[turbofan][arm64] Use immediates instead of MiscField for stack operations.

This avoid to depend on MiscField to be big enough to hold the offset/size.
This patch also remove the Arm64PokePair which is no longer used.

R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/1039753002

Cr-Commit-Position: refs/heads/master@{#27505}

src/compiler/arm64/code-generator-arm64.cc

@@ -610,24 +610,16 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       // Pseudo instruction turned into cbz/cbnz in AssembleArchBranch.
       break;
     case kArm64Claim: {
-      int words = MiscField::decode(instr->opcode());
-      __ Claim(words);
+      __ Claim(i.InputInt32(0));
       break;
     }
     case kArm64Poke: {
-      int slot = MiscField::decode(instr->opcode());
-      Operand operand(slot * kPointerSize);
+      Operand operand(i.InputInt32(1) * kPointerSize);
       __ Poke(i.InputRegister(0), operand);
       break;
     }
-    case kArm64PokePairZero: {
-      // TODO(dcarney): test slot offset and register order.
-      int slot = MiscField::decode(instr->opcode()) - 1;
-      __ PokePair(i.InputRegister(0), xzr, slot * kPointerSize);
-      break;
-    }
     case kArm64PokePair: {
-      int slot = MiscField::decode(instr->opcode()) - 1;
+      int slot = i.InputInt32(2) - 1;
       __ PokePair(i.InputRegister(1), i.InputRegister(0), slot * kPointerSize);
       break;
     }

src/compiler/arm64/instruction-codes-arm64.h

@@ -77,7 +77,6 @@ namespace compiler {
   V(Arm64CompareAndBranch32)       \
   V(Arm64Claim)                    \
   V(Arm64Poke)                     \
-  V(Arm64PokePairZero)             \
   V(Arm64PokePair)                 \
   V(Arm64Float64Cmp)               \
   V(Arm64Float64Add)               \

src/compiler/arm64/instruction-selector-arm64.cc

@@ -1168,7 +1168,7 @@ void InstructionSelector::VisitCall(Node* node, BasicBlock* handler) {
   if (aligned_push_count > 0) {
     // TODO(dcarney): it would be better to bump the csp here only
     //                and emit paired stores with increment for non c frames.
-    Emit(kArm64Claim | MiscField::encode(aligned_push_count), g.NoOutput());
+    Emit(kArm64Claim, g.NoOutput(), g.TempImmediate(aligned_push_count));
   }
   // Move arguments to the stack.
   {
@@ -1176,15 +1176,16 @@ void InstructionSelector::VisitCall(Node* node, BasicBlock* handler) {
     // Emit the uneven pushes.
     if (pushed_count_uneven) {
       Node* input = buffer.pushed_nodes[slot];
-      Emit(kArm64Poke | MiscField::encode(slot), g.NoOutput(),
-           g.UseRegister(input));
+      Emit(kArm64Poke, g.NoOutput(), g.UseRegister(input),
+           g.TempImmediate(slot));
       slot--;
     }
     // Now all pushes can be done in pairs.
     for (; slot >= 0; slot -= 2) {
-      Emit(kArm64PokePair | MiscField::encode(slot), g.NoOutput(),
+      Emit(kArm64PokePair, g.NoOutput(),
            g.UseRegister(buffer.pushed_nodes[slot]),
-           g.UseRegister(buffer.pushed_nodes[slot - 1]));
+           g.UseRegister(buffer.pushed_nodes[slot - 1]),
+           g.TempImmediate(slot));
     }
   }