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      1 // Copyright 2012 the V8 project authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #include "src/mips/codegen-mips.h"
      6 
      7 #if V8_TARGET_ARCH_MIPS
      8 
      9 #include <memory>
     10 
     11 #include "src/codegen.h"
     12 #include "src/macro-assembler.h"
     13 #include "src/mips/simulator-mips.h"
     14 
     15 namespace v8 {
     16 namespace internal {
     17 
     18 
     19 #define __ masm.
     20 
     21 #if defined(V8_HOST_ARCH_MIPS)
     22 MemCopyUint8Function CreateMemCopyUint8Function(Isolate* isolate,
     23                                                 MemCopyUint8Function stub) {
     24 #if defined(USE_SIMULATOR) || defined(_MIPS_ARCH_MIPS32R6) || \
     25     defined(_MIPS_ARCH_MIPS32RX)
     26   return stub;
     27 #else
     28   size_t actual_size;
     29   byte* buffer =
     30       static_cast<byte*>(base::OS::Allocate(3 * KB, &actual_size, true));
     31   if (buffer == nullptr) return stub;
     32 
     33   // This code assumes that cache lines are 32 bytes and if the cache line is
     34   // larger it will not work correctly.
     35   MacroAssembler masm(isolate, buffer, static_cast<int>(actual_size),
     36                       CodeObjectRequired::kNo);
     37 
     38   {
     39     Label lastb, unaligned, aligned, chkw,
     40           loop16w, chk1w, wordCopy_loop, skip_pref, lastbloop,
     41           leave, ua_chk16w, ua_loop16w, ua_skip_pref, ua_chkw,
     42           ua_chk1w, ua_wordCopy_loop, ua_smallCopy, ua_smallCopy_loop;
     43 
     44     // The size of each prefetch.
     45     uint32_t pref_chunk = 32;
     46     // The maximum size of a prefetch, it must not be less than pref_chunk.
     47     // If the real size of a prefetch is greater than max_pref_size and
     48     // the kPrefHintPrepareForStore hint is used, the code will not work
     49     // correctly.
     50     uint32_t max_pref_size = 128;
     51     DCHECK(pref_chunk < max_pref_size);
     52 
     53     // pref_limit is set based on the fact that we never use an offset
     54     // greater then 5 on a store pref and that a single pref can
     55     // never be larger then max_pref_size.
     56     uint32_t pref_limit = (5 * pref_chunk) + max_pref_size;
     57     int32_t pref_hint_load = kPrefHintLoadStreamed;
     58     int32_t pref_hint_store = kPrefHintPrepareForStore;
     59     uint32_t loadstore_chunk = 4;
     60 
     61     // The initial prefetches may fetch bytes that are before the buffer being
     62     // copied. Start copies with an offset of 4 so avoid this situation when
     63     // using kPrefHintPrepareForStore.
     64     DCHECK(pref_hint_store != kPrefHintPrepareForStore ||
     65            pref_chunk * 4 >= max_pref_size);
     66 
     67     // If the size is less than 8, go to lastb. Regardless of size,
     68     // copy dst pointer to v0 for the retuen value.
     69     __ slti(t2, a2, 2 * loadstore_chunk);
     70     __ bne(t2, zero_reg, &lastb);
     71     __ mov(v0, a0);  // In delay slot.
     72 
     73     // If src and dst have different alignments, go to unaligned, if they
     74     // have the same alignment (but are not actually aligned) do a partial
     75     // load/store to make them aligned. If they are both already aligned
     76     // we can start copying at aligned.
     77     __ xor_(t8, a1, a0);
     78     __ andi(t8, t8, loadstore_chunk - 1);  // t8 is a0/a1 word-displacement.
     79     __ bne(t8, zero_reg, &unaligned);
     80     __ subu(a3, zero_reg, a0);  // In delay slot.
     81 
     82     __ andi(a3, a3, loadstore_chunk - 1);  // Copy a3 bytes to align a0/a1.
     83     __ beq(a3, zero_reg, &aligned);  // Already aligned.
     84     __ subu(a2, a2, a3);  // In delay slot. a2 is the remining bytes count.
     85 
     86     if (kArchEndian == kLittle) {
     87       __ lwr(t8, MemOperand(a1));
     88       __ addu(a1, a1, a3);
     89       __ swr(t8, MemOperand(a0));
     90       __ addu(a0, a0, a3);
     91     } else {
     92       __ lwl(t8, MemOperand(a1));
     93       __ addu(a1, a1, a3);
     94       __ swl(t8, MemOperand(a0));
     95       __ addu(a0, a0, a3);
     96     }
     97     // Now dst/src are both aligned to (word) aligned addresses. Set a2 to
     98     // count how many bytes we have to copy after all the 64 byte chunks are
     99     // copied and a3 to the dst pointer after all the 64 byte chunks have been
    100     // copied. We will loop, incrementing a0 and a1 until a0 equals a3.
    101     __ bind(&aligned);
    102     __ andi(t8, a2, 0x3f);
    103     __ beq(a2, t8, &chkw);  // Less than 64?
    104     __ subu(a3, a2, t8);  // In delay slot.
    105     __ addu(a3, a0, a3);  // Now a3 is the final dst after loop.
    106 
    107     // When in the loop we prefetch with kPrefHintPrepareForStore hint,
    108     // in this case the a0+x should be past the "t0-32" address. This means:
    109     // for x=128 the last "safe" a0 address is "t0-160". Alternatively, for
    110     // x=64 the last "safe" a0 address is "t0-96". In the current version we
    111     // will use "pref hint, 128(a0)", so "t0-160" is the limit.
    112     if (pref_hint_store == kPrefHintPrepareForStore) {
    113       __ addu(t0, a0, a2);  // t0 is the "past the end" address.
    114       __ Subu(t9, t0, pref_limit);  // t9 is the "last safe pref" address.
    115     }
    116 
    117     __ Pref(pref_hint_load, MemOperand(a1, 0 * pref_chunk));
    118     __ Pref(pref_hint_load, MemOperand(a1, 1 * pref_chunk));
    119     __ Pref(pref_hint_load, MemOperand(a1, 2 * pref_chunk));
    120     __ Pref(pref_hint_load, MemOperand(a1, 3 * pref_chunk));
    121 
    122     if (pref_hint_store != kPrefHintPrepareForStore) {
    123       __ Pref(pref_hint_store, MemOperand(a0, 1 * pref_chunk));
    124       __ Pref(pref_hint_store, MemOperand(a0, 2 * pref_chunk));
    125       __ Pref(pref_hint_store, MemOperand(a0, 3 * pref_chunk));
    126     }
    127     __ bind(&loop16w);
    128     __ lw(t0, MemOperand(a1));
    129 
    130     if (pref_hint_store == kPrefHintPrepareForStore) {
    131       __ sltu(v1, t9, a0);  // If a0 > t9, don't use next prefetch.
    132       __ Branch(USE_DELAY_SLOT, &skip_pref, gt, v1, Operand(zero_reg));
    133     }
    134     __ lw(t1, MemOperand(a1, 1, loadstore_chunk));  // Maybe in delay slot.
    135 
    136     __ Pref(pref_hint_store, MemOperand(a0, 4 * pref_chunk));
    137     __ Pref(pref_hint_store, MemOperand(a0, 5 * pref_chunk));
    138 
    139     __ bind(&skip_pref);
    140     __ lw(t2, MemOperand(a1, 2, loadstore_chunk));
    141     __ lw(t3, MemOperand(a1, 3, loadstore_chunk));
    142     __ lw(t4, MemOperand(a1, 4, loadstore_chunk));
    143     __ lw(t5, MemOperand(a1, 5, loadstore_chunk));
    144     __ lw(t6, MemOperand(a1, 6, loadstore_chunk));
    145     __ lw(t7, MemOperand(a1, 7, loadstore_chunk));
    146     __ Pref(pref_hint_load, MemOperand(a1, 4 * pref_chunk));
    147 
    148     __ sw(t0, MemOperand(a0));
    149     __ sw(t1, MemOperand(a0, 1, loadstore_chunk));
    150     __ sw(t2, MemOperand(a0, 2, loadstore_chunk));
    151     __ sw(t3, MemOperand(a0, 3, loadstore_chunk));
    152     __ sw(t4, MemOperand(a0, 4, loadstore_chunk));
    153     __ sw(t5, MemOperand(a0, 5, loadstore_chunk));
    154     __ sw(t6, MemOperand(a0, 6, loadstore_chunk));
    155     __ sw(t7, MemOperand(a0, 7, loadstore_chunk));
    156 
    157     __ lw(t0, MemOperand(a1, 8, loadstore_chunk));
    158     __ lw(t1, MemOperand(a1, 9, loadstore_chunk));
    159     __ lw(t2, MemOperand(a1, 10, loadstore_chunk));
    160     __ lw(t3, MemOperand(a1, 11, loadstore_chunk));
    161     __ lw(t4, MemOperand(a1, 12, loadstore_chunk));
    162     __ lw(t5, MemOperand(a1, 13, loadstore_chunk));
    163     __ lw(t6, MemOperand(a1, 14, loadstore_chunk));
    164     __ lw(t7, MemOperand(a1, 15, loadstore_chunk));
    165     __ Pref(pref_hint_load, MemOperand(a1, 5 * pref_chunk));
    166 
    167     __ sw(t0, MemOperand(a0, 8, loadstore_chunk));
    168     __ sw(t1, MemOperand(a0, 9, loadstore_chunk));
    169     __ sw(t2, MemOperand(a0, 10, loadstore_chunk));
    170     __ sw(t3, MemOperand(a0, 11, loadstore_chunk));
    171     __ sw(t4, MemOperand(a0, 12, loadstore_chunk));
    172     __ sw(t5, MemOperand(a0, 13, loadstore_chunk));
    173     __ sw(t6, MemOperand(a0, 14, loadstore_chunk));
    174     __ sw(t7, MemOperand(a0, 15, loadstore_chunk));
    175     __ addiu(a0, a0, 16 * loadstore_chunk);
    176     __ bne(a0, a3, &loop16w);
    177     __ addiu(a1, a1, 16 * loadstore_chunk);  // In delay slot.
    178     __ mov(a2, t8);
    179 
    180     // Here we have src and dest word-aligned but less than 64-bytes to go.
    181     // Check for a 32 bytes chunk and copy if there is one. Otherwise jump
    182     // down to chk1w to handle the tail end of the copy.
    183     __ bind(&chkw);
    184     __ Pref(pref_hint_load, MemOperand(a1, 0 * pref_chunk));
    185     __ andi(t8, a2, 0x1f);
    186     __ beq(a2, t8, &chk1w);  // Less than 32?
    187     __ nop();  // In delay slot.
