move abi code in a new file

1 files changed, 512 insertions, 0 deletions

diff --git a/sysv.c b/sysv.c
new file mode 100644
index 0000000..78c2f07
--- /dev/null
+++ b/sysv.c
@@ -0,0 +1,512 @@
+#include "all.h"
+
+typedef struct AClass AClass;
+typedef struct RAlloc RAlloc;
+
+struct AClass {
+	int inmem;
+	int align;
+	uint size;
+	int cls[2];
+};
+
+static void
+aclass(AClass *a, Typ *t)
+{
+	int e, s, n, cls;
+	uint sz, al;
+
+	sz = t->size;
+	al = 1u << t->align;
+
+	/* the ABI requires sizes to be rounded
+	 * up to the nearest multiple of 8, moreover
+	 * it makes it easy load and store structures
+	 * in registers
+	 */
+	if (al < 8)
+		al = 8;
+	sz = (sz + al-1) & -al;
+
+	a->size = sz;
+	a->align = t->align;
+
+	if (t->dark || sz > 16) {
+		/* large or unaligned structures are
+		 * required to be passed in memory
+		 */
+		a->inmem = 1;
+		return;
+	}
+
+	a->inmem = 0;
+	for (e=0, s=0; e<2; e++) {
+		cls = -1;
+		for (n=0; n<8 && t->seg[s].len; s++) {
+			if (t->seg[s].ispad) {
+				/* don't change anything */
+			}
+			else if (t->seg[s].isflt) {
+				if (cls == -1)
+					cls = Kd;
+			}
+			else
+				cls = Kl;
+			n += t->seg[s].len;
+		}
+		assert(n <= 8);
+		a->cls[e] = cls;
+	}
+}
+
+static void
+blit(Ref rstk, uint soff, Ref rsrc, uint sz, Fn *fn)
+{
+	Ref r, r1;
+	uint boff;
+
+	/* it's an impolite blit, we might go across the end
+	 * of the source object a little bit... */
+	for (boff=0; sz>0; sz-=8, soff+=8, boff+=8) {
+		r = newtmp("abi", Kl, fn);
+		r1 = newtmp("abi", Kl, fn);
+		emit(OStorel, 0, R, r, r1);
+		emit(OAdd, Kl, r1, rstk, getcon(soff, fn));
+		r1 = newtmp("abi", Kl, fn);
+		emit(OLoad, Kl, r, r1, R);
+		emit(OAdd, Kl, r1, rsrc, getcon(boff, fn));
+		chuse(rsrc, +1, fn);
+		chuse(rstk, +1, fn);
+	}
+}
+
+static int
+retr(Ref reg[2], AClass *aret)
+{
+	static int retreg[2][2] = {{RAX, RDX}, {XMM0, XMM0+1}};
+	int n, k, ca, nr[2];
+
+	nr[0] = nr[1] = 0;
+	ca = 0;
+	for (n=0; aret->cls[n]>=0 && n<2; n++) {
+		k = KBASE(aret->cls[n]);
+		reg[n] = TMP(retreg[k][nr[k]++]);
+		ca += 1 << (2 * k);
+	}
+	return ca;
+}
+
+static void
+selret(Blk *b, Fn *fn)
+{
+	int j, k, ca;
+	Ref r, r0, reg[2];
+	AClass aret;
+
+	j = b->jmp.type;
+
+	if (!isret(j) || j == JRet0)
+		return;
+
+	r0 = b->jmp.arg;
+	b->jmp.type = JRet0;
+
+	if (j == JRetc) {
+		aclass(&aret, &typ[fn->retty]);
+		if (aret.inmem) {
+			assert(rtype(fn->retr) == RTmp);
+			emit(OCopy, Kl, TMP(RAX), fn->retr, R);
+			chuse(fn->retr, +1, fn);
+			blit(fn->retr, 0, r0, aret.size, fn);
+			ca = 1;
+		} else {
+			ca = retr(reg, &aret);
+			if (aret.size > 8) {
+				r = newtmp("abi", Kl, fn);
+				emit(OLoad, Kl, reg[1], r, R);
+				emit(OAdd, Kl, r, r0, getcon(8, fn));
+				chuse(r0, +1, fn);
+			}
+			emit(OLoad, Kl, reg[0], r0, R);
+		}
+	} else {
+		k = j - JRetw;
+		if (KBASE(k) == 0) {
+			emit(OCopy, k, TMP(RAX), r0, R);
+			ca = 1;
+		} else {
+			emit(OCopy, k, TMP(XMM0), r0, R);
+			ca = 1 << 2;
+		}
+	}
+
+	b->jmp.arg = CALL(ca);
+}
+
+static int
+classify(Ins *i0, Ins *i1, AClass *ac, int op, AClass *aret)
+{
+	int nint, ni, nsse, ns, n, *pn;
+	AClass *a;
+	Ins *i;
+
+	if (aret && aret->inmem)
+		nint = 5; /* hidden argument */
+	else
+		nint = 6;
+	nsse = 8;
+	for (i=i0, a=ac; i<i1; i++, a++) {
+		if (i->op == op) {
+			if (KBASE(i->cls) == 0)
+				pn = &nint;
+			else
+				pn = &nsse;
+			if (*pn > 0) {
+				--*pn;
+				a->inmem = 0;
+			} else
+				a->inmem = 2;
+			a->align = 3;
+			a->size = 8;
+			a->cls[0] = i->cls;
+		} else {
+			n = i->arg[0].val & AMask;
+			aclass(a, &typ[n]);
+			if (a->inmem)
+				continue;
+			ni = ns = 0;
+			for (n=0; n<2; n++)
+				if (KBASE(a->cls[n]) == 0)
+					ni++;
+				else
+					ns++;
+			if (nint >= ni && nsse >= ns) {
+				nint -= ni;
+				nsse -= ns;
+			} else
+				a->inmem = 1;
+		}
+	}
+
+	return ((6-nint) << 4) | ((8-nsse) << 8);
+}
+
+int rsave[] = {
+	RDI, RSI, RDX, RCX, R8, R9, R10, R11, RAX,
+	XMM0, XMM1, XMM2, XMM3, XMM4, XMM5, XMM6, XMM7,
+	XMM8, XMM9, XMM10, XMM11, XMM12, XMM13, XMM14
+};
+int rclob[] = {RBX, R12, R13, R14, R15};
+
+MAKESURE(rsave_has_correct_size, sizeof rsave == NRSave * sizeof(int));
+MAKESURE(rclob_has_correct_size, sizeof rclob == NRClob * sizeof(int));
+
+bits
+retregs(Ref r, int p[2])
+{
+	bits b;
+	int ni, nf;
+
+	assert(rtype(r) == RACall);
+	b = 0;
+	ni = r.val & 3;
+	nf = (r.val >> 2) & 3;
+	if (ni >= 1)
+		b |= BIT(RAX);
+	if (ni >= 2)
+		b |= BIT(RDX);
+	if (nf >= 1)
+		b |= BIT(XMM0);
+	if (nf >= 2)
+		b |= BIT(XMM1);
+	if (p) {
+		p[0] = ni;
+		p[1] = nf;
+	}
+	return b;
+}
+
+bits
+argregs(Ref r, int p[2])
+{
+	bits b;
+	int j, ni, nf;
+
+	assert(rtype(r) == RACall);
+	b = 0;
+	ni = (r.val >> 4) & 15;
+	nf = (r.val >> 8) & 15;
+	for (j=0; j<ni; j++)
+		b |= BIT(rsave[j]);
+	for (j=0; j<nf; j++)
+		b |= BIT(XMM0+j);
+	if (p) {
+		p[0] = ni + 1;
+		p[1] = nf;
+	}
+	return b | BIT(RAX);
+}
+
+static Ref
+rarg(int ty, int *ni, int *ns)
+{
+	if (KBASE(ty) == 0)
+		return TMP(rsave[(*ni)++]);
+	else
+		return TMP(XMM0 + (*ns)++);
+}
+
+struct RAlloc {
+	Ins i;
+	RAlloc *link;
+};
+
+static void
+selcall(Fn *fn, Ins *i0, Ins *i1, RAlloc **rap)
+{
+	Ins *i;
+	AClass *ac, *a, aret;
+	int ca, ni, ns;
+	uint stk, off;
+	Ref r, r1, r2, reg[2], regcp[2];
+	RAlloc *ra;
+
+	ac = alloc((i1-i0) * sizeof ac[0]);
+	if (!req(i1->arg[1], R)) {
+		assert(rtype(i1->arg[1]) == RAType);
+		aclass(&aret, &typ[i1->arg[1].val & AMask]);
+		ca = classify(i0, i1, ac, OArg, &aret);
+	} else
+		ca = classify(i0, i1, ac, OArg, 0);
+
+	for (stk=0, a=&ac[i1-i0]; a>ac;)
+		if ((--a)->inmem) {
+			assert(a->align <= 4);
+			stk += a->size;
+			if (a->align == 4)
+				stk += stk & 15;
+		}
+	stk += stk & 15;
+	if (stk) {
+		r = getcon(-(int64_t)stk, fn);
+		emit(OSAlloc, Kl, R, r, R);
+	}
+
+	if (!req(i1->arg[1], R)) {
+		if (aret.inmem) {
+			/* get the return location from eax
+			 * it saves one callee-save reg */
+			r1 = newtmp("abi", Kl, fn);
+			emit(OCopy, Kl, i1->to, TMP(RAX), R);
+			ca += 1;
+		} else {
+			if (aret.size > 8) {
+				r = newtmp("abi", Kl, fn);
+				regcp[1] = newtmp("abi", aret.cls[1], fn);
+				emit(OStorel, 0, R, regcp[1], r);
+				emit(OAdd, Kl, r, i1->to, getcon(8, fn));
+				chuse(i1->to, +1, fn);
+				ca += 1 << (2 * KBASE(aret.cls[1]));
+			}
+			regcp[0] = newtmp("abi", aret.cls[0], fn);
+			emit(OStorel, 0, R, regcp[0], i1->to);
+			ca += 1 << (2 * KBASE(aret.cls[0]));
+			retr(reg, &aret);
+			if (aret.size > 8)
+				emit(OCopy, aret.cls[1], regcp[1], reg[1], R);
+			emit(OCopy, aret.cls[0], regcp[0], reg[0], R);
+			r1 = i1->to;
+		}
+		/* allocate return pad */
+		ra = alloc(sizeof *ra);
+		/* specific to NAlign == 3 */
+		aret.align -= 2;
+		if (aret.align < 0)
+			aret.align = 0;
+		ra->i.op = OAlloc + aret.align;
+		ra->i.cls = Kl;
+		ra->i.to = r1;
+		ra->i.arg[0] = getcon(aret.size, fn);
+		ra->link = (*rap);
+		*rap = ra;
+	} else {
+		ra = 0;
+		if (KBASE(i1->cls) == 0) {
+			emit(OCopy, i1->cls, i1->to, TMP(RAX), R);
+			ca += 1;
+		} else {
+			emit(OCopy, i1->cls, i1->to, TMP(XMM0), R);
+			ca += 1 << 2;
+		}
+	}
+	emit(OCall, i1->cls, R, i1->arg[0], CALL(ca));
+	emit(OCopy, Kw, TMP(RAX), getcon((ca >> 8) & 15, fn), R);
+
+	ni = ns = 0;
+	if (ra && aret.inmem)
+		emit(OCopy, Kl, rarg(Kl, &ni, &ns), ra->i.to, R); /* pass hidden argument */
+	for (i=i0, a=ac; i<i1; i++, a++) {
+		if (a->inmem)
+			continue;
+		r1 = rarg(a->cls[0], &ni, &ns);
+		if (i->op == OArgc) {
+			if (a->size > 8) {
+				r2 = rarg(a->cls[1], &ni, &ns);
+				r = newtmp("abi", Kl, fn);
+				emit(OLoad, a->cls[1], r2, r, R);
+				emit(OAdd, Kl, r, i->arg[1], getcon(8, fn));
+				chuse(i->arg[1], +1, fn);
+			}
+			emit(OLoad, a->cls[0], r1, i->arg[1], R);
+		} else
+			emit(OCopy, i->cls, r1, i->arg[0], R);
+	}
+
+	if (!stk)
+		return;
+
+	r = newtmp("abi", Kl, fn);
+	chuse(r, -1, fn);
+	for (i=i0, a=ac, off=0; i<i1; i++, a++) {
+		if (!a->inmem)
+			continue;
+		if (i->op == OArgc) {
+			if (a->align == 4)
+				off += off & 15;
+			blit(r, off, i->arg[1], a->size, fn);
+		} else {
+			r1 = newtmp("abi", Kl, fn);
+			emit(OStorel, 0, R, i->arg[0], r1);
+			emit(OAdd, Kl, r1, r, getcon(off, fn));
+			chuse(r, +1, fn);
+		}
+		off += a->size;
+	}
+	emit(OSAlloc, Kl, r, getcon(stk, fn), R);
+}
+
+static void
+selpar(Fn *fn, Ins *i0, Ins *i1)
+{
+	AClass *ac, *a, aret;
+	Ins *i;
+	int ni, ns, s, al;
+	Ref r, r1;
+
+	ac = alloc((i1-i0) * sizeof ac[0]);
+	curi = insb;
+	ni = ns = 0;
+
+	if (fn->retty >= 0) {
+		aclass(&aret, &typ[fn->retty]);
+		if (aret.inmem) {
+			r = newtmp("abi", Kl, fn);
+			*curi++ = (Ins){OCopy, r, {rarg(Kl, &ni, &ns)}, Kl};
+			fn->retr = r;
+		}
+		classify(i0, i1, ac, OPar, &aret);
+	} else
+		classify(i0, i1, ac, OPar, 0);
+
+	/* specific to NAlign == 3 */
+
+	s = 4;
+	for (i=i0, a=ac; i<i1; i++, a++) {
+		switch (a->inmem) {
+		case 1:
+			assert(a->align <= 4);
+			if (a->align == 4)
+				s = (s+3) & -4;
+			fn->tmp[i->to.val].slot = -s; /* HACK! */
+			s += a->size / 4;
+			continue;
+		case 2:
+			*curi++ = (Ins){OLoad, i->to, {SLOT(-s)}, i->cls};
+			s += 2;
+			continue;
+		}
+		r1 = rarg(a->cls[0], &ni, &ns);
+		if (i->op == OParc) {
+			r = newtmp("abi", Kl, fn);
+			*curi++ = (Ins){OCopy, r, {r1}, Kl};
+			a->cls[0] = r.val;
+			if (a->size > 8) {
+				r1 = rarg(a->cls[1], &ni, &ns);
+				r = newtmp("abi", Kl, fn);
+				*curi++ = (Ins){OCopy, r, {r1}, Kl};
+				a->cls[1] = r.val;
+			}
+		} else
+			*curi++ = (Ins){OCopy, i->to, {r1}, i->cls};
+	}
+	for (i=i0, a=ac; i<i1; i++, a++) {
+		if (i->op != OParc || a->inmem)
+			continue;
+		for (al=0; a->align >> (al+2); al++)
+			;
+		r = TMP(a->cls[0]);
+		r1 = i->to;
+		*curi++ = (Ins){OAlloc+al, r1, {getcon(a->size, fn)}, Kl};
+		*curi++ = (Ins){OStorel, R, {r, r1}, 0};
+		if (a->size > 8) {
+			r = newtmp("abi", Kl, fn);
+			*curi++ = (Ins){OAdd, r, {r1, getcon(8, fn)}, Kl};
+			r1 = TMP(a->cls[1]);
+			*curi++ = (Ins){OStorel, R, {r1, r}, 0};
+		}
+	}
+}
+
+void
+abi(Fn *fn)
+{
+	Blk *b;
+	Ins *i, *i0, *ip;
+	RAlloc *ral;
+	int n;
+
+	/* lower arguments */
+	for (b=fn->start, i=b->ins; i-b->ins < b->nins; i++)
+		if (i->op != OPar && i->op != OParc)
+			break;
+	selpar(fn, b->ins, i);
+	n = b->nins - (i - b->ins) + (curi - insb);
+	i0 = alloc(n * sizeof(Ins));
+	ip = icpy(ip = i0, insb, curi - insb);
+	ip = icpy(ip, i, &b->ins[b->nins] - i);
+	b->nins = n;
+	b->ins = i0;
+
+	/* lower calls and returns */
+	ral = 0;
+	b = fn->start;
+	do {
+		if (!(b = b->link))
+			b = fn->start; /* do it last */
+		curi = &insb[NIns];
+		selret(b, fn);
+		for (i=&b->ins[b->nins]; i!=b->ins;) {
+			if ((--i)->op == OCall) {
+				for (i0=i; i0>b->ins; i0--)
+					if ((i0-1)->op != OArg)
+					if ((i0-1)->op != OArgc)
+						break;
+				selcall(fn, i0, i, &ral);
+				i = i0;
+				continue;
+			}
+			assert(i->op != OArg && i->op != OArgc);
+			emiti(*i);
+		}
+		if (b == fn->start)
+			for (; ral; ral=ral->link)
+				emiti(ral->i);
+		b->nins = &insb[NIns] - curi;
+		idup(&b->ins, curi, b->nins);
+	} while (b != fn->start);
+
+	if (debug['A']) {
+		fprintf(stderr, "\n> After ABI lowering:\n");
+		printfn(fn, stderr);
+	}
+}