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      1 /* libs/pixelflinger/codeflinger/ARMAssemblerInterface.cpp
      2 **
      3 ** Copyright 2006, The Android Open Source Project
      4 **
      5 ** Licensed under the Apache License, Version 2.0 (the "License");
      6 ** you may not use this file except in compliance with the License.
      7 ** You may obtain a copy of the License at
      8 **
      9 **     http://www.apache.org/licenses/LICENSE-2.0
     10 **
     11 ** Unless required by applicable law or agreed to in writing, software
     12 ** distributed under the License is distributed on an "AS IS" BASIS,
     13 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     14 ** See the License for the specific language governing permissions and
     15 ** limitations under the License.
     16 */
     17 
     18 
     19 #include <errno.h>
     20 #include <stdlib.h>
     21 #include <stdint.h>
     22 #include <sys/types.h>
     23 
     24 #include <cutils/log.h>
     25 #include "codeflinger/ARMAssemblerInterface.h"
     26 
     27 namespace android {
     28 
     29 // ----------------------------------------------------------------------------
     30 
     31 ARMAssemblerInterface::~ARMAssemblerInterface()
     32 {
     33 }
     34 
     35 int ARMAssemblerInterface::buildImmediate(
     36         uint32_t immediate, uint32_t& rot, uint32_t& imm)
     37 {
     38     rot = 0;
     39     imm = immediate;
     40     if (imm > 0x7F) { // skip the easy cases
     41         while (!(imm&3)  || (imm&0xFC000000)) {
     42             uint32_t newval;
     43             newval = imm >> 2;
     44             newval |= (imm&3) << 30;
     45             imm = newval;
     46             rot += 2;
     47             if (rot == 32) {
     48                 rot = 0;
     49                 break;
     50             }
     51         }
     52     }
     53     rot = (16 - (rot>>1)) & 0xF;
     54 
     55     if (imm>=0x100)
     56         return -EINVAL;
     57 
     58     if (((imm>>(rot<<1)) | (imm<<(32-(rot<<1)))) != immediate)
     59         return -1;
     60 
     61     return 0;
     62 }
     63 
     64 // shifters...
     65 
     66 bool ARMAssemblerInterface::isValidImmediate(uint32_t immediate)
     67 {
     68     uint32_t rot, imm;
     69     return buildImmediate(immediate, rot, imm) == 0;
     70 }
     71 
     72 uint32_t ARMAssemblerInterface::imm(uint32_t immediate)
     73 {
     74     uint32_t rot, imm;
     75     int err = buildImmediate(immediate, rot, imm);
     76 
     77     LOG_ALWAYS_FATAL_IF(err==-EINVAL,
     78                         "immediate %08x cannot be encoded",
     79                         immediate);
     80 
     81     LOG_ALWAYS_FATAL_IF(err,
     82                         "immediate (%08x) encoding bogus!",
     83                         immediate);
     84 
     85     return (1<<25) | (rot<<8) | imm;
     86 }
     87 
     88 uint32_t ARMAssemblerInterface::reg_imm(int Rm, int type, uint32_t shift)
     89 {
     90     return ((shift&0x1F)<<7) | ((type&0x3)<<5) | (Rm&0xF);
     91 }
     92 
     93 uint32_t ARMAssemblerInterface::reg_rrx(int Rm)
     94 {
     95     return (ROR<<5) | (Rm&0xF);
     96 }
     97 
     98 uint32_t ARMAssemblerInterface::reg_reg(int Rm, int type, int Rs)
     99 {
    100     return ((Rs&0xF)<<8) | ((type&0x3)<<5) | (1<<4) | (Rm&0xF);
    101 }
    102 
    103 // addressing modes...
    104 // LDR(B)/STR(B)/PLD (immediate and Rm can be negative, which indicate U=0)
    105 uint32_t ARMAssemblerInterface::immed12_pre(int32_t immed12, int W)
    106 {
    107     LOG_ALWAYS_FATAL_IF(abs(immed12) >= 0x800,
    108                         "LDR(B)/STR(B)/PLD immediate too big (%08x)",
    109                         immed12);
    110     return (1<<24) | (((uint32_t(immed12)>>31)^1)<<23) |
    111             ((W&1)<<21) | (abs(immed12)&0x7FF);
    112 }
    113 
    114 uint32_t ARMAssemblerInterface::immed12_post(int32_t immed12)
    115 {
    116     LOG_ALWAYS_FATAL_IF(abs(immed12) >= 0x800,
    117                         "LDR(B)/STR(B)/PLD immediate too big (%08x)",
    118                         immed12);
    119 
    120     return (((uint32_t(immed12)>>31)^1)<<23) | (abs(immed12)&0x7FF);
    121 }
    122 
    123 uint32_t ARMAssemblerInterface::reg_scale_pre(int Rm, int type,
    124         uint32_t shift, int W)
    125 {
    126     return  (1<<25) | (1<<24) |
    127             (((uint32_t(Rm)>>31)^1)<<23) | ((W&1)<<21) |
    128             reg_imm(abs(Rm), type, shift);
    129 }
    130 
    131 uint32_t ARMAssemblerInterface::reg_scale_post(int Rm, int type, uint32_t shift)
    132 {
    133     return (1<<25) | (((uint32_t(Rm)>>31)^1)<<23) | reg_imm(abs(Rm), type, shift);
    134 }
    135 
    136 // LDRH/LDRSB/LDRSH/STRH (immediate and Rm can be negative, which indicate U=0)
    137 uint32_t ARMAssemblerInterface::immed8_pre(int32_t immed8, int W)
    138 {
    139     uint32_t offset = abs(immed8);
    140 
    141     LOG_ALWAYS_FATAL_IF(abs(immed8) >= 0x100,
    142                         "LDRH/LDRSB/LDRSH/STRH immediate too big (%08x)",
    143                         immed8);
    144 
    145     return  (1<<24) | (1<<22) | (((uint32_t(immed8)>>31)^1)<<23) |
    146             ((W&1)<<21) | (((offset&0xF0)<<4)|(offset&0xF));
    147 }
    148 
    149 uint32_t ARMAssemblerInterface::immed8_post(int32_t immed8)
    150 {
    151     uint32_t offset = abs(immed8);
    152 
    153     LOG_ALWAYS_FATAL_IF(abs(immed8) >= 0x100,
    154                         "LDRH/LDRSB/LDRSH/STRH immediate too big (%08x)",
    155                         immed8);
    156 
    157     return (1<<22) | (((uint32_t(immed8)>>31)^1)<<23) |
    158             (((offset&0xF0)<<4) | (offset&0xF));
    159 }
    160 
    161 uint32_t ARMAssemblerInterface::reg_pre(int Rm, int W)
    162 {
    163     return (1<<24) | (((uint32_t(Rm)>>31)^1)<<23) | ((W&1)<<21) | (abs(Rm)&0xF);
    164 }
    165 
    166 uint32_t ARMAssemblerInterface::reg_post(int Rm)
    167 {
    168     return (((uint32_t(Rm)>>31)^1)<<23) | (abs(Rm)&0xF);
    169 }
    170 
    171 
    172 }; // namespace android
    173 
    174