[Liftoff] Implement i32.popcnt with C fallback

This adds support for i32.popcnt. If no hardware instruction for popcnt
is available, call out to C.

R=titzer@chromium.org

Bug: v8:6600
Change-Id: I9ae9e1d1e1392168d19c0eedcdd33eeea609a54f
Reviewed-on: https://chromium-review.googlesource.com/860658
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Ben Titzer <titzer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50528}

src/assembler.h

@@ -1329,10 +1329,12 @@ class RegisterBase {
 
   int bit() const { return 1 << code(); }
 
-  inline bool operator==(SubType other) const {
+  inline constexpr bool operator==(SubType other) const {
     return reg_code_ == other.reg_code_;
   }
-  inline bool operator!=(SubType other) const { return !(*this == other); }
+  inline constexpr bool operator!=(SubType other) const {
+    return reg_code_ != other.reg_code_;
+  }
 
  protected:
   explicit constexpr RegisterBase(int code) : reg_code_(code) {}

src/wasm/baseline/arm/liftoff-assembler-arm.h

@@ -69,57 +69,42 @@ void LiftoffAssembler::Fill(LiftoffRegister reg, uint32_t index) {
   UNIMPLEMENTED();
 }
 
-#define UNIMPLEMENTED_I32_BINOP(name)                                \
-  void LiftoffAssembler::emit_i32_##name(Register dst, Register lhs, \
-                                         Register rhs) {             \
-    UNIMPLEMENTED();                                                 \
+#define UNIMPLEMENTED_GP_BINOP(name)                             \
+  void LiftoffAssembler::emit_##name(Register dst, Register lhs, \
+                                     Register rhs) {             \
+    UNIMPLEMENTED();                                             \
+  }
+#define UNIMPLEMENTED_GP_UNOP(name)                                \
+  bool LiftoffAssembler::emit_##name(Register dst, Register src) { \
+    UNIMPLEMENTED();                                               \
+  }
+#define UNIMPLEMENTED_FP_BINOP(name)                                         \
+  void LiftoffAssembler::emit_##name(DoubleRegister dst, DoubleRegister lhs, \
+                                     DoubleRegister rhs) {                   \
+    UNIMPLEMENTED();                                                         \
   }
 
-// clang-format off
-UNIMPLEMENTED_I32_BINOP(add)
-UNIMPLEMENTED_I32_BINOP(sub)
-UNIMPLEMENTED_I32_BINOP(mul)
-UNIMPLEMENTED_I32_BINOP(and)
-UNIMPLEMENTED_I32_BINOP(or)
-UNIMPLEMENTED_I32_BINOP(xor)
-UNIMPLEMENTED_I32_BINOP(shl)
-UNIMPLEMENTED_I32_BINOP(sar)
-UNIMPLEMENTED_I32_BINOP(shr)
-// clang-format on
-
-#undef UNIMPLEMENTED_I32_BINOP
-
-void LiftoffAssembler::emit_i32_eqz(Register dst, Register src) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_i32_clz(Register dst, Register src) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_i32_ctz(Register dst, Register src) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_ptrsize_add(Register dst, Register lhs,
-                                        Register rhs) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_f32_add(DoubleRegister dst, DoubleRegister lhs,
-                                    DoubleRegister rhs) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_f32_sub(DoubleRegister dst, DoubleRegister lhs,
-                                    DoubleRegister rhs) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_f32_mul(DoubleRegister dst, DoubleRegister lhs,
-                                    DoubleRegister rhs) {
-  UNIMPLEMENTED();
-}
+UNIMPLEMENTED_GP_BINOP(i32_add)
+UNIMPLEMENTED_GP_BINOP(i32_sub)
+UNIMPLEMENTED_GP_BINOP(i32_mul)
+UNIMPLEMENTED_GP_BINOP(i32_and)
+UNIMPLEMENTED_GP_BINOP(i32_or)
+UNIMPLEMENTED_GP_BINOP(i32_xor)
+UNIMPLEMENTED_GP_BINOP(i32_shl)
+UNIMPLEMENTED_GP_BINOP(i32_sar)
+UNIMPLEMENTED_GP_BINOP(i32_shr)
+UNIMPLEMENTED_GP_UNOP(i32_eqz)
+UNIMPLEMENTED_GP_UNOP(i32_clz)
+UNIMPLEMENTED_GP_UNOP(i32_ctz)
+UNIMPLEMENTED_GP_UNOP(i32_popcnt)
+UNIMPLEMENTED_GP_BINOP(ptrsize_add)
+UNIMPLEMENTED_FP_BINOP(f32_add)
+UNIMPLEMENTED_FP_BINOP(f32_sub)
+UNIMPLEMENTED_FP_BINOP(f32_mul)
+
+#undef UNIMPLEMENTED_GP_BINOP
+#undef UNIMPLEMENTED_GP_UNOP
+#undef UNIMPLEMENTED_FP_BINOP
 
 void LiftoffAssembler::emit_i32_test(Register reg) { UNIMPLEMENTED(); }
 
@@ -154,6 +139,26 @@ void LiftoffAssembler::DropStackSlotsAndRet(uint32_t num_stack_slots) {
   UNIMPLEMENTED();
 }
 
+void LiftoffAssembler::PrepareCCall(uint32_t num_params, const Register* args) {
+  UNIMPLEMENTED();
+}
+
+void LiftoffAssembler::SetCCallRegParamAddr(Register dst, uint32_t param_idx,
+                                            uint32_t num_params) {
+  UNIMPLEMENTED();
+}
+
+void LiftoffAssembler::SetCCallStackParamAddr(uint32_t stack_param_idx,
+                                              uint32_t param_idx,
+                                              uint32_t num_params) {
+  UNIMPLEMENTED();
+}
+
+void LiftoffAssembler::EmitCCall(ExternalReference ext_ref,
+                                 uint32_t num_params) {
+  UNIMPLEMENTED();
+}
+
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8

src/wasm/baseline/arm64/liftoff-assembler-arm64.h

@@ -69,57 +69,42 @@ void LiftoffAssembler::Fill(LiftoffRegister reg, uint32_t index) {
   UNIMPLEMENTED();
 }
 
-#define UNIMPLEMENTED_I32_BINOP(name)                                \
-  void LiftoffAssembler::emit_i32_##name(Register dst, Register lhs, \
-                                         Register rhs) {             \
-    UNIMPLEMENTED();                                                 \
+#define UNIMPLEMENTED_GP_BINOP(name)                             \
+  void LiftoffAssembler::emit_##name(Register dst, Register lhs, \
+                                     Register rhs) {             \
+    UNIMPLEMENTED();                                             \
+  }
+#define UNIMPLEMENTED_GP_UNOP(name)                                \
+  bool LiftoffAssembler::emit_##name(Register dst, Register src) { \
+    UNIMPLEMENTED();                                               \
+  }
+#define UNIMPLEMENTED_FP_BINOP(name)                                         \
+  void LiftoffAssembler::emit_##name(DoubleRegister dst, DoubleRegister lhs, \
+                                     DoubleRegister rhs) {                   \
+    UNIMPLEMENTED();                                                         \
   }
 
-// clang-format off
-UNIMPLEMENTED_I32_BINOP(add)
-UNIMPLEMENTED_I32_BINOP(sub)
-UNIMPLEMENTED_I32_BINOP(mul)
-UNIMPLEMENTED_I32_BINOP(and)
-UNIMPLEMENTED_I32_BINOP(or)
-UNIMPLEMENTED_I32_BINOP(xor)
-UNIMPLEMENTED_I32_BINOP(shl)
-UNIMPLEMENTED_I32_BINOP(sar)
-UNIMPLEMENTED_I32_BINOP(shr)
-// clang-format on
-
-#undef UNIMPLEMENTED_I32_BINOP
-
-void LiftoffAssembler::emit_i32_eqz(Register dst, Register src) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_i32_clz(Register dst, Register src) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_i32_ctz(Register dst, Register src) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_ptrsize_add(Register dst, Register lhs,
-                                        Register rhs) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_f32_add(DoubleRegister dst, DoubleRegister lhs,
-                                    DoubleRegister rhs) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_f32_sub(DoubleRegister dst, DoubleRegister lhs,
-                                    DoubleRegister rhs) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_f32_mul(DoubleRegister dst, DoubleRegister lhs,
-                                    DoubleRegister rhs) {
-  UNIMPLEMENTED();
-}
+UNIMPLEMENTED_GP_BINOP(i32_add)
+UNIMPLEMENTED_GP_BINOP(i32_sub)
+UNIMPLEMENTED_GP_BINOP(i32_mul)
+UNIMPLEMENTED_GP_BINOP(i32_and)
+UNIMPLEMENTED_GP_BINOP(i32_or)
+UNIMPLEMENTED_GP_BINOP(i32_xor)
+UNIMPLEMENTED_GP_BINOP(i32_shl)
+UNIMPLEMENTED_GP_BINOP(i32_sar)
+UNIMPLEMENTED_GP_BINOP(i32_shr)
+UNIMPLEMENTED_GP_UNOP(i32_eqz)
+UNIMPLEMENTED_GP_UNOP(i32_clz)
+UNIMPLEMENTED_GP_UNOP(i32_ctz)
+UNIMPLEMENTED_GP_UNOP(i32_popcnt)
+UNIMPLEMENTED_GP_BINOP(ptrsize_add)
+UNIMPLEMENTED_FP_BINOP(f32_add)
+UNIMPLEMENTED_FP_BINOP(f32_sub)
+UNIMPLEMENTED_FP_BINOP(f32_mul)
+
+#undef UNIMPLEMENTED_GP_BINOP
+#undef UNIMPLEMENTED_GP_UNOP
+#undef UNIMPLEMENTED_FP_BINOP
 
 void LiftoffAssembler::emit_i32_test(Register reg) { UNIMPLEMENTED(); }
 
@@ -154,6 +139,26 @@ void LiftoffAssembler::DropStackSlotsAndRet(uint32_t num_stack_slots) {
   UNIMPLEMENTED();
 }
 
+void LiftoffAssembler::PrepareCCall(uint32_t num_params, const Register* args) {
+  UNIMPLEMENTED();
+}
+
+void LiftoffAssembler::SetCCallRegParamAddr(Register dst, uint32_t param_idx,
+                                            uint32_t num_params) {
+  UNIMPLEMENTED();
+}
+
+void LiftoffAssembler::SetCCallStackParamAddr(uint32_t stack_param_idx,
+                                              uint32_t param_idx,
+                                              uint32_t num_params) {
+  UNIMPLEMENTED();
+}
+
+void LiftoffAssembler::EmitCCall(ExternalReference ext_ref,
+                                 uint32_t num_params) {
+  UNIMPLEMENTED();
+}
+
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8

src/wasm/baseline/ia32/liftoff-assembler-ia32.h

@@ -33,6 +33,10 @@ static_assert(kByteRegs.GetNumRegsSet() == 4, "should have four byte regs");
 static_assert((kByteRegs & kGpCacheRegList) == kByteRegs,
               "kByteRegs only contains gp cache registers");
 
+// Use this register to store the address of the last argument pushed on the
+// stack for a call to C.
+static constexpr Register kCCallLastArgAddrReg = eax;
+
 }  // namespace liftoff
 
 static constexpr DoubleRegister kScratchDoubleReg = xmm7;
@@ -322,7 +326,7 @@ void LiftoffAssembler::emit_i32_shr(Register dst, Register lhs, Register rhs) {
   liftoff::EmitShiftOperation(this, dst, lhs, rhs, &Assembler::shr_cl);
 }
 
-void LiftoffAssembler::emit_i32_eqz(Register dst, Register src) {
+bool LiftoffAssembler::emit_i32_eqz(Register dst, Register src) {
   Register tmp_byte_reg = dst;
   // Only the lower 4 registers can be addressed as 8-bit registers.
   if (!dst.is_byte_register()) {
@@ -333,9 +337,10 @@ void LiftoffAssembler::emit_i32_eqz(Register dst, Register src) {
   test(src, src);
   setcc(zero, tmp_byte_reg);
   movzx_b(dst, tmp_byte_reg);
+  return true;
 }
 
