Remove peephole optimiziations from IA32 and ARM assembler.

src/arm/assembler-arm.cc

 // 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 271 matching lines @@
 const Instr kLdrStrOffsetMask = 0x00000fff;
 
 
 // Spare buffer.
 static const int kMinimalBufferSize = 4*KB;
 
 
 Assembler::Assembler(Isolate* arg_isolate, void* buffer, int buffer_size)
     : AssemblerBase(arg_isolate),
       positions_recorder_(this),
-      allow_peephole_optimization_(false),
       emit_debug_code_(FLAG_debug_code) {
-  allow_peephole_optimization_ = FLAG_peephole_optimization;
   if (buffer == NULL) {
     // Do our own buffer management.
     if (buffer_size <= kMinimalBufferSize) {
       buffer_size = kMinimalBufferSize;
 
       if (isolate()->assembler_spare_buffer() != NULL) {
         buffer = isolate()->assembler_spare_buffer();
         isolate()->set_assembler_spare_buffer(NULL);
       }
     }
@@ skipping 784 matching lines @@
 
 void Assembler::rsb(Register dst, Register src1, const Operand& src2,
                     SBit s, Condition cond) {
   addrmod1(cond | RSB | s, src1, dst, src2);
 }
 
 
 void Assembler::add(Register dst, Register src1, const Operand& src2,
                     SBit s, Condition cond) {
   addrmod1(cond | ADD | s, src1, dst, src2);
-
-  // Eliminate pattern: push(r), pop()
-  //   str(src, MemOperand(sp, 4, NegPreIndex), al);
-  //   add(sp, sp, Operand(kPointerSize));
-  // Both instructions can be eliminated.
-  if (can_peephole_optimize(2) &&
-      // Pattern.
-      instr_at(pc_ - 1 * kInstrSize) == kPopInstruction &&
-      (instr_at(pc_ - 2 * kInstrSize) & ~kRdMask) == kPushRegPattern) {
-    pc_ -= 2 * kInstrSize;
-    if (FLAG_print_peephole_optimization) {
-      PrintF("%x push(reg)/pop() eliminated\n", pc_offset());
-    }
-  }
 }
 
 
 void Assembler::adc(Register dst, Register src1, const Operand& src2,
                     SBit s, Condition cond) {
   addrmod1(cond | ADC | s, src1, dst, src2);
 }
 
 
 void Assembler::sbc(Register dst, Register src1, const Operand& src2,
@@ skipping 284 matching lines @@
   emit(cond | instr | B24 | B21 | fields | 15*B12);
 }
 
