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      1 /*
      2  * Copyright (C) 2009 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 /*
     18  * This file contains codegen and support common to all supported
     19  * ARM variants.  It is included by:
     20  *
     21  *        Codegen-$(TARGET_ARCH_VARIANT).c
     22  *
     23  * which combines this common code with specific support found in the
     24  * applicable directory below this one.
     25  */
     26 
     27 #include "compiler/Loop.h"
     28 
     29 /* Array holding the entry offset of each template relative to the first one */
     30 static intptr_t templateEntryOffsets[TEMPLATE_LAST_MARK];
     31 
     32 /* Track exercised opcodes */
     33 static int opcodeCoverage[256];
     34 
     35 static void setMemRefType(ArmLIR *lir, bool isLoad, int memType)
     36 {
     37     u8 *maskPtr;
     38     u8 mask;
     39     assert( EncodingMap[lir->opCode].flags & (IS_LOAD | IS_STORE));
     40     if (isLoad) {
     41         maskPtr = &lir->useMask;
     42         mask = ENCODE_MEM_USE;
     43     } else {
     44         maskPtr = &lir->defMask;
     45         mask = ENCODE_MEM_DEF;
     46     }
     47     /* Clear out the memref flags */
     48     *maskPtr &= ~mask;
     49     /* ..and then add back the one we need */
     50     switch(memType) {
     51         case kLiteral:
     52             assert(isLoad);
     53             *maskPtr |= (ENCODE_LITERAL | ENCODE_LITPOOL_REF);
     54             break;
     55         case kDalvikReg:
     56             *maskPtr |= (ENCODE_DALVIK_REG | ENCODE_FRAME_REF);
     57             break;
     58         case kHeapRef:
     59             *maskPtr |= ENCODE_HEAP_REF;
     60             break;
     61         default:
     62             LOGE("Jit: invalid memref kind - %d", memType);
     63             assert(0);  // Bail if debug build, set worst-case in the field
     64             *maskPtr |= ENCODE_ALL;
     65     }
     66 }
     67 
     68 /*
     69  * Mark load/store instructions that access Dalvik registers through rFP +
     70  * offset.
     71  */
     72 static void annotateDalvikRegAccess(ArmLIR *lir, int regId, bool isLoad)
     73 {
     74     setMemRefType(lir, isLoad, kDalvikReg);
     75 
     76     /*
     77      * Store the Dalvik register id in aliasInfo. Mark he MSB if it is a 64-bit
     78      * access.
     79      */
     80     lir->aliasInfo = regId;
     81     if (DOUBLEREG(lir->operands[0])) {
     82         lir->aliasInfo |= 0x80000000;
     83     }
     84 }
     85 
     86 /*
     87  * Decode the register id and mark the corresponding bit(s).
     88  */
     89 static inline void setupRegMask(u8 *mask, int reg)
     90 {
     91     u8 seed;
     92     int shift;
     93     int regId = reg & 0x1f;
     94 
     95     /*
     96      * Each double register is equal to a pair of single-precision FP registers
     97      */
     98     seed = DOUBLEREG(reg) ? 3 : 1;
     99     /* FP register starts at bit position 16 */
    100     shift = FPREG(reg) ? kFPReg0 : 0;
    101     /* Expand the double register id into single offset */
    102     shift += regId;
    103     *mask |= seed << shift;
    104 }
    105 
    106 /*
    107  * Set up the proper fields in the resource mask
    108  */
    109 static void setupResourceMasks(ArmLIR *lir)
    110 {
    111     int opCode = lir->opCode;
    112     int flags;
    113 
    114     if (opCode <= 0) {
    115         lir->useMask = lir->defMask = 0;
    116         return;
    117     }
    118 
    119     flags = EncodingMap[lir->opCode].flags;
    120 
    121     /* Set up the mask for resources that are updated */
    122     if (flags & (IS_LOAD | IS_STORE)) {
    123         /* Default to heap - will catch specialized classes later */
    124         setMemRefType(lir, flags & IS_LOAD, kHeapRef);
    125     }
    126 
    127     if (flags & IS_BRANCH) {
    128         lir->defMask |= ENCODE_REG_PC;
    129         lir->useMask |= ENCODE_REG_PC;
    130     }
    131 
    132     if (flags & REG_DEF0) {
    133         setupRegMask(&lir->defMask, lir->operands[0]);
    134     }
    135 
    136     if (flags & REG_DEF1) {
    137         setupRegMask(&lir->defMask, lir->operands[1]);
    138     }
    139 
    140     if (flags & REG_DEF_SP) {
    141         lir->defMask |= ENCODE_REG_SP;
    142     }
    143 
    144     if (flags & REG_DEF_LR) {
    145         lir->defMask |= ENCODE_REG_LR;
    146     }
    147 
    148     if (flags & REG_DEF_LIST0) {
    149         lir->defMask |= ENCODE_REG_LIST(lir->operands[0]);
    150     }
    151 
    152     if (flags & REG_DEF_LIST1) {
