CPU/Recompiler: Implement b{gez,ltz}(al)?

README.md

@@ -60,8 +60,9 @@ To access the menus with the controller, press the right stick down and use the
  - Passes amidog's CPU and GTE tests, partial passing of CPX tests
 
 ## Screenshots
-![Spyro 2](https://raw.githubusercontent.com/stenzek/duckstation/md-images/spyro.jpg)
+![Final Fantasy 7](https://raw.githubusercontent.com/stenzek/duckstation/md-images/ff7.jpg)
 ![Final Fantasy 8](https://raw.githubusercontent.com/stenzek/duckstation/md-images/ff8.jpg)
+![Spyro 2](https://raw.githubusercontent.com/stenzek/duckstation/md-images/spyro.jpg)
 
 ## Disclaimers
 

src/core/cpu_recompiler_code_generator.cpp

@@ -93,6 +93,7 @@ bool CodeGenerator::CompileInstruction(const CodeBlockInstruction& cbi)
 
     case InstructionOp::j:
     case InstructionOp::jal:
+    case InstructionOp::b:
     case InstructionOp::beq:
     case InstructionOp::bne:
     case InstructionOp::bgtz:
@@ -1029,7 +1030,7 @@ bool CodeGenerator::Compile_Branch(const CodeBlockInstruction& cbi)
         OrValues(AndValues(m_register_cache.ReadGuestRegister(Reg::pc, false), Value::FromConstantU32(0xF0000000)),
                  Value::FromConstantU32(cbi.instruction.j.target << 2));
 
-      EmitBranch(Condition::Always, (cbi.instruction.op == InstructionOp::jal) ? Reg::ra : Reg::count,
+      EmitBranch(Condition::Always, (cbi.instruction.op == InstructionOp::jal) ? Reg::ra : Reg::count, false,
                  std::move(branch_target));
     }
     break;
@@ -1041,15 +1042,13 @@ bool CodeGenerator::Compile_Branch(const CodeBlockInstruction& cbi)
       // npc = rs, link to rt
       Value branch_target = m_register_cache.ReadGuestRegister(cbi.instruction.r.rs);
       EmitBranch(Condition::Always,
-                 (cbi.instruction.r.funct == InstructionFunct::jalr) ? cbi.instruction.r.rd : Reg::count,
+                 (cbi.instruction.r.funct == InstructionFunct::jalr) ? cbi.instruction.r.rd : Reg::count, false,
                  std::move(branch_target));
     }
     break;
 
     case InstructionOp::beq:
     case InstructionOp::bne:
-    case InstructionOp::bgtz:
-    case InstructionOp::blez:
     {
       // npc = pc + (sext(imm) << 2)
       Value branch_target = AddValues(m_register_cache.ReadGuestRegister(Reg::pc, false),
@@ -1060,27 +1059,42 @@ bool CodeGenerator::Compile_Branch(const CodeBlockInstruction& cbi)
       Value rhs = m_register_cache.ReadGuestRegister(cbi.instruction.i.rt);
       EmitCmp(lhs.host_reg, rhs);
 
-      Condition condition;
-      switch (cbi.instruction.op)
-      {
-        case InstructionOp::beq:
-          condition = Condition::Equal;
-          break;
-        case InstructionOp::bne:
-          condition = Condition::NotEqual;
+      const Condition condition = (cbi.instruction.op == InstructionOp::beq) ? Condition::Equal : Condition::NotEqual;
+      EmitBranch(condition, Reg::count, false, std::move(branch_target));
+    }
     break;
+
     case InstructionOp::bgtz:
-          condition = Condition::GreaterThanZero;
-          break;
     case InstructionOp::blez:
-          condition = Condition::LessOrEqualToZero;
-          break;
-        default:
-          condition = Condition::Always;
-          break;
+    {
+      // npc = pc + (sext(imm) << 2)
+      Value branch_target = AddValues(m_register_cache.ReadGuestRegister(Reg::pc, false),
+                                      Value::FromConstantU32(cbi.instruction.i.imm_sext32() << 2));
+
+      // branch <- rs op 0
+      Value lhs = m_register_cache.ReadGuestRegister(cbi.instruction.i.rs, true, true);
+      EmitCmp(lhs.host_reg, Value::FromConstantU32(0));
+
+      const Condition condition =
+        (cbi.instruction.op == InstructionOp::bgtz) ? Condition::Greater : Condition::LessOrEqual;
+      EmitBranch(condition, Reg::count, false, std::move(branch_target));
     }
+    break;
 
