PPC: [Atomics] Make Atomics.exchange a builtin using TF

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

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/code-generator.h"
 
 #include "src/compilation-info.h"
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
@@ skipping 774 matching lines @@
     Register value = i.InputRegister(index);                 \
     __ lwsync();                                             \
     if (mode == kMode_MRI) {                                 \
       __ asm_instr(value, operand);                          \
     } else {                                                 \
       __ asm_instrx(value, operand);                         \
     }                                                        \
     __ sync();                                               \
     DCHECK_EQ(LeaveRC, i.OutputRCBit());                     \
   } while (0)
+#define ASSEMBLE_ATOMIC_EXCHANGE_INTEGER(load_instr, store_instr)       \
+  do {                                                                  \
+    Label exchange;                                                     \
+    __ bind(&exchange);                                                 \
+    __ load_instr(i.OutputRegister(0),                                  \
+                  MemOperand(i.InputRegister(0), i.InputRegister(1)));  \
+    __ store_instr(i.InputRegister(2),                                  \
+                   MemOperand(i.InputRegister(0), i.InputRegister(1))); \
+    __ bne(&exchange, cr0);                                             \
+  } while (0)
 
 void CodeGenerator::AssembleDeconstructFrame() {
   __ LeaveFrame(StackFrame::MANUAL);
 }
 
 void CodeGenerator::AssemblePrepareTailCall() {
   if (frame_access_state()->has_frame()) {
     __ RestoreFrameStateForTailCall();
   }
   frame_access_state()->SetFrameAccessToSP();
@@ skipping 1167 matching lines @@
     case kAtomicStoreWord8:
       ASSEMBLE_ATOMIC_STORE_INTEGER(stb, stbx);
       break;
     case kAtomicStoreWord16:
       ASSEMBLE_ATOMIC_STORE_INTEGER(sth, sthx);
       break;
     case kAtomicStoreWord32:
       ASSEMBLE_ATOMIC_STORE_INTEGER(stw, stwx);
       break;
     case kAtomicExchangeInt8:
+      ASSEMBLE_ATOMIC_EXCHANGE_INTEGER(lbarx, stbcx);
+      __ extsb(i.OutputRegister(0), i.OutputRegister(0));
+      break;
     case kAtomicExchangeUint8:
+      ASSEMBLE_ATOMIC_EXCHANGE_INTEGER(lbarx, stbcx);
+      break;
     case kAtomicExchangeInt16:
+      ASSEMBLE_ATOMIC_EXCHANGE_INTEGER(lharx, sthcx);
+      __ extsh(i.OutputRegister(0), i.OutputRegister(0));
+      break;
     case kAtomicExchangeUint16:
+      ASSEMBLE_ATOMIC_EXCHANGE_INTEGER(lharx, sthcx);
+      break;
     case kAtomicExchangeWord32:
+      ASSEMBLE_ATOMIC_EXCHANGE_INTEGER(lwarx, stwcx);
+      break;
     case kAtomicCompareExchangeInt8:
     case kAtomicCompareExchangeUint8:
     case kAtomicCompareExchangeInt16:
     case kAtomicCompareExchangeUint16:
     case kAtomicCompareExchangeWord32:
       UNREACHABLE();
       break;
     default:
       UNREACHABLE();
       break;
@@ skipping 600 matching lines @@
       padding_size -= v8::internal::Assembler::kInstrSize;
     }
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8