assembler/MacroAssemblerARM.cpp

   1 /*
   2  * Copyright (C) 2009 University of Szeged
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY UNIVERSITY OF SZEGED ``AS IS'' AND ANY
  15  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  17  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL UNIVERSITY OF SZEGED OR
  18  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  19  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  20  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  21  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  22  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  24  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 #include "config.h"
  28
  29 #if ENABLE(ASSEMBLER) && CPU(ARM_TRADITIONAL)
  30
  31 #include "MacroAssemblerARM.h"
  32
  33 #if OS(LINUX)
  34 #include <sys/types.h>
  35 #include <sys/stat.h>
  36 #include <fcntl.h>
  37 #include <unistd.h>
  38 #include <elf.h>
  39 #include <asm/hwcap.h>
  40 #endif
  41
  42 namespace JSC {
  43
  44 static bool isVFPPresent()
  45 {
  46 #if OS(LINUX)
  47     int fd = open("/proc/self/auxv", O_RDONLY);
  48     if (fd > 0) {
  49         Elf32_auxv_t aux;
  50         while (read(fd, &aux, sizeof(Elf32_auxv_t))) {
  51             if (aux.a_type == AT_HWCAP) {
  52                 close(fd);
  53                 return aux.a_un.a_val & HWCAP_VFP;
  54             }
  55         }
  56         close(fd);
  57     }
  58 #endif
  59
  60     return false;
  61 }
  62
  63 const bool MacroAssemblerARM::s_isVFPPresent = isVFPPresent();
  64
  65 #if CPU(ARMV5_OR_LOWER)
  66 /* On ARMv5 and below, natural alignment is required. */
  67 void MacroAssemblerARM::load32WithUnalignedHalfWords(BaseIndex address, RegisterID dest)
  68 {
  69     ARMWord op2;
  70
  71     ASSERT(address.scale >= 0 && address.scale <= 3);
  72     op2 = m_assembler.lsl(address.index, static_cast<int>(address.scale));
  73
  74     if (address.offset >= 0 && address.offset + 0x2 <= 0xff) {
  75         m_assembler.add_r(ARMRegisters::S0, address.base, op2);
  76         m_assembler.ldrh_u(dest, ARMRegisters::S0, ARMAssembler::getOp2Byte(address.offset));
  77         m_assembler.ldrh_u(ARMRegisters::S0, ARMRegisters::S0, ARMAssembler::getOp2Byte(address.offset + 0x2));
  78     } else if (address.offset < 0 && address.offset >= -0xff) {
  79         m_assembler.add_r(ARMRegisters::S0, address.base, op2);
  80         m_assembler.ldrh_d(dest, ARMRegisters::S0, ARMAssembler::getOp2Byte(-address.offset));
  81         m_assembler.ldrh_d(ARMRegisters::S0, ARMRegisters::S0, ARMAssembler::getOp2Byte(-address.offset - 0x2));
  82     } else {
  83         m_assembler.ldr_un_imm(ARMRegisters::S0, address.offset);
  84         m_assembler.add_r(ARMRegisters::S0, ARMRegisters::S0, op2);
  85         m_assembler.ldrh_r(dest, address.base, ARMRegisters::S0);
  86         m_assembler.add_r(ARMRegisters::S0, ARMRegisters::S0, ARMAssembler::OP2_IMM | 0x2);
  87         m_assembler.ldrh_r(ARMRegisters::S0, address.base, ARMRegisters::S0);
  88     }
  89     m_assembler.orr_r(dest, dest, m_assembler.lsl(ARMRegisters::S0, 16));
  90 }
  91 #endif
  92
  93 }
  94
  95 #endif // ENABLE(ASSEMBLER) && CPU(ARM_TRADITIONAL)