import updated compilers from sources

1 files changed, 206 insertions, 0 deletions

diff --git a/sys/src/cmd/6c/div.c b/sys/src/cmd/6c/div.c
new file mode 100644
index 000000000..cb5886789
--- /dev/null
+++ b/sys/src/cmd/6c/div.c
@@ -0,0 +1,206 @@
+#include "gc.h"
+
+/*
+ * Based on: Granlund, T.; Montgomery, P.L.
+ * "Division by Invariant Integers using Multiplication".
+ * SIGPLAN Notices, Vol. 29, June 1994, page 61.
+ */
+
+#define	TN(n)	((uvlong)1 << (n))
+#define	T31	TN(31)
+#define	T32	TN(32)
+
+int
+multiplier(ulong d, int p, uvlong *mp)
+{
+	int l;
+	uvlong mlo, mhi, tlo, thi;
+
+	l = topbit(d - 1) + 1;
+	mlo = (((TN(l) - d) << 32) / d) + T32;
+	if(l + p == 64)
+		mhi = (((TN(l) + 1 - d) << 32) / d) + T32;
+	else
+		mhi = (TN(32 + l) + TN(32 + l - p)) / d;
+	/*assert(mlo < mhi);*/
+	while(l > 0) {
+		tlo = mlo >> 1;
+		thi = mhi >> 1;
+		if(tlo == thi)
+			break;
+		mlo = tlo;
+		mhi = thi;
+		l--;
+	}
+	*mp = mhi;
+	return l;
+}
+
+int
+sdiv(ulong d, ulong *mp, int *sp)
+{
+	int s;
+	uvlong m;
+
+	s = multiplier(d, 32 - 1, &m);
+	*mp = m;
+	*sp = s;
+	if(m >= T31)
+		return 1;
+	else
+		return 0;
+}
+
+int
+udiv(ulong d, ulong *mp, int *sp, int *pp)
+{
+	int p, s;
+	uvlong m;
+
+	s = multiplier(d, 32, &m);
+	p = 0;
+	if(m >= T32) {
+		while((d & 1) == 0) {
+			d >>= 1;
+			p++;
+		}
+		s = multiplier(d, 32 - p, &m);
+	}
+	*mp = m;
+	*pp = p;
+	if(m >= T32) {
+		/*assert(p == 0);*/
+		*sp = s - 1;
+		return 1;
+	}
+	else {
+		*sp = s;
+		return 0;
+	}
+}
+
+void
+sdivgen(Node *l, Node *r, Node *ax, Node *dx)
+{
+	int a, s;
+	ulong m;
+	vlong c;
+
+	c = r->vconst;
+	if(c < 0)
+		c = -c;
+	a = sdiv(c, &m, &s);
+//print("a=%d i=%ld s=%d m=%lux\n", a, (long)r->vconst, s, m);
+	gins(AMOVL, nodconst(m), ax);
+	gins(AIMULL, l, Z);
+	gins(AMOVL, l, ax);
+	if(a)
+		gins(AADDL, ax, dx);
+	gins(ASHRL, nodconst(31), ax);
+	gins(ASARL, nodconst(s), dx);
+	gins(AADDL, ax, dx);
+	if(r->vconst < 0)
+		gins(ANEGL, Z, dx);
+}
+
+void
+udivgen(Node *l, Node *r, Node *ax, Node *dx)
+{
+	int a, s, t;
+	ulong m;
+	Node nod;
+
+	a = udiv(r->vconst, &m, &s, &t);
+//print("a=%ud i=%ld p=%d s=%d m=%lux\n", a, (long)r->vconst, t, s, m);
+	if(t != 0) {
+		gins(AMOVL, l, ax);
+		gins(ASHRL, nodconst(t), ax);
+		gins(AMOVL, nodconst(m), dx);
+		gins(AMULL, dx, Z);
+	}
+	else if(a) {
+		if(l->op != OREGISTER) {
+			regalloc(&nod, l, Z);
+			gins(AMOVL, l, &nod);
+			l = &nod;
+		}
+		gins(AMOVL, nodconst(m), ax);
+		gins(AMULL, l, Z);
+		gins(AADDL, l, dx);
+		gins(ARCRL, nodconst(1), dx);
+		if(l == &nod)
+			regfree(l);
+	}
+	else {
+		gins(AMOVL, nodconst(m), ax);
+		gins(AMULL, l, Z);
+	}
+	if(s != 0)
+		gins(ASHRL, nodconst(s), dx);
+}
+
+void
+sext(Node *d, Node *s, Node *l)
+{
+	if(s->reg == D_AX && !nodreg(d, Z, D_DX)) {
+		reg[D_DX]++;
+		gins(ACDQ, Z, Z);
+	}
+	else {
+		regalloc(d, l, Z);
+		gins(AMOVL, s, d);
+		gins(ASARL, nodconst(31), d);
+	}
+}
+
+void
+sdiv2(long c, int v, Node *l, Node *n)
+{
+	Node nod;
+
+	if(v > 0) {
+		if(v > 1) {
+			sext(&nod, n, l);
+			gins(AANDL, nodconst((1 << v) - 1), &nod);
+			gins(AADDL, &nod, n);
+			regfree(&nod);
+		}
+		else {
+			gins(ACMPL, n, nodconst(0x80000000));
+			gins(ASBBL, nodconst(-1), n);
+		}
+		gins(ASARL, nodconst(v), n);
+	}
+	if(c < 0)
+		gins(ANEGL, Z, n);
+}
+
+void
+smod2(long c, int v, Node *l, Node *n)
+{
+	Node nod;
+
+	if(c == 1) {
+		zeroregm(n);
+		return;
+	}
+
+	sext(&nod, n, l);
+	if(v == 0) {
+		zeroregm(n);
+		gins(AXORL, &nod, n);
+		gins(ASUBL, &nod, n);
+	}
+	else if(v > 1) {
+		gins(AANDL, nodconst((1 << v) - 1), &nod);
+		gins(AADDL, &nod, n);
+		gins(AANDL, nodconst((1 << v) - 1), n);
+		gins(ASUBL, &nod, n);
+	}
+	else {
+		gins(AANDL, nodconst(1), n);
+		gins(AXORL, &nod, n);
+		gins(ASUBL, &nod, n);
+	}
+	regfree(&nod);
+}