 
 // Load/Store instructions.
 void Assembler::ldr(Register dst, const MemOperand& src, Condition cond) {
   if (dst.is(pc)) {
     positions_recorder()->WriteRecordedPositions();
   }
   addrmod2(cond | B26 | L, dst, src);
-
-  // Eliminate pattern: push(ry), pop(rx)
-  //   str(ry, MemOperand(sp, 4, NegPreIndex), al)
-  //   ldr(rx, MemOperand(sp, 4, PostIndex), al)
-  // Both instructions can be eliminated if ry = rx.
-  // If ry != rx, a register copy from ry to rx is inserted
-  // after eliminating the push and the pop instructions.
-  if (can_peephole_optimize(2)) {
-    Instr push_instr = instr_at(pc_ - 2 * kInstrSize);
-    Instr pop_instr = instr_at(pc_ - 1 * kInstrSize);
-
-    if (IsPush(push_instr) && IsPop(pop_instr)) {
-      if (Instruction::RdValue(pop_instr) != Instruction::RdValue(push_instr)) {
-        // For consecutive push and pop on different registers,
-        // we delete both the push & pop and insert a register move.
-        // push ry, pop rx --> mov rx, ry
-        Register reg_pushed, reg_popped;
-        reg_pushed = GetRd(push_instr);
-        reg_popped = GetRd(pop_instr);
-        pc_ -= 2 * kInstrSize;
-        // Insert a mov instruction, which is better than a pair of push & pop
-        mov(reg_popped, reg_pushed);
-        if (FLAG_print_peephole_optimization) {
-          PrintF("%x push/pop (diff reg) replaced by a reg move\n",
-                 pc_offset());
-        }
-      } else {
-        // For consecutive push and pop on the same register,
-        // both the push and the pop can be deleted.
-        pc_ -= 2 * kInstrSize;
-        if (FLAG_print_peephole_optimization) {
-          PrintF("%x push/pop (same reg) eliminated\n", pc_offset());
-        }
-      }
-    }
-  }
-
-  if (can_peephole_optimize(2)) {
-    Instr str_instr = instr_at(pc_ - 2 * kInstrSize);
-    Instr ldr_instr = instr_at(pc_ - 1 * kInstrSize);
-
-    if ((IsStrRegFpOffset(str_instr) &&
-         IsLdrRegFpOffset(ldr_instr)) ||
-       (IsStrRegFpNegOffset(str_instr) &&
-         IsLdrRegFpNegOffset(ldr_instr))) {
-      if ((ldr_instr & kLdrStrInstrArgumentMask) ==
-            (str_instr & kLdrStrInstrArgumentMask)) {
-        // Pattern: Ldr/str same fp+offset, same register.
-        //
-        // The following:
-        // str rx, [fp, #-12]
-        // ldr rx, [fp, #-12]
-        //
-        // Becomes:
-        // str rx, [fp, #-12]
-
-        pc_ -= 1 * kInstrSize;
-        if (FLAG_print_peephole_optimization) {
-          PrintF("%x str/ldr (fp + same offset), same reg\n", pc_offset());
-        }
-      } else if ((ldr_instr & kLdrStrOffsetMask) ==
-                 (str_instr & kLdrStrOffsetMask)) {
-        // Pattern: Ldr/str same fp+offset, different register.
-        //
-        // The following:
-        // str rx, [fp, #-12]
-        // ldr ry, [fp, #-12]
-        //
-        // Becomes:
-        // str rx, [fp, #-12]
-        // mov ry, rx
-
-        Register reg_stored, reg_loaded;
-        reg_stored = GetRd(str_instr);
-        reg_loaded = GetRd(ldr_instr);
-        pc_ -= 1 * kInstrSize;
-        // Insert a mov instruction, which is better than ldr.
-        mov(reg_loaded, reg_stored);
-        if (FLAG_print_peephole_optimization) {
-          PrintF("%x str/ldr (fp + same offset), diff reg \n", pc_offset());
-        }
-      }
-    }
-  }
-
-  if (can_peephole_optimize(3)) {
-    Instr mem_write_instr = instr_at(pc_ - 3 * kInstrSize);
-    Instr ldr_instr = instr_at(pc_ - 2 * kInstrSize);
-    Instr mem_read_instr = instr_at(pc_ - 1 * kInstrSize);
-    if (IsPush(mem_write_instr) &&
-        IsPop(mem_read_instr)) {
-      if ((IsLdrRegFpOffset(ldr_instr) ||
-        IsLdrRegFpNegOffset(ldr_instr))) {
-        if (Instruction::RdValue(mem_write_instr) ==
-                                  Instruction::RdValue(mem_read_instr)) {
-          // Pattern: push & pop from/to same register,
-          // with a fp+offset ldr in between
-          //
-          // The following:
-          // str rx, [sp, #-4]!
-          // ldr rz, [fp, #-24]
-          // ldr rx, [sp], #+4
-          //
-          // Becomes:
-          // if(rx == rz)
-          //   delete all
-          // else
-          //   ldr rz, [fp, #-24]
-
-          if (Instruction::RdValue(mem_write_instr) ==
-              Instruction::RdValue(ldr_instr)) {
-            pc_ -= 3 * kInstrSize;
-          } else {
-            pc_ -= 3 * kInstrSize;
-            // Reinsert back the ldr rz.
-            emit(ldr_instr);
-          }
-          if (FLAG_print_peephole_optimization) {
-            PrintF("%x push/pop -dead ldr fp+offset in middle\n", pc_offset());
-          }
-        } else {
-          // Pattern: push & pop from/to different registers
-          // with a fp+offset ldr in between
-          //
-          // The following:
-          // str rx, [sp, #-4]!
-          // ldr rz, [fp, #-24]
-          // ldr ry, [sp], #+4
-          //
-          // Becomes:
-          // if(ry == rz)
-          //   mov ry, rx;
-          // else if(rx != rz)
-          //   ldr rz, [fp, #-24]
-          //   mov ry, rx
-          // else if((ry != rz) || (rx == rz)) becomes:
-          //   mov ry, rx
-          //   ldr rz, [fp, #-24]
-
-          Register reg_pushed, reg_popped;
-          if (Instruction::RdValue(mem_read_instr) ==
-              Instruction::RdValue(ldr_instr)) {
-            reg_pushed = GetRd(mem_write_instr);
-            reg_popped = GetRd(mem_read_instr);
-            pc_ -= 3 * kInstrSize;
-            mov(reg_popped, reg_pushed);
-          } else if (Instruction::RdValue(mem_write_instr) !=
-                     Instruction::RdValue(ldr_instr)) {
-            reg_pushed = GetRd(mem_write_instr);
-            reg_popped = GetRd(mem_read_instr);
-            pc_ -= 3 * kInstrSize;
-            emit(ldr_instr);
-            mov(reg_popped, reg_pushed);
-          } else if ((Instruction::RdValue(mem_read_instr) !=
-                      Instruction::RdValue(ldr_instr)) ||
-                     (Instruction::RdValue(mem_write_instr) ==
-                      Instruction::RdValue(ldr_instr))) {
-            reg_pushed = GetRd(mem_write_instr);
-            reg_popped = GetRd(mem_read_instr);
-            pc_ -= 3 * kInstrSize;
-            mov(reg_popped, reg_pushed);
-            emit(ldr_instr);
-          }
-          if (FLAG_print_peephole_optimization) {
-            PrintF("%x push/pop (ldr fp+off in middle)\n", pc_offset());
-          }
-        }
-      }
-    }
-  }
 }
 
 
 void Assembler::str(Register src, const MemOperand& dst, Condition cond) {
   addrmod2(cond | B26, src, dst);
-
-  // Eliminate pattern: pop(), push(r)
-  //     add sp, sp, #4 LeaveCC, al; str r, [sp, #-4], al
-  // ->  str r, [sp, 0], al
-  if (can_peephole_optimize(2) &&
-     // Pattern.
-     instr_at(pc_ - 1 * kInstrSize) == (kPushRegPattern | src.code() * B12) &&
-     instr_at(pc_ - 2 * kInstrSize) == kPopInstruction) {
-    pc_ -= 2 * kInstrSize;
-    emit(al | B26 | 0 | Offset | sp.code() * B16 | src.code() * B12);
-    if (FLAG_print_peephole_optimization) {
-      PrintF("%x pop()/push(reg) eliminated\n", pc_offset());
-    }
-  }
 }
 
 
 void Assembler::ldrb(Register dst, const MemOperand& src, Condition cond) {
   addrmod2(cond | B26 | B | L, dst, src);
 }
 
 
 void Assembler::strb(Register src, const MemOperand& dst, Condition cond) {
   addrmod2(cond | B26 | B, src, dst);
@@ skipping 1236 matching lines @@
 
   // Since a constant pool was just emitted, move the check offset forward by
   // the standard interval.
   next_buffer_check_ = pc_offset() + kCheckConstInterval;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM