arm64/isel.c

   1 #include "all.h"
   2
   3 enum Imm {
   4         Iother,
   5         Iplo12,
   6         Iphi12,
   7         Iplo24,
   8         Inlo12,
   9         Inhi12,
  10         Inlo24
  11 };
  12
  13 static enum Imm
  14 imm(Con *c, int k, int64_t *pn)
  15 {
  16         int64_t n;
  17         int i;
  18
  19         if (c->type != CBits)
  20                 return Iother;
  21         n = c->bits.i;
  22         if (k == Kw)
  23                 n = (int32_t)n;
  24         i = Iplo12;
  25         if (n < 0) {
  26                 i = Inlo12;
  27                 n = -n;
  28         }
  29         *pn = n;
  30         if ((n & 0x000fff) == n)
  31                 return i;
  32         if ((n & 0xfff000) == n)
  33                 return i + 1;
  34         if ((n & 0xffffff) == n)
  35                 return i + 2;
  36         return Iother;
  37 }
  38
  39 int
  40 arm64_logimm(uint64_t x, int k)
  41 {
  42         uint64_t n;
  43
  44         if (k == Kw)
  45                 x = (x & 0xffffffff) | x << 32;
  46         if (x & 1)
  47                 x = ~x;
  48         if (x == 0)
  49                 return 0;
  50         if (x == 0xaaaaaaaaaaaaaaaa)
  51                 return 1;
  52         n = x & 0xf;
  53         if (0x1111111111111111 * n == x)
  54                 goto Check;
  55         n = x & 0xff;
  56         if (0x0101010101010101 * n == x)
  57                 goto Check;
  58         n = x & 0xffff;
  59         if (0x0001000100010001 * n == x)
  60                 goto Check;
  61         n = x & 0xffffffff;
  62         if (0x0000000100000001 * n == x)
  63                 goto Check;
  64         n = x;
  65 Check:
  66         return (n & (n + (n & -n))) == 0;
  67 }
  68
  69 static void
  70 fixarg(Ref *pr, int k, int phi, Fn *fn)
  71 {
  72         char buf[32];
  73         Con *c, cc;
  74         Ref r0, r1, r2, r3;
  75         int s, n;
  76
  77         r0 = *pr;
  78         switch (rtype(r0)) {
  79         case RCon:
  80                 c = &fn->con[r0.val];
  81                 if (T.apple
  82                 && c->type == CAddr
  83                 && c->sym.type == SThr) {
  84                         r1 = newtmp("isel", Kl, fn);
  85                         *pr = r1;
  86                         if (c->bits.i) {
  87                                 r2 = newtmp("isel", Kl, fn);
  88                                 cc = (Con){.type = CBits};
  89                                 cc.bits.i = c->bits.i;
  90                                 r3 = newcon(&cc, fn);
  91                                 emit(Oadd, Kl, r1, r2, r3);
  92                                 r1 = r2;
  93                         }
  94                         emit(Ocopy, Kl, r1, TMP(R0), R);
  95                         r1 = newtmp("isel", Kl, fn);
  96                         r2 = newtmp("isel", Kl, fn);
  97                         emit(Ocall, 0, R, r1, CALL(33));
  98                         emit(Ocopy, Kl, TMP(R0), r2, R);
  99                         emit(Oload, Kl, r1, r2, R);
 100                         cc = *c;
 101                         cc.bits.i = 0;
 102                         r3 = newcon(&cc, fn);
 103                         emit(Ocopy, Kl, r2, r3, R);
 104                         break;
 105                 }
 106                 if (KBASE(k) == 0 && phi)
 107                         return;
 108                 r1 = newtmp("isel", k, fn);
 109                 if (KBASE(k) == 0) {
 110                         emit(Ocopy, k, r1, r0, R);
 111                 } else {
 112                         n = stashbits(&c->bits, KWIDE(k) ? 8 : 4);
 113                         vgrow(&fn->con, ++fn->ncon);
 114                         c = &fn->con[fn->ncon-1];
 115                         sprintf(buf, "%sfp%d", T.asloc, n);
 116                         *c = (Con){.type = CAddr};
 117                         c->sym.id = intern(buf);
 118                         r2 = newtmp("isel", Kl, fn);
 119                         emit(Oload, k, r1, r2, R);
 120                         emit(Ocopy, Kl, r2, CON(c-fn->con), R);
 121                 }
 122                 *pr = r1;
 123                 break;
 124         case RTmp:
 125                 s = fn->tmp[r0.val].slot;
 126                 if (s == -1)
 127                         break;
 128                 r1 = newtmp("isel", Kl, fn);
 129                 emit(Oaddr, Kl, r1, SLOT(s), R);
 130                 *pr = r1;
 131                 break;
 132         }
 133 }
 134
 135 static int
 136 selcmp(Ref arg[2], int k, Fn *fn)
 137 {
 138         Ref r, *iarg;
 139         Con *c;
 140         int swap, cmp, fix;
 141         int64_t n;
 142
 143         if (KBASE(k) == 1) {
 144                 emit(Oafcmp, k, R, arg[0], arg[1]);
 145                 iarg = curi->arg;
 146                 fixarg(&iarg[0], k, 0, fn);
 147                 fixarg(&iarg[1], k, 0, fn);
 148                 return 0;
 149         }
 150         swap = rtype(arg[0]) == RCon;
 151         if (swap) {
 152                 r = arg[1];
 153                 arg[1] = arg[0];
 154                 arg[0] = r;
 155         }
 156         fix = 1;
 157         cmp = Oacmp;
 158         r = arg[1];
 159         if (rtype(r) == RCon) {
 160                 c = &fn->con[r.val];
 161                 switch (imm(c, k, &n)) {
 162                 default:
 163                         break;
 164                 case Iplo12:
 165                 case Iphi12:
 166                         fix = 0;
 167                         break;
 168                 case Inlo12:
 169                 case Inhi12:
 170                         cmp = Oacmn;
 171                         r = getcon(n, fn);
 172                         fix = 0;
 173                         break;
 174                 }
 175         }
 176         emit(cmp, k, R, arg[0], r);
 177         iarg = curi->arg;
 178         fixarg(&iarg[0], k, 0, fn);
 179         if (fix)
 180                 fixarg(&iarg[1], k, 0, fn);
 181         return swap;
 182 }
 183
 184 static int
 185 callable(Ref r, Fn *fn)
 186 {
 187         Con *c;
 188
 189         if (rtype(r) == RTmp)
 190                 return 1;
 191         if (rtype(r) == RCon) {
 192                 c = &fn->con[r.val];
 193                 if (c->type == CAddr)
 194                 if (c->bits.i == 0)
 195                         return 1;
 196         }
 197         return 0;
 198 }
 199
 200 static void
 201 sel(Ins i, Fn *fn)
 202 {
 203         Ref *iarg;
 204         Ins *i0;
 205         int ck, cc;
 206
 207         if (INRANGE(i.op, Oalloc, Oalloc1)) {
 208                 i0 = curi - 1;
 209                 salloc(i.to, i.arg[0], fn);
 210                 fixarg(&i0->arg[0], Kl, 0, fn);
 211                 return;
 212         }
 213         if (iscmp(i.op, &ck, &cc)) {
 214                 emit(Oflag, i.cls, i.to, R, R);
 215                 i0 = curi;
 216                 if (selcmp(i.arg, ck, fn))
 217                         i0->op += cmpop(cc);
 218                 else
 219                         i0->op += cc;
 220                 return;
 221         }
 222         if (i.op == Ocall)
 223         if (callable(i.arg[0], fn)) {
 224                 emiti(i);
 225                 return;
 226         }
 227         if (i.op != Onop) {
 228                 emiti(i);
 229                 iarg = curi->arg; /* fixarg() can change curi */
 230                 fixarg(&iarg[0], argcls(&i, 0), 0, fn);
 231                 fixarg(&iarg[1], argcls(&i, 1), 0, fn);
 232         }
 233 }
 234
 235 static void
 236 seljmp(Blk *b, Fn *fn)
 237 {
 238         Ref r;
 239         Ins *i, *ir;
 240         int ck, cc, use;
 241
 242         if (b->jmp.type == Jret0
 243         || b->jmp.type == Jjmp
 244         || b->jmp.type == Jhlt)
 245                 return;
 246         assert(b->jmp.type == Jjnz);
 247         r = b->jmp.arg;
 248         use = -1;
 249         b->jmp.arg = R;
 250         ir = 0;
 251         i = &b->ins[b->nins];
 252         while (i > b->ins)
 253                 if (req((--i)->to, r)) {
 254                         use = fn->tmp[r.val].nuse;
 255                         ir = i;
 256                         break;
 257                 }
 258         if (ir && use == 1
 259         && iscmp(ir->op, &ck, &cc)) {
 260                 if (selcmp(ir->arg, ck, fn))
 261                         cc = cmpop(cc);
 262                 b->jmp.type = Jjf + cc;
 263                 *ir = (Ins){.op = Onop};
 264         }
 265         else {
 266                 selcmp((Ref[]){r, CON_Z}, Kw, fn);
 267                 b->jmp.type = Jjfine;
 268         }
 269 }
 270
 271 void
 272 arm64_isel(Fn *fn)
 273 {
 274         Blk *b, **sb;
 275         Ins *i;
 276         Phi *p;
 277         uint n, al;
 278         int64_t sz;
 279
 280         /* assign slots to fast allocs */
 281         b = fn->start;
 282         /* specific to NAlign == 3 */ /* or change n=4 and sz /= 4 below */
 283         for (al=Oalloc, n=4; al<=Oalloc1; al++, n*=2)
 284                 for (i=b->ins; i<&b->ins[b->nins]; i++)
 285                         if (i->op == al) {
 286                                 if (rtype(i->arg[0]) != RCon)
 287                                         break;
 288                                 sz = fn->con[i->arg[0].val].bits.i;
 289                                 if (sz < 0 || sz >= INT_MAX-15)
 290                                         err("invalid alloc size %"PRId64, sz);
 291                                 sz = (sz + n-1) & -n;
 292                                 sz /= 4;
 293                                 fn->tmp[i->to.val].slot = fn->slot;
 294                                 fn->slot += sz;
 295                                 *i = (Ins){.op = Onop};
 296                         }
 297
 298         for (b=fn->start; b; b=b->link) {
 299                 curi = &insb[NIns];
 300                 for (sb=(Blk*[3]){b->s1, b->s2, 0}; *sb; sb++)
 301                         for (p=(*sb)->phi; p; p=p->link) {
 302                                 for (n=0; p->blk[n] != b; n++)
 303                                         assert(n+1 < p->narg);
 304                                 fixarg(&p->arg[n], p->cls, 1, fn);
 305                         }
 306                 seljmp(b, fn);
 307                 for (i=&b->ins[b->nins]; i!=b->ins;)
 308                         sel(*--i, fn);
 309                 b->nins = &insb[NIns] - curi;
 310                 idup(&b->ins, curi, b->nins);
 311         }
 312
 313         if (debug['I']) {
 314                 fprintf(stderr, "\n> After instruction selection:\n");
 315                 printfn(fn, stderr);
 316         }
 317 }