From 0f7c23c02286412eb5c229d8331e881f67983124 Mon Sep 17 00:00:00 2001
From: Philip Rebohle <philip.rebohle@tu-dortmund.de>
Date: Wed, 5 Jun 2019 01:09:39 +0200
Subject: [PATCH] [dxbc] Always use raw storage buffers if alignment
 requirements are met

---
 src/dxbc/dxbc_compiler.cpp | 20 +++++++++++++++-----
 src/dxbc/dxbc_options.cpp  |  1 +
 src/dxbc/dxbc_options.h    |  3 +++
 3 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/src/dxbc/dxbc_compiler.cpp b/src/dxbc/dxbc_compiler.cpp
index dd1b8588..4c68ca9f 100644
--- a/src/dxbc/dxbc_compiler.cpp
+++ b/src/dxbc/dxbc_compiler.cpp
@@ -1076,7 +1076,11 @@ namespace dxvk {
       ? computeUavBinding(m_programInfo.type(), registerId)
       : computeSrvBinding(m_programInfo.type(), registerId);
     
-    if (m_moduleInfo.options.useRawSsbo) {
+    // Test whether we should use a raw SSBO for this resource
+    bool useRawSsbo = m_moduleInfo.options.useRawSsbo
+                   && m_moduleInfo.options.minSsboAlignment <= resAlign;
+    
+    if (useRawSsbo) {
       uint32_t elemType   = getScalarTypeId(DxbcScalarType::Uint32);
       uint32_t arrayType  = m_module.defRuntimeArrayTypeUnique(elemType);
       uint32_t structType = m_module.defStructTypeUnique(1, &arrayType);
@@ -1159,7 +1163,7 @@ namespace dxvk {
     // Store descriptor info for the shader interface
     DxvkResourceSlot resource;
     resource.slot = bindingId;
-    resource.type = m_moduleInfo.options.useRawSsbo
+    resource.type = useRawSsbo
       ? VK_DESCRIPTOR_TYPE_STORAGE_BUFFER
       : (isUav
         ? VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER
@@ -2693,7 +2697,8 @@ namespace dxvk {
     const DxbcBufferInfo bufferInfo = getBufferInfo(ins.src[0]);
 
     bool isSsbo = m_moduleInfo.options.useRawSsbo
-      && bufferInfo.type != DxbcResourceType::Typed;
+               && m_moduleInfo.options.minSsboAlignment <= bufferInfo.align
+               && bufferInfo.type != DxbcResourceType::Typed;
     
     // We'll store this as a scalar unsigned integer
     DxbcRegisterValue result = isSsbo
@@ -4835,6 +4840,7 @@ namespace dxvk {
     // of obtaining the final pointer are used.
     bool isTgsm = operand.type == DxbcOperandType::ThreadGroupSharedMemory;
     bool isSsbo = m_moduleInfo.options.useRawSsbo
+               && m_moduleInfo.options.minSsboAlignment <= resourceInfo.align
                && resourceInfo.type != DxbcResourceType::Typed
                && !isTgsm;
     
@@ -4899,7 +4905,9 @@ namespace dxvk {
     // Shared memory is the only type of buffer that
     // is not accessed through a texel buffer view
     bool isTgsm = operand.type == DxbcOperandType::ThreadGroupSharedMemory;
-    bool isSsbo = m_moduleInfo.options.useRawSsbo && !isTgsm;
+    bool isSsbo = m_moduleInfo.options.useRawSsbo
+               && m_moduleInfo.options.minSsboAlignment <= bufferInfo.align
+               && !isTgsm;
     
     // Common types and IDs used while loading the data
     uint32_t bufferId = isTgsm || isSsbo ? 0 : m_module.opLoad(bufferInfo.typeId, bufferInfo.varId);
@@ -4985,7 +4993,9 @@ namespace dxvk {
     
     // Thread Group Shared Memory is not accessed through a texel buffer view
     bool isTgsm = operand.type == DxbcOperandType::ThreadGroupSharedMemory;
-    bool isSsbo = m_moduleInfo.options.useRawSsbo && !isTgsm;
+    bool isSsbo = m_moduleInfo.options.useRawSsbo
+               && m_moduleInfo.options.minSsboAlignment <= bufferInfo.align
+               && !isTgsm;
     
     // Perform UAV writes only if the UAV is bound and if there
     // is nothing else preventing us from writing to it.
diff --git a/src/dxbc/dxbc_options.cpp b/src/dxbc/dxbc_options.cpp
index 6d35400b..e11794ed 100644
--- a/src/dxbc/dxbc_options.cpp
+++ b/src/dxbc/dxbc_options.cpp
@@ -32,6 +32,7 @@ namespace dxvk {
       = (devInfo.core.properties.limits.minStorageBufferOffsetAlignment <= sizeof(uint32_t));
     useSdivForBufferIndex
       = adapter->matchesDriver(DxvkGpuVendor::Nvidia, VK_DRIVER_ID_NVIDIA_PROPRIETARY_KHR, 0, 0);
+    minSsboAlignment = devInfo.core.properties.limits.minStorageBufferOffsetAlignment;
     
     strictDivision           = options.strictDivision;
     zeroInitWorkgroupMemory  = options.zeroInitWorkgroupMemory;
diff --git a/src/dxbc/dxbc_options.h b/src/dxbc/dxbc_options.h
index 5846756b..a1e6bcda 100644
--- a/src/dxbc/dxbc_options.h
+++ b/src/dxbc/dxbc_options.h
@@ -42,6 +42,9 @@ namespace dxvk {
 
     /// Clear thread-group shared memory to zero
     bool zeroInitWorkgroupMemory = false;
+
+    /// Minimum storage buffer alignment
+    VkDeviceSize minSsboAlignment = 0;
   };
   
 }
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