idk

.dir-locals.el

@@ -0,0 +1,2 @@
+((c-mode . ((tab-width . 4)
+            (indent-tabs-mode . t))))

all.h

@@ -160,6 +160,7 @@ enum J {
 	X(retw)   X(retl)   X(rets)   X(retd)   \
 	X(retsb)  X(retub)  X(retsh)  X(retuh)  \
 	X(retc)   X(ret0)   X(jmp)    X(jnz)    \
+        X(tail) \
 	X(jfieq)  X(jfine)  X(jfisge) X(jfisgt) \
 	X(jfisle) X(jfislt) X(jfiuge) X(jfiugt) \
 	X(jfiule) X(jfiult) X(jffeq)  X(jffge)  \

parse.c

@@ -53,6 +53,7 @@ enum Token {
 	Tphi,
 	Tjmp,
 	Tjnz,
+        Ttail,
 	Tret,
 	Thlt,
 	Texport,
@@ -113,6 +114,7 @@ static char *kwmap[Ntok] = {
 	[Tphi] = "phi",
 	[Tjmp] = "jmp",
 	[Tjnz] = "jnz",
+	[Ttail] = "tail",
 	[Tret] = "ret",
 	[Thlt] = "hlt",
 	[Texport] = "export",
@@ -664,6 +666,9 @@ parseline(PState ps)
 			curb->jmp.arg = r;
 		}
 		goto Close;
+	case Ttail:
+	  curb->jmp.type = Jtail;
+	  goto Close;
 	case Tjmp:
 		curb->jmp.type = Jjmp;
 		goto Jump;
@@ -1434,6 +1439,9 @@ printfn(Fn *fn, FILE *f)
 			if (b->s1 != b->link)
 				fprintf(f, "\tjmp @%s\n", b->s1->name);
 			break;
+		case Jtail:
+		  fprintf (f, "\ttail\n");
+		  break;
 		default:
 			fprintf(f, "\t%s ", jtoa[b->jmp.type]);
 			if (b->jmp.type == Jjnz) {

result

@@ -1 +0,0 @@
-/nix/store/662p38x2aqlrk0hnx0nskcj4100as900-qbe-git

test/tail.ssa

@@ -0,0 +1,8 @@
+function w $factorial (w %n, w %acc) {
+@start
+	jnz %n, @z, @nz
+@z
+	ret %acc
+@nz
+	tail
+}