[riscv64]Clean call/jump register

Change-Id: I33d7bdfc14af9ad169c79a3efd6af6ba2f2362c2
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2814726
Commit-Queue: Brice Dobry <brice.dobry@futurewei.com>
Reviewed-by: Brice Dobry <brice.dobry@futurewei.com>
Cr-Commit-Position: refs/heads/master@{#74124}

src/builtins/riscv64/builtins-riscv64.cc

@@ -1727,12 +1727,12 @@ void Generate_ContinueToBuiltinHelper(MacroAssembler* masm,
                 sp, BuiltinContinuationFrameConstants::kFixedFrameSizeFromFp));
   // Load builtin index (stored as a Smi) and use it to get the builtin start
   // address from the builtins table.
-  __ Pop(t0);
+  __ Pop(t6);
   __ Add64(sp, sp,
            Operand(BuiltinContinuationFrameConstants::kFixedFrameSizeFromFp));
   __ Pop(ra);
-  __ LoadEntryFromBuiltinIndex(t0);
-  __ Jump(t0);
+  __ LoadEntryFromBuiltinIndex(t6);
+  __ Jump(t6);
 }
 }  // namespace
 
@@ -3476,9 +3476,9 @@ void Generate_DeoptimizationEntry(MacroAssembler* masm,
     }
   }
 
-  __ pop(t3);  // Get continuation, leave pc on stack.
+  __ pop(t6);  // Get continuation, leave pc on stack.
   __ pop(ra);
-  __ Jump(t3);
+  __ Jump(t6);
   __ stop();
 }
 

src/codegen/riscv64/macro-assembler-riscv64.cc

@@ -4584,12 +4584,10 @@ void TurboAssembler::ResetSpeculationPoisonRegister() {
 void TurboAssembler::CallForDeoptimization(Builtins::Name target, int,
                                            Label* exit, DeoptimizeKind kind,
                                            Label* ret, Label*) {
-  UseScratchRegisterScope temps(this);
   BlockTrampolinePoolScope block_trampoline_pool(this);
-  Register scratch = temps.Acquire();
-  Ld(scratch,
+  Ld(t6,
      MemOperand(kRootRegister, IsolateData::builtin_entry_slot_offset(target)));
-  Call(scratch);
+  Call(t6);
   DCHECK_EQ(SizeOfCodeGeneratedSince(exit),
             (kind == DeoptimizeKind::kLazy)
                 ? Deoptimizer::kLazyDeoptExitSize

src/codegen/riscv64/register-riscv64.h

@@ -337,7 +337,7 @@ constexpr Register kJavaScriptCallTargetRegister = kJSFunctionRegister;
 constexpr Register kJavaScriptCallNewTargetRegister = a3;
 constexpr Register kJavaScriptCallExtraArg1Register = a2;
 
-constexpr Register kOffHeapTrampolineRegister = t3;
+constexpr Register kOffHeapTrampolineRegister = t6;
 constexpr Register kRuntimeCallFunctionRegister = a1;
 constexpr Register kRuntimeCallArgCountRegister = a0;
 constexpr Register kRuntimeCallArgvRegister = a2;

src/compiler/backend/riscv64/code-generator-riscv64.cc

@@ -611,8 +611,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
         Address wasm_code = static_cast<Address>(constant.ToInt64());
         __ Call(wasm_code, constant.rmode());
       } else {
-        __ Add64(kScratchReg, i.InputRegister(0), 0);
-        __ Call(kScratchReg);
+        __ Add64(t6, i.InputRegister(0), 0);
+        __ Call(t6);
       }
       RecordCallPosition(instr);
       frame_access_state()->ClearSPDelta();

src/wasm/baseline/riscv64/liftoff-assembler-riscv64.h

@@ -2557,8 +2557,8 @@ void LiftoffAssembler::CallIndirect(const ValueKindSig* sig,
                                     compiler::CallDescriptor* call_descriptor,
                                     Register target) {
   if (target == no_reg) {
-    pop(kScratchReg);
-    Call(kScratchReg);
+    pop(t6);
+    Call(t6);
   } else {
     Call(target);
   }
@@ -2566,8 +2566,8 @@ void LiftoffAssembler::CallIndirect(const ValueKindSig* sig,
 
 void LiftoffAssembler::TailCallIndirect(Register target) {
   if (target == no_reg) {
-    Pop(kScratchReg);
-    Jump(kScratchReg);
+    Pop(t6);
+    Jump(t6);
   } else {
     Jump(target);
   }