    188     __ lw(t0, MemOperand(a1));
    189     __ lw(t1, MemOperand(a1, 1, loadstore_chunk));
    190     __ lw(t2, MemOperand(a1, 2, loadstore_chunk));
    191     __ lw(t3, MemOperand(a1, 3, loadstore_chunk));
    192     __ lw(t4, MemOperand(a1, 4, loadstore_chunk));
    193     __ lw(t5, MemOperand(a1, 5, loadstore_chunk));
    194     __ lw(t6, MemOperand(a1, 6, loadstore_chunk));
    195     __ lw(t7, MemOperand(a1, 7, loadstore_chunk));
    196     __ addiu(a1, a1, 8 * loadstore_chunk);
    197     __ sw(t0, MemOperand(a0));
    198     __ sw(t1, MemOperand(a0, 1, loadstore_chunk));
    199     __ sw(t2, MemOperand(a0, 2, loadstore_chunk));
    200     __ sw(t3, MemOperand(a0, 3, loadstore_chunk));
    201     __ sw(t4, MemOperand(a0, 4, loadstore_chunk));
    202     __ sw(t5, MemOperand(a0, 5, loadstore_chunk));
    203     __ sw(t6, MemOperand(a0, 6, loadstore_chunk));
    204     __ sw(t7, MemOperand(a0, 7, loadstore_chunk));
    205     __ addiu(a0, a0, 8 * loadstore_chunk);
    206 
    207     // Here we have less than 32 bytes to copy. Set up for a loop to copy
    208     // one word at a time. Set a2 to count how many bytes we have to copy
    209     // after all the word chunks are copied and a3 to the dst pointer after
    210     // all the word chunks have been copied. We will loop, incrementing a0
    211     // and a1 untill a0 equals a3.
    212     __ bind(&chk1w);
    213     __ andi(a2, t8, loadstore_chunk - 1);
    214     __ beq(a2, t8, &lastb);
    215     __ subu(a3, t8, a2);  // In delay slot.
    216     __ addu(a3, a0, a3);
    217 
    218     __ bind(&wordCopy_loop);
    219     __ lw(t3, MemOperand(a1));
    220     __ addiu(a0, a0, loadstore_chunk);
    221     __ addiu(a1, a1, loadstore_chunk);
    222     __ bne(a0, a3, &wordCopy_loop);
    223     __ sw(t3, MemOperand(a0, -1, loadstore_chunk));  // In delay slot.
    224 
    225     __ bind(&lastb);
    226     __ Branch(&leave, le, a2, Operand(zero_reg));
    227     __ addu(a3, a0, a2);
    228 
    229     __ bind(&lastbloop);
    230     __ lb(v1, MemOperand(a1));
    231     __ addiu(a0, a0, 1);
    232     __ addiu(a1, a1, 1);
    233     __ bne(a0, a3, &lastbloop);
    234     __ sb(v1, MemOperand(a0, -1));  // In delay slot.
    235 
    236     __ bind(&leave);
    237     __ jr(ra);
    238     __ nop();
    239 
    240     // Unaligned case. Only the dst gets aligned so we need to do partial
    241     // loads of the source followed by normal stores to the dst (once we
    242     // have aligned the destination).
    243     __ bind(&unaligned);
    244     __ andi(a3, a3, loadstore_chunk - 1);  // Copy a3 bytes to align a0/a1.
    245     __ beq(a3, zero_reg, &ua_chk16w);
    246     __ subu(a2, a2, a3);  // In delay slot.
    247 
    248     if (kArchEndian == kLittle) {
    249       __ lwr(v1, MemOperand(a1));
    250       __ lwl(v1,
    251              MemOperand(a1, 1, loadstore_chunk, MemOperand::offset_minus_one));
    252       __ addu(a1, a1, a3);
    253       __ swr(v1, MemOperand(a0));
    254       __ addu(a0, a0, a3);
    255     } else {
    256       __ lwl(v1, MemOperand(a1));
    257       __ lwr(v1,
    258              MemOperand(a1, 1, loadstore_chunk, MemOperand::offset_minus_one));
    259       __ addu(a1, a1, a3);
    260       __ swl(v1, MemOperand(a0));
    261       __ addu(a0, a0, a3);
    262     }
    263 
    264     // Now the dst (but not the source) is aligned. Set a2 to count how many
    265     // bytes we have to copy after all the 64 byte chunks are copied and a3 to
    266     // the dst pointer after all the 64 byte chunks have been copied. We will
    267     // loop, incrementing a0 and a1 until a0 equals a3.
    268     __ bind(&ua_chk16w);
    269     __ andi(t8, a2, 0x3f);
    270     __ beq(a2, t8, &ua_chkw);
    271     __ subu(a3, a2, t8);  // In delay slot.
    272     __ addu(a3, a0, a3);
    273 
    274     if (pref_hint_store == kPrefHintPrepareForStore) {
    275       __ addu(t0, a0, a2);
    276       __ Subu(t9, t0, pref_limit);
    277     }
    278 
    279     __ Pref(pref_hint_load, MemOperand(a1, 0 * pref_chunk));
    280     __ Pref(pref_hint_load, MemOperand(a1, 1 * pref_chunk));
    281     __ Pref(pref_hint_load, MemOperand(a1, 2 * pref_chunk));
    282 
    283     if (pref_hint_store != kPrefHintPrepareForStore) {
    284       __ Pref(pref_hint_store, MemOperand(a0, 1 * pref_chunk));
    285       __ Pref(pref_hint_store, MemOperand(a0, 2 * pref_chunk));
    286       __ Pref(pref_hint_store, MemOperand(a0, 3 * pref_chunk));
    287     }
    288 
    289     __ bind(&ua_loop16w);
    290     __ Pref(pref_hint_load, MemOperand(a1, 3 * pref_chunk));
    291     if (kArchEndian == kLittle) {
    292       __ lwr(t0, MemOperand(a1));
    293       __ lwr(t1, MemOperand(a1, 1, loadstore_chunk));
    294       __ lwr(t2, MemOperand(a1, 2, loadstore_chunk));
    295 
    296       if (pref_hint_store == kPrefHintPrepareForStore) {
    297         __ sltu(v1, t9, a0);
    298         __ Branch(USE_DELAY_SLOT, &ua_skip_pref, gt, v1, Operand(zero_reg));
    299       }
    300       __ lwr(t3, MemOperand(a1, 3, loadstore_chunk));  // Maybe in delay slot.
    301 
    302       __ Pref(pref_hint_store, MemOperand(a0, 4 * pref_chunk));
    303       __ Pref(pref_hint_store, MemOperand(a0, 5 * pref_chunk));
    304 
    305       __ bind(&ua_skip_pref);
    306       __ lwr(t4, MemOperand(a1, 4, loadstore_chunk));
    307       __ lwr(t5, MemOperand(a1, 5, loadstore_chunk));
    308       __ lwr(t6, MemOperand(a1, 6, loadstore_chunk));
    309       __ lwr(t7, MemOperand(a1, 7, loadstore_chunk));
    310       __ lwl(t0,
    311              MemOperand(a1, 1, loadstore_chunk, MemOperand::offset_minus_one));
    312       __ lwl(t1,
    313              MemOperand(a1, 2, loadstore_chunk, MemOperand::offset_minus_one));
    314       __ lwl(t2,
    315              MemOperand(a1, 3, loadstore_chunk, MemOperand::offset_minus_one));
    316       __ lwl(t3,
    317              MemOperand(a1, 4, loadstore_chunk, MemOperand::offset_minus_one));
    318       __ lwl(t4,
    319              MemOperand(a1, 5, loadstore_chunk, MemOperand::offset_minus_one));
    320       __ lwl(t5,
    321              MemOperand(a1, 6, loadstore_chunk, MemOperand::offset_minus_one));
    322       __ lwl(t6,
    323              MemOperand(a1, 7, loadstore_chunk, MemOperand::offset_minus_one));
    324       __ lwl(t7,
    325              MemOperand(a1, 8, loadstore_chunk, MemOperand::offset_minus_one));
    326     } else {
    327       __ lwl(t0, MemOperand(a1));
    328       __ lwl(t1, MemOperand(a1, 1, loadstore_chunk));
    329       __ lwl(t2, MemOperand(a1, 2, loadstore_chunk));
    330 
    331       if (pref_hint_store == kPrefHintPrepareForStore) {
    332         __ sltu(v1, t9, a0);
    333         __ Branch(USE_DELAY_SLOT, &ua_skip_pref, gt, v1, Operand(zero_reg));
    334       }
    335       __ lwl(t3, MemOperand(a1, 3, loadstore_chunk));  // Maybe in delay slot.
    336 
    337       __ Pref(pref_hint_store, MemOperand(a0, 4 * pref_chunk));
    338       __ Pref(pref_hint_store, MemOperand(a0, 5 * pref_chunk));
    339 
    340       __ bind(&ua_skip_pref);
    341       __ lwl(t4, MemOperand(a1, 4, loadstore_chunk));
    342       __ lwl(t5, MemOperand(a1, 5, loadstore_chunk));
    343       __ lwl(t6, MemOperand(a1, 6, loadstore_chunk));
    344       __ lwl(t7, MemOperand(a1, 7, loadstore_chunk));
    345       __ lwr(t0,
    346              MemOperand(a1, 1, loadstore_chunk, MemOperand::offset_minus_one));
    347       __ lwr(t1,
    348              MemOperand(a1, 2, loadstore_chunk, MemOperand::offset_minus_one));
    349       __ lwr(t2,
    350              MemOperand(a1, 3, loadstore_chunk, MemOperand::offset_minus_one));
    351       __ lwr(t3,
    352              MemOperand(a1, 4, loadstore_chunk, MemOperand::offset_minus_one));
    353       __ lwr(t4,
    354              MemOperand(a1, 5, loadstore_chunk, MemOperand::offset_minus_one));
    355       __ lwr(t5,
    356              MemOperand(a1, 6, loadstore_chunk, MemOperand::offset_minus_one));
    357       __ lwr(t6,
    358              MemOperand(a1, 7, loadstore_chunk, MemOperand::offset_minus_one));
    359       __ lwr(t7,
    360              MemOperand(a1, 8, loadstore_chunk, MemOperand::offset_minus_one));
    361     }
    362     __ Pref(pref_hint_load, MemOperand(a1, 4 * pref_chunk));
    363     __ sw(t0, MemOperand(a0));
    364     __ sw(t1, MemOperand(a0, 1, loadstore_chunk));
    365     __ sw(t2, MemOperand(a0, 2, loadstore_chunk));
    366     __ sw(t3, MemOperand(a0, 3, loadstore_chunk));
    367     __ sw(t4, MemOperand(a0, 4, loadstore_chunk));
    368     __ sw(t5, MemOperand(a0, 5, loadstore_chunk));
    369     __ sw(t6, MemOperand(a0, 6, loadstore_chunk));
    370     __ sw(t7, MemOperand(a0, 7, loadstore_chunk));
    371     if (kArchEndian == kLittle) {
    372       __ lwr(t0, MemOperand(a1, 8, loadstore_chunk));
    373       __ lwr(t1, MemOperand(a1, 9, loadstore_chunk));
    374       __ lwr(t2, MemOperand(a1, 10, loadstore_chunk));
    375       __ lwr(t3, MemOperand(a1, 11, loadstore_chunk));
    376       __ lwr(t4, MemOperand(a1, 12, loadstore_chunk));
    377       __ lwr(t5, MemOperand(a1, 13, loadstore_chunk));
    378       __ lwr(t6, MemOperand(a1, 14, loadstore_chunk));
    379       __ lwr(t7, MemOperand(a1, 15, loadstore_chunk));
    380       __ lwl(t0,
    381              MemOperand(a1, 9, loadstore_chunk, MemOperand::offset_minus_one));
    382       __ lwl(t1,
    383              MemOperand(a1, 10, loadstore_chunk, MemOperand::offset_minus_one));
    384       __ lwl(t2,
    385              MemOperand(a1, 11, loadstore_chunk, MemOperand::offset_minus_one));
    386       __ lwl(t3,
    387              MemOperand(a1, 12, loadstore_chunk, MemOperand::offset_minus_one));
    388       __ lwl(t4,
    389              MemOperand(a1, 13, loadstore_chunk, MemOperand::offset_minus_one));
    390       __ lwl(t5,
    391              MemOperand(a1, 14, loadstore_chunk, MemOperand::offset_minus_one));
    392       __ lwl(t6,
    393              MemOperand(a1, 15, loadstore_chunk, MemOperand::offset_minus_one));
    394       __ lwl(t7,
    395              MemOperand(a1, 16, loadstore_chunk, MemOperand::offset_minus_one));
    396     } else {
    397       __ lwl(t0, MemOperand(a1, 8, loadstore_chunk));
    398       __ lwl(t1, MemOperand(a1, 9, loadstore_chunk));
    399       __ lwl(t2, MemOperand(a1, 10, loadstore_chunk));
    400       __ lwl(t3, MemOperand(a1, 11, loadstore_chunk));
    401       __ lwl(t4, MemOperand(a1, 12, loadstore_chunk));
    402       __ lwl(t5, MemOperand(a1, 13, loadstore_chunk));
    403       __ lwl(t6, MemOperand(a1, 14, loadstore_chunk));
    404       __ lwl(t7, MemOperand(a1, 15, loadstore_chunk));
    405       __ lwr(t0,
    406              MemOperand(a1, 9, loadstore_chunk, MemOperand::offset_minus_one));
    407       __ lwr(t1,
    408              MemOperand(a1, 10, loadstore_chunk, MemOperand::offset_minus_one));
    409       __ lwr(t2,
    410              MemOperand(a1, 11, loadstore_chunk, MemOperand::offset_minus_one));
    411       __ lwr(t3,
    412              MemOperand(a1, 12, loadstore_chunk, MemOperand::offset_minus_one));
    413       __ lwr(t4,
    414              MemOperand(a1, 13, loadstore_chunk, MemOperand::offset_minus_one));
    415       __ lwr(t5,
    416              MemOperand(a1, 14, loadstore_chunk, MemOperand::offset_minus_one));
    417       __ lwr(t6,
    418              MemOperand(a1, 15, loadstore_chunk, MemOperand::offset_minus_one));
    419       __ lwr(t7,
    420              MemOperand(a1, 16, loadstore_chunk, MemOperand::offset_minus_one));
    421     }
    422     __ Pref(pref_hint_load, MemOperand(a1, 5 * pref_chunk));
    423     __ sw(t0, MemOperand(a0, 8, loadstore_chunk));
    424     __ sw(t1, MemOperand(a0, 9, loadstore_chunk));
    425     __ sw(t2, MemOperand(a0, 10, loadstore_chunk));
    426     __ sw(t3, MemOperand(a0, 11, loadstore_chunk));
    427     __ sw(t4, MemOperand(a0, 12, loadstore_chunk));
    428     __ sw(t5, MemOperand(a0, 13, loadstore_chunk));
    429     __ sw(t6, MemOperand(a0, 14, loadstore_chunk));
    430     __ sw(t7, MemOperand(a0, 15, loadstore_chunk));
    431     __ addiu(a0, a0, 16 * loadstore_chunk);
    432     __ bne(a0, a3, &ua_loop16w);
    433     __ addiu(a1, a1, 16 * loadstore_chunk);  // In delay slot.
    434     __ mov(a2, t8);
    435 
    436     // Here less than 64-bytes. Check for
    437     // a 32 byte chunk and copy if there is one. Otherwise jump down to
    438     // ua_chk1w to handle the tail end of the copy.
    439     __ bind(&ua_chkw);
    440     __ Pref(pref_hint_load, MemOperand(a1));
    441     __ andi(t8, a2, 0x1f);
    442 
    443     __ beq(a2, t8, &ua_chk1w);
    444     __ nop();  // In delay slot.
    445     if (kArchEndian == kLittle) {
    446       __ lwr(t0, MemOperand(a1));
    447       __ lwr(t1, MemOperand(a1, 1, loadstore_chunk));
    448       __ lwr(t2, MemOperand(a1, 2, loadstore_chunk));
    449       __ lwr(t3, MemOperand(a1, 3, loadstore_chunk));
    450       __ lwr(t4, MemOperand(a1, 4, loadstore_chunk));
    451       __ lwr(t5, MemOperand(a1, 5, loadstore_chunk));
    452       __ lwr(t6, MemOperand(a1, 6, loadstore_chunk));
    453       __ lwr(t7, MemOperand(a1, 7, loadstore_chunk));
    454       __ lwl(t0,
    455              MemOperand(a1, 1, loadstore_chunk, MemOperand::offset_minus_one));
    456       __ lwl(t1,
    457              MemOperand(a1, 2, loadstore_chunk, MemOperand::offset_minus_one));
    458       __ lwl(t2,
    459              MemOperand(a1, 3, loadstore_chunk, MemOperand::offset_minus_one));
    460       __ lwl(t3,
    461              MemOperand(a1, 4, loadstore_chunk, MemOperand::offset_minus_one));
    462       __ lwl(t4,
    463              MemOperand(a1, 5, loadstore_chunk, MemOperand::offset_minus_one));
    464       __ lwl(t5,
    465              MemOperand(a1, 6, loadstore_chunk, MemOperand::offset_minus_one));
    466       __ lwl(t6,
    467              MemOperand(a1, 7, loadstore_chunk, MemOperand::offset_minus_one));
    468       __ lwl(t7,
    469              MemOperand(a1, 8, loadstore_chunk, MemOperand::offset_minus_one));
    470     } else {
    471       __ lwl(t0, MemOperand(a1));
    472       __ lwl(t1, MemOperand(a1, 1, loadstore_chunk));
    473       __ lwl(t2, MemOperand(a1, 2, loadstore_chunk));
    474       __ lwl(t3, MemOperand(a1, 3, loadstore_chunk));
    475       __ lwl(t4, MemOperand(a1, 4, loadstore_chunk));
    476       __ lwl(t5, MemOperand(a1, 5, loadstore_chunk));
    477       __ lwl(t6, MemOperand(a1, 6, loadstore_chunk));
    478       __ lwl(t7, MemOperand(a1, 7, loadstore_chunk));
    479       __ lwr(t0,
    480              MemOperand(a1, 1, loadstore_chunk, MemOperand::offset_minus_one));
    481       __ lwr(t1,
    482              MemOperand(a1, 2, loadstore_chunk, MemOperand::offset_minus_one));
    483       __ lwr(t2,
    484              MemOperand(a1, 3, loadstore_chunk, MemOperand::offset_minus_one));
    485       __ lwr(t3,
    486              MemOperand(a1, 4, loadstore_chunk, MemOperand::offset_minus_one));
    487       __ lwr(t4,
    488              MemOperand(a1, 5, loadstore_chunk, MemOperand::offset_minus_one));
    489       __ lwr(t5,
    490              MemOperand(a1, 6, loadstore_chunk, MemOperand::offset_minus_one));
    491       __ lwr(t6,
    492              MemOperand(a1, 7, loadstore_chunk, MemOperand::offset_minus_one));
    493       __ lwr(t7,
    494              MemOperand(a1, 8, loadstore_chunk, MemOperand::offset_minus_one));
    495     }
    496     __ addiu(a1, a1, 8 * loadstore_chunk);
    497     __ sw(t0, MemOperand(a0));
    498     __ sw(t1, MemOperand(a0, 1, loadstore_chunk));
    499     __ sw(t2, MemOperand(a0, 2, loadstore_chunk));
    500     __ sw(t3, MemOperand(a0, 3, loadstore_chunk));
    501     __ sw(t4, MemOperand(a0, 4, loadstore_chunk));
    502     __ sw(t5, MemOperand(a0, 5, loadstore_chunk));
    503     __ sw(t6, MemOperand(a0, 6, loadstore_chunk));
    504     __ sw(t7, MemOperand(a0, 7, loadstore_chunk));
    505     __ addiu(a0, a0, 8 * loadstore_chunk);
    506 
    507     // Less than 32 bytes to copy. Set up for a loop to
    508     // copy one word at a time.
    509     __ bind(&ua_chk1w);
    510     __ andi(a2, t8, loadstore_chunk - 1);
    511     __ beq(a2, t8, &ua_smallCopy);
    512     __ subu(a3, t8, a2);  // In delay slot.
    513     __ addu(a3, a0, a3);
    514 
    515     __ bind(&ua_wordCopy_loop);
    516     if (kArchEndian == kLittle) {
    517       __ lwr(v1, MemOperand(a1));
    518       __ lwl(v1,
    519              MemOperand(a1, 1, loadstore_chunk, MemOperand::offset_minus_one));
    520     } else {
    521       __ lwl(v1, MemOperand(a1));
    522       __ lwr(v1,
    523              MemOperand(a1, 1, loadstore_chunk, MemOperand::offset_minus_one));
    524     }
    525     __ addiu(a0, a0, loadstore_chunk);
    526     __ addiu(a1, a1, loadstore_chunk);
    527     __ bne(a0, a3, &ua_wordCopy_loop);
    528     __ sw(v1, MemOperand(a0, -1, loadstore_chunk));  // In delay slot.
    529 
    530     // Copy the last 8 bytes.
    531     __ bind(&ua_smallCopy);
    532     __ beq(a2, zero_reg, &leave);
    533     __ addu(a3, a0, a2);  // In delay slot.
    534 
    535     __ bind(&ua_smallCopy_loop);
    536     __ lb(v1, MemOperand(a1));
    537     __ addiu(a0, a0, 1);
    538     __ addiu(a1, a1, 1);
    539     __ bne(a0, a3, &ua_smallCopy_loop);
    540     __ sb(v1, MemOperand(a0, -1));  // In delay slot.
    541 
    542     __ jr(ra);
    543     __ nop();
    544   }
    545   CodeDesc desc;
    546   masm.GetCode(&desc);
    547   DCHECK(!RelocInfo::RequiresRelocation(desc));
    548 
    549   Assembler::FlushICache(isolate, buffer, actual_size);
    550   base::OS::ProtectCode(buffer, actual_size);
    551   return FUNCTION_CAST<MemCopyUint8Function>(buffer);
    552 #endif
    553 }
    554 #endif
    555 
    556 UnaryMathFunctionWithIsolate CreateSqrtFunction(Isolate* isolate) {
    557 #if defined(USE_SIMULATOR)
    558   return nullptr;
    559 #else
    560   size_t actual_size;
    561   byte* buffer =
    562       static_cast<byte*>(base::OS::Allocate(1 * KB, &actual_size, true));
    563   if (buffer == nullptr) return nullptr;
    564 
    565   MacroAssembler masm(isolate, buffer, static_cast<int>(actual_size),
    566                       CodeObjectRequired::kNo);
    567 
    568   __ MovFromFloatParameter(f12);
    569   __ sqrt_d(f0, f12);
    570   __ MovToFloatResult(f0);
    571   __ Ret();
    572 
    573   CodeDesc desc;
    574   masm.GetCode(&desc);
    575   DCHECK(!RelocInfo::RequiresRelocation(desc));
    576 
    577   Assembler::FlushICache(isolate, buffer, actual_size);
    578   base::OS::ProtectCode(buffer, actual_size);
    579   return FUNCTION_CAST<UnaryMathFunctionWithIsolate>(buffer);
    580 #endif
    581 }
    582 
    583 #undef __
    584 
    585 
    586 // -------------------------------------------------------------------------
    587 // Platform-specific RuntimeCallHelper functions.
    588 
    589 void StubRuntimeCallHelper::BeforeCall(MacroAssembler* masm) const {
    590   masm->EnterFrame(StackFrame::INTERNAL);
    591   DCHECK(!masm->has_frame());
    592   masm->set_has_frame(true);
    593 }
    594 
    595 
    596 void StubRuntimeCallHelper::AfterCall(MacroAssembler* masm) const {
    597   masm->LeaveFrame(StackFrame::INTERNAL);
    598   DCHECK(masm->has_frame());
    599   masm->set_has_frame(false);
    600 }
    601 
    602 
    603 // -------------------------------------------------------------------------
    604 // Code generators
    605 
    606 #define __ ACCESS_MASM(masm)
    607 
    608 void StringCharLoadGenerator::Generate(MacroAssembler* masm,
    609                                        Register string,
    610                                        Register index,
    611                                        Register result,
    612                                        Label* call_runtime) {
    613   Label indirect_string_loaded;
    614   __ bind(&indirect_string_loaded);
    615 
    616   // Fetch the instance type of the receiver into result register.
    617   __ lw(result, FieldMemOperand(string, HeapObject::kMapOffset));
    618   __ lbu(result, FieldMemOperand(result, Map::kInstanceTypeOffset));
    619 
    620   // We need special handling for indirect strings.
    621   Label check_sequential;
    622   __ And(at, result, Operand(kIsIndirectStringMask));
    623   __ Branch(&check_sequential, eq, at, Operand(zero_reg));
    624 
    625   // Dispatch on the indirect string shape: slice or cons.
    626   Label cons_string, thin_string;
    627   __ And(at, result, Operand(kStringRepresentationMask));
    628   __ Branch(&cons_string, eq, at, Operand(kConsStringTag));
    629   __ Branch(&thin_string, eq, at, Operand(kThinStringTag));
    630 
    631   // Handle slices.
    632   __ lw(result, FieldMemOperand(string, SlicedString::kOffsetOffset));
    633   __ lw(string, FieldMemOperand(string, SlicedString::kParentOffset));
    634   __ sra(at, result, kSmiTagSize);
    635   __ Addu(index, index, at);
    636   __ jmp(&indirect_string_loaded);
    637 
    638   // Handle thin strings.
    639   __ bind(&thin_string);
    640   __ lw(string, FieldMemOperand(string, ThinString::kActualOffset));
    641   __ jmp(&indirect_string_loaded);
    642 
    643   // Handle cons strings.
    644   // Check whether the right hand side is the empty string (i.e. if
    645   // this is really a flat string in a cons string). If that is not
    646   // the case we would rather go to the runtime system now to flatten
    647   // the string.
    648   __ bind(&cons_string);
    649   __ lw(result, FieldMemOperand(string, ConsString::kSecondOffset));
    650   __ LoadRoot(at, Heap::kempty_stringRootIndex);
    651   __ Branch(call_runtime, ne, result, Operand(at));
    652   // Get the first of the two strings and load its instance type.
    653   __ lw(string, FieldMemOperand(string, ConsString::kFirstOffset));
    654   __ jmp(&indirect_string_loaded);
    655 
    656   // Distinguish sequential and external strings. Only these two string
    657   // representations can reach here (slices and flat cons strings have been
    658   // reduced to the underlying sequential or external string).
    659   Label external_string, check_encoding;
    660   __ bind(&check_sequential);
    661   STATIC_ASSERT(kSeqStringTag == 0);
    662   __ And(at, result, Operand(kStringRepresentationMask));
    663   __ Branch(&external_string, ne, at, Operand(zero_reg));
    664 
    665   // Prepare sequential strings
    666   STATIC_ASSERT(SeqTwoByteString::kHeaderSize == SeqOneByteString::kHeaderSize);
    667   __ Addu(string,
    668           string,
    669           SeqTwoByteString::kHeaderSize - kHeapObjectTag);
    670   __ jmp(&check_encoding);
    671 
    672   // Handle external strings.
    673   __ bind(&external_string);
    674   if (FLAG_debug_code) {
    675     // Assert that we do not have a cons or slice (indirect strings) here.
    676     // Sequential strings have already been ruled out.
    677     __ And(at, result, Operand(kIsIndirectStringMask));
    678     __ Assert(eq, kExternalStringExpectedButNotFound,
    679         at, Operand(zero_reg));
    680   }
    681   // Rule out short external strings.
    682   STATIC_ASSERT(kShortExternalStringTag != 0);
    683   __ And(at, result, Operand(kShortExternalStringMask));
    684   __ Branch(call_runtime, ne, at, Operand(zero_reg));
    685   __ lw(string, FieldMemOperand(string, ExternalString::kResourceDataOffset));
    686 
    687   Label one_byte, done;
    688   __ bind(&check_encoding);
    689   STATIC_ASSERT(kTwoByteStringTag == 0);
    690   __ And(at, result, Operand(kStringEncodingMask));
    691   __ Branch(&one_byte, ne, at, Operand(zero_reg));
    692   // Two-byte string.
    693   __ Lsa(at, string, index, 1);
    694   __ lhu(result, MemOperand(at));
    695   __ jmp(&done);
    696   __ bind(&one_byte);
    697   // One_byte string.
    698   __ Addu(at, string, index);
    699   __ lbu(result, MemOperand(at));
    700   __ bind(&done);
    701 }
    702 
    703 #ifdef DEBUG
    704 // nop(CODE_AGE_MARKER_NOP)
    705 static const uint32_t kCodeAgePatchFirstInstruction = 0x00010180;
    706 #endif
    707 
    708 
    709 CodeAgingHelper::CodeAgingHelper(Isolate* isolate) {
    710   USE(isolate);
    711   DCHECK(young_sequence_.length() == kNoCodeAgeSequenceLength);
    712   // Since patcher is a large object, allocate it dynamically when needed,
    713   // to avoid overloading the stack in stress conditions.
    714   // DONT_FLUSH is used because the CodeAgingHelper is initialized early in
    715   // the process, before MIPS simulator ICache is setup.
    716   std::unique_ptr<CodePatcher> patcher(
    717       new CodePatcher(isolate, young_sequence_.start(),
    718                       young_sequence_.length() / Assembler::kInstrSize,
    719                       CodePatcher::DONT_FLUSH));
    720   PredictableCodeSizeScope scope(patcher->masm(), young_sequence_.length());
    721   patcher->masm()->PushStandardFrame(a1);
    722   patcher->masm()->nop(Assembler::CODE_AGE_SEQUENCE_NOP);
    723 }
    724 
    725 
    726 #ifdef DEBUG
    727 bool CodeAgingHelper::IsOld(byte* candidate) const {
    728   return Memory::uint32_at(candidate) == kCodeAgePatchFirstInstruction;
    729 }
    730 #endif
    731 
    732 
    733 bool Code::IsYoungSequence(Isolate* isolate, byte* sequence) {
    734   bool result = isolate->code_aging_helper()->IsYoung(sequence);
    735   DCHECK(result || isolate->code_aging_helper()->IsOld(sequence));
    736   return result;
    737 }
    738 
    739 Code::Age Code::GetCodeAge(Isolate* isolate, byte* sequence) {
    740   if (IsYoungSequence(isolate, sequence)) return kNoAgeCodeAge;
    741 
    742   Address target_address =
    743       Assembler::target_address_at(sequence + Assembler::kInstrSize);
    744   Code* stub = GetCodeFromTargetAddress(target_address);
    745   return GetAgeOfCodeAgeStub(stub);
    746 }
    747 
    748 void Code::PatchPlatformCodeAge(Isolate* isolate, byte* sequence,
    749                                 Code::Age age) {
    750   uint32_t young_length = isolate->code_aging_helper()->young_sequence_length();
    751   if (age == kNoAgeCodeAge) {
    752     isolate->code_aging_helper()->CopyYoungSequenceTo(sequence);
    753     Assembler::FlushICache(isolate, sequence, young_length);
    754   } else {
    755     Code* stub = GetCodeAgeStub(isolate, age);
    756     CodePatcher patcher(isolate, sequence,
    757                         young_length / Assembler::kInstrSize);
    758     // Mark this code sequence for FindPlatformCodeAgeSequence().
    759     patcher.masm()->nop(Assembler::CODE_AGE_MARKER_NOP);
    760     // Load the stub address to t9 and call it,
    761     // GetCodeAge() extracts the stub address from this instruction.
    762     patcher.masm()->li(
    763         t9,
    764         Operand(reinterpret_cast<uint32_t>(stub->instruction_start())),
    765         CONSTANT_SIZE);
    766     patcher.masm()->nop();  // Prevent jalr to jal optimization.
    767     patcher.masm()->jalr(t9, a0);
    768     patcher.masm()->nop();  // Branch delay slot nop.
    769     patcher.masm()->nop();  // Pad the empty space.
    770   }
    771 }
    772 
    773 
    774 #undef __
    775 
    776 }  // namespace internal
    777 }  // namespace v8
    778 
    779 #endif  // V8_TARGET_ARCH_MIPS
    780