ARM: Merge redundant entries in literal pool.

src/arm/assembler-arm.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions
 // are met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 1425 matching lines @@
   static bool IsMovT(Instr instr);
   static bool IsMovW(Instr instr);
 
   // Constants in pools are accessed via pc relative addressing, which can
   // reach +/-4KB for integer PC-relative loads and +/-1KB for floating-point
   // PC-relative loads, thereby defining a maximum distance between the
   // instruction and the accessed constant.
   static const int kMaxDistToIntPool = 4*KB;
   static const int kMaxDistToFPPool = 1*KB;
   // All relocations could be integer, it therefore acts as the limit.
-  static const int kMaxNumPendingRelocInfo = kMaxDistToIntPool/kInstrSize;
+  static const int kMaxNumPending32RelocInfo = kMaxDistToIntPool/kInstrSize;
+  static const int kMaxNumPending64RelocInfo = kMaxDistToFPPool/kInstrSize;
 
   // Postpone the generation of the constant pool for the specified number of
   // instructions.
   void BlockConstPoolFor(int instructions);
 
   // Check if is time to emit a constant pool.
   void CheckConstPool(bool force_emit, bool require_jump);
 
  protected:
   // Relocation for a type-recording IC has the AST id added to it.  This
@@ skipping 17 matching lines @@
       // Prevent constant pool checks happening by setting the next check to
       // the biggest possible offset.
       next_buffer_check_ = kMaxInt;
     }
   }
 
   // Resume constant pool emission. Need to be called as many time as
   // StartBlockConstPool to have an effect.
   void EndBlockConstPool() {
     if (--const_pool_blocked_nesting_ == 0) {
+#ifdef DEBUG
+      // Max pool start (if we need a jump and an alignment).
+      int start = pc_offset() + kInstrSize + 2 * kPointerSize;
       // Check the constant pool hasn't been blocked for too long.
-      ASSERT((num_pending_reloc_info_ == 0) ||
-             (pc_offset() < (first_const_pool_use_ + kMaxDistToIntPool)));
+      ASSERT((num_pending_32_bit_reloc_info_ == 0) ||
+             (start + num_pending_64_bit_reloc_info_ * kDoubleSize <
+              (first_const_pool_32_use_ + kMaxDistToIntPool)));
       ASSERT((num_pending_64_bit_reloc_info_ == 0) ||
-             (pc_offset() < (first_const_pool_use_ + kMaxDistToFPPool)));
+             (start < (first_const_pool_64_use_ + kMaxDistToFPPool)));
+#endif
       // Two cases:
       //  * no_const_pool_before_ >= next_buffer_check_ and the emission is
       //    still blocked
       //  * no_const_pool_before_ < next_buffer_check_ and the next emit will
       //    trigger a check.
       next_buffer_check_ = no_const_pool_before_;
     }
   }
 
   bool is_const_pool_blocked() const {
@@ skipping 28 matching lines @@
   static const int kCheckPoolIntervalInst = 32;
   static const int kCheckPoolInterval = kCheckPoolIntervalInst * kInstrSize;
 
 
   // Emission of the constant pool may be blocked in some code sequences.
   int const_pool_blocked_nesting_;  // Block emission if this is not zero.
   int no_const_pool_before_;  // Block emission before this pc offset.
 
   // Keep track of the first instruction requiring a constant pool entry
   // since the previous constant pool was emitted.
-  int first_const_pool_use_;
+  int first_const_pool_32_use_;
+  int first_const_pool_64_use_;
 
   // Relocation info generation
   // Each relocation is encoded as a variable size value
   static const int kMaxRelocSize = RelocInfoWriter::kMaxSize;
   RelocInfoWriter reloc_info_writer;
 
   // Relocation info records are also used during code generation as temporary
   // containers for constants and code target addresses until they are emitted
   // to the constant pool. These pending relocation info records are temporarily
   // stored in a separate buffer until a constant pool is emitted.
   // If every instruction in a long sequence is accessing the pool, we need one
   // pending relocation entry per instruction.
 
-  // the buffer of pending relocation info
-  RelocInfo pending_reloc_info_[kMaxNumPendingRelocInfo];
-  // number of pending reloc info entries in the buffer
-  int num_pending_reloc_info_;
-  // Number of pending reloc info entries included above which also happen to
-  // be 64-bit.
+  // The buffers of pending relocation info.
+  RelocInfo pending_32_bit_reloc_info_[kMaxNumPending32RelocInfo];
+  RelocInfo pending_64_bit_reloc_info_[kMaxNumPending64RelocInfo];
+  // Number of pending reloc info entries in the 32 bits buffer.
+  int num_pending_32_bit_reloc_info_;
+  // Number of pending reloc info entries in the 64 bits buffer.
   int num_pending_64_bit_reloc_info_;
 
   // The bound position, before this we cannot do instruction elimination.
   int last_bound_pos_;
 
   // Code emission
   inline void CheckBuffer();
   void GrowBuffer();
   inline void emit(Instr x);
 
@@ skipping 40 matching lines @@
  public:
   explicit EnsureSpace(Assembler* assembler) {
     assembler->CheckBuffer();
   }
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_ASSEMBLER_ARM_H_