    153         lir->defMask |= ENCODE_REG_LIST(lir->operands[1]);
    154     }
    155 
    156     if (flags & SETS_CCODES) {
    157         lir->defMask |= ENCODE_CCODE;
    158     }
    159 
    160     /* Conservatively treat the IT block */
    161     if (flags & IS_IT) {
    162         lir->defMask = ENCODE_ALL;
    163     }
    164 
    165     /* Set up the mask for resources that are used */
    166     if (flags & IS_BRANCH) {
    167         lir->useMask |= ENCODE_REG_PC;
    168     }
    169 
    170     if (flags & (REG_USE0 | REG_USE1 | REG_USE2 | REG_USE3)) {
    171         int i;
    172 
    173         for (i = 0; i < 4; i++) {
    174             if (flags & (1 << (kRegUse0 + i))) {
    175                 setupRegMask(&lir->useMask, lir->operands[i]);
    176             }
    177         }
    178     }
    179 
    180     if (flags & REG_USE_PC) {
    181         lir->useMask |= ENCODE_REG_PC;
    182     }
    183 
    184     if (flags & REG_USE_SP) {
    185         lir->useMask |= ENCODE_REG_SP;
    186     }
    187 
    188     if (flags & REG_USE_LIST0) {
    189         lir->useMask |= ENCODE_REG_LIST(lir->operands[0]);
    190     }
    191 
    192     if (flags & REG_USE_LIST1) {
    193         lir->useMask |= ENCODE_REG_LIST(lir->operands[1]);
    194     }
    195 
    196     if (flags & USES_CCODES) {
    197         lir->useMask |= ENCODE_CCODE;
    198     }
    199 }
    200 
    201 /*
    202  * The following are building blocks to construct low-level IRs with 0 - 4
    203  * operands.
    204  */
    205 static ArmLIR *newLIR0(CompilationUnit *cUnit, ArmOpCode opCode)
    206 {
    207     ArmLIR *insn = dvmCompilerNew(sizeof(ArmLIR), true);
    208     assert(isPseudoOpCode(opCode) || (EncodingMap[opCode].flags & NO_OPERAND));
    209     insn->opCode = opCode;
    210     setupResourceMasks(insn);
    211     dvmCompilerAppendLIR(cUnit, (LIR *) insn);
    212     return insn;
    213 }
    214 
    215 static ArmLIR *newLIR1(CompilationUnit *cUnit, ArmOpCode opCode,
    216                            int dest)
    217 {
    218     ArmLIR *insn = dvmCompilerNew(sizeof(ArmLIR), true);
    219     assert(isPseudoOpCode(opCode) || (EncodingMap[opCode].flags & IS_UNARY_OP));
    220     insn->opCode = opCode;
    221     insn->operands[0] = dest;
    222     setupResourceMasks(insn);
    223     dvmCompilerAppendLIR(cUnit, (LIR *) insn);
    224     return insn;
    225 }
    226 
    227 static ArmLIR *newLIR2(CompilationUnit *cUnit, ArmOpCode opCode,
    228                            int dest, int src1)
    229 {
    230     ArmLIR *insn = dvmCompilerNew(sizeof(ArmLIR), true);
    231     assert(isPseudoOpCode(opCode) ||
    232            (EncodingMap[opCode].flags & IS_BINARY_OP));
    233     insn->opCode = opCode;
    234     insn->operands[0] = dest;
    235     insn->operands[1] = src1;
    236     setupResourceMasks(insn);
    237     dvmCompilerAppendLIR(cUnit, (LIR *) insn);
    238     return insn;
    239 }
    240 
    241 static ArmLIR *newLIR3(CompilationUnit *cUnit, ArmOpCode opCode,
    242                            int dest, int src1, int src2)
    243 {
    244     ArmLIR *insn = dvmCompilerNew(sizeof(ArmLIR), true);
    245     if (!(EncodingMap[opCode].flags & IS_TERTIARY_OP)) {
    246         LOGE("Bad LIR3: %s[%d]",EncodingMap[opCode].name,opCode);
    247     }
    248     assert(isPseudoOpCode(opCode) ||
    249            (EncodingMap[opCode].flags & IS_TERTIARY_OP));
    250     insn->opCode = opCode;
    251     insn->operands[0] = dest;
    252     insn->operands[1] = src1;
    253     insn->operands[2] = src2;
    254     setupResourceMasks(insn);
    255     dvmCompilerAppendLIR(cUnit, (LIR *) insn);
    256     return insn;
    257 }
    258 
    259 #if defined(_ARMV7_A) || defined(_ARMV7_A_NEON)
    260 static ArmLIR *newLIR4(CompilationUnit *cUnit, ArmOpCode opCode,
    261                            int dest, int src1, int src2, int info)
    262 {
    263     ArmLIR *insn = dvmCompilerNew(sizeof(ArmLIR), true);
    264     assert(isPseudoOpCode(opCode) ||
    265            (EncodingMap[opCode].flags & IS_QUAD_OP));
    266     insn->opCode = opCode;
    267     insn->operands[0] = dest;
    268     insn->operands[1] = src1;
    269     insn->operands[2] = src2;
    270     insn->operands[3] = info;
    271     setupResourceMasks(insn);
    272     dvmCompilerAppendLIR(cUnit, (LIR *) insn);
    273     return insn;
    274 }
    275 #endif
    276 
    277 /*
    278  * If the next instruction is a move-result or move-result-long,
    279  * return the target Dalvik sReg[s] and convert the next to a
    280  * nop.  Otherwise, return INVALID_SREG.  Used to optimize method inlining.
    281  */
    282 static RegLocation inlinedTarget(CompilationUnit *cUnit, MIR *mir,
    283                                   bool fpHint)
    284 {
    285     if (mir->next &&
    286         ((mir->next->dalvikInsn.opCode == OP_MOVE_RESULT) ||
    287          (mir->next->dalvikInsn.opCode == OP_MOVE_RESULT_OBJECT))) {
    288         mir->next->dalvikInsn.opCode = OP_NOP;
    289         return dvmCompilerGetDest(cUnit, mir->next, 0);
    290     } else {
    291         RegLocation res = LOC_DALVIK_RETURN_VAL;
    292         res.fp = fpHint;
    293         return res;
    294     }
    295 }
    296 
    297 /*
    298  * Search the existing constants in the literal pool for an exact or close match
    299  * within specified delta (greater or equal to 0).
    300  */
    301 static ArmLIR *scanLiteralPool(CompilationUnit *cUnit, int value,
    302                                    unsigned int delta)
    303 {
    304     LIR *dataTarget = cUnit->wordList;
    305     while (dataTarget) {
    306         if (((unsigned) (value - ((ArmLIR *) dataTarget)->operands[0])) <=
    307             delta)
    308             return (ArmLIR *) dataTarget;
    309         dataTarget = dataTarget->next;
    310     }
    311     return NULL;
    312 }
    313 
    314 /*
    315  * The following are building blocks to insert constants into the pool or
    316  * instruction streams.
    317  */
    318 
    319 /* Add a 32-bit constant either in the constant pool or mixed with code */
    320 static ArmLIR *addWordData(CompilationUnit *cUnit, int value, bool inPlace)
    321 {
    322     /* Add the constant to the literal pool */
    323     if (!inPlace) {
    324         ArmLIR *newValue = dvmCompilerNew(sizeof(ArmLIR), true);
    325         newValue->operands[0] = value;
    326         newValue->generic.next = cUnit->wordList;
    327         cUnit->wordList = (LIR *) newValue;
    328         return newValue;
    329     } else {
    330         /* Add the constant in the middle of code stream */
    331         newLIR1(cUnit, kArm16BitData, (value & 0xffff));
    332         newLIR1(cUnit, kArm16BitData, (value >> 16));
    333     }
    334     return NULL;
    335 }
    336 
    337 static RegLocation inlinedTargetWide(CompilationUnit *cUnit, MIR *mir,
    338                                       bool fpHint)
    339 {
    340     if (mir->next &&
    341         (mir->next->dalvikInsn.opCode == OP_MOVE_RESULT_WIDE)) {
    342         mir->next->dalvikInsn.opCode = OP_NOP;
    343         return dvmCompilerGetDestWide(cUnit, mir->next, 0, 1);
    344     } else {
    345         RegLocation res = LOC_DALVIK_RETURN_VAL_WIDE;
    346         res.fp = fpHint;
    347         return res;
    348     }
    349 }
    350 
    351 
    352 /*
    353  * Generate an kArmPseudoBarrier marker to indicate the boundary of special
    354  * blocks.
    355  */
    356 static void genBarrier(CompilationUnit *cUnit)
    357 {
    358     ArmLIR *barrier = newLIR0(cUnit, kArmPseudoBarrier);
    359     /* Mark all resources as being clobbered */
    360     barrier->defMask = -1;
    361 }
    362 
    363 /* Create the PC reconstruction slot if not already done */
    364 extern ArmLIR *genCheckCommon(CompilationUnit *cUnit, int dOffset,
    365                               ArmLIR *branch,
    366                               ArmLIR *pcrLabel)
    367 {
    368     /* Forget all def info (because we might rollback here.  Bug #2367397 */
    369     dvmCompilerResetDefTracking(cUnit);
    370 
    371     /* Set up the place holder to reconstruct this Dalvik PC */
    372     if (pcrLabel == NULL) {
    373         int dPC = (int) (cUnit->method->insns + dOffset);
    374         pcrLabel = dvmCompilerNew(sizeof(ArmLIR), true);
    375         pcrLabel->opCode = kArmPseudoPCReconstructionCell;
    376         pcrLabel->operands[0] = dPC;
    377         pcrLabel->operands[1] = dOffset;
    378         /* Insert the place holder to the growable list */
    379         dvmInsertGrowableList(&cUnit->pcReconstructionList, pcrLabel);
    380     }
    381     /* Branch to the PC reconstruction code */
    382     branch->generic.target = (LIR *) pcrLabel;
    383     return pcrLabel;
    384 }
    385