jdk8-mips64-public/hotspot: src/cpu/x86/vm/nativeInst

src/cpu/x86/vm/nativeInst_x86.cpp@f3de1255b035 (annotated)

src/cpu/x86/vm/nativeInst_x86.cpp

Wed, 07 May 2008 08:06:46 -0700

author: rasbold
date: Wed, 07 May 2008 08:06:46 -0700
changeset 580: f3de1255b035
parent 551: 018d5b58dd4f
child 631: d1605aabd0a1
permissions: -rw-r--r--

6603011: RFE: Optimize long division
Summary: Transform long division by constant into multiply
Reviewed-by: never, kvn

 /*
  * Copyright 1997-2007 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  * CA 95054 USA or visit www.sun.com if you need additional information or
  * have any questions.
  *
  */
 # include "incls/_precompiled.incl"
 # include "incls/_nativeInst_x86.cpp.incl"
 void NativeInstruction::wrote(int offset) {
   ICache::invalidate_word(addr_at(offset));
 }
 void NativeCall::verify() {
   // Make sure code pattern is actually a call imm32 instruction.
   int inst = ubyte_at(0);
   if (inst != instruction_code) {
     tty->print_cr("Addr: " INTPTR_FORMAT " Code: 0x%x", instruction_address(),
                                                         inst);
     fatal("not a call disp32");
   }
 }
 address NativeCall::destination() const {
   // Getting the destination of a call isn't safe because that call can
   // be getting patched while you're calling this.  There's only special
   // places where this can be called but not automatically verifiable by
   // checking which locks are held.  The solution is true atomic patching
   // on x86, nyi.
   return return_address() + displacement();
 }
 void NativeCall::print() {
   tty->print_cr(PTR_FORMAT ": call " PTR_FORMAT,
                 instruction_address(), destination());
 }
 // Inserts a native call instruction at a given pc
 void NativeCall::insert(address code_pos, address entry) {
   intptr_t disp = (intptr_t)entry - ((intptr_t)code_pos + 1 + 4);
 #ifdef AMD64
   guarantee(disp == (intptr_t)(jint)disp, "must be 32-bit offset");
 #endif // AMD64
   *code_pos = instruction_code;
   *((int32_t *)(code_pos+1)) = (int32_t) disp;
   ICache::invalidate_range(code_pos, instruction_size);
 }
 // MT-safe patching of a call instruction.
 // First patches first word of instruction to two jmp's that jmps to them
 // selfs (spinlock). Then patches the last byte, and then atomicly replaces
 // the jmp's with the first 4 byte of the new instruction.
 void NativeCall::replace_mt_safe(address instr_addr, address code_buffer) {
   assert(Patching_lock->is_locked() ||
          SafepointSynchronize::is_at_safepoint(), "concurrent code patching");
   assert (instr_addr != NULL, "illegal address for code patching");
   NativeCall* n_call =  nativeCall_at (instr_addr); // checking that it is a call
   if (os::is_MP()) {
     guarantee((intptr_t)instr_addr % BytesPerWord == 0, "must be aligned");
   }
   // First patch dummy jmp in place
   unsigned char patch[4];
   assert(sizeof(patch)==sizeof(jint), "sanity check");
   patch[0] = 0xEB;       // jmp rel8
   patch[1] = 0xFE;       // jmp to self
   patch[2] = 0xEB;
   patch[3] = 0xFE;
   // First patch dummy jmp in place
   *(jint*)instr_addr = *(jint *)patch;
   // Invalidate.  Opteron requires a flush after every write.
   n_call->wrote(0);
   // Patch 4th byte
   instr_addr[4] = code_buffer[4];
   n_call->wrote(4);
   // Patch bytes 0-3
   *(jint*)instr_addr = *(jint *)code_buffer;
   n_call->wrote(0);
 #ifdef ASSERT
    // verify patching
    for ( int i = 0; i < instruction_size; i++) {
      address ptr = (address)((intptr_t)code_buffer + i);
      int a_byte = (*ptr) & 0xFF;
      assert(*((address)((intptr_t)instr_addr + i)) == a_byte, "mt safe patching failed");
    }
 #endif
 }
 // Similar to replace_mt_safe, but just changes the destination.  The
 // important thing is that free-running threads are able to execute this
 // call instruction at all times.  If the displacement field is aligned
 // we can simply rely on atomicity of 32-bit writes to make sure other threads
 // will see no intermediate states.  Otherwise, the first two bytes of the
 // call are guaranteed to be aligned, and can be atomically patched to a
 // self-loop to guard the instruction while we change the other bytes.
 // We cannot rely on locks here, since the free-running threads must run at
 // full speed.
 //
 // Used in the runtime linkage of calls; see class CompiledIC.
 // (Cf. 4506997 and 4479829, where threads witnessed garbage displacements.)
 void NativeCall::set_destination_mt_safe(address dest) {
   debug_only(verify());
   // Make sure patching code is locked.  No two threads can patch at the same
   // time but one may be executing this code.
   assert(Patching_lock->is_locked() ||
          SafepointSynchronize::is_at_safepoint(), "concurrent code patching");
   // Both C1 and C2 should now be generating code which aligns the patched address
   // to be within a single cache line except that C1 does not do the alignment on
   // uniprocessor systems.
   bool is_aligned = ((uintptr_t)displacement_address() + 0) / cache_line_size ==
                     ((uintptr_t)displacement_address() + 3) / cache_line_size;
   guarantee(!os::is_MP() || is_aligned, "destination must be aligned");
   if (is_aligned) {
     // Simple case:  The destination lies within a single cache line.
     set_destination(dest);
   } else if ((uintptr_t)instruction_address() / cache_line_size ==
              ((uintptr_t)instruction_address()+1) / cache_line_size) {
     // Tricky case:  The instruction prefix lies within a single cache line.
     intptr_t disp = dest - return_address();
 #ifdef AMD64
     guarantee(disp == (intptr_t)(jint)disp, "must be 32-bit offset");
 #endif // AMD64
     int call_opcode = instruction_address()[0];
     // First patch dummy jump in place:
     {
       u_char patch_jump[2];
       patch_jump[0] = 0xEB;       // jmp rel8
       patch_jump[1] = 0xFE;       // jmp to self
       assert(sizeof(patch_jump)==sizeof(short), "sanity check");
       *(short*)instruction_address() = *(short*)patch_jump;
     }
     // Invalidate.  Opteron requires a flush after every write.
     wrote(0);
     // (Note: We assume any reader which has already started to read
     // the unpatched call will completely read the whole unpatched call
     // without seeing the next writes we are about to make.)
     // Next, patch the last three bytes:
     u_char patch_disp[5];
     patch_disp[0] = call_opcode;
     *(int32_t*)&patch_disp[1] = (int32_t)disp;
     assert(sizeof(patch_disp)==instruction_size, "sanity check");
     for (int i = sizeof(short); i < instruction_size; i++)
       instruction_address()[i] = patch_disp[i];
     // Invalidate.  Opteron requires a flush after every write.
     wrote(sizeof(short));
     // (Note: We assume that any reader which reads the opcode we are
     // about to repatch will also read the writes we just made.)
     // Finally, overwrite the jump:
     *(short*)instruction_address() = *(short*)patch_disp;
     // Invalidate.  Opteron requires a flush after every write.
     wrote(0);
     debug_only(verify());
     guarantee(destination() == dest, "patch succeeded");
   } else {
     // Impossible:  One or the other must be atomically writable.
     ShouldNotReachHere();
   }
 }
 void NativeMovConstReg::verify() {
 #ifdef AMD64
   // make sure code pattern is actually a mov reg64, imm64 instruction
   if ((ubyte_at(0) != Assembler::REX_W && ubyte_at(0) != Assembler::REX_WB) ||
       (ubyte_at(1) & (0xff ^ register_mask)) != 0xB8) {
     print();
     fatal("not a REX.W[B] mov reg64, imm64");
   }
 #else
   // make sure code pattern is actually a mov reg, imm32 instruction
   u_char test_byte = *(u_char*)instruction_address();
   u_char test_byte_2 = test_byte & ( 0xff ^ register_mask);
   if (test_byte_2 != instruction_code) fatal("not a mov reg, imm32");
 #endif // AMD64
 }
 void NativeMovConstReg::print() {
   tty->print_cr(PTR_FORMAT ": mov reg, " INTPTR_FORMAT,
                 instruction_address(), data());
 }
 //-------------------------------------------------------------------
 #ifndef AMD64
 void NativeMovRegMem::copy_instruction_to(address new_instruction_address) {
   int inst_size = instruction_size;
   // See if there's an instruction size prefix override.
   if ( *(address(this))   == instruction_operandsize_prefix &&
        *(address(this)+1) != instruction_code_xmm_code ) { // Not SSE instr
     inst_size += 1;
   }
   if ( *(address(this)) == instruction_extended_prefix ) inst_size += 1;
   for (int i = 0; i < instruction_size; i++) {