-void LiftoffAssembler::emit_i32_clz(Register dst, Register src) {
+bool LiftoffAssembler::emit_i32_clz(Register dst, Register src) {
   Label nonzero_input;
   Label continuation;
   test(src, src);
@@ -350,9 +355,10 @@ void LiftoffAssembler::emit_i32_clz(Register dst, Register src) {
   xor_(dst, 31);
 
   bind(&continuation);
+  return true;
 }
 
-void LiftoffAssembler::emit_i32_ctz(Register dst, Register src) {
+bool LiftoffAssembler::emit_i32_ctz(Register dst, Register src) {
   Label nonzero_input;
   Label continuation;
   test(src, src);
@@ -365,6 +371,14 @@ void LiftoffAssembler::emit_i32_ctz(Register dst, Register src) {
   bsf(dst, src);
 
   bind(&continuation);
+  return true;
+}
+
+bool LiftoffAssembler::emit_i32_popcnt(Register dst, Register src) {
+  if (!CpuFeatures::IsSupported(POPCNT)) return false;
+  CpuFeatureScope scope(this, POPCNT);
+  popcnt(dst, src);
+  return true;
 }
 
 void LiftoffAssembler::emit_ptrsize_add(Register dst, Register lhs,
@@ -517,6 +531,37 @@ void LiftoffAssembler::DropStackSlotsAndRet(uint32_t num_stack_slots) {
   ret(static_cast<int>(num_stack_slots * kPointerSize));
 }
 
+void LiftoffAssembler::PrepareCCall(uint32_t num_params, const Register* args) {
+  for (size_t param = 0; param < num_params; ++param) {
+    push(args[param]);
+  }
+  mov(liftoff::kCCallLastArgAddrReg, esp);
+  constexpr Register kScratch = ebx;
+  static_assert(kScratch != liftoff::kCCallLastArgAddrReg, "collision");
+  PrepareCallCFunction(num_params, kScratch);
+}
+
+void LiftoffAssembler::SetCCallRegParamAddr(Register dst, uint32_t param_idx,
+                                            uint32_t num_params) {
+  int offset = kPointerSize * static_cast<int>(num_params - 1 - param_idx);
+  lea(dst, Operand(liftoff::kCCallLastArgAddrReg, offset));
+}
+
+void LiftoffAssembler::SetCCallStackParamAddr(uint32_t stack_param_idx,
+                                              uint32_t param_idx,
+                                              uint32_t num_params) {
+  constexpr Register kScratch = ebx;
+  static_assert(kScratch != liftoff::kCCallLastArgAddrReg, "collision");
+  int offset = kPointerSize * static_cast<int>(num_params - 1 - param_idx);
+  lea(kScratch, Operand(liftoff::kCCallLastArgAddrReg, offset));
+  mov(Operand(esp, param_idx * kPointerSize), kScratch);
+}
+
+void LiftoffAssembler::EmitCCall(ExternalReference ext_ref,
+                                 uint32_t num_params) {
+  CallCFunction(ext_ref, static_cast<int>(num_params));
+}
+
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8

src/wasm/baseline/liftoff-assembler.cc

@@ -368,6 +368,14 @@ void LiftoffAssembler::SpillLocals() {
   }
 }
 
+void LiftoffAssembler::SpillAllRegisters() {
+  // TODO(clemensh): Don't update use counters in the loop, just reset them
+  // afterwards.
+  for (uint32_t i = 0, e = cache_state_.stack_height(); i < e; ++i) {
+    Spill(i);
+  }
+}
+
 void LiftoffAssembler::PrepareCall(wasm::FunctionSig* sig,
                                    compiler::CallDescriptor* call_desc) {
   uint32_t num_params = static_cast<uint32_t>(sig->parameter_count());
@@ -378,8 +386,6 @@ void LiftoffAssembler::PrepareCall(wasm::FunctionSig* sig,
   // Input 0 is the call target.
   constexpr size_t kInputShift = 1;
 
-  StackTransferRecipe stack_transfers(this);
-
   // Spill all cache slots which are not being used as parameters.
   // Don't update any register use counters, they will be reset later anyway.
   for (uint32_t idx = 0, end = cache_state_.stack_height() - num_params;
@@ -390,6 +396,8 @@ void LiftoffAssembler::PrepareCall(wasm::FunctionSig* sig,
     slot.MakeStack();
   }
 
+  StackTransferRecipe stack_transfers(this);
+
   // Now move all parameter values into the right slot for the call.
   // Process parameters backward, such that we can just pop values from the
   // stack.
@@ -413,14 +421,14 @@ void LiftoffAssembler::PrepareCall(wasm::FunctionSig* sig,
     cache_state_.stack_state.pop_back();
   }
 
+  // Execute the stack transfers before filling the context register.
+  stack_transfers.Execute();
+
   // Reset register use counters.
   cache_state_.used_registers = {};
   memset(cache_state_.register_use_count, 0,
          sizeof(cache_state_.register_use_count));
 
-  // Execute the stack transfers before filling the context register.
-  stack_transfers.Execute();
-
   // Fill the wasm context into the right register.
   compiler::LinkageLocation context_loc =
       call_desc->GetInputLocation(kInputShift);

src/wasm/baseline/liftoff-assembler.h

@@ -263,6 +263,7 @@ class LiftoffAssembler : public TurboAssembler {
 
   void Spill(uint32_t index);
   void SpillLocals();
+  void SpillAllRegisters();
 
   // Load parameters into the right registers / stack slots for the call.
   void PrepareCall(wasm::FunctionSig*, compiler::CallDescriptor*);
@@ -308,9 +309,10 @@ class LiftoffAssembler : public TurboAssembler {
   inline void emit_i32_shr(Register dst, Register lhs, Register rhs);
 
