harec

commit 34c063ebdda44768262a2ecae2cb3b4f320f8c8b
parent 70cd7548e3cea3bf2b326c1328879912de348d99
Author: Drew DeVault <sir@cmpwn.com>
Date:   Thu,  8 Jul 2021 17:02:21 -0400

gen: emit memcpy for initializing large arrays

Signed-off-by: Drew DeVault <sir@cmpwn.com>

Diffstat:
M
src/gen.c
 | 
40
++++++++++++++++++++++++++++------------
M
tests/01-arrays.ha
 | 
9
+++++++++

2 files changed, 37 insertions(+), 12 deletions(-)
diff --git a/src/gen.c b/src/gen.c
@@ -1599,19 +1599,35 @@ gen_array(struct gen_context *ctx,
 	}
 
 	pushc(ctx->current, "expanding array to length %zd", type->array.length);
-	struct qbe_value last = {0};
-	if (type_is_aggregate(type->array.members)) {
-		alloc_temp(ctx, &last, type->array.members, "expand.%d");
-		qval_deref(&last);
+	if (type->array.length < 16) {
+		struct qbe_value last = {0};
+		if (type_is_aggregate(type->array.members)) {
+			alloc_temp(ctx, &last, type->array.members, "expand.%d");
+			qval_deref(&last);
+		} else {
+			gen_temp(ctx, &last,
+				qtype_for_type(ctx, type->array.members, false),
+				"expand.%d");
+		}
+		gen_load(ctx, &last, &val, type_is_signed(type->array.members));
+		for (; n < type->array.length; ++n) {
+			pushi(ctx->current, &ptr, Q_ADD, &ptr, &size, NULL);
+			gen_store(ctx, &val, &last);
+		}
 	} else {
-		gen_temp(ctx, &last,
-			qtype_for_type(ctx, type->array.members, false),
-			"expand.%d");
-	}
-	gen_load(ctx, &last, &val, type_is_signed(type->array.members));
-	for (; n < type->array.length; ++n) {
-		pushi(ctx->current, &ptr, Q_ADD, &ptr, &size, NULL);
-		gen_store(ctx, &val, &last);
+		struct qbe_value totalsize = {0};
+		constl(&totalsize, (type->array.length - n) * type->array.members->size);
+		struct qbe_value offset = {0};
+		gen_temp(ctx, &offset, &qbe_long, "ptr.%d");
+		pushi(ctx->current, &offset, Q_ADD, &val, &size, NULL);
+		val.type = &qbe_long;
+
+		struct qbe_value rtmemcpy = {0};
+		rtmemcpy.kind = QV_GLOBAL;
+		rtmemcpy.name = strdup("rt.memcpy");
+		rtmemcpy.type = &qbe_long;
+		pushi(ctx->current, NULL, Q_CALL, &rtmemcpy,
+				&offset, &val, &totalsize, NULL);
 	}
 }
 
diff --git a/tests/01-arrays.ha b/tests/01-arrays.ha
@@ -82,6 +82,15 @@ fn expanded() void = {
 	for (let i = 0z; i < len(c); i += 1) {
 		assert(c[i] == expected[i]);
 	};
+
+	let q: [65535]int = [1, 2, 3...];
+	let expected = [1, 2, 3];
+	for (let i = 0z; i < len(expected); i += 1) {
+		assert(q[i] == expected[i]);
+	};
+	for (let i = 3z; i < len(q); i += 1) {
+		assert(q[i] == 3);
+	};
 };
 
 fn extype() void = {