commit 9e93137bc3cfb79fe09918c771ca16e59299a03a
parent be248126f80f3ebe585ddaf30e940b1e247b85d3
Author: Drew DeVault <sir@cmpwn.com>
Date: Sat, 7 Aug 2021 10:43:50 +0200
gen: cast array => slice
This required generalizing the cast_at format a bit to achieve optimal
results.
Signed-off-by: Drew DeVault <sir@cmpwn.com>
Diffstat:
3 files changed, 138 insertions(+), 61 deletions(-)
diff --git a/src/gen.c b/src/gen.c
@@ -454,23 +454,84 @@ gen_expr_call(struct gen_context *ctx, const struct expression *expr)
static struct gen_value gen_expr_cast(struct gen_context *ctx,
const struct expression *expr);
+static struct gen_value
+gen_expr_type_test(struct gen_context *ctx, const struct expression *expr)
+{
+ const struct type *secondary = expr->cast.secondary,
+ *from = expr->cast.value->result;
+ assert(type_dealias(from)->storage == STORAGE_TAGGED);
+ const struct type *subtype = tagged_select_subtype(from, secondary);
+ assert(subtype && subtype == secondary); // Lowered by check
+
+ struct gen_value val = gen_expr(ctx, expr->cast.value);
+ struct qbe_value qval = mkqval(ctx, &val);
+ struct qbe_value tag = mkqtmp(ctx,
+ qtype_lookup(ctx, &builtin_type_uint, false),
+ ".%d");
+ enum qbe_instr load = load_for_type(ctx, &builtin_type_uint);
+ pushi(ctx->current, &tag, load, &qval, NULL);
+ struct qbe_value expected = constl(secondary->id);
+ struct gen_value result = mktemp(ctx, &builtin_type_bool, ".%d");
+ struct qbe_value qr = mkqval(ctx, &result);
+ pushi(ctx->current, &qr, Q_CEQW, &tag, &expected, NULL);
+ return result;
+}
+
static void
-gen_expr_cast_at(struct gen_context *ctx,
+gen_type_assertion(struct gen_context *ctx,
+ const struct expression *expr,
+ struct qbe_value base)
+{
+ const struct type *want = expr->result;
+ struct qbe_value tag = mkqtmp(ctx,
+ qtype_lookup(ctx, &builtin_type_uint, false),
+ ".%d");
+ enum qbe_instr load = load_for_type(ctx, &builtin_type_uint);
+ pushi(ctx->current, &tag, load, &base, NULL);
+ struct qbe_value expected = constl(want->id);
+ struct gen_value result = mktemp(ctx, &builtin_type_bool, ".%d");
+ struct qbe_value qr = mkqval(ctx, &result);
+ pushi(ctx->current, &qr, Q_CEQW, &tag, &expected, NULL);
+
+ struct qbe_statement failedl, passedl;
+ struct qbe_value bfailed = mklabel(ctx, &failedl, "failed.%d");
+ struct qbe_value bpassed = mklabel(ctx, &passedl, "passed.%d");
+ pushi(ctx->current, NULL, Q_JNZ, &qr, &bpassed, &bfailed, NULL);
+ push(&ctx->current->body, &failedl);
+
+ gen_fixed_abort(ctx, expr->loc, ABORT_TYPE_ASSERTION);
+
+ push(&ctx->current->body, &passedl);
+}
+
+static void
+gen_expr_cast_slice_at(struct gen_context *ctx,
const struct expression *expr, struct gen_value out)
{
- // This function is only concerned with casting to tagged unions, which
- // is more efficient with the _at usage. For all other cases, it falls
- // back to gen_expr_cast.
const struct type *to = expr->result, *from = expr->cast.value->result;
- if (type_dealias(to)->storage != STORAGE_TAGGED
- || expr->cast.kind == C_TEST) {
- struct gen_value result = gen_expr_cast(ctx, expr);
- if (!expr->terminates) {
- gen_store(ctx, out, result);
- }
- return;
- }
+ assert(from->storage == STORAGE_ARRAY);
+ assert(from->array.length != SIZE_UNDEFINED);
+
+ struct gen_value value = gen_expr(ctx, expr->cast.value);
+ struct qbe_value qvalue = mkqval(ctx, &value);
+ struct qbe_value base = mklval(ctx, &out);
+ struct qbe_value sz = constl(to->size);
+ enum qbe_instr store = store_for_type(ctx, &builtin_type_size);
+ pushi(ctx->current, NULL, store, &qvalue, &base, NULL);
+ struct qbe_value qptr = mkqtmp(ctx, ctx->arch.ptr, ".%d");
+ sz = constl(builtin_type_size.size);
+ struct qbe_value ln = constl(from->array.length);
+ pushi(ctx->current, &qptr, Q_ADD, &base, &sz, NULL);
+ pushi(ctx->current, NULL, store, &ln, &qptr, NULL);
+ pushi(ctx->current, &qptr, Q_ADD, &qptr, &sz, NULL);
+ pushi(ctx->current, NULL, store, &ln, &qptr, NULL);
+}
+static void
+gen_expr_cast_tagged_at(struct gen_context *ctx,
+ const struct expression *expr, struct gen_value out)
+{
+ const struct type *to = expr->result, *from = expr->cast.value->result;
const struct type *subtype = tagged_select_subtype(to, from);
assert(subtype || tagged_subset_compat(to, from));
if (!subtype && to->align == from->align) {
@@ -528,54 +589,47 @@ gen_expr_cast_at(struct gen_context *ctx,
}
}
-static struct gen_value
-gen_expr_type_test(struct gen_context *ctx, const struct expression *expr)
+static bool
+cast_prefers_at(const struct expression *expr)
{
- const struct type *secondary = expr->cast.secondary,
- *from = expr->cast.value->result;
- assert(type_dealias(from)->storage == STORAGE_TAGGED);
- const struct type *subtype = tagged_select_subtype(from, secondary);
- assert(subtype && subtype == secondary); // Lowered by check
-
- struct gen_value val = gen_expr(ctx, expr->cast.value);
- struct qbe_value qval = mkqval(ctx, &val);
- struct qbe_value tag = mkqtmp(ctx,
- qtype_lookup(ctx, &builtin_type_uint, false),
- ