[liftoff] Simplify ParallelRegisterMove

We often want to pass a list of moves of fixed length. Instead of
constructing an array on the caller's stack and passing it via
{ArrayVector}, we should just pass it via {std::initializer_list}. This
also avoids to spell out the internal name
{LiftoffAssembler::ParallelRegisterMoveTuple}.

R=thibaudm@chromium.org

Bug: v8:10576
Change-Id: Ibe7ac5a5a02686533333cb45652cbb2b99ad9c60
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2287498
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68799}

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

@@ -949,9 +949,8 @@ void LiftoffAssembler::AtomicLoad(LiftoffRegister dst, Register src_addr,
   ldrexd(dst_low, dst_high, actual_addr);
   dmb(ISH);
 
-  LiftoffAssembler::ParallelRegisterMoveTuple reg_moves[]{
-      {dst, LiftoffRegister::ForPair(dst_low, dst_high), kWasmI64}};
-  ParallelRegisterMove(ArrayVector(reg_moves));
+  ParallelRegisterMove(
+      {{dst, LiftoffRegister::ForPair(dst_low, dst_high), kWasmI64}});
 }
 
 void LiftoffAssembler::AtomicStore(Register dst_addr, Register offset_reg,
@@ -1071,15 +1070,13 @@ inline void AtomicI64CompareExchange(LiftoffAssembler* lasm,
   __ SpillRegisters(dst_addr, offset, result_low, result_high, new_value_low,
                     new_value_high, store_result, expected_low, expected_high);
 
-  LiftoffAssembler::ParallelRegisterMoveTuple reg_moves[]{
-      {LiftoffRegister::ForPair(new_value_low, new_value_high), new_value,
-       kWasmI64},
-      {LiftoffRegister::ForPair(expected_low, expected_high), expected,
-       kWasmI64},
-      {LiftoffRegister(dst_addr), LiftoffRegister(dst_addr_reg), kWasmI32},
-      {LiftoffRegister(offset),
-       LiftoffRegister(offset_reg != no_reg ? offset_reg : offset), kWasmI32}};
-  __ ParallelRegisterMove(ArrayVector(reg_moves));
+  __ ParallelRegisterMove(
+      {{LiftoffRegister::ForPair(new_value_low, new_value_high), new_value,
+        kWasmI64},
+       {LiftoffRegister::ForPair(expected_low, expected_high), expected,
+        kWasmI64},
+       {dst_addr, dst_addr_reg, kWasmI32},
+       {offset, offset_reg != no_reg ? offset_reg : offset, kWasmI32}});
 
   {
     UseScratchRegisterScope temps(lasm);
@@ -1106,9 +1103,8 @@ inline void AtomicI64CompareExchange(LiftoffAssembler* lasm,
   __ dmb(ISH);
   __ bind(&done);
 
-  LiftoffAssembler::ParallelRegisterMoveTuple reg_moves_result[]{
-      {result, LiftoffRegister::ForPair(result_low, result_high), kWasmI64}};
-  __ ParallelRegisterMove(ArrayVector(reg_moves_result));
+  __ ParallelRegisterMove(
+      {{result, LiftoffRegister::ForPair(result_low, result_high), kWasmI64}});
 }
 #undef __
 }  // namespace liftoff

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

@@ -707,12 +707,9 @@ inline void AtomicBinop64(LiftoffAssembler* lasm, Binop op, Register dst_addr,
   }
   // Spill all these registers if they are still holding other values.
   liftoff::SpillRegisters(lasm, old_hi, old_lo, new_hi, base, offset);
-  {
-    LiftoffAssembler::ParallelRegisterMoveTuple reg_moves[]{
-        {LiftoffRegister::ForPair(base, offset),
-         LiftoffRegister::ForPair(dst_addr, offset_reg), kWasmI64}};
-    __ ParallelRegisterMove(ArrayVector(reg_moves));
-  }
+  __ ParallelRegisterMove(
+      {{LiftoffRegister::ForPair(base, offset),
+        LiftoffRegister::ForPair(dst_addr, offset_reg), kWasmI64}});
 
