ARM/ARM64: Fix smashed CODE_REG in intrinsics with InvokeMathCFunctionInstrs.

runtime/vm/intrinsifier_arm64.cc

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_ARM64.
 #if defined(TARGET_ARCH_ARM64)
 
 #include "vm/intrinsifier.h"
 
 #include "vm/assembler.h"
@@ skipping 14 matching lines @@
 // if the intrinsified method always executes a return.
 // The FP register should not be modified, because it is used by the profiler.
 // The PP and THR registers (see constants_arm64.h) must be preserved.
 
 #define __ assembler->
 
 
 intptr_t Intrinsifier::ParameterSlotFromSp() { return -1; }
 
 
+static bool IsABIPreservedRegister(Register reg) {
+  return ((1 << reg) & kAbiPreservedCpuRegs) != 0;
+}
+
+
 void Intrinsifier::IntrinsicCallPrologue(Assembler* assembler) {
+  ASSERT(IsABIPreservedRegister(CODE_REG));
+  ASSERT(!IsABIPreservedRegister(ARGS_DESC_REG));
+  ASSERT(IsABIPreservedRegister(CALLEE_SAVED_TEMP));
+  ASSERT(IsABIPreservedRegister(CALLEE_SAVED_TEMP2));
+  ASSERT(CALLEE_SAVED_TEMP != CODE_REG);
+  ASSERT(CALLEE_SAVED_TEMP != ARGS_DESC_REG);
+  ASSERT(CALLEE_SAVED_TEMP2 != CODE_REG);
+  ASSERT(CALLEE_SAVED_TEMP2 != ARGS_DESC_REG);
+
   assembler->Comment("IntrinsicCallPrologue");
   assembler->mov(CALLEE_SAVED_TEMP, LR);
-  assembler->mov(CALLEE_SAVED_TEMP2, R4);
+  assembler->mov(CALLEE_SAVED_TEMP2, ARGS_DESC_REG);
 }
 
 
 void Intrinsifier::IntrinsicCallEpilogue(Assembler* assembler) {
   assembler->Comment("IntrinsicCallEpilogue");
   assembler->mov(LR, CALLEE_SAVED_TEMP);
-  assembler->mov(R4, CALLEE_SAVED_TEMP2);
+  assembler->mov(ARGS_DESC_REG, CALLEE_SAVED_TEMP2);
 }
 
 
 // Intrinsify only for Smi value and index. Non-smi values need a store buffer
 // update. Array length is always a Smi.
 void Intrinsifier::ObjectArraySetIndexed(Assembler* assembler) {
   if (Isolate::Current()->type_checks()) {
     return;
   }
 
@@ skipping 2137 matching lines @@
   __ cmp(R0, Operand(0));
   __ LoadObject(R0, Bool::False());
   __ LoadObject(TMP, Bool::True());
   __ csel(R0, TMP, R0, NE);
   __ ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64