   // i32 unops.
-  inline void emit_i32_eqz(Register dst, Register src);
-  inline void emit_i32_clz(Register dst, Register src);
-  inline void emit_i32_ctz(Register dst, Register src);
+  inline bool emit_i32_eqz(Register dst, Register src);
+  inline bool emit_i32_clz(Register dst, Register src);
+  inline bool emit_i32_ctz(Register dst, Register src);
+  inline bool emit_i32_popcnt(Register dst, Register src);
 
   inline void emit_ptrsize_add(Register dst, Register lhs, Register rhs);
 
@@ -334,12 +336,21 @@ class LiftoffAssembler : public TurboAssembler {
 
   // Push a value to the stack (will become a caller frame slot).
   inline void PushCallerFrameSlot(const VarState& src, uint32_t src_index);
-
   inline void PushRegisters(LiftoffRegList);
   inline void PopRegisters(LiftoffRegList);
 
   inline void DropStackSlotsAndRet(uint32_t num_stack_slots);
 
+  // Push arguments on the stack (in the caller frame), then align the stack.
+  // The address of the last argument will be stored to {arg_addr_dst}. Previous
+  // arguments will be located at pointer sized buckets above that address.
+  inline void PrepareCCall(uint32_t num_params, const Register* args);
+  inline void SetCCallRegParamAddr(Register dst, uint32_t param_idx,
+                                   uint32_t num_params);
+  inline void SetCCallStackParamAddr(uint32_t stack_param_idx,
+                                     uint32_t param_idx, uint32_t num_params);
+  inline void EmitCCall(ExternalReference ext_ref, uint32_t num_params);
+
   ////////////////////////////////////
   // End of platform-specific part. //
   ////////////////////////////////////

src/wasm/baseline/liftoff-compiler.cc

@@ -421,26 +421,83 @@ class LiftoffCompiler {
 
   void EndControl(Decoder* decoder, Control* c) {}
 
-  void I32UnOp(void (LiftoffAssembler::*emit_fn)(Register, Register)) {
+  void GenerateCCall(Register res_reg, uint32_t num_args,
+                     const Register* arg_regs, ExternalReference ext_ref) {
+    static constexpr int kNumReturns = 1;
+    static constexpr int kMaxArgs = 2;
+    static constexpr MachineType kReps[]{
+        MachineType::Uint32(), MachineType::Pointer(), MachineType::Pointer()};
+    static_assert(arraysize(kReps) == kNumReturns + kMaxArgs, "mismatch");
+    DCHECK_LE(num_args, kMaxArgs);
+
+    MachineSignature sig(kNumReturns, num_args, kReps);
+    compiler::CallDescriptor* desc =
+        compiler::Linkage::GetSimplifiedCDescriptor(&compilation_zone_, &sig);
+
+    // Before making a call, spill all cache registers.
+    __ SpillAllRegisters();
+
+    // Store arguments on our stack, then align the stack for calling to c.
+    uint32_t num_params = static_cast<uint32_t>(desc->ParameterCount());
+    __ PrepareCCall(num_params, arg_regs);
+
+    // Set parameters (in sp[0], sp[8], ...).
+    uint32_t num_stack_params = 0;
+    for (uint32_t param = 0; param < num_params; ++param) {
+      constexpr size_t kInputShift = 1;  // Input 0 is the call target.
+
+      compiler::LinkageLocation loc =
+          desc->GetInputLocation(param + kInputShift);
+      if (loc.IsRegister()) {
+        Register reg = Register::from_code(loc.AsRegister());
+        // Load address of that parameter to the register.
+        __ SetCCallRegParamAddr(reg, param, num_params);
+      } else {
+        DCHECK(loc.IsCallerFrameSlot());
+        __ SetCCallStackParamAddr(num_stack_params, param, num_params);
+        ++num_stack_params;
+      }
+    }
+
+    // Now execute the call.
+    __ EmitCCall(ext_ref, num_params);
+
+    // Load return value.
+    compiler::LinkageLocation return_loc = desc->GetReturnLocation(0);
+    DCHECK(return_loc.IsRegister());
+    Register return_reg = Register::from_code(return_loc.AsRegister());
+    if (return_reg != res_reg) {
+      __ Move(LiftoffRegister(res_reg), LiftoffRegister(return_reg));
+    }
+  }
+
+  void I32UnOp(bool (LiftoffAssembler::*emit_fn)(Register, Register),
+               ExternalReference (*fallback_fn)(Isolate*)) {
     LiftoffRegList pinned_regs;
     LiftoffRegister dst_reg =
         pinned_regs.set(__ GetUnaryOpTargetRegister(kGpReg));
     LiftoffRegister src_reg =
         pinned_regs.set(__ PopToRegister(kGpReg, pinned_regs));
-    (asm_->*emit_fn)(dst_reg.gp(), src_reg.gp());
+    if (!emit_fn || !(asm_->*emit_fn)(dst_reg.gp(), src_reg.gp())) {
+      ExternalReference ext_ref = fallback_fn(asm_->isolate());
+      Register args[] = {src_reg.gp()};
+      GenerateCCall(dst_reg.gp(), arraysize(args), args, ext_ref);
+    }
     __ PushRegister(kWasmI32, dst_reg);
   }
 
   void UnOp(Decoder* decoder, WasmOpcode opcode, FunctionSig*,
             const Value& value, Value* result) {
-#define CASE_UNOP(opcode, type, fn)           \
-  case WasmOpcode::kExpr##opcode:             \
-    type##UnOp(&LiftoffAssembler::emit_##fn); \
+#define CASE_UNOP(opcode, type, fn, ext_ref_fn)           \
+  case WasmOpcode::kExpr##opcode:                         \
+    type##UnOp(&LiftoffAssembler::emit_##fn, ext_ref_fn); \
     break;
     switch (opcode) {
-      CASE_UNOP(I32Eqz, I32, i32_eqz)
-      CASE_UNOP(I32Clz, I32, i32_clz)
-      CASE_UNOP(I32Ctz, I32, i32_ctz)
+      CASE_UNOP(I32Eqz, I32, i32_eqz, nullptr)
+      CASE_UNOP(I32Clz, I32, i32_clz, nullptr)
+      CASE_UNOP(I32Ctz, I32, i32_ctz, nullptr)
+      CASE_UNOP(I32Popcnt, I32, i32_popcnt,
+                &ExternalReference::wasm_word32_popcnt)
       default:
         return unsupported(decoder, WasmOpcodes::OpcodeName(opcode));
     }

src/wasm/baseline/mips/liftoff-assembler-mips.h

@@ -69,57 +69,42 @@ void LiftoffAssembler::Fill(LiftoffRegister reg, uint32_t index) {
   UNIMPLEMENTED();
 }
 
