From f933aa1c7677a7668ce19648283ee72d8803e2ec Mon Sep 17 00:00:00 2001
From: Jake Turner <jake@evansturner.co.uk>
Date: Thu, 24 Oct 2024 16:13:37 +0100
Subject: [PATCH] Moved some bit field helper functions to common code

To be shared between DXBC and DXIL Debugger
BitwiseReverseLSB16
PopCount
---
 renderdoc/driver/shaders/dxbc/dx_debug.cpp   | 19 +++++++++++++++++++
 renderdoc/driver/shaders/dxbc/dx_debug.h     |  3 +++
 renderdoc/driver/shaders/dxbc/dxbc_debug.cpp | 19 -------------------
 3 files changed, 22 insertions(+), 19 deletions(-)

diff --git a/renderdoc/driver/shaders/dxbc/dx_debug.cpp b/renderdoc/driver/shaders/dxbc/dx_debug.cpp
index c87dd0b0f..48e71360f 100644
--- a/renderdoc/driver/shaders/dxbc/dx_debug.cpp
+++ b/renderdoc/driver/shaders/dxbc/dx_debug.cpp
@@ -412,6 +412,25 @@ float flush_denorm(const float f)
   return ret;
 }
 
+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;
+}
+
+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;
+}
+
 void get_sample_position(uint32_t sampleIndex, uint32_t sampleCount, float *position)
 {
   // assume standard sample pattern - this might not hold in all cases
diff --git a/renderdoc/driver/shaders/dxbc/dx_debug.h b/renderdoc/driver/shaders/dxbc/dx_debug.h
index cd787f442..90725fe9f 100644
--- a/renderdoc/driver/shaders/dxbc/dx_debug.h
+++ b/renderdoc/driver/shaders/dxbc/dx_debug.h
@@ -117,5 +117,8 @@ float round_ne(float x);
 double round_ne(double x);
 float flush_denorm(const float f);
 
+uint32_t BitwiseReverseLSB16(uint32_t x);
+uint32_t PopCount(uint32_t x);
+
 void get_sample_position(uint32_t sampleIndex, uint32_t sampleCount, float *position);
 };
diff --git a/renderdoc/driver/shaders/dxbc/dxbc_debug.cpp b/renderdoc/driver/shaders/dxbc/dxbc_debug.cpp
index 87142098d..d459aa8af 100644
--- a/renderdoc/driver/shaders/dxbc/dxbc_debug.cpp
+++ b/renderdoc/driver/shaders/dxbc/dxbc_debug.cpp
@@ -1639,25 +1639,6 @@ ShaderVariable ThreadState::GetSrc(const Operand &oper, const Operation &op, boo
   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;
-}
-
 void FlattenSingleVariable(const rdcstr &cbufferName, uint32_t byteOffset, const rdcstr &basename,
                            const ShaderVariable &v, rdcarray<ShaderVariable> &outvars,
                            rdcarray<SourceVariableMapping> &sourcevars)