[vm, compiler] Make the leaf runtime call spill set more consistent between architectures.

Remove unnecessary spill of FpuTMP.
Remove unnecessary spill of TMP on x64.

TEST=ci
Change-Id: I6e56e4dfe1a817ff2c1f53229be305640b89eee6
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/446740
Reviewed-by: Alexander Markov <[email protected]>
Commit-Queue: Ryan Macnak <[email protected]>

Author: rmacnak-google

runtime/vm/compiler/assembler/assembler_arm64.cc

@@ -1864,10 +1864,8 @@ void Assembler::CallRuntime(const RuntimeEntry& entry,
   }
 }
 
-// FPU: Only the bottom 64-bits of v8-v15 are preserved by the caller. The upper
-// bits might be in use by Dart, so we save the whole register.
 static const RegisterSet kRuntimeCallSavedRegisters(kDartVolatileCpuRegs,
-                                                    kAllFpuRegistersList);
+                                                    kDartVolatileFpuRegs);
 
 #undef __
 #define __ assembler_->

runtime/vm/compiler/assembler/assembler_riscv.cc

@@ -4889,7 +4889,7 @@ void Assembler::CallRuntime(const RuntimeEntry& entry,
 }
 
 static const RegisterSet kRuntimeCallSavedRegisters(kDartVolatileCpuRegs,
-                                                    kAbiVolatileFpuRegs);
+                                                    kDartVolatileFpuRegs);
 
 #define __ assembler_->
 

runtime/vm/compiler/assembler/assembler_x64.cc

@@ -2076,6 +2076,9 @@ void Assembler::CallRuntime(const RuntimeEntry& entry,
   }
 }
 
+static const RegisterSet kRuntimeCallSavedRegisters(kDartVolatileCpuRegs,
+                                                    kDartVolatileFpuRegs);
+
 #define __ assembler_->
 
 LeafRuntimeScope::LeafRuntimeScope(Assembler* assembler,
@@ -2086,8 +2089,7 @@ LeafRuntimeScope::LeafRuntimeScope(Assembler* assembler,
   __ EnterFrame(0);
 
   if (preserve_registers_) {
-    // TODO(vegorov): avoid saving FpuTMP, it is used only as scratch.
-    __ PushRegisters(kVolatileRegisterSet);
+    __ PushRegisters(kRuntimeCallSavedRegisters);
   } else {
     // These registers must always be preserved.
     ASSERT(IsCalleeSavedRegister(THR));
@@ -2115,10 +2117,9 @@ LeafRuntimeScope::~LeafRuntimeScope() {
     // RSP might have been modified to reserve space for arguments
     // and ensure proper alignment of the stack frame.
     // We need to restore it before restoring registers.
-    __ leaq(RSP, Address(RBP, -kVolatileRegisterSet.SpillSize()));
+    __ leaq(RSP, Address(RBP, -kRuntimeCallSavedRegisters.SpillSize()));
 
-    // TODO(vegorov): avoid saving FpuTMP, it is used only as scratch.
-    __ PopRegisters(kVolatileRegisterSet);
+    __ PopRegisters(kRuntimeCallSavedRegisters);
   } else {
     const intptr_t kPushedRegistersSize =
         (target::frame_layout.dart_fixed_frame_size - 2) *

runtime/vm/constants_arm64.h

@@ -556,6 +556,7 @@ const RegList kAbiPartiallyVolatileFpuRegs =
     R(V8) | R(V9) | R(V10) | R(V11) | R(V12) | R(V13) | R(V14) | R(V15);
 const RegList kAbiVolatileFpuRegs =
     kAbiFullyVolatileFpuRegs | kAbiPartiallyVolatileFpuRegs;
+const RegList kDartVolatileFpuRegs = kAbiVolatileFpuRegs & ~R(FpuTMP);
 
 constexpr int kStoreBufferWrapperSize = 32;
 

runtime/vm/constants_riscv.h

@@ -530,6 +530,7 @@ constexpr RegList kAbiPreservedFpuRegs = R(FS0) | R(FS1) | R(FS2) | R(FS3) |
 constexpr int kAbiPreservedFpuRegCount = 12;
 constexpr intptr_t kReservedFpuRegisters = 0;
 constexpr intptr_t kNumberOfReservedFpuRegisters = 0;
+constexpr RegList kDartVolatileFpuRegs = kAbiVolatileFpuRegs & ~R(FpuTMP);
 
 constexpr int kStoreBufferWrapperSize = 26;
 

runtime/vm/constants_x64.h

@@ -474,6 +474,7 @@ const RegList kAbiVolatileFpuRegs = kAllFpuRegistersList;
 // Registers available to Dart that are not preserved by runtime calls.
 const RegList kDartVolatileCpuRegs =
     kDartAvailableCpuRegs & ~kAbiPreservedCpuRegs;
+const RegList kDartVolatileFpuRegs = kAbiVolatileFpuRegs & ~R(FpuTMP);
 
 enum ScaleFactor {
   TIMES_1 = 0,