-#define UNIMPLEMENTED_I32_BINOP(name)                                \
-  void LiftoffAssembler::emit_i32_##name(Register dst, Register lhs, \
-                                         Register rhs) {             \
-    UNIMPLEMENTED();                                                 \
+#define UNIMPLEMENTED_GP_BINOP(name)                             \
+  void LiftoffAssembler::emit_##name(Register dst, Register lhs, \
+                                     Register rhs) {             \
+    UNIMPLEMENTED();                                             \
+  }
+#define UNIMPLEMENTED_GP_UNOP(name)                                \
+  bool LiftoffAssembler::emit_##name(Register dst, Register src) { \
+    UNIMPLEMENTED();                                               \
+  }
+#define UNIMPLEMENTED_FP_BINOP(name)                                         \
+  void LiftoffAssembler::emit_##name(DoubleRegister dst, DoubleRegister lhs, \
+                                     DoubleRegister rhs) {                   \
+    UNIMPLEMENTED();                                                         \
   }
 
-// clang-format off
-UNIMPLEMENTED_I32_BINOP(add)
-UNIMPLEMENTED_I32_BINOP(sub)
-UNIMPLEMENTED_I32_BINOP(mul)
-UNIMPLEMENTED_I32_BINOP(and)
-UNIMPLEMENTED_I32_BINOP(or)
-UNIMPLEMENTED_I32_BINOP(xor)
-UNIMPLEMENTED_I32_BINOP(shl)
-UNIMPLEMENTED_I32_BINOP(sar)
-UNIMPLEMENTED_I32_BINOP(shr)
-// clang-format on
-
-#undef UNIMPLEMENTED_I32_BINOP
-
-void LiftoffAssembler::emit_i32_eqz(Register dst, Register src) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_i32_clz(Register dst, Register src) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_i32_ctz(Register dst, Register src) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_ptrsize_add(Register dst, Register lhs,
-                                        Register rhs) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_f32_add(DoubleRegister dst, DoubleRegister lhs,
-                                    DoubleRegister rhs) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_f32_sub(DoubleRegister dst, DoubleRegister lhs,
-                                    DoubleRegister rhs) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_f32_mul(DoubleRegister dst, DoubleRegister lhs,
-                                    DoubleRegister rhs) {
-  UNIMPLEMENTED();
-}
+UNIMPLEMENTED_GP_BINOP(i32_add)
+UNIMPLEMENTED_GP_BINOP(i32_sub)
+UNIMPLEMENTED_GP_BINOP(i32_mul)
+UNIMPLEMENTED_GP_BINOP(i32_and)
+UNIMPLEMENTED_GP_BINOP(i32_or)
+UNIMPLEMENTED_GP_BINOP(i32_xor)
+UNIMPLEMENTED_GP_BINOP(i32_shl)
+UNIMPLEMENTED_GP_BINOP(i32_sar)
+UNIMPLEMENTED_GP_BINOP(i32_shr)
+UNIMPLEMENTED_GP_UNOP(i32_eqz)
+UNIMPLEMENTED_GP_UNOP(i32_clz)
+UNIMPLEMENTED_GP_UNOP(i32_ctz)
+UNIMPLEMENTED_GP_UNOP(i32_popcnt)
+UNIMPLEMENTED_GP_BINOP(ptrsize_add)
+UNIMPLEMENTED_FP_BINOP(f32_add)
+UNIMPLEMENTED_FP_BINOP(f32_sub)
+UNIMPLEMENTED_FP_BINOP(f32_mul)
+
+#undef UNIMPLEMENTED_GP_BINOP
+#undef UNIMPLEMENTED_GP_UNOP
+#undef UNIMPLEMENTED_FP_BINOP
 
 void LiftoffAssembler::emit_i32_test(Register reg) { UNIMPLEMENTED(); }
 
@@ -154,6 +139,26 @@ void LiftoffAssembler::DropStackSlotsAndRet(uint32_t num_stack_slots) {
   UNIMPLEMENTED();
 }
 
+void LiftoffAssembler::PrepareCCall(uint32_t num_params, const Register* args) {
+  UNIMPLEMENTED();
+}
+
+void LiftoffAssembler::SetCCallRegParamAddr(Register dst, uint32_t param_idx,
+                                            uint32_t num_params) {
+  UNIMPLEMENTED();
+}
+
+void LiftoffAssembler::SetCCallStackParamAddr(uint32_t stack_param_idx,
+                                              uint32_t param_idx,
+                                              uint32_t num_params) {
+  UNIMPLEMENTED();
+}
+
+void LiftoffAssembler::EmitCCall(ExternalReference ext_ref,
+                                 uint32_t num_params) {
+  UNIMPLEMENTED();
+}
+
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8

src/wasm/baseline/mips64/liftoff-assembler-mips64.h

@@ -69,57 +69,42 @@ void LiftoffAssembler::Fill(LiftoffRegister reg, uint32_t index) {
   UNIMPLEMENTED();
 }
 
-#define UNIMPLEMENTED_I32_BINOP(name)                                \
-  void LiftoffAssembler::emit_i32_##name(Register dst, Register lhs, \
-                                         Register rhs) {             \
-    UNIMPLEMENTED();                                                 \
+#define UNIMPLEMENTED_GP_BINOP(name)                             \
+  void LiftoffAssembler::emit_##name(Register dst, Register lhs, \
+                                     Register rhs) {             \
+    UNIMPLEMENTED();                                             \
+  }
+#define UNIMPLEMENTED_GP_UNOP(name)                                \
+  bool LiftoffAssembler::emit_##name(Register dst, Register src) { \
+    UNIMPLEMENTED();                                               \
+  }
+#define UNIMPLEMENTED_FP_BINOP(name)                                         \
+  void LiftoffAssembler::emit_##name(DoubleRegister dst, DoubleRegister lhs, \
+                                     DoubleRegister rhs) {                   \
+    UNIMPLEMENTED();                                                         \
   }
 
-// clang-format off
-UNIMPLEMENTED_I32_BINOP(add)
-UNIMPLEMENTED_I32_BINOP(sub)
-UNIMPLEMENTED_I32_BINOP(mul)
-UNIMPLEMENTED_I32_BINOP(and)
-UNIMPLEMENTED_I32_BINOP(or)
-UNIMPLEMENTED_I32_BINOP(xor)
-UNIMPLEMENTED_I32_BINOP(shl)
-UNIMPLEMENTED_I32_BINOP(sar)
-UNIMPLEMENTED_I32_BINOP(shr)
-// clang-format on
-
-#undef UNIMPLEMENTED_I32_BINOP
-
-void LiftoffAssembler::emit_i32_eqz(Register dst, Register src) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_i32_clz(Register dst, Register src) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_i32_ctz(Register dst, Register src) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_ptrsize_add(Register dst, Register lhs,
-                                        Register rhs) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_f32_add(DoubleRegister dst, DoubleRegister lhs,
-                                    DoubleRegister rhs) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_f32_sub(DoubleRegister dst, DoubleRegister lhs,
-                                    DoubleRegister rhs) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_f32_mul(DoubleRegister dst, DoubleRegister lhs,
-                                    DoubleRegister rhs) {
-  UNIMPLEMENTED();
-}
+UNIMPLEMENTED_GP_BINOP(i32_add)
+UNIMPLEMENTED_GP_BINOP(i32_sub)
+UNIMPLEMENTED_GP_BINOP(i32_mul)
+UNIMPLEMENTED_GP_BINOP(i32_and)
+UNIMPLEMENTED_GP_BINOP(i32_or)
+UNIMPLEMENTED_GP_BINOP(i32_xor)
+UNIMPLEMENTED_GP_BINOP(i32_shl)
+UNIMPLEMENTED_GP_BINOP(i32_sar)
+UNIMPLEMENTED_GP_BINOP(i32_shr)
+UNIMPLEMENTED_GP_UNOP(i32_eqz)
+UNIMPLEMENTED_GP_UNOP(i32_clz)
+UNIMPLEMENTED_GP_UNOP(i32_ctz)
+UNIMPLEMENTED_GP_UNOP(i32_popcnt)
+UNIMPLEMENTED_GP_BINOP(ptrsize_add)
+UNIMPLEMENTED_FP_BINOP(f32_add)
+UNIMPLEMENTED_FP_BINOP(f32_sub)
+UNIMPLEMENTED_FP_BINOP(f32_mul)
+
+#undef UNIMPLEMENTED_GP_BINOP
+#undef UNIMPLEMENTED_GP_UNOP
+#undef UNIMPLEMENTED_FP_BINOP
 
 void LiftoffAssembler::emit_i32_test(Register reg) { UNIMPLEMENTED(); }
 
@@ -154,6 +139,26 @@ void LiftoffAssembler::DropStackSlotsAndRet(uint32_t num_stack_slots) {
   UNIMPLEMENTED();
 }
 
+void LiftoffAssembler::PrepareCCall(uint32_t num_params, const Register* args) {
+  UNIMPLEMENTED();
+}
+
+void LiftoffAssembler::SetCCallRegParamAddr(Register dst, uint32_t param_idx,
+                                            uint32_t num_params) {
+  UNIMPLEMENTED();
+}
+
+void LiftoffAssembler::SetCCallStackParamAddr(uint32_t stack_param_idx,
+                                              uint32_t param_idx,
+                                              uint32_t num_params) {
+  UNIMPLEMENTED();
+}
+
+void LiftoffAssembler::EmitCCall(ExternalReference ext_ref,
+                                 uint32_t num_params) {
+  UNIMPLEMENTED();
+}
+
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8

src/wasm/baseline/ppc/liftoff-assembler-ppc.h

@@ -69,57 +69,42 @@ void LiftoffAssembler::Fill(LiftoffRegister reg, uint32_t index) {
   UNIMPLEMENTED();
 }
 
-#define UNIMPLEMENTED_I32_BINOP(name)                                \
-  void LiftoffAssembler::emit_i32_##name(Register dst, Register lhs, \
-                                         Register rhs) {             \
-    UNIMPLEMENTED();                                                 \
+#define UNIMPLEMENTED_GP_BINOP(name)                             \
+  void LiftoffAssembler::emit_##name(Register dst, Register lhs, \
+                                     Register rhs) {             \
+    UNIMPLEMENTED();                                             \
+  }
+#define UNIMPLEMENTED_GP_UNOP(name)                                \
+  bool LiftoffAssembler::emit_##name(Register dst, Register src) { \
+    UNIMPLEMENTED();                                               \
+  }
+#define UNIMPLEMENTED_FP_BINOP(name)                                         \
+  void LiftoffAssembler::emit_##name(DoubleRegister dst, DoubleRegister lhs, \
+                                     DoubleRegister rhs) {                   \
+    UNIMPLEMENTED();                                                         \
   }
 
