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

runtime/vm/intrinsifier_arm.cc

 // Copyright (c) 2013, 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_ARM.
 #if defined(TARGET_ARCH_ARM)
 
 #include "vm/intrinsifier.h"
 
 #include "vm/assembler.h"
@@ skipping 16 matching lines @@
 // The FP register should not be modified, because it is used by the profiler.
 // The PP and THR registers (see constants_arm.h) must be preserved.
 
 #define __ assembler->
 
 
 intptr_t Intrinsifier::ParameterSlotFromSp() { return -1; }
 
 
 void Intrinsifier::IntrinsicCallPrologue(Assembler* assembler) {
+  COMPILE_ASSERT((1 << CODE_REG) & kAbiPreservedCpuRegs);

[Vyacheslav Egorov (Google), 2016/05/25 11:15:31]

(...) != 0

our style does not allow implicit integral to boolean coercion - even though it
allows to write concise and still readable code.

[rmacnak, 2016/05/25 16:58:51]

Factored out as IsABIPreservedRegister.

+  COMPILE_ASSERT((1 << ARGS_DESC_REG) & kAbiPreservedCpuRegs);
+  COMPILE_ASSERT((1 << CALLEE_SAVED_TEMP) & kAbiPreservedCpuRegs);
+  COMPILE_ASSERT(CALLEE_SAVED_TEMP != CODE_REG);
+  COMPILE_ASSERT(CALLEE_SAVED_TEMP != ARGS_DESC_REG);
+
   // Save LR by moving it to a callee saved temporary register.
   assembler->Comment("IntrinsicCallPrologue");
   assembler->mov(CALLEE_SAVED_TEMP, Operand(LR));
 }
 
 
 void Intrinsifier::IntrinsicCallEpilogue(Assembler* assembler) {
   // Restore LR.
   assembler->Comment("IntrinsicCallEpilogue");
   assembler->mov(LR, Operand(CALLEE_SAVED_TEMP));
@@ skipping 2071 matching lines @@
   __ ldr(R0, Address(R0, TimelineStream::enabled_offset()));
   __ cmp(R0, Operand(0));
   __ LoadObject(R0, Bool::True(), NE);
   __ LoadObject(R0, Bool::False(), EQ);
   __ Ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM