new layout, put LICENSE in root

1 files changed, 0 insertions, 1136 deletions

diff --git a/src/isel.c b/src/isel.c
deleted file mode 100644
index 2a55733..0000000
--- a/src/isel.c
+++ /dev/null
@@ -1,1136 +0,0 @@
-#include "all.h"
-#include <limits.h>
-
-/* For x86_64, do the following:
- *
- * - lower calls
- * - check that constants are used only in
- *   places allowed
- * - ensure immediates always fit in 32b
- * - explicit machine register contraints
- *   on instructions like division.
- * - implement fast locals (the streak of
- *   constant allocX in the first basic block)
- * - recognize complex addressing modes
- *
- * Invariant: the use counts that are used
- *            in sel() must be sound.  This
- *            is not so trivial, maybe the
- *            dce should be moved out...
- */
-
-typedef struct ANum ANum;
-typedef struct AClass AClass;
-typedef struct RAlloc RAlloc;
-
-struct ANum {
-	char n, l, r;
-	Ins *i;
-	Ref mem;
-};
-
-static void amatch(Addr *, Ref, ANum *, Fn *, int);
-
-static int
-fcmptoi(int fc)
-{
-	switch (fc) {
-	default:   diag("isel: fcmptoi defaulted");
-	case FCle: return ICule;
-	case FClt: return ICult;
-	case FCgt: return ICugt;
-	case FCge: return ICuge;
-	case FCne: return ICne;
-	case FCeq: return ICeq;
-	case FCo:  return ICXnp;
-	case FCuo: return ICXp;
-	}
-}
-
-static int
-iscmp(int op, int *pk, int *pc)
-{
-	int k, c;
-
-	if (OCmpw <= op && op <= OCmpw1) {
-		c = op - OCmpw;
-		k = Kw;
-	}
-	else if (OCmpl <= op && op <= OCmpl1) {
-		c = op - OCmpl;
-		k = Kl;
-	}
-	else if (OCmps <= op && op <= OCmps1) {
-		c = fcmptoi(op - OCmps);
-		k = Ks;
-	}
-	else if (OCmpd <= op && op <= OCmpd1) {
-		c = fcmptoi(op - OCmpd);
-		k = Kd;
-	}
-	else
-		return 0;
-	if (pk)
-		*pk = k;
-	if (pc)
-		*pc = c;
-	return 1;
-}
-
-static int
-noimm(Ref r, Fn *fn)
-{
-	int64_t val;
-
-	if (rtype(r) != RCon)
-		return 0;
-	switch (fn->con[r.val].type) {
-	default:
-		diag("isel: invalid constant");
-	case CAddr:
-		/* we only support the 'small'
-		 * code model of the ABI, this
-		 * means that we can always
-		 * address data with 32bits
-		 */
-		return 0;
-	case CBits:
-		val = fn->con[r.val].bits.i;
-		return (val < INT32_MIN || val > INT32_MAX);
-	}
-}
-
-static int
-rslot(Ref r, Fn *fn)
-{
-	if (rtype(r) != RTmp)
-		return -1;
-	return fn->tmp[r.val].slot;
-}
-
-static int
-argcls(Ins *i, int n)
-{
-	return opdesc[i->op].argcls[n][i->cls];
-}
-
-static void
-fixarg(Ref *r, int k, int phi, Fn *fn)
-{
-	Addr a;
-	Ref r0, r1;
-	int s, n;
-
-	r1 = r0 = *r;
-	s = rslot(r0, fn);
-	if (KBASE(k) == 1 && rtype(r0) == RCon) {
-		/* load floating points from memory
-		 * slots, they can't be used as
-		 * immediates
-		 */
-		r1 = MEM(fn->nmem);
-		vgrow(&fn->mem, ++fn->nmem);
-		memset(&a, 0, sizeof a);
-		a.offset.type = CAddr;