-// clang-format off
-UNIMPLEMENTED_I32_BINOP(add)
-UNIMPLEMENTED_I32_BINOP(sub)
-UNIMPLEMENTED_I32_BINOP(mul)
-UNIMPLEMENTED_I32_BINOP(and)
-UNIMPLEMENTED_I32_BINOP(or)
-UNIMPLEMENTED_I32_BINOP(xor)
-UNIMPLEMENTED_I32_BINOP(shl)
-UNIMPLEMENTED_I32_BINOP(sar)
-UNIMPLEMENTED_I32_BINOP(shr)
-// clang-format on
-
-#undef UNIMPLEMENTED_I32_BINOP
-
-void LiftoffAssembler::emit_i32_eqz(Register dst, Register src) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_i32_clz(Register dst, Register src) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_i32_ctz(Register dst, Register src) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_ptrsize_add(Register dst, Register lhs,
-                                        Register rhs) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_f32_add(DoubleRegister dst, DoubleRegister lhs,
-                                    DoubleRegister rhs) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_f32_sub(DoubleRegister dst, DoubleRegister lhs,
-                                    DoubleRegister rhs) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_f32_mul(DoubleRegister dst, DoubleRegister lhs,
-                                    DoubleRegister rhs) {
-  UNIMPLEMENTED();
-}
+UNIMPLEMENTED_GP_BINOP(i32_add)
+UNIMPLEMENTED_GP_BINOP(i32_sub)
+UNIMPLEMENTED_GP_BINOP(i32_mul)
+UNIMPLEMENTED_GP_BINOP(i32_and)
+UNIMPLEMENTED_GP_BINOP(i32_or)
+UNIMPLEMENTED_GP_BINOP(i32_xor)
+UNIMPLEMENTED_GP_BINOP(i32_shl)
+UNIMPLEMENTED_GP_BINOP(i32_sar)
+UNIMPLEMENTED_GP_BINOP(i32_shr)
+UNIMPLEMENTED_GP_UNOP(i32_eqz)
+UNIMPLEMENTED_GP_UNOP(i32_clz)
+UNIMPLEMENTED_GP_UNOP(i32_ctz)
+UNIMPLEMENTED_GP_UNOP(i32_popcnt)
+UNIMPLEMENTED_GP_BINOP(ptrsize_add)
+UNIMPLEMENTED_FP_BINOP(f32_add)
+UNIMPLEMENTED_FP_BINOP(f32_sub)
+UNIMPLEMENTED_FP_BINOP(f32_mul)
+
+#undef UNIMPLEMENTED_GP_BINOP
+#undef UNIMPLEMENTED_GP_UNOP
+#undef UNIMPLEMENTED_FP_BINOP
 
 void LiftoffAssembler::emit_i32_test(Register reg) { UNIMPLEMENTED(); }
 
@@ -154,6 +139,26 @@ void LiftoffAssembler::DropStackSlotsAndRet(uint32_t num_stack_slots) {
   UNIMPLEMENTED();
 }
 
+void LiftoffAssembler::PrepareCCall(uint32_t num_params, const Register* args) {
+  UNIMPLEMENTED();
+}
+
+void LiftoffAssembler::SetCCallRegParamAddr(Register dst, uint32_t param_idx,
+                                            uint32_t num_params) {
+  UNIMPLEMENTED();
+}
+
+void LiftoffAssembler::SetCCallStackParamAddr(uint32_t stack_param_idx,
+                                              uint32_t param_idx,
+                                              uint32_t num_params) {
+  UNIMPLEMENTED();
+}
+
+void LiftoffAssembler::EmitCCall(ExternalReference ext_ref,
+                                 uint32_t num_params) {
+  UNIMPLEMENTED();
+}
+
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8

src/wasm/baseline/s390/liftoff-assembler-s390.h

@@ -69,57 +69,42 @@ void LiftoffAssembler::Fill(LiftoffRegister reg, uint32_t index) {
   UNIMPLEMENTED();
 }
 
-#define UNIMPLEMENTED_I32_BINOP(name)                                \
-  void LiftoffAssembler::emit_i32_##name(Register dst, Register lhs, \
-                                         Register rhs) {             \
-    UNIMPLEMENTED();                                                 \
+#define UNIMPLEMENTED_GP_BINOP(name)                             \
+  void LiftoffAssembler::emit_##name(Register dst, Register lhs, \
+                                     Register rhs) {             \
+    UNIMPLEMENTED();                                             \
+  }
+#define UNIMPLEMENTED_GP_UNOP(name)                                \
+  bool LiftoffAssembler::emit_##name(Register dst, Register src) { \
+    UNIMPLEMENTED();                                               \
+  }
+#define UNIMPLEMENTED_FP_BINOP(name)                                         \
+  void LiftoffAssembler::emit_##name(DoubleRegister dst, DoubleRegister lhs, \
+                                     DoubleRegister rhs) {                   \
+    UNIMPLEMENTED();                                                         \
   }
 
-// clang-format off
-UNIMPLEMENTED_I32_BINOP(add)
-UNIMPLEMENTED_I32_BINOP(sub)
-UNIMPLEMENTED_I32_BINOP(mul)
-UNIMPLEMENTED_I32_BINOP(and)
-UNIMPLEMENTED_I32_BINOP(or)
-UNIMPLEMENTED_I32_BINOP(xor)
-UNIMPLEMENTED_I32_BINOP(shl)
-UNIMPLEMENTED_I32_BINOP(sar)
-UNIMPLEMENTED_I32_BINOP(shr)
-// clang-format on
-
-#undef UNIMPLEMENTED_I32_BINOP
-
-void LiftoffAssembler::emit_i32_eqz(Register dst, Register src) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_i32_clz(Register dst, Register src) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_i32_ctz(Register dst, Register src) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_ptrsize_add(Register dst, Register lhs,
-                                        Register rhs) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_f32_add(DoubleRegister dst, DoubleRegister lhs,
-                                    DoubleRegister rhs) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_f32_sub(DoubleRegister dst, DoubleRegister lhs,
-                                    DoubleRegister rhs) {
-  UNIMPLEMENTED();
-}
-
-void LiftoffAssembler::emit_f32_mul(DoubleRegister dst, DoubleRegister lhs,
-                                    DoubleRegister rhs) {
-  UNIMPLEMENTED();
-}
+UNIMPLEMENTED_GP_BINOP(i32_add)
+UNIMPLEMENTED_GP_BINOP(i32_sub)
+UNIMPLEMENTED_GP_BINOP(i32_mul)
+UNIMPLEMENTED_GP_BINOP(i32_and)
+UNIMPLEMENTED_GP_BINOP(i32_or)
+UNIMPLEMENTED_GP_BINOP(i32_xor)
+UNIMPLEMENTED_GP_BINOP(i32_shl)
+UNIMPLEMENTED_GP_BINOP(i32_sar)
+UNIMPLEMENTED_GP_BINOP(i32_shr)
+UNIMPLEMENTED_GP_UNOP(i32_eqz)
+UNIMPLEMENTED_GP_UNOP(i32_clz)
+UNIMPLEMENTED_GP_UNOP(i32_ctz)
+UNIMPLEMENTED_GP_UNOP(i32_popcnt)
+UNIMPLEMENTED_GP_BINOP(ptrsize_add)
+UNIMPLEMENTED_FP_BINOP(f32_add)
+UNIMPLEMENTED_FP_BINOP(f32_sub)
+UNIMPLEMENTED_FP_BINOP(f32_mul)
+
+#undef UNIMPLEMENTED_GP_BINOP
+#undef UNIMPLEMENTED_GP_UNOP
+#undef UNIMPLEMENTED_FP_BINOP
 
