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-rw-r--r--amd64/emit.c48
-rw-r--r--amd64/isel.c33
2 files changed, 62 insertions, 19 deletions
diff --git a/amd64/emit.c b/amd64/emit.c
index df4c4cd..7c88955 100644
--- a/amd64/emit.c
+++ b/amd64/emit.c
@@ -240,14 +240,21 @@ opermatch(enum operpat pat, struct oper oper)
#define DS(S) D(S, sizeof S - 1)
static bool usebp; /* use RBP? */
+static const char *curfnsym;
+static uchar *fnstart;
/* Given an instruction description table, find the first entry that matches
* the operands (where dst, src are the operands in intel syntax order) and encode it */
static void
encode(uchar **pcode, const struct desc *tab, int ntab, enum irclass k, struct oper dst, struct oper src)
{
- const uchar *opc; int nopc, mod, rex;
- bool sib = 0; uchar reg; struct oper mem; const struct desc *en = NULL;
+ const uchar *opc;
+ int nopc, mod, rex;
+ const char *sym;
+ uchar reg;
+ struct oper mem;
+ bool sib = 0;
+ const struct desc *en = NULL;
for (int i = 0; i < ntab; ++i) {
if ((tab[i].psiz & cls2siz[k]) && opermatch(tab[i].ptd, dst) && opermatch(tab[i].pts, src)) {
@@ -313,16 +320,17 @@ encode(uchar **pcode, const struct desc *tab, int ntab, enum irclass k, struct o
else if (en->r8 && in_range(reg, RSP, RDI)) B(0x40);
if (mem.t == OSYM) {
- /* XXX PIC */
D(opc, nopc);
if (mem.cindex == NOINDEX) {
/* %rip(var) */
static uchar offs[NOPERENC] = { [EN_MI8] = 1, [EN_MI16] = 2, [EN_MI32] = 4 };
+ enum relockind r = (!conht[mem.con].deref && ccopt.pic) ? (rex ? REL_GOTPCRELX : REL_GOTPCRELX_REX) : REL_PCREL32;
int off = -4 - offs[en->operenc];
B(/*mod 0*/ (reg & 7) << 3 | RBP);
- objreloc(xcon2sym(mem.con), REL_PCREL32, Stext, *pcode - objout.textbegin, mem.disp + off);
+ objreloc(xcon2sym(mem.con), r, Stext, *pcode - objout.textbegin, mem.disp + off);
} else {
/* var(,%reg,shift) */
+ assert(!ccopt.pic && !ccopt.pie && "cannot encode [RIP-rel + REG] for position independent");
B(/*mod 0*/ (reg & 7) << 3 | RSP);
B(mem.cshift << 6 | mem.cindex << 3 | RBP); /* SIB [index*s + disp32] */
objreloc(xcon2sym(mem.con), REL_ABS32S, Stext, *pcode - objout.textbegin, mem.disp);
@@ -393,8 +401,15 @@ encode(uchar **pcode, const struct desc *tab, int ntab, enum irclass k, struct o
if (rex) B(0x40 | rex);
D(opc, nopc);
assert(dst.t == OSYM);
- objreloc(xcon2sym(dst.con), REL_PCREL32, Stext, *pcode - objout.textbegin, -4);
- I32(0);
+ sym = xcon2sym(dst.con);
+ if (sym != curfnsym) {
+ enum relockind r = (ccopt.pie|ccopt.pic) ? REL_PLT32 : REL_PCREL32;
+ objreloc(sym, r, Stext, *pcode - objout.textbegin, -4);
+ I32(0);
+ } else {
+ /* self-recursive call */
+ I32(fnstart - *pcode - 4);
+ }
break;
}
}
@@ -478,6 +493,7 @@ DEFINSTR2(Xxchg,
)
DEFINSTR2(Xlea,
{4|8, PGPR, PMEM, "\x8D", EN_RM}, /* LEA r32/64,m32/64 */
+ { 8, PGPR, PSYM, "\x8D", EN_RM}, /* LEA rel32 */
)
DEFINSTR2(Xadd,
{4|8, PGPR, PGPR, "\x03", EN_RR}, /* ADD r32/64, r32/64 */
@@ -764,12 +780,22 @@ gencopy(uchar **pcode, enum irclass cls, struct block *blk, int curi, struct ope
}
/* normal (not 2-address) case */
Lea:
+ if (isaddrcon(addr->base) && ccopt.pic) {
+ assert(!addr->disp && !addr->index.bits);
+ val = addr->base;
+ goto GOTLoad;
+ }
Xlea(pcode, cls, dst, ref2oper(val));
} else if (val.bits == ZEROREF.bits && dst.t == OREG && !flagslivep(blk, curi)) {
/* dst = 0 -> xor dst, dst; but only if it is ok to clobber flags */
Xxor(pcode, kisint(cls) ? KI4 : cls, dst, dst);
} else if (isaddrcon(val)) {
- Xlea(pcode, cls, dst, mkoper(OSYM, .con = val.i, .cindex = NOINDEX));
+ if (ccopt.pic) GOTLoad:
+ /* for mov reg, [rip(sym@GOTPCREL)] */
+ Xmov(pcode, cls, dst, mkoper(OSYM, .con = val.i, .cindex = NOINDEX));
+ else
+ /* for lea reg, [rip(sym)] */
+ Xlea(pcode, cls, dst, mkoper(OSYM, .con = val.i, .cindex = NOINDEX));
} else {
struct oper src = mkimmdatregoper(val);
if (memcmp(&dst, &src, sizeof dst) != 0)
@@ -1067,7 +1093,6 @@ emitbin(struct function *fn)
{
struct block *blk;
uchar **pcode = &objout.code;
- uchar *start;
int npush = 0;
uint epilogueaddr = 0;
bool saverestore;
@@ -1079,7 +1104,8 @@ emitbin(struct function *fn)
memset(blkaddr, 0, nblkaddr * sizeof *blkaddr);
nops(pcode, 16);
- start = *pcode;
+ fnstart = *pcode;
+ curfnsym = fn->name;
/** prologue **/
@@ -1129,7 +1155,7 @@ emitbin(struct function *fn)
}
if (blk->jmp.t == Jret) {
/* epilogue */
- uint here = *pcode - start;
+ uint here = *pcode - fnstart;
if (epilogueaddr) {
int disp = epilogueaddr - (here + 2);
if ((uint)(disp + 128) < 256) {/* can use 1-byte displacement? */
@@ -1149,7 +1175,7 @@ emitbin(struct function *fn)
}
} else emitbranch(pcode, blk);
} while ((blk = blk->lnext) != fn->entry);
- objdeffunc(fn->name, fn->globl, start - objout.textbegin, *pcode - start);
+ objdeffunc(fn->name, fn->globl, fnstart - objout.textbegin, *pcode - fnstart);
}
void
diff --git a/amd64/isel.c b/amd64/isel.c
index fcd4ab3..1054502 100644
--- a/amd64/isel.c
+++ b/amd64/isel.c
@@ -44,6 +44,13 @@ static const uchar opflags[] = {
static int iflagsrc = -1;
static void
+picfixsym(union ref *r, struct block *blk, int *curi)
+{
+ if (!ccopt.pic || !isaddrcon(*r)) return;
+ *r = insertinstr(blk, (*curi)++, mkinstr(Ocopy, KPTR, .l = *r));
+}
+
+static void
fixarg(union ref *r, struct instr *ins, struct block *blk, int *curi)
{
int sh;
@@ -72,6 +79,7 @@ fixarg(union ref *r, struct instr *ins, struct block *blk, int *curi)
wr32le(data, pun.i);
}
*r = mkdatref(NULL, siz, /*align*/siz, data, siz, /*deref*/1);
+ picfixsym(r, blk, curi);
} else if (in_range(op, Odiv, Ourem) && kisint(ins->cls))
goto DivImm;
} else if (r->t == RICON && in_range(op, Odiv, Ourem) && kisint(ins->cls)) {
@@ -195,9 +203,7 @@ aadd(struct addr *addr, union ref r)
} else if (isnumcon(r)) {
return acon(addr, r);
} else if (isaddrcon(r)) {
- /* XXX PIC */
if (!addr->base.bits && !isaddrcon(addr->index)) addr->base = r;
- else if (!addr->index.bits && !isaddrcon(addr->base)) addr->index = r;
else return 0;
} else if (r.t == RREG) {
/* temporaries are single assignment, but register aren't, so they can't be *
@@ -212,7 +218,7 @@ aadd(struct addr *addr, union ref r)
}
static bool
-fuseaddr(union ref *r)
+fuseaddr(union ref *r, struct block *blk, int *curi)
{
struct addr addr = { 0 };
@@ -221,6 +227,15 @@ fuseaddr(union ref *r)
if (r->t != RTMP) return 0;
if (!aadd(&addr, *r)) return 0;
+ if (ccopt.pic || (ccopt.pie && isaddrcon(addr.base) && addr.index.bits)) {
+ /* pic needs to load from GOT */
+ /* pie cannot encode RIP-relative address with index register */
+ /* first load symbol address into a temp register */
+ union ref temp = mkaddr((struct addr){.base = addr.base, .disp = ccopt.pic ? 0 : addr.disp});
+ addr.base = insertinstr(blk, (*curi)++, mkinstr(Ocopy, KPTR, .l = temp));
+ if (!ccopt.pic) addr.disp = 0;
+ }
+
*r = mkaddr(addr);
return 1;
}
@@ -318,7 +333,7 @@ sel(struct function *fn, struct instr *ins, struct block *blk, int *curi)
/* sub x,1 -> dec x */
ins->op = op = Oxdec;
ins->r = NOREF;
- } else if (iscon(ins->l)) {
+ } else if (isintcon(ins->l)) {
/* sub imm, x -> sub x, imm; neg x */
struct instr sub = *ins;
rswap(sub.l, sub.r);
@@ -333,7 +348,7 @@ sel(struct function *fn, struct instr *ins, struct block *blk, int *curi)
temp.op = Ocopy;
temp.cls = ins->cls;
temp.l = mkref(RTMP, ins - instrtab);
- if (fuseaddr(&temp.l)) {
+ if (fuseaddr(&temp.l, blk, curi)) {
*ins = temp;
break;
}
@@ -362,19 +377,21 @@ sel(struct function *fn, struct instr *ins, struct block *blk, int *curi)
if (!(in_range(op, Omul, Oumul) && kisint(ins->cls) && isimm32(ins->r))) /* for (I)MUL r,r/m,imm */
ins->inplace = 1;
if (iscon(ins->l))
- ins->l = insertinstr(blk, (*curi)++, mkinstr(Ocopy, concls(ins->l), ins->l));
+ ins->l = insertinstr(blk, (*curi)++, mkinstr(Ocopy, ins->cls, ins->l));
if (ins->r.bits)
case Omove:
fixarg(&ins->r, ins, blk, curi);
break;
case Oloads1: case Oloadu1: case Oloads2: case Oloadu2:
case Oloads4: case Oloadu4: case Oloadi8: case Oloadf4: case Oloadf8:
- if (!fuseaddr(&ins->l) && ins->l.t != RTMP && ins->l.t != RREG)
+ if (!fuseaddr(&ins->l, blk, curi) && ins->l.t != RTMP && ins->l.t != RREG)
ins->l = insertinstr(blk, (*curi)++, mkinstr(Ocopy, KPTR, ins->l));
+ picfixsym(&ins->l, blk, curi);
break;
case Ostore1: case Ostore2: case Ostore4: case Ostore8:
- if (!fuseaddr(&ins->l) && ins->l.t != RTMP && ins->l.t != RREG)
+ if (!fuseaddr(&ins->l, blk, curi) && ins->l.t != RTMP && ins->l.t != RREG)
ins->l = insertinstr(blk, (*curi)++, mkinstr(Ocopy, KPTR, ins->l));
+ picfixsym(&ins->l, blk, curi);
fixarg(&ins->r, ins, blk, curi);
break;
case Ocvtf4f8: case Ocvtf8f4: case Ocvtf4s: case Ocvtf8s:
generated by cgit v1.2.3 (git 2.39.1) at 2026-05-02 00:33:07 +0000