-		a.offset.local = 1;
-		n = stashfp(fn->con[r0.val].bits.i, KWIDE(k));
-		sprintf(a.offset.label, "fp%d", n);
-		fn->mem[fn->nmem-1] = a;
-	}
-	else if (!phi && k == Kl && noimm(r0, fn)) {
-		/* load constants that do not fit in
-		 * a 32bit signed integer into a
-		 * long temporary
-		 */
-		r1 = newtmp("isel", Kl, fn);
-		emit(OCopy, Kl, r1, r0, R);
-	}
-	else if (s != -1) {
-		/* load fast locals' addresses into
-		 * temporaries right before the
-		 * instruction
-		 */
-		r1 = newtmp("isel", Kl, fn);
-		emit(OAddr, Kl, r1, SLOT(s), R);
-	}
-	*r = r1;
-}
-
-static void
-chuse(Ref r, int du, Fn *fn)
-{
-	if (rtype(r) == RTmp)
-		fn->tmp[r.val].nuse += du;
-}
-
-static void
-seladdr(Ref *r, ANum *an, Fn *fn)
-{
-	Addr a;
-	Ref r0, r1;
-
-	r0 = *r;
-	if (rtype(r0) == RTmp) {
-		chuse(r0, -1, fn);
-		r1 = an[r0.val].mem;
-		if (req(r1, R)) {
-			amatch(&a, r0, an, fn, 1);
-			vgrow(&fn->mem, ++fn->nmem);
-			fn->mem[fn->nmem-1] = a;
-			r1 = MEM(fn->nmem-1);
-			chuse(a.base, +1, fn);
-			chuse(a.index, +1, fn);
-			if (rtype(a.base) != RTmp)
-			if (rtype(a.index) != RTmp)
-				an[r0.val].mem = r1;
-		}
-		*r = r1;
-	}
-}
-
-static void
-selcmp(Ref arg[2], int k, Fn *fn)
-{
-	Ref r;
-
-	if (rtype(arg[0]) == RCon) {
-		r = arg[1];
-		arg[1] = arg[0];
-		arg[0] = r;
-	}
-	assert(rtype(arg[0]) != RCon);
-	emit(OXCmp, k, R, arg[1], arg[0]);
-	fixarg(&curi->arg[0], k, 0, fn);
-}
-
-static void
-sel(Ins i, ANum *an, Fn *fn)
-{
-	Ref r0, r1;
-	int x, k, kc;
-	int64_t val;
-	Ins *i0;
-
-	if (rtype(i.to) == RTmp)
-	if (!isreg(i.to) && !isreg(i.arg[0]) && !isreg(i.arg[1]))
-	if (fn->tmp[i.to.val].nuse == 0) {
-		chuse(i.arg[0], -1, fn);
-		chuse(i.arg[1], -1, fn);
-		return;
-	}
-	i0 = curi;
-	k = i.cls;
-	switch (i.op) {
-	case ODiv:
-	case ORem:
-	case OUDiv:
-	case OURem:
-		if (i.op == ODiv || i.op == OUDiv)
-			r0 = TMP(RAX), r1 = TMP(RDX);
-		else
-			r0 = TMP(RDX), r1 = TMP(RAX);
-		emit(OCopy, k, i.to, r0, R);
-		emit(OCopy, k, R, r1, R);
-		if (rtype(i.arg[1]) == RCon) {
-			/* immediates not allowed for
-			 * divisions in x86
-			 */
-			r0 = newtmp("isel", k, fn);
-		} else
-			r0 = i.arg[1];
-		if (i.op == ODiv || i.op == ORem) {
-			emit(OXIDiv, k, R, r0, R);
-			emit(OSign, k, TMP(RDX), TMP(RAX), R);
-		} else {
-			emit(OXDiv, k, R, r0, R);
-			emit(OCopy, k, TMP(RDX), CON_Z, R);
-		}
-		emit(OCopy, k, TMP(RAX), i.arg[0], R);
-		if (rtype(i.arg[1]) == RCon)
-			emit(OCopy, k, r0, i.arg[1], R);
-		break;
-	case OSar:
-	case OShr:
-	case OShl:
-		if (rtype(i.arg[1]) == RCon)
-			goto Emit;
-		r0 = i.arg[1];
-		i.arg[1] = TMP(RCX);
-		emit(OCopy, Kw, R, TMP(RCX), R);
-		emiti(i);
-		emit(OCopy, Kw, TMP(RCX), r0, R);
-		break;
-	case ONop:
-		break;
-	case OStored:
-	case OStores:
-	case OStorel:
-	case OStorew:
-	case OStoreh:
-	case OStoreb:
-		if (rtype(i.arg[0]) == RCon) {
-			if (i.op == OStored)
-				i.op = OStorel;
-			if (i.op == OStores)
-				i.op = OStorew;
-		}
-		seladdr(&i.arg[1], an, fn);
-		goto Emit;
-	case_OLoad:
-		seladdr(&i.arg[0], an, fn);
-		goto Emit;
-	case OCall:
-	case OSAlloc:
-	case OCopy:
-	case OAdd:
-	case OSub:
-	case OMul:
-	case OAnd:
-	case OOr:
-	case OXor:
-	case OXTest:
-	case OFtosi:
-	case OSitof:
-	case OExts:
-	case OTruncd:
-	case OCast:
-	case_OExt:
-Emit:
-		emiti(i);
-		fixarg(&curi->arg[0], argcls(curi, 0), 0, fn);
-		fixarg(&curi->arg[1], argcls(curi, 1), 0, fn);
-		break;
-	case OAlloc:
-	case OAlloc+1:
-	case OAlloc+2: /* == OAlloc1 */
-		/* we need to make sure
-		 * the stack remains aligned
-		 * (rsp = 0) mod 16
-		 */
-		if (rtype(i.arg[0]) == RCon) {
-			assert(fn->con[i.arg[0].val].type == CBits);
-			val = fn->con[i.arg[0].val].bits.i;
-			val = (val + 15)  & ~INT64_C(15);
-			if (val < 0 || val > INT32_MAX)
-				diag("isel: alloc too large");
-			emit(OSAlloc, Kl, i.to, getcon(val, fn), R);
-		} else {
-			/* r0 = (i.arg[0] + 15) & -16 */
-			r0 = newtmp("isel", Kl, fn);
-			r1 = newtmp("isel", Kl, fn);
-			emit(OSAlloc, Kl, i.to, r0, R);
-			emit(OAnd, Kl, r0, r1, getcon(-16, fn));
-			emit(OAdd, Kl, r1, i.arg[0], getcon(15, fn));
-		}
-		break;
-	default:
-		if (isext(i.op))
-			goto case_OExt;
-		if (isload(i.op))
-			goto case_OLoad;
-		if (iscmp(i.op, &kc, &x)) {
-			if (rtype(i.arg[0]) == RCon)
-				x = icmpop(x);
-			emit(OXSet+x, k, i.to, R, R);
-			selcmp(i.arg, kc, fn);
-			break;
-		}
-		diag("isel: non-exhaustive implementation");
-	}
-
-	while (i0 > curi && --i0)
-		if (rslot(i0->arg[0], fn) != -1
-		||  rslot(i0->arg[1], fn) != -1)
-			diag("isel: usupported address argument");
-}
-
-static Ins *
-flagi(Ins *i0, Ins *i)
-{
-	while (i>i0) {
-		i--;
-		if (opdesc[i->op].sflag)
-			return i;
-		if (opdesc[i->op].lflag)
-			continue;
-		return 0;
-	}
-	return 0;
-}
-
-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 void
-seljmp(Blk *b, Fn *fn)
-{
-	Ref r;
-	int c, k;
-	Ins *fi;
-
-	if (b->jmp.type == JRet0 || b->jmp.type == JJmp)
-		return;
-	assert(b->jmp.type == JJnz);
-	r = b->jmp.arg;
-	b->jmp.arg = R;
-	assert(!req(r, R));
-	if (rtype(r) == RCon) {
-		b->jmp.type = JJmp;
-		if (req(r, CON_Z))
-			b->s1 = b->s2;
-		b->s2 = 0;
-		return;
-	}
-	fi = flagi(b->ins, &b->ins[b->nins]);
-	if (fi && req(fi->to, r)) {
-		if (iscmp(fi->op, &k, &c)) {
-			if (rtype(fi->arg[0]) == RCon)
-				c = icmpop(c);
-			b->jmp.type = JXJc + c;
-			if (fn->tmp[r.val].nuse == 1) {
-				assert(fn->tmp[r.val].ndef == 1);
-				selcmp(fi->arg, k, fn);
-				*fi = (Ins){.op = ONop};
-			}
-			return;
-		}
-		if (fi->op == OAnd && fn->tmp[r.val].nuse == 1
-		&& (rtype(fi->arg[0]) == RTmp ||
-		    rtype(fi->arg[1]) == RTmp)) {
-			fi->op = OXTest;
-			fi->to = R;
-			b->jmp.type = JXJc + ICne;
-			if (rtype(fi->arg[1]) == RCon) {
-				r = fi->arg[1];
-				fi->arg[1] = fi->arg[0];
-				fi->arg[0] = r;
-			}
-			return;
-		}
-		/* since flags are not tracked in liveness,
-		 * the result of the flag-setting instruction
-		 * has to be marked as live
-		 */
-		if (fn->tmp[r.val].nuse == 1)
-			emit(OCopy, Kw, R, r, R);
-		b->jmp.type = JXJc + ICne;
-		return;
-	}
-	selcmp((Ref[2]){r, CON_Z}, Kw, fn); /* todo, add long branch if non-zero */
-	b->jmp.type = JXJc + ICne;
-}
-
-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);
-		assert(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);
-
-	assert(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;
-		assert(NAlign == 3);
-		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};
-		}
-	}
-}
-
-static int
-aref(Ref r, ANum *ai)
-{
-	switch (rtype(r)) {
-	default:
-		diag("isel: aref defaulted");
-	case RCon:
-		return 2;
-	case RTmp:
-		return ai[r.val].n;
-	}
-}
-
-static int
-ascale(Ref r, Con *con)
-{
-	int64_t n;
-
-	if (rtype(r) != RCon)
-		return 0;
-	if (con[r.val].type != CBits)
-		return 0;
-	n = con[r.val].bits.i;
-	return n == 1 || n == 2 || n == 4 || n == 8;
-}
-
-static void
-anumber(ANum *ai, Blk *b, Con *con)
-{
-	/* This should be made obsolete by a proper
-	 * reassoc pass.
-	 *
-	 * Rules:
-	 *
-	 *   RTmp(_) -> 0    tmp
-	 *   ( RTmp(_) -> 1    slot )
-	 *   RCon(_) -> 2    con
-	 *   0 * 2   -> 3    s * i (when constant is 1,2,4,8)
-	 */
-	static char add[10][10] = {
-		[2] [2] = 2,              /* folding */
-		[2] [5] = 5, [5] [2] = 5,
-		[2] [6] = 6, [6] [2] = 6,
-		[2] [7] = 7, [7] [2] = 7,
-		[0] [0] = 4,              /* 4: b + s * i */
-		[0] [3] = 4, [3] [0] = 4,
-		[2] [3] = 5, [3] [2] = 5, /* 5: o + s * i */
-		[0] [2] = 6, [2] [0] = 6, /* 6: o + b */
-		[2] [4] = 7, [4] [2] = 7, /* 7: o + b + s * i */
-		[0] [5] = 7, [5] [0] = 7,
-		[6] [3] = 7, [3] [6] = 7,
-
-	};
-	int a, a1, a2, n1, n2, t1, t2;
-	Ins *i;
-
-	for (i=b->ins; i-b->ins < b->nins; i++) {
-		if (rtype(i->to) == RTmp)
-			ai[i->to.val].i = i;
-		if (i->op != OAdd && i->op != OMul)
-			continue;
-		a1 = aref(i->arg[0], ai);
-		a2 = aref(i->arg[1], ai);
-		t1 = a1 != 1 && a1 != 2;
-		t2 = a2 != 1 && a2 != 2;
-		if (i->op == OAdd) {
-			a = add[n1 = a1][n2 = a2];
-			if (t1 && a < add[0][a2])
-				a = add[n1 = 0][n2 = a2];
-			if (t2 && a < add[a1][0])
-				a = add[n1 = a1][n2 = 0];
-			if (t1 && t2 && a < add[0][0])
-				a = add[n1 = 0][n2 = 0];
-		} else {
-			n1 = n2 = a = 0;
-			if (ascale(i->arg[0], con) && t2)
-				a = 3, n1 = 2, n2 = 0;
-			if (t1 && ascale(i->arg[1], con))
-				a = 3, n1 = 0, n2 = 2;
-		}
-		ai[i->to.val].n = a;
-		ai[i->to.val].l = n1;
-		ai[i->to.val].r = n2;
-	}
-}
-
-static void
-amatch(Addr *a, Ref r, ANum *ai, Fn *fn, int top)
-{
-	Ins *i;
