From b9aa04dbb32dee4dc7a37038fd47b9aa67bcf939 Mon Sep 17 00:00:00 2001
From: ceriel <none@none>
Date: Fri, 15 Jul 1988 11:23:44 +0000
Subject: [PATCH] fixed problem with temporary DEALLOCATES: sometimes a
 register was used for stacking, that was only temporarily deallocated

---
 mach/proto/cg/codegen.c | 26 ++++++++++++++++++--------
 mach/proto/cg/equiv.c   |  2 +-
 mach/proto/cg/reg.c     |  6 +++---
 mach/proto/cg/subr.c    |  4 ++--
 4 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/mach/proto/cg/codegen.c b/mach/proto/cg/codegen.c
index 93f6a5fed..4da1fe085 100644
--- a/mach/proto/cg/codegen.c
+++ b/mach/proto/cg/codegen.c
@@ -287,9 +287,14 @@ if (Debug)
 		i++; tp--;
 	}
 	if (tokpatlen>stackheight) {
+		int k;
 		stackpad = tokpatlen-stackheight;
-		for (j=stackheight-1;j>=0;j--)
-			fakestack[j+stackpad] = fakestack[j];
+		for (j=stackheight-1, k = j + stackpad;j>=0;j--, k--) {
+			fakestack[k] = fakestack[j];
+			/* fakestack[j+stackpad] = fakestack[j]; does not
+			   compile under Xenix
+			*/
+		}
 		for (j=0;j<stackpad;j++)
 			fakestack[j].t_token=0;
 		stackheight += stackpad;
@@ -457,7 +462,7 @@ if (Debug > 1) fprintf(stderr, "cost after coercions: %u\n", t);
 		do {
 			npos=exactmatch=0;
 			for(rpp=reglist[propno];rp= *rpp; rpp++)
-				if (getrefcount(rp-machregs)==0) {
+				if (getrefcount(rp-machregs, FALSE)==0) {
 					pos[npos++] = rp-machregs;
 					if (eqtoken(&rp->r_contents,&token))
 						exactmatch++;
@@ -539,7 +544,7 @@ if (Debug > 1) fprintf(stderr, "cost after coercions: %u\n", t);
 		}
 	} else {
 		decision = forced;
-		if (getrefcount(decision)!=0) {
+		if (getrefcount(decision, FALSE)!=0) {
 			totalcost = INFINITY;
 			BROKE();
 		}
@@ -606,7 +611,11 @@ if (Debug > 1) fprintf(stderr, "cost after coercions: %u\n", t);
 	}
 	for (i=0;i<repllen;i++) {
 		assert(stackheight<MAXFSTACK);
-		fakestack[stackheight++] = reptoken[i];
+		fakestack[stackheight] = reptoken[i];
+		stackheight++;
+		/* do not combine previous two statements; that does not
+		   compile under Xenix V3.2
+		*/
 	}
 	for(i=0;i<nallreg;i++)
 		chrefcount(allreg[i],-1,FALSE);
@@ -616,9 +625,10 @@ if (Debug > 1) fprintf(stderr, "cost after coercions: %u\n", t);
 	emrepllen=(codep[-1]>>5)&07;
 	j=emp-emlines;
 	if (emrepllen>j) {
-		assert(nemlines+emrepllen-j<MAXEMLINES);
-		for (i=nemlines;i>=0;i--)
-			emlines[i+emrepllen-j] = emlines[i];
+		int k = nemlines + emrepllen - j;
+		assert(k<MAXEMLINES);
+		for (i=nemlines;i>=0;i--, k--)
+			emlines[k] = emlines[i];
 		nemlines += emrepllen-j;
 		emp += emrepllen-j;
 	}
diff --git a/mach/proto/cg/equiv.c b/mach/proto/cg/equiv.c
index 73d8b6a03..3ed200546 100644
--- a/mach/proto/cg/equiv.c
+++ b/mach/proto/cg/equiv.c
@@ -38,7 +38,7 @@ tuples(regls,nregneeded) rl_p *regls; {
 
 	for (i=0;i<NREGS;i++) {
 		regclass[i] = class++;
-		if (getrefcount(i) == 0) {
+		if (getrefcount(i, FALSE) == 0) {
 			for (j=0;j<i;j++) {
 				if (eqregclass(i,j) &&
 				    eqtoken(&machregs[i].r_contents,
diff --git a/mach/proto/cg/reg.c b/mach/proto/cg/reg.c
index 50caf5622..a0443c7da 100644
--- a/mach/proto/cg/reg.c
+++ b/mach/proto/cg/reg.c
@@ -38,7 +38,7 @@ chrefcount(regno,amount,tflag) {
 #endif
 }
 
-getrefcount(regno) {
+getrefcount(regno, tflag) {
 	register struct reginfo *rp;
 	register i,maxcount;
 
@@ -46,13 +46,13 @@ getrefcount(regno) {
 #if MAXMEMBERS!=0
 	if (rp->r_members[0]==0)
 #endif
-		return(rp->r_refcount);
+		return(rp->r_refcount - (tflag ? rp->r_tcount : 0));
 #if MAXMEMBERS!=0
 	else {
 		maxcount=0;
 		for (i=0;i<MAXMEMBERS;i++)
 			if (rp->r_members[i]!=0)
-				maxcount=max(maxcount,getrefcount(rp->r_members[i]));
+				maxcount=max(maxcount,getrefcount(rp->r_members[i], tflag));
 		return(maxcount);
 	}
 #endif
diff --git a/mach/proto/cg/subr.c b/mach/proto/cg/subr.c
index 82c98ef45..27b10dc20 100644
--- a/mach/proto/cg/subr.c
+++ b/mach/proto/cg/subr.c
@@ -30,7 +30,7 @@ match(tp,tep,optexp) register token_p tp; register set_p tep; {
 	if (tp->t_token == -1) {        /* register frame */
 		bitno = tp->t_att[0].ar+1;
 		if (tep->set_val[bitno>>4]&(1<<(bitno&017)))
-			if (tep->set_val[0]&1 || getrefcount(tp->t_att[0].ar)<=1)
+			if (tep->set_val[0]&1 || getrefcount(tp->t_att[0].ar, FALSE)<=1)
 				goto oklabel;
 		return(0);
 	} else {                /* token frame */
@@ -432,7 +432,7 @@ unsigned stackupto(limit,ply,toplevel) token_p limit; {
 				if (cp->c1_prop>=0) {
 					for (rpp=reglist[cp->c1_prop];
 					       (rp = *rpp)!=0 &&
-					       getrefcount(rp-machregs)!=0;
+					       getrefcount(rp-machregs, TRUE)!=0;
 						  rpp++)
 						;
 					if (rp==0)
-- 
2.34.1