rsx/fp/cfg: Add unit test for special cond inversion

rpcs3/tests/test_rsx_cfg.cpp

@@ -228,4 +228,27 @@ namespace rsx::assembler
 		ASSERT_EQ(graph.blocks.size(), 1);
 		EXPECT_EQ(graph.blocks.front().instructions.size(), 1);
 	}
+
+	TEST(CFG, FpToCFG_EmptyIFWithELSE)
+	{
+		auto ir = FPIR::from_source(
+			"IF.LT;"                // Empty branch
+			"ELSE;"                 // With real ELSE
+			"	MOV R1, R2;"        // Content. Should execute if branch cond fails (IF.GE)
+			"ENDIF;"
+			"MOV R0, R1;"           // False merge block.
+		);
+
+		RSXFragmentProgram program{};
+		auto bytecode = ir.compile();
+		program.data = bytecode.data();
+
+		FlowGraph graph = deconstruct_fragment_program(program);
+
+		ASSERT_EQ(graph.blocks.size(), 3);
+		ASSERT_EQ(graph.blocks.front().instructions.size(), 1);
+		EXPECT_EQ(SRC0{ .HEX = graph.blocks.front().instructions[0].bytecode[1] }.exec_if_lt, 0);
+		EXPECT_EQ(SRC0{ .HEX = graph.blocks.front().instructions[0].bytecode[1] }.exec_if_gr, 1);
+		EXPECT_EQ(SRC0{ .HEX = graph.blocks.front().instructions[0].bytecode[1] }.exec_if_eq, 1);
+	}
 }