From 1ea07954fb71d3445aab4f11411ed7187e7c911f Mon Sep 17 00:00:00 2001
From: ReinUsesLisp <reinuseslisp@airmail.cc>
Date: Fri, 18 Oct 2019 01:23:10 -0300
Subject: shader_ir/memory: Ignore global memory when tracking fails

Ignore global memory operations instead of invoking undefined behaviour
when constant buffer tracking fails and we are blasting through asserts,
ignore the operation.

In the case of LDG this means filling the destination registers with
zeroes; for STG this means ignore the instruction as a whole.

The default behaviour is still to abort execution on failure.
---
 src/video_core/shader/decode/memory.cpp | 39 +++++++++++++++++++--------------
 src/video_core/shader/shader_ir.h       |  5 +++--
 2 files changed, 26 insertions(+), 18 deletions(-)

diff --git a/src/video_core/shader/decode/memory.cpp b/src/video_core/shader/decode/memory.cpp
index 7923d4d69..335d78146 100644
--- a/src/video_core/shader/decode/memory.cpp
+++ b/src/video_core/shader/decode/memory.cpp
@@ -166,9 +166,17 @@ u32 ShaderIR::DecodeMemory(NodeBlock& bb, u32 pc) {
         }();
 
         const auto [real_address_base, base_address, descriptor] =
-            TrackAndGetGlobalMemory(bb, instr, false);
+            TrackGlobalMemory(bb, instr, false);
 
         const u32 count = GetUniformTypeElementsCount(type);
+        if (!real_address_base || !base_address) {
+            // Tracking failed, load zeroes.
+            for (u32 i = 0; i < count; ++i) {
+                SetRegister(bb, instr.gpr0.Value() + i, Immediate(0.0f));
+            }
+            break;
+        }
+
         for (u32 i = 0; i < count; ++i) {
             const Node it_offset = Immediate(i * 4);
             const Node real_address =
@@ -260,22 +268,19 @@ u32 ShaderIR::DecodeMemory(NodeBlock& bb, u32 pc) {
         }();
 
         const auto [real_address_base, base_address, descriptor] =
-            TrackAndGetGlobalMemory(bb, instr, true);
-
-        // Encode in temporary registers like this: real_base_address, {registers_to_be_written...}
-        SetTemporary(bb, 0, real_address_base);
+            TrackGlobalMemory(bb, instr, true);
+        if (!real_address_base || !base_address) {
+            // Tracking failed, skip the store.
+            break;
+        }
 
         const u32 count = GetUniformTypeElementsCount(type);
-        for (u32 i = 0; i < count; ++i) {
-            SetTemporary(bb, i + 1, GetRegister(instr.gpr0.Value() + i));
-        }
         for (u32 i = 0; i < count; ++i) {
             const Node it_offset = Immediate(i * 4);
-            const Node real_address =
-                Operation(OperationCode::UAdd, NO_PRECISE, real_address_base, it_offset);
+            const Node real_address = Operation(OperationCode::UAdd, real_address_base, it_offset);
             const Node gmem = MakeNode<GmemNode>(real_address, base_address, descriptor);
-
-            bb.push_back(Operation(OperationCode::Assign, gmem, GetTemporary(i + 1)));
+            const Node value = GetRegister(instr.gpr0.Value() + i);
+            bb.push_back(Operation(OperationCode::Assign, gmem, value));
         }
         break;
     }
@@ -301,15 +306,17 @@ u32 ShaderIR::DecodeMemory(NodeBlock& bb, u32 pc) {
     return pc;
 }
 
-std::tuple<Node, Node, GlobalMemoryBase> ShaderIR::TrackAndGetGlobalMemory(NodeBlock& bb,
-                                                                           Instruction instr,
-                                                                           bool is_write) {
+std::tuple<Node, Node, GlobalMemoryBase> ShaderIR::TrackGlobalMemory(NodeBlock& bb,
+                                                                     Instruction instr,
+                                                                     bool is_write) {
     const auto addr_register{GetRegister(instr.gmem.gpr)};
     const auto immediate_offset{static_cast<u32>(instr.gmem.offset)};
 
     const auto [base_address, index, offset] =
         TrackCbuf(addr_register, global_code, static_cast<s64>(global_code.size()));
-    ASSERT(base_address != nullptr);
+    ASSERT_OR_EXECUTE_MSG(base_address != nullptr,
+                          { return std::make_tuple(nullptr, nullptr, GlobalMemoryBase{}); },
+                          "Global memory tracking failed");
 
     bb.push_back(Comment(fmt::format("Base address is c[0x{:x}][0x{:x}]", index, offset)));
 
diff --git a/src/video_core/shader/shader_ir.h b/src/video_core/shader/shader_ir.h
index 105981d67..91cd0a534 100644
--- a/src/video_core/shader/shader_ir.h
+++ b/src/video_core/shader/shader_ir.h
@@ -371,8 +371,9 @@ private:
     std::pair<Node, s64> TrackRegister(const GprNode* tracked, const NodeBlock& code,
                                        s64 cursor) const;
 
-    std::tuple<Node, Node, GlobalMemoryBase> TrackAndGetGlobalMemory(
-        NodeBlock& bb, Tegra::Shader::Instruction instr, bool is_write);
+    std::tuple<Node, Node, GlobalMemoryBase> TrackGlobalMemory(NodeBlock& bb,
+                                                               Tegra::Shader::Instruction instr,
+                                                               bool is_write);
 
     const ProgramCode& program_code;
     const u32 main_offset;
-- 
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