uint32_t bf = srcOpers[0].value.uv[i];
-        bf = bf - ((bf >> 1) & 0x55555555);
-        bf = (bf & 0x33333333) + ((bf >> 2) & 0x33333333);
-        ret.value.uv[i] = (((bf + (bf >> 4)) & 0x0F0F0F0F) * 0x01010101) >> 24;
+        ret.value.uv[i] = PopCount(srcOpers[0].value.uv[i]);
       }
 
       s.SetDst(op.operands[0], op, ret);