X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=sys%2Fsrc%2Fcmd%2F8c%2Fpeep.c;h=482f17a65c835adce7c1b8e027d5313d5e1a4017;hb=a00b6bdbfa72a1688a866edf5f825720c9874ada;hp=d67f751440f342a94cee8c9226d8044444f31119;hpb=e5888a1ffdae813d7575f5fb02275c6bb07e5199;p=plan9front.git

diff --git a/sys/src/cmd/8c/peep.c b/sys/src/cmd/8c/peep.c
old mode 100755
new mode 100644
index d67f75144..482f17a65
--- a/sys/src/cmd/8c/peep.c
+++ b/sys/src/cmd/8c/peep.c
@@ -67,8 +67,6 @@ peep(void)
 	pc = 0;	/* speculating it won't kill */
 
 loop1:
-	if(debug['b'])
-		comtarg();
 
 	t = 0;
 	for(r=firstr; r!=R; r=r->link) {
@@ -139,6 +137,39 @@ loop1:
 				p->from = zprog.from;
 			}
 			break;
+
+		case ACMPL:
+			if(p->to.type != D_CONST || p->to.offset != 0 || regtyp(&p->from) == 0)
+				break;
+			if(p->link == P || (p->link->as != AJEQ && p->link->as != AJNE))
+				break;
+			r1 = uniqp(r);
+			while(r1 != R && r1->prog->as == ANOP)
+				r1 = uniqp(r1);
+			if(r1 == R || r1->prog->to.type != p->from.type)
+				break;
+			p1 = r1->prog;
+			switch(p1->as){
+			case ASALL:
+			case ASARL:
+			case ASHLL:
+			case ASHRL:
+				/* shift doesnt affect ZF when shift count is zero */
+				if(p1->from.type != D_CONST || p1->from.offset == 0)
+					break;
+			case AANDL:
+			case AORL:
+			case AXORL:
+			case ANEGL:
+			case AADDL:
+			case AADCL:
+			case ASUBL:
+			case ASBBL:
+			case AINCL:
+			case ADECL:
+				excise(r);
+			}
+			break;
 		}
 	}
 	if(t)
@@ -233,9 +264,6 @@ subprop(Reg *r0)
 			break;
 		p = r->prog;
 		switch(p->as) {
-		case ACALL:
-			return 0;
-
 		case AIMULL:
 		case AIMULW:
 			if(p->to.type != D_NONE)
@@ -252,6 +280,23 @@ subprop(Reg *r0)
 		case AMULL:
 		case AMULW:
 
+		case AREP:
+		case AREPN:
+		case ALOOP:
+		case ALOOPNE:
+
+		case ACWD:
+		case ACDQ:
+
+		case ASTOSB:
+		case ASTOSL:
+		case AMOVSB:
+		case AMOVSL:
+		case AFSTSW:
+
+		case ACALL:
+			return 0;
+
 		case AROLB:
 		case AROLL:
 		case AROLW:
@@ -270,16 +315,28 @@ subprop(Reg *r0)
 		case ASHRB:
 		case ASHRL:
 		case ASHRW:
+			if(p->from.type == D_CX && v1->type == D_CX)
+				return 0;
+			break;
 
-		case AREP:
-		case AREPN:
-
-		case ACWD:
-		case ACDQ:
-
-		case AMOVSL:
-		case AFSTSW:
-			return 0;
+		case AORL:
+		case AANDL:
+		case AXORL:
+		case AADDL:
+		case AADCL:
+			/*
+			 * can swap when:
+			 *  ADD R2, R1
+			 *  MOV R1, R2
+			 * convert to:
+			 *  ADD R1, R2
+			 *  MOV R2, R1	/ no use for R1
+			 */
+			if(p->to.type == v1->type && p->from.type == v2->type){
+				copysub(&p->from, v2, v1, 1);
+				goto gotit;
+			}
+			break;
 
 		case AMOVL:
 			if(p->to.type == v1->type)
@@ -641,10 +698,21 @@ copyu(Prog *p, Adr *v, Adr *s)
 			return 2;
 		goto caseread;
 
-	case AMOVSL:
 	case AREP:
 	case AREPN:
-		if(v->type == D_CX || v->type == D_DI || v->type == D_SI)
+		if(v->type == D_CX)
+			return 2;
+		goto caseread;
+
+	case AMOVSB:
+	case AMOVSL:
+		if(v->type == D_DI || v->type == D_SI)
+			return 2;
+		goto caseread;
+
+	case ASTOSB:
+	case ASTOSL:
+		if(v->type == D_AX || v->type == D_DI)
 			return 2;
 		goto caseread;