1 files changed, 42 insertions, 0 deletions
diff --git a/tests/programs/exactsize.zc b/tests/programs/exactsize.zc
new file mode 100644
index 0000000..c3b22cc
--- /dev/null
+++ b/tests/programs/exactsize.zc
@@ -0,0 +1,42 @@
+include rt;
+// exact-size bounds: a heap block knows the n words new asked for (bits 32..62 of
+// p[-4]), not just its power-of-two block. rt.bnd(p, i, 1, 1) is 1 when p[i] is
+// outside: the same recipe every backend inlines in front of p[i].
+struct P { int a; int b; int c; }
+struct Q { int a; }
+// n-1 inside, n outside, osize is n, and p[n-1] is usable
+int edge(int n) {
+	word* p = rt.new(n);
+	p[n - 1] = n;
+	return rt.bnd(p, n - 1, 1, 1) * 100 + rt.bnd(p, n, 1, 1) * 10 + (rt.osize(p) == n) + (p[n - 1] == n) - 1;
+}
+int zero() { word* p = rt.new(0); return rt.bnd(p, 0, 1, 1) * 10 + rt.osize(p); }
+int bytes() { word* p = rt.new(3); return rt.bnd(p, 23, 1, 8) * 10 + rt.bnd(p, 24, 1, 8); }	// 3 words are 24 bytes
+int where;
+int leaf() { P* a = rt.new(P); a.c = 3; where = (&a.a) as int; return a.c; }	// a is recycled at the function's end
+// recycle: the next 1-word object reuses the 3-word block, with n = 1
+int reuse() {
+	Q* q = rt.new(Q); int same = where == ((&q.a) as int);
+	return same * 1000 + rt.osize(q) * 100 + rt.bnd(q, 0, 1, 1) * 10 + rt.bnd(q, 1, 1, 1);
+}
+// grow: the items block is replaced by one with its own exact n (16 words for 9 ints)
+int grow() {
+	int[?] d = rt.new(int[?], 0); int i = 0; word* h; word* p;
+	while (i < 9) { d.push(i); i++; }
+	h = &d[0]; p = h;
+	return rt.osize(p) * 100 + rt.bnd(p, 15, 1, 1) * 10 + rt.bnd(p, 16, 1, 1);
+}
+// deep enough to grow the stacks: their segments are heap blocks the core allocates
+// (src/core/stack.h, src/js/tinyvm.ts) with n set too. after they go back, blocks reused
+// from them carry their own n.
+int deep(int k) { if (k == 0) return 0; return deep(k - 1) + 1; }
+fn main() {
+	rt.put_n(edge(1)); rt.put_c(32); rt.put_n(edge(3)); rt.put_c(32); rt.put_n(edge(5)); rt.put_c(32);
+	rt.put_n(edge(6)); rt.put_c(32); rt.put_n(edge(7)); rt.put_c(32); rt.put_n(edge(11)); rt.put_c(32);
+	rt.put_n(edge(13)); rt.put_c(32); rt.put_n(edge(100)); rt.put_c(10);
+	rt.put_n(zero()); rt.put_c(32); rt.put_n(bytes()); rt.put_c(10);
+	leaf(); rt.put_n(reuse()); rt.put_c(10);
+	rt.put_n(grow()); rt.put_c(10);
+	rt.put_n(deep(200000)); rt.put_c(32); rt.put_n(edge(9)); rt.put_c(32); rt.put_n(edge(21)); rt.put_c(10);
+	return 0;
+}