From 03be4a7973167cc6e5b48df0b9a38cc399c0b593 Mon Sep 17 00:00:00 2001
From: Jake Turner <jake@evansturner.co.uk>
Date: Mon, 6 May 2024 09:22:46 +0100
Subject: [PATCH] RD DXIL Disassembly: decode "dx.op.dot[234]"

Example Output

%37 = call float @dx.op.dot2.f32(i32 54, float %12, float %15, float %18, float %21)
%39 = call float @dx.op.dot3.f32(i32 55, float %18, float %21, float %24, float %27, float %30, float %33)
%41 = call float @dx.op.dot4.f32(i32 56, float %27, float %30, float %33, float %36, float %12, float %12, float %12, float %12)

Becomes:

float _37 = dot({_12, _15}, {_18, _21});
float _39 = dot({_18, _21, _24}, {_27, _30, _33});
float _41 = dot({_27, _30, _33, _36}, {_12, _12, _12, _12});
---
 renderdoc/driver/shaders/dxil/dxil_bytecode.h |  3 +
 .../driver/shaders/dxil/dxil_disassemble.cpp  | 57 +++++++++++++++++++
 2 files changed, 60 insertions(+)

diff --git a/renderdoc/driver/shaders/dxil/dxil_bytecode.h b/renderdoc/driver/shaders/dxil/dxil_bytecode.h
index 15f65776d..55cf92133 100644
--- a/renderdoc/driver/shaders/dxil/dxil_bytecode.h
+++ b/renderdoc/driver/shaders/dxil/dxil_bytecode.h
@@ -315,6 +315,9 @@ enum class DXOp : uint32_t
   loadInput = 4,
   storeInput = 5,
   UMin = 40,
+  dot2 = 54,
+  dot3 = 55,
+  dot4 = 56,
   createHandle = 57,
   cbufferLoad = 59,
   cbufferLoadLegacy = 59,
diff --git a/renderdoc/driver/shaders/dxil/dxil_disassemble.cpp b/renderdoc/driver/shaders/dxil/dxil_disassemble.cpp
index a8ca18361..437405245 100644
--- a/renderdoc/driver/shaders/dxil/dxil_disassemble.cpp
+++ b/renderdoc/driver/shaders/dxil/dxil_disassemble.cpp
@@ -2918,6 +2918,63 @@ void Program::MakeRDDisassemblyString(const DXBC::Reflection *reflection)
                 showDxFuncName = true;
               }
             }
+            else if(showDxFuncName && funcCallName.beginsWith("dx.op.dot"))
+            {
+              // Dot4(ax,ay,az,aw,bx,by,bz,bw)
+              // Dot3(ax,ay,az,bx,by,bz)
+              // Dot2(ax,ay,bx,by)
+              showDxFuncName = false;
+              uint32_t dxopCode;
+              RDCASSERT(getival<uint32_t>(inst.args[0], dxopCode));
+              uint32_t countComponents = 0;
+              if(funcCallName.beginsWith("dx.op.dot4"))
+              {
+                countComponents = 4;
+                RDCASSERTEQUAL(dxopCode, (uint32_t)DXOp::dot4);
+              }
+              else if(funcCallName.beginsWith("dx.op.dot3"))
+              {
+                countComponents = 3;
+                RDCASSERTEQUAL(dxopCode, (uint32_t)DXOp::dot3);
+              }
+              else if(funcCallName.beginsWith("dx.op.dot2"))
+              {
+                countComponents = 2;
+                RDCASSERTEQUAL(dxopCode, (uint32_t)DXOp::dot2);
+              }
+              lineStr += "dot(";
+              lineStr += "{";
+              bool needComma = false;
+              uint32_t aVecStart = 1;
+              uint32_t aVecEnd = 1 + countComponents;
+              for(uint32_t a = aVecStart; a < aVecEnd; ++a)
+              {
+                if(!isUndef(inst.args[a]))
+                {
+                  if(needComma)
+                    lineStr += ", ";
+                  lineStr += ArgToString(inst.args[a], false);
+                  needComma = true;
+                }
+              }
+              lineStr += "}";
+              needComma = false;
+              uint32_t bVecStart = aVecEnd;
+              uint32_t bVecEnd = bVecStart + countComponents;
+              lineStr += ", {";
+              for(uint32_t a = bVecStart; a < bVecEnd; ++a)
+              {
+                if(!isUndef(inst.args[a]))
+                {
+                  if(needComma)
+                    lineStr += ", ";
+                  lineStr += ArgToString(inst.args[a], false);
+                  needComma = true;
+                }
+              }
+              lineStr += "}";
+              lineStr += ")";
+            }
             else if(funcCallName.beginsWith("llvm.dbg."))
             {
             }