     *(new_instruction_address + i) = *(address(this) + i);
   }
 }
 void NativeMovRegMem::verify() {
   // make sure code pattern is actually a mov [reg+offset], reg instruction
   u_char test_byte = *(u_char*)instruction_address();
   if ( ! ( (test_byte == instruction_code_reg2memb)
       || (test_byte == instruction_code_mem2regb)
       || (test_byte == instruction_code_mem2regl)
       || (test_byte == instruction_code_reg2meml)
       || (test_byte == instruction_code_mem2reg_movzxb )
       || (test_byte == instruction_code_mem2reg_movzxw )
       || (test_byte == instruction_code_mem2reg_movsxb )
       || (test_byte == instruction_code_mem2reg_movsxw )
       || (test_byte == instruction_code_float_s)
       || (test_byte == instruction_code_float_d)
       || (test_byte == instruction_code_long_volatile) ) )
   {
     u_char byte1 = ((u_char*)instruction_address())[1];
     u_char byte2 = ((u_char*)instruction_address())[2];
     if ((test_byte != instruction_code_xmm_ss_prefix &&
          test_byte != instruction_code_xmm_sd_prefix &&
          test_byte != instruction_operandsize_prefix) ||
         byte1 != instruction_code_xmm_code ||
         (byte2 != instruction_code_xmm_load &&
          byte2 != instruction_code_xmm_lpd  &&
          byte2 != instruction_code_xmm_store)) {
           fatal ("not a mov [reg+offs], reg instruction");
     }
   }
 }
 void NativeMovRegMem::print() {
   tty->print_cr("0x%x: mov reg, [reg + %x]", instruction_address(), offset());
 }
 //-------------------------------------------------------------------
 void NativeLoadAddress::verify() {
   // make sure code pattern is actually a mov [reg+offset], reg instruction
   u_char test_byte = *(u_char*)instruction_address();
   if ( ! (test_byte == instruction_code) ) {
     fatal ("not a lea reg, [reg+offs] instruction");
   }
 }
 void NativeLoadAddress::print() {
   tty->print_cr("0x%x: lea [reg + %x], reg", instruction_address(), offset());
 }
 #endif // !AMD64
 //--------------------------------------------------------------------------------
 void NativeJump::verify() {
   if (*(u_char*)instruction_address() != instruction_code) {
     fatal("not a jump instruction");
   }
 }
 void NativeJump::insert(address code_pos, address entry) {
   intptr_t disp = (intptr_t)entry - ((intptr_t)code_pos + 1 + 4);
 #ifdef AMD64
   guarantee(disp == (intptr_t)(int32_t)disp, "must be 32-bit offset");
 #endif // AMD64
   *code_pos = instruction_code;
   *((int32_t*)(code_pos + 1)) = (int32_t)disp;
   ICache::invalidate_range(code_pos, instruction_size);
 }
 void NativeJump::check_verified_entry_alignment(address entry, address verified_entry) {
   // Patching to not_entrant can happen while activations of the method are
   // in use. The patching in that instance must happen only when certain
   // alignment restrictions are true. These guarantees check those
   // conditions.
 #ifdef AMD64
   const int linesize = 64;
 #else
   const int linesize = 32;
 #endif // AMD64
   // Must be wordSize aligned
   guarantee(((uintptr_t) verified_entry & (wordSize -1)) == 0,
             "illegal address for code patching 2");
   // First 5 bytes must be within the same cache line - 4827828
   guarantee((uintptr_t) verified_entry / linesize ==
             ((uintptr_t) verified_entry + 4) / linesize,
             "illegal address for code patching 3");
 }
 // MT safe inserting of a jump over an unknown instruction sequence (used by nmethod::makeZombie)
 // The problem: jmp <dest> is a 5-byte instruction. Atomical write can be only with 4 bytes.
 // First patches the first word atomically to be a jump to itself.
 // Then patches the last byte  and then atomically patches the first word (4-bytes),
 // thus inserting the desired jump
 // This code is mt-safe with the following conditions: entry point is 4 byte aligned,
 // entry point is in same cache line as unverified entry point, and the instruction being
 // patched is >= 5 byte (size of patch).
 //
 // In C2 the 5+ byte sized instruction is enforced by code in MachPrologNode::emit.
 // In C1 the restriction is enforced by CodeEmitter::method_entry
 //
 void NativeJump::patch_verified_entry(address entry, address verified_entry, address dest) {
