Revert "[dxbc] Bound-check dynamically indexed constant buffer reads"

This reverts commit 621aed5fdbaf92764944be7b3a27cbb3df63ba94.

Breaks Dishonored 2. Apparently, out-of-bounds access to constant buffers
is allowed as long as it doesn't exceed the range of bound constants.

src/dxbc/dxbc_compiler.cpp

@@ -4210,6 +4210,35 @@ namespace dxvk {
   }
   
   
+  DxbcRegisterPointer DxbcCompiler::emitGetConstBufPtr(
+    const DxbcRegister&           operand) {
+    // Constant buffers take a two-dimensional index:
+    //    (0) register index (immediate)
+    //    (1) constant offset (relative)
+    DxbcRegisterInfo info;
+    info.type.ctype   = DxbcScalarType::Float32;
+    info.type.ccount  = 4;
+    info.type.alength = 0;
+    info.sclass = spv::StorageClassUniform;
+    
+    const uint32_t regId = operand.idx[0].offset;
+    const DxbcRegisterValue constId = emitIndexLoad(operand.idx[1]);
+    
+    const uint32_t ptrTypeId = getPointerTypeId(info);
+    
+    const std::array<uint32_t, 2> indices =
+      {{ m_module.consti32(0), constId.id }};
+    
+    DxbcRegisterPointer result;
+    result.type.ctype  = info.type.ctype;
+    result.type.ccount = info.type.ccount;
+    result.id = m_module.opAccessChain(ptrTypeId,
+      m_constantBuffers.at(regId).varId,
+      indices.size(), indices.data());
+    return result;
+  }
+  
+  
   DxbcRegisterPointer DxbcCompiler::emitGetImmConstBufPtr(
     const DxbcRegister&           operand) {
     if (m_immConstBuf == 0)
@@ -4252,6 +4281,9 @@ namespace dxvk {
       case DxbcOperandType::Output:
         return emitGetOutputPtr(operand);
       
+      case DxbcOperandType::ConstantBuffer:
+        return emitGetConstBufPtr(operand);
+      
       case DxbcOperandType::ImmediateConstantBuffer:
         return emitGetImmConstBufPtr(operand);
       
@@ -4708,22 +4740,6 @@ namespace dxvk {
   }
   
   
-  DxbcRegisterValue DxbcCompiler::emitIndexBoundCheck(
-          DxbcRegisterValue       index,
-          DxbcRegisterValue       count) {
-    index = emitRegisterBitcast(index, DxbcScalarType::Uint32);
-    count = emitRegisterBitcast(count, DxbcScalarType::Uint32);
-
-    DxbcRegisterValue result;
-    result.type.ctype  = DxbcScalarType::Bool;
-    result.type.ccount = index.type.ccount;
-    result.id = m_module.opULessThan(
-      getVectorTypeId(result.type),
-      index.id, count.id);
-    return result;
-  }
-
-
   DxbcRegisterValue DxbcCompiler::emitIndexLoad(
           DxbcRegIndex            index) {
     if (index.relReg != nullptr) {
@@ -4786,56 +4802,9 @@ namespace dxvk {
   }
   
   
-  DxbcRegisterValue DxbcCompiler::emitConstBufLoadRaw(
-    const DxbcRegister&           operand) {
-    // Constant buffers take a two-dimensional index:
-    //    (0) register index (immediate)
-    //    (1) constant offset (relative)
-    DxbcRegisterInfo info;
-    info.type.ctype   = DxbcScalarType::Float32;
-    info.type.ccount  = 4;
-    info.type.alength = 0;
-    info.sclass = spv::StorageClassUniform;
-    
-    const uint32_t regId = operand.idx[0].offset;
-    const DxbcRegisterValue constId = emitIndexLoad(operand.idx[1]);
-    
-    const uint32_t ptrTypeId = getPointerTypeId(info);
-    
-    const std::array<uint32_t, 2> indices =
-      {{ m_module.consti32(0), constId.id }};
-    
-    DxbcRegisterPointer pointer;
-    pointer.type.ctype  = info.type.ctype;
-    pointer.type.ccount = info.type.ccount;
-    pointer.id = m_module.opAccessChain(ptrTypeId,
-      m_constantBuffers.at(regId).varId,
-      indices.size(), indices.data());
-    
-    DxbcRegisterValue value = emitValueLoad(pointer);
-
-    // For dynamically indexed constant buffers, we should
-    // return a vec4(ß.0f) if the index is out of bounds
-    if (operand.idx[1].relReg != nullptr) {
-      DxbcRegisterValue cbSize;
-      cbSize.type = { DxbcScalarType::Uint32, 1 };
-      cbSize.id   = m_module.constu32(m_constantBuffers.at(regId).size);
-      DxbcRegisterValue inBounds = emitRegisterExtend(emitIndexBoundCheck(constId, cbSize), 4);
-      
-      value.id = m_module.opSelect(
-        getVectorTypeId(value.type), inBounds.id, value.id,
-        m_module.constvec4f32(0.0f, 0.0f, 0.0f, 0.0f));
-    }
-
-    return value;
-  }
-
-
   DxbcRegisterValue DxbcCompiler::emitRegisterLoadRaw(
     const DxbcRegister&           reg) {
-    return reg.type == DxbcOperandType::ConstantBuffer
+    return emitValueLoad(emitGetOperandPtr(reg));
-      ? emitConstBufLoadRaw(reg)
-      : emitValueLoad(emitGetOperandPtr(reg));
   }
   
   

src/dxbc/dxbc_compiler.h

@@ -819,6 +819,9 @@ namespace dxvk {
     DxbcRegisterPointer emitGetOutputPtr(
       const DxbcRegister&           operand);
     
+    DxbcRegisterPointer emitGetConstBufPtr(
+      const DxbcRegister&           operand);
+    
     DxbcRegisterPointer emitGetImmConstBufPtr(
       const DxbcRegister&           operand);
     
@@ -876,10 +879,6 @@ namespace dxvk {
     
     //////////////////////////////
     // Operand load/store methods
-    DxbcRegisterValue emitIndexBoundCheck(
-            DxbcRegisterValue       index,
-            DxbcRegisterValue       count);
-
     DxbcRegisterValue emitIndexLoad(
             DxbcRegIndex            index);
     
@@ -891,9 +890,6 @@ namespace dxvk {
             DxbcRegisterValue       value,
             DxbcRegMask             writeMask);
     
-    DxbcRegisterValue emitConstBufLoadRaw(
-      const DxbcRegister&           operand);
-    
     DxbcRegisterValue emitRegisterLoadRaw(
       const DxbcRegister&           reg);