Block THR also in ParallelMoveResolver, by sharing list of globally reserved regs.

runtime/vm/flow_graph_compiler.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_XXX.
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
@@ skipping 1172 matching lines @@
     if (!blocked_registers[regno]) {
       blocked_registers[regno] = true;
       return static_cast<Register>(regno);
     }
   }
   UNREACHABLE();
   return kNoRegister;
 }
 
 
+#define REG_MASK_BIT(reg) ((reg) != kNoRegister) ? (1 << (reg)) : 0
+// Mask of globally reserved registers. Some other registers are only reserved
+// in particular code (e.g., ARGS_DESC_REG in intrinsics).
+static const uword kReservedCpuRegisters = REG_MASK_BIT(SPREG)
+                                         | REG_MASK_BIT(FPREG)
+                                         | REG_MASK_BIT(TMP)
+                                         | REG_MASK_BIT(TMP2)
+                                         | REG_MASK_BIT(PP)
+                                         | REG_MASK_BIT(THR);
+
+
 void FlowGraphCompiler::AllocateRegistersLocally(Instruction* instr) {
   ASSERT(!is_optimizing());
 
   instr->InitializeLocationSummary(zone(),
                                    false);  // Not optimizing.
   LocationSummary* locs = instr->locs();
 
   bool blocked_registers[kNumberOfCpuRegisters];
 
   // Mark all available registers free.
   for (intptr_t i = 0; i < kNumberOfCpuRegisters; i++) {
     blocked_registers[i] = false;
   }
 
+  // Block all registers globally reserved by the assembler, etc.
+  for (intptr_t i = 0; i < kNumberOfCpuRegisters; i++) {
+    if ((kReservedCpuRegisters & (1 << i)) != 0) {
+      blocked_registers[i] = true;
+    }
+  }
+
   // Mark all fixed input, temp and output registers as used.
   for (intptr_t i = 0; i < locs->input_count(); i++) {
     Location loc = locs->in(i);
     if (loc.IsRegister()) {
       // Check that a register is not specified twice in the summary.
       ASSERT(!blocked_registers[loc.reg()]);
       blocked_registers[loc.reg()] = true;
     }
   }
 
   for (intptr_t i = 0; i < locs->temp_count(); i++) {
     Location loc = locs->temp(i);
     if (loc.IsRegister()) {
       // Check that a register is not specified twice in the summary.
       ASSERT(!blocked_registers[loc.reg()]);
       blocked_registers[loc.reg()] = true;
     }
   }
 
   if (locs->out(0).IsRegister()) {
     // Fixed output registers are allowed to overlap with
     // temps and inputs.
     blocked_registers[locs->out(0).reg()] = true;
   }
 
-  // Do not allocate known registers.
-  blocked_registers[SPREG] = true;
-  blocked_registers[FPREG] = true;
-  if (TMP != kNoRegister) {
-    blocked_registers[TMP] = true;
-  }
-  if (TMP2 != kNoRegister) {
-    blocked_registers[TMP2] = true;
-  }
-  if (PP != kNoRegister) {
-    blocked_registers[PP] = true;
-  }
-  blocked_registers[THR] = true;
-
   // Block all non-free registers.
   for (intptr_t i = 0; i < kFirstFreeCpuRegister; i++) {
     blocked_registers[i] = true;
   }
   for (intptr_t i = kLastFreeCpuRegister + 1; i < kNumberOfCpuRegisters; i++) {
     blocked_registers[i] = true;
   }
 
   // Allocate all unallocated input locations.
   const bool should_pop = !instr->IsPushArgument() && !instr->IsPushTemp();
@@ skipping 233 matching lines @@
 }
 
 
 ParallelMoveResolver::ScratchFpuRegisterScope::~ScratchFpuRegisterScope() {
   if (spilled_) {
     resolver_->RestoreFpuScratch(reg_);
   }
 }
 
 
-static inline intptr_t MaskBit(Register reg) {
-  return (reg != kNoRegister) ? (1 << reg) : 0;
-}
-
-
 ParallelMoveResolver::ScratchRegisterScope::ScratchRegisterScope(
     ParallelMoveResolver* resolver, Register blocked)
     : resolver_(resolver),
       reg_(kNoRegister),
       spilled_(false) {
-  uword blocked_mask = MaskBit(blocked)
-                     | MaskBit(SPREG)
-                     | MaskBit(FPREG)
-                     | MaskBit(TMP)
-                     | MaskBit(TMP2)
-                     | MaskBit(PP);
+  uword blocked_mask = REG_MASK_BIT(blocked) | kReservedCpuRegisters;
   if (resolver->compiler_->intrinsic_mode()) {
     // Block additional registers that must be preserved for intrinsics.
-    blocked_mask |= MaskBit(ARGS_DESC_REG);
+    blocked_mask |= REG_MASK_BIT(ARGS_DESC_REG);
   }
   reg_ = static_cast<Register>(
       resolver_->AllocateScratchRegister(Location::kRegister,
                                          blocked_mask,
                                          kFirstFreeCpuRegister,
                                          kLastFreeCpuRegister,
                                          &spilled_));
 
   if (spilled_) {
     resolver->SpillScratch(reg_);
@@ skipping 200 matching lines @@
 
 
 void FlowGraphCompiler::FrameStateClear() {
   ASSERT(!is_optimizing());
   frame_state_.TruncateTo(0);
 }
 #endif
 
 
 }  // namespace dart