   // complete jump instruction (to be inserted) is in code_buffer;
   unsigned char code_buffer[5];
   code_buffer[0] = instruction_code;
   intptr_t disp = (intptr_t)dest - ((intptr_t)verified_entry + 1 + 4);
 #ifdef AMD64
   guarantee(disp == (intptr_t)(int32_t)disp, "must be 32-bit offset");
 #endif // AMD64
   *(int32_t*)(code_buffer + 1) = (int32_t)disp;
   check_verified_entry_alignment(entry, verified_entry);
   // Can't call nativeJump_at() because it's asserts jump exists
   NativeJump* n_jump = (NativeJump*) verified_entry;
   //First patch dummy jmp in place
   unsigned char patch[4];
   assert(sizeof(patch)==sizeof(int32_t), "sanity check");
   patch[0] = 0xEB;       // jmp rel8
   patch[1] = 0xFE;       // jmp to self
   patch[2] = 0xEB;
   patch[3] = 0xFE;
   // First patch dummy jmp in place
   *(int32_t*)verified_entry = *(int32_t *)patch;
   n_jump->wrote(0);
   // Patch 5th byte (from jump instruction)
   verified_entry[4] = code_buffer[4];
   n_jump->wrote(4);
   // Patch bytes 0-3 (from jump instruction)
   *(int32_t*)verified_entry = *(int32_t *)code_buffer;
   // Invalidate.  Opteron requires a flush after every write.
   n_jump->wrote(0);
 }
 void NativePopReg::insert(address code_pos, Register reg) {
   assert(reg->encoding() < 8, "no space for REX");
   assert(NativePopReg::instruction_size == sizeof(char), "right address unit for update");
   *code_pos = (u_char)(instruction_code | reg->encoding());
   ICache::invalidate_range(code_pos, instruction_size);
 }
 void NativeIllegalInstruction::insert(address code_pos) {
   assert(NativeIllegalInstruction::instruction_size == sizeof(short), "right address unit for update");
   *(short *)code_pos = instruction_code;
   ICache::invalidate_range(code_pos, instruction_size);
 }
 void NativeGeneralJump::verify() {
   assert(((NativeInstruction *)this)->is_jump() ||
          ((NativeInstruction *)this)->is_cond_jump(), "not a general jump instruction");
 }
 void NativeGeneralJump::insert_unconditional(address code_pos, address entry) {
   intptr_t disp = (intptr_t)entry - ((intptr_t)code_pos + 1 + 4);
 #ifdef AMD64
   guarantee(disp == (intptr_t)(int32_t)disp, "must be 32-bit offset");
 #endif // AMD64
   *code_pos = unconditional_long_jump;
   *((int32_t *)(code_pos+1)) = (int32_t) disp;
   ICache::invalidate_range(code_pos, instruction_size);
 }
 // MT-safe patching of a long jump instruction.
 // First patches first word of instruction to two jmp's that jmps to them
 // selfs (spinlock). Then patches the last byte, and then atomicly replaces
 // the jmp's with the first 4 byte of the new instruction.
 void NativeGeneralJump::replace_mt_safe(address instr_addr, address code_buffer) {
    assert (instr_addr != NULL, "illegal address for code patching (4)");
    NativeGeneralJump* n_jump =  nativeGeneralJump_at (instr_addr); // checking that it is a jump
    // Temporary code
    unsigned char patch[4];
    assert(sizeof(patch)==sizeof(int32_t), "sanity check");
    patch[0] = 0xEB;       // jmp rel8
    patch[1] = 0xFE;       // jmp to self
    patch[2] = 0xEB;
    patch[3] = 0xFE;
    // First patch dummy jmp in place
    *(int32_t*)instr_addr = *(int32_t *)patch;
     n_jump->wrote(0);
    // Patch 4th byte
    instr_addr[4] = code_buffer[4];
     n_jump->wrote(4);
    // Patch bytes 0-3
    *(jint*)instr_addr = *(jint *)code_buffer;
     n_jump->wrote(0);
 #ifdef ASSERT
    // verify patching
    for ( int i = 0; i < instruction_size; i++) {
      address ptr = (address)((intptr_t)code_buffer + i);
      int a_byte = (*ptr) & 0xFF;
      assert(*((address)((intptr_t)instr_addr + i)) == a_byte, "mt safe patching failed");
    }
 #endif
 }
 address NativeGeneralJump::jump_destination() const {
   int op_code = ubyte_at(0);
   bool is_rel32off = (op_code == 0xE9 || op_code == 0x0F);
   int  offset  = (op_code == 0x0F)  ? 2 : 1;
   int  length  = offset + ((is_rel32off) ? 4 : 1);
   if (is_rel32off)
     return addr_at(0) + length + int_at(offset);
   else
     return addr_at(0) + length + sbyte_at(offset);
 }
 bool NativeInstruction::is_dtrace_trap() {
   return (*(int32_t*)this & 0xff) == 0xcc;
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/cpu/x86/vm/nativeInst_x86.cpp@f3de1255b035 (annotated)

src/cpu/x86/vm/nativeInst_x86.cpp