-	int nl, nr, t, s;
-	Ref al, ar;
-
-	if (top)
-		memset(a, 0, sizeof *a);
-	if (rtype(r) == RCon) {
-		addcon(&a->offset, &fn->con[r.val]);
-		return;
-	}
-	assert(rtype(r) == RTmp);
-	i = ai[r.val].i;
-	nl = ai[r.val].l;
-	nr = ai[r.val].r;
-	if (i) {
-		if (nl > nr) {
-			al = i->arg[1];
-			ar = i->arg[0];
-			t = nl, nl = nr, nr = t;
-		} else {
-			al = i->arg[0];
-			ar = i->arg[1];
-		}
-	}
-	switch (ai[r.val].n) {
-	default:
-		diag("isel: amatch defaulted");
-	case 3: /* s * i */
-		if (!top) {
-			a->index = al;
-			a->scale = fn->con[ar.val].bits.i;
-		} else
-			a->base = r;
-		break;
-	case 4: /* b + s * i */
-		switch (nr) {
-		case 0:
-			if (fn->tmp[ar.val].slot != -1) {
-				al = i->arg[1];
-				ar = i->arg[0];
-			}
-			a->index = ar;
-			a->scale = 1;
-			break;
-		case 3:
-			amatch(a, ar, ai, fn, 0);
-			break;
-		}
-		r = al;
-	case 0:
-		s = fn->tmp[r.val].slot;
-		if (s != -1)
-			r = SLOT(s);
-		a->base = r;
-		break;
-	case 2: /* constants */
-	case 5: /* o + s * i */
-	case 6: /* o + b */
-	case 7: /* o + b + s * i */
-		amatch(a, ar, ai, fn, 0);
-		amatch(a, al, ai, fn, 0);
-		break;
-	}
-}
-
-/* instruction selection
- * requires use counts (as given by parsing)
- */
-void
-isel(Fn *fn)
-{
-	Blk *b, **sb;
-	Ins *i, *i0, *ip;
-	Phi *p;
-	uint a;
-	int n, al;
-	int64_t sz;
-	ANum *ainfo;
-	RAlloc *ral;
-
-	for (n=0; n<fn->ntmp; n++)
-		fn->tmp[n].slot = -1;
-	fn->slot = 0;
-
-	/* 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 function 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 call lowering:\n");
-		printfn(fn, stderr);
-	}
-
-	/* assign slots to fast allocs */
-	b = fn->start;
-	assert(NAlign == 3 && "change n=4 and sz /= 4 below");
-	for (al=OAlloc, n=4; al<=OAlloc1; al++, n*=2)
-		for (i=b->ins; i-b->ins < b->nins; i++)
-			if (i->op == al) {
-				if (rtype(i->arg[0]) != RCon)
-					break;
-				sz = fn->con[i->arg[0].val].bits.i;
-				if (sz < 0 || sz >= INT_MAX-3)
-					diag("isel: invalid alloc size");
-				sz = (sz + n-1) & -n;
-				sz /= 4;
-				fn->tmp[i->to.val].slot = fn->slot;
-				fn->slot += sz;
-				*i = (Ins){.op = ONop};
-			}
-
-	/* process basic blocks */
-	n = fn->ntmp;
-	ainfo = emalloc(n * sizeof ainfo[0]);
-	for (b=fn->start; b; b=b->link) {
-		curi = &insb[NIns];
-		for (sb=(Blk*[3]){b->s1, b->s2, 0}; *sb; sb++)
-			for (p=(*sb)->phi; p; p=p->link) {
-				for (a=0; p->blk[a] != b; a++)
-					assert(a+1 < p->narg);
-				fixarg(&p->arg[a], p->cls, 1, fn);
-			}
-		memset(ainfo, 0, n * sizeof ainfo[0]);
-		anumber(ainfo, b, fn->con);
-		seljmp(b, fn);
-		for (i=&b->ins[b->nins]; i!=b->ins;)
-			sel(*--i, ainfo, fn);
-		b->nins = &insb[NIns] - curi;
-		idup(&b->ins, curi, b->nins);
-	}
-	free(ainfo);
-
-	if (debug['I']) {
-		fprintf(stderr, "\n> After instruction selection:\n");
-		printfn(fn, stderr);
-	}
-}