 void LiftoffAssembler::emit_i32_test(Register reg) { UNIMPLEMENTED(); }
 
@@ -154,6 +139,26 @@ void LiftoffAssembler::DropStackSlotsAndRet(uint32_t num_stack_slots) {
   UNIMPLEMENTED();
 }
 
+void LiftoffAssembler::PrepareCCall(uint32_t num_params, const Register* args) {
+  UNIMPLEMENTED();
+}
+
+void LiftoffAssembler::SetCCallRegParamAddr(Register dst, uint32_t param_idx,
+                                            uint32_t num_params) {
+  UNIMPLEMENTED();
+}
+
+void LiftoffAssembler::SetCCallStackParamAddr(uint32_t stack_param_idx,
+                                              uint32_t param_idx,
+                                              uint32_t num_params) {
+  UNIMPLEMENTED();
+}
+
+void LiftoffAssembler::EmitCCall(ExternalReference ext_ref,
+                                 uint32_t num_params) {
+  UNIMPLEMENTED();
+}
+
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8

src/wasm/baseline/x64/liftoff-assembler-x64.h

@@ -27,6 +27,10 @@ inline Operand GetStackSlot(uint32_t index) {
 // TODO(clemensh): Make this a constexpr variable once Operand is constexpr.
 inline Operand GetContextOperand() { return Operand(rbp, -16); }
 
+// Use this register to store the address of the last argument pushed on the
+// stack for a call to C.
+static constexpr Register kCCallLastArgAddrReg = rax;
+
 }  // namespace liftoff
 
 void LiftoffAssembler::ReserveStackSpace(uint32_t bytes) {
@@ -311,13 +315,14 @@ void LiftoffAssembler::emit_i32_shr(Register dst, Register lhs, Register rhs) {
   liftoff::EmitShiftOperation(this, dst, lhs, rhs, &Assembler::shrl_cl);
 }
 
-void LiftoffAssembler::emit_i32_eqz(Register dst, Register src) {
+bool LiftoffAssembler::emit_i32_eqz(Register dst, Register src) {
   testl(src, src);
   setcc(zero, dst);
   movzxbl(dst, dst);
+  return true;
 }
 
-void LiftoffAssembler::emit_i32_clz(Register dst, Register src) {
+bool LiftoffAssembler::emit_i32_clz(Register dst, Register src) {
   Label nonzero_input;
   Label continuation;
   testl(src, src);
@@ -332,9 +337,10 @@ void LiftoffAssembler::emit_i32_clz(Register dst, Register src) {
   xorl(dst, Immediate(31));
 
   bind(&continuation);
+  return true;
 }
 
-void LiftoffAssembler::emit_i32_ctz(Register dst, Register src) {
+bool LiftoffAssembler::emit_i32_ctz(Register dst, Register src) {
   Label nonzero_input;
   Label continuation;
   testl(src, src);
@@ -347,6 +353,14 @@ void LiftoffAssembler::emit_i32_ctz(Register dst, Register src) {
   bsfl(dst, src);
 
   bind(&continuation);
+  return true;
+}
+
+bool LiftoffAssembler::emit_i32_popcnt(Register dst, Register src) {
+  if (!CpuFeatures::IsSupported(POPCNT)) return false;
+  CpuFeatureScope scope(this, POPCNT);
+  popcntl(dst, src);
+  return true;
 }
 
 void LiftoffAssembler::emit_ptrsize_add(Register dst, Register lhs,
@@ -493,6 +507,32 @@ void LiftoffAssembler::DropStackSlotsAndRet(uint32_t num_stack_slots) {
   ret(static_cast<int>(num_stack_slots * kPointerSize));
 }
 
+void LiftoffAssembler::PrepareCCall(uint32_t num_params, const Register* args) {
+  for (size_t param = 0; param < num_params; ++param) {
+    pushq(args[param]);
+  }
+  movq(liftoff::kCCallLastArgAddrReg, rsp);
+  PrepareCallCFunction(num_params);
+}
+
+void LiftoffAssembler::SetCCallRegParamAddr(Register dst, uint32_t param_idx,
+                                            uint32_t num_params) {
+  int offset = kPointerSize * static_cast<int>(num_params - 1 - param_idx);
+  leaq(dst, Operand(liftoff::kCCallLastArgAddrReg, offset));
+}
+
+void LiftoffAssembler::SetCCallStackParamAddr(uint32_t stack_param_idx,
+                                              uint32_t param_idx,
+                                              uint32_t num_params) {
+  // On x64, all C call arguments fit in registers.
+  UNREACHABLE();
+}
+
+void LiftoffAssembler::EmitCCall(ExternalReference ext_ref,
+                                 uint32_t num_params) {
+  CallCFunction(ext_ref, static_cast<int>(num_params));
+}
+
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8