-      EmitBranch(condition, Reg::count, std::move(branch_target));
+    case InstructionOp::b:
+    {
+      // npc = pc + (sext(imm) << 2)
+      Value branch_target = AddValues(m_register_cache.ReadGuestRegister(Reg::pc, false),
+                                      Value::FromConstantU32(cbi.instruction.i.imm_sext32() << 2));
+
+      const u8 rt = static_cast<u8>(cbi.instruction.i.rt.GetValue());
+      const bool bgez = ConvertToBoolUnchecked(rt & u8(1));
+      const Condition condition = bgez ? Condition::PositiveOrZero : Condition::Negative;
+      const bool link = (rt & u8(0x1E)) == u8(0x10);
+
+      Value lhs = m_register_cache.ReadGuestRegister(cbi.instruction.i.rs, true, true);
+      EmitTest(lhs.host_reg, lhs);
+      EmitBranch(condition, link ? Reg::ra : Reg::count, link, std::move(branch_target));
     }
     break;
 

src/core/cpu_recompiler_code_generator.h

@@ -74,7 +74,7 @@ public:
   void EmitStoreGuestMemory(const Value& address, const Value& value);
 
   // Branching, generates two paths.
-  void EmitBranch(Condition condition, Reg lr_reg, Value&& branch_target);
+  void EmitBranch(Condition condition, Reg lr_reg, bool always_link, Value&& branch_target);
 
   u32 PrepareStackForCall();
   void RestoreStackAfterCall(u32 adjust_size);

src/core/cpu_recompiler_code_generator_x64.cpp

@@ -1621,35 +1621,58 @@ static void EmitConditionalJump(Condition condition, bool invert, Xbyak::CodeGen
       invert ? emit->jno(label) : emit->jo(label);
       break;
 
-    case Condition::GreaterThanZero:
+    case Condition::Greater:
       invert ? emit->jng(label) : emit->jg(label);
       break;
 
-    case Condition::LessOrEqualToZero:
+    case Condition::GreaterEqual:
+      invert ? emit->jnge(label) : emit->jge(label);
+      break;
+
+    case Condition::Less:
+      invert ? emit->jnl(label) : emit->jl(label);
+      break;
+
+    case Condition::LessOrEqual:
       invert ? emit->jnle(label) : emit->jle(label);
       break;
 
+    case Condition::Negative:
+      invert ? emit->jns(label) : emit->js(label);
+      break;
+
+    case Condition::PositiveOrZero:
+      invert ? emit->js(label) : emit->jns(label);
+      break;
+
     default:
       UnreachableCode();
       break;
   }
 }
 
-void CodeGenerator::EmitBranch(Condition condition, Reg lr_reg, Value&& branch_target)
+void CodeGenerator::EmitBranch(Condition condition, Reg lr_reg, bool always_link, Value&& branch_target)
 {
-  Xbyak::Label skip_branch;
-
   // we have to always read the old PC.. when we can push/pop the register cache state this won't be needed
   Value old_npc;
   if (lr_reg != Reg::count)
+  {
     old_npc = m_register_cache.ReadGuestRegister(Reg::npc, false, true);
+    if (always_link)
+    {
+      // can't cache because we have two branches
+      m_register_cache.WriteGuestRegister(lr_reg, std::move(old_npc));
+      m_register_cache.FlushGuestRegister(lr_reg, true, true);
+    }
+  }
 
   // condition is inverted because we want the case for skipping it
+  Xbyak::Label skip_branch;
   if (condition != Condition::Always)
     EmitConditionalJump(condition, true, m_emit, skip_branch);
 
   // save the old PC if we want to
-  if (lr_reg != Reg::count)
+  if (lr_reg != Reg::count && !always_link)
   {
     // can't cache because we have two branches
     m_register_cache.WriteGuestRegister(lr_reg, std::move(old_npc));

src/core/cpu_recompiler_types.h

@@ -30,8 +30,12 @@ enum class Condition: u8
   NotEqual,
   Equal,
   Overflow,
-  GreaterThanZero,
-  LessOrEqualToZero,
+  Greater,
+  GreaterEqual,
+  LessOrEqual,
+  Less,
+  Negative,
+  PositiveOrZero,
 
   NotZero = NotEqual,
   Zero = Equal