   Operand dst_op_lo = Operand(base, offset, times_1, offset_imm);
   Operand dst_op_hi = Operand(base, offset, times_1, offset_imm + 4);
@@ -759,12 +756,9 @@ inline void AtomicBinop64(LiftoffAssembler* lasm, Binop op, Register dst_addr,
   // Restore the root register, and we are done.
   __ pop(kRootRegister);
 
-  {
-    // Move the result into the correct registers.
-    LiftoffAssembler::ParallelRegisterMoveTuple reg_moves[]{
-        {result, LiftoffRegister::ForPair(old_lo, old_hi), kWasmI64}};
-    __ ParallelRegisterMove(ArrayVector(reg_moves));
-  }
+  // Move the result into the correct registers.
+  __ ParallelRegisterMove(
+      {{result, LiftoffRegister::ForPair(old_lo, old_hi), kWasmI64}});
 }
 
 #undef __
@@ -1346,10 +1340,9 @@ void LiftoffAssembler::emit_i64_mul(LiftoffRegister dst, LiftoffRegister lhs,
   liftoff::SpillRegisters(this, dst_hi, dst_lo, lhs_hi, rhs_lo);
 
   // Move lhs and rhs into the respective registers.
-  ParallelRegisterMoveTuple reg_moves[]{
-      {LiftoffRegister::ForPair(lhs_lo, lhs_hi), lhs, kWasmI64},
-      {LiftoffRegister::ForPair(rhs_lo, rhs_hi), rhs, kWasmI64}};
-  ParallelRegisterMove(ArrayVector(reg_moves));
+  ParallelRegisterMove(
+      {{LiftoffRegister::ForPair(lhs_lo, lhs_hi), lhs, kWasmI64},
+       {LiftoffRegister::ForPair(rhs_lo, rhs_hi), rhs, kWasmI64}});
 
   // First mul: lhs_hi' = lhs_hi * rhs_lo.
   imul(lhs_hi, rhs_lo);

src/wasm/baseline/liftoff-assembler.cc

@@ -867,7 +867,7 @@ void LiftoffAssembler::Move(LiftoffRegister dst, LiftoffRegister src,
 }
 
 void LiftoffAssembler::ParallelRegisterMove(
-    Vector<ParallelRegisterMoveTuple> tuples) {
+    Vector<const ParallelRegisterMoveTuple> tuples) {
   StackTransferRecipe stack_transfers(this);
   for (auto tuple : tuples) {
     if (tuple.dst == tuple.src) continue;

src/wasm/baseline/liftoff-assembler.h

@@ -452,7 +452,13 @@ class LiftoffAssembler : public TurboAssembler {
     ParallelRegisterMoveTuple(Dst dst, Src src, ValueType type)
         : dst(dst), src(src), type(type) {}
   };
-  void ParallelRegisterMove(Vector<ParallelRegisterMoveTuple>);
+
+  void ParallelRegisterMove(Vector<const ParallelRegisterMoveTuple>);
+
+  void ParallelRegisterMove(
+      std::initializer_list<ParallelRegisterMoveTuple> moves) {
+    ParallelRegisterMove(VectorOf(moves));
+  }
 
   void MoveToReturnLocations(const FunctionSig*,
                              compiler::CallDescriptor* descriptor);

src/wasm/baseline/liftoff-compiler.cc

@@ -3216,11 +3216,9 @@ class LiftoffCompiler {
     WasmAtomicNotifyDescriptor descriptor;
     DCHECK_EQ(0, descriptor.GetStackParameterCount());
     DCHECK_EQ(2, descriptor.GetRegisterParameterCount());
-    LiftoffAssembler::ParallelRegisterMoveTuple reg_moves[]{
-        {LiftoffRegister(descriptor.GetRegisterParameter(0)),
-         LiftoffRegister(index), kWasmI32},
-        {LiftoffRegister(descriptor.GetRegisterParameter(1)), count, kWasmI32}};
-    __ ParallelRegisterMove(ArrayVector(reg_moves));
+    __ ParallelRegisterMove(
+        {{descriptor.GetRegisterParameter(0), index, kWasmI32},
+         {descriptor.GetRegisterParameter(1), count, kWasmI32}});
 
     __ CallRuntimeStub(WasmCode::kWasmAtomicNotify);
     RegisterDebugSideTableEntry(DebugSideTableBuilder::kDidSpill);