rsx: Vertex program analyser improvements

rpcs3/Emu/RSX/Program/ProgramStateCache.cpp

@@ -50,7 +50,6 @@ vertex_program_utils::vertex_program_metadata vertex_program_utils::analyse_vert
 	{
 		u32 current_instruction = start;
 		std::set<u32> conditional_targets;
-		bool has_printed_error = false;
 
 		while (true)
 		{
@@ -60,20 +59,13 @@ vertex_program_utils::vertex_program_metadata vertex_program_utils::analyse_vert
 			{
 				if (!fast_exit)
 				{
-					if (!has_printed_error)
-					{
-						// This can be harmless if a dangling RET was encountered before
-						rsx_log.error("vp_analyser: Possible infinite loop detected");
-						has_printed_error = true;
-					}
-					current_instruction++;
-					continue;
-				}
-				else
-				{
-					// Block walk, looking for earliest exit
-					break;
+					// This can be harmless if a dangling RET was encountered before.
+					// This can also be legal in case of BRB...BRI loops since BRIs are conditional. Might just be a loop with exit cond.
+					rsx_log.warning("vp_analyser: Possible infinite loop detected");
 				}
+
+				// There is never any reason to continue scanning after self-intersecting on the control-flow tree.
+				break;
 			}
 
 			const auto instruction = v128::loadu(&data[current_instruction * 4]);
@@ -211,9 +203,23 @@ vertex_program_utils::vertex_program_metadata vertex_program_utils::analyse_vert
 			}
 			}
 
-			if ((d3.end && (fast_exit || current_instruction >= instruction_range.second)) ||
-				(current_instruction + 1) == rsx::max_vertex_program_instructions)
+			// Check exit conditions...
+			if (d3.end)
 			{
+				// We have seen an end of instructions marker.
+				// Multiple exits may exist, usually skipped over by branching. Do not exit on end unless there is no branching.
+				if (!has_branch_instruction || fast_exit || current_instruction >= instruction_range.second)
+				{
+					// Conditions:
+					// 1. No branching so far. This will always be the exit.
+					// 2. Fast exit flag is set. This happens when walking through subroutines.
+					// 3. We've gone beyond the known instruction range. In this scenario, this is the furthest end marker seen so far. It has to be reached by some earlier branch.
+					break;
+				}
+			}
+			else if ((current_instruction + 1) == rsx::max_vertex_program_instructions)
+			{
+				// No more instructions to read.
 				break;
 			}
 
@@ -288,6 +294,17 @@ vertex_program_utils::vertex_program_metadata vertex_program_utils::analyse_vert
 			}
 		}
 
+		// Typical ubershaders have the dispatch at the top with subroutines following. However...
+		// some games have the dispatch block at the end and the subroutines above them.
+		// We need to simulate a jump-to-entry in this situation
+		// Normally this condition is handled by the conditional_targets walk, but sometimes this doesn't work due to cyclic branches
+		if (instruction_range.first < dst_prog.entry)
+		{
+			// Is there a subroutine that jumps into the entry? If not, add to jump table
+			const auto target = dst_prog.entry - instruction_range.first;
+			dst_prog.jump_table.insert(target);
+		}
+
 		// Verification
 		for (const u32 target : dst_prog.jump_table)
 		{

rpcs3/Emu/RSX/Program/VertexProgramDecompiler.cpp

@@ -445,7 +445,7 @@ std::string VertexProgramDecompiler::Decompile()
 	const auto& data = m_prog.data;
 	m_instr_count = data.size() / 4;
 
-	bool is_has_BRA = false;
+	bool has_BRA = false;
 	bool program_end = false;
 	u32 i = 1;
 	u32 last_label_addr = 0;
@@ -527,7 +527,7 @@ std::string VertexProgramDecompiler::Decompile()
 		}
 	};
 
-	if (is_has_BRA || !m_prog.jump_table.empty())
+	if (has_BRA || !m_prog.jump_table.empty())
 	{
 		m_cur_instr = &m_instructions[0];
 
@@ -573,7 +573,7 @@ std::string VertexProgramDecompiler::Decompile()
 		{
 			//TODO: Subroutines can also have arbitrary jumps!
 			u32 jump_position = find_jump_lvl(i);
-			if (is_has_BRA || jump_position != umax)
+			if (has_BRA || jump_position != umax)
 			{
 				m_cur_instr->close_scopes++;
 				AddCode("}");
@@ -782,7 +782,7 @@ std::string VertexProgramDecompiler::Decompile()
 		}
 	}
 
-	if (is_has_BRA || !m_prog.jump_table.empty())
+	if (has_BRA || !m_prog.jump_table.empty())
 	{
 		m_cur_instr = &m_instructions[m_instr_count - 1];
 		m_cur_instr->close_scopes++;