fix amd64 addressing mode matcher

The numberer made some arranging choices when
numbering arguments of an instruction, but these
decisions were ignored when matching.  The fix
is to reconcile numbering and matching.

1 files changed, 15 insertions, 20 deletions

diff --git a/amd64/isel.c b/amd64/isel.c
index 2519ae5..6aea850 100644
--- a/amd64/isel.c
+++ b/amd64/isel.c
@@ -25,7 +25,7 @@ struct ANum {
 	Ins *i;
 };
 
-static void amatch(Addr *, Ref, ANum *, Fn *, int);
+static int amatch(Addr *, Ref, int, ANum *, Fn *);
 
 static int
 noimm(Ref r, Fn *fn)
@@ -131,8 +131,8 @@ seladdr(Ref *r, ANum *an, Fn *fn)
 
 	r0 = *r;
 	if (rtype(r0) == RTmp) {
-		amatch(&a, r0, an, fn, 1);
-		if (req(a.base, r0))
+		memset(&a, 0, sizeof a);
+		if (!amatch(&a, r0, an[r0.val].n, an, fn))
 			return;
 		if (a.offset.type == CAddr)
 		if (!req(a.base, R)) {
@@ -488,18 +488,16 @@ anumber(ANum *ai, Blk *b, Con *con)
 	}
 }
 
-static void
-amatch(Addr *a, Ref r, ANum *ai, Fn *fn, int top)
+static int
+amatch(Addr *a, Ref r, int n, ANum *ai, Fn *fn)
 {
 	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;
+		return 1;
 	}
 	assert(rtype(r) == RTmp);
 	i = ai[r.val].i;
@@ -515,14 +513,11 @@ amatch(Addr *a, Ref r, ANum *ai, Fn *fn, int top)
 			ar = i->arg[1];
 		}
 	}
-	switch (ai[r.val].n) {
+	switch (n) {
 	case 3: /* s * i */
-		if (!top) {
-			a->index = al;
-			a->scale = fn->con[ar.val].bits.i;
-		} else
-			a->base = r;
-		break;
+		a->index = al;
+		a->scale = fn->con[ar.val].bits.i;
+		return 0;
 	case 4: /* b + s * i */
 		switch (nr) {
 		case 0:
@@ -534,7 +529,7 @@ amatch(Addr *a, Ref r, ANum *ai, Fn *fn, int top)
 			a->scale = 1;
 			break;
 		case 3:
-			amatch(a, ar, ai, fn, 0);
+			amatch(a, ar, nr, ai, fn);
 			break;
 		}
 		r = al;
@@ -544,14 +539,14 @@ amatch(Addr *a, Ref r, ANum *ai, Fn *fn, int top)
 		if (s != -1)
 			r = SLOT(s);
 		a->base = r;
-		break;
+		return n || s != -1;
 	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;
+		amatch(a, ar, nr, ai, fn);
+		amatch(a, al, nl, ai, fn);
+		return 1;
 	default:
 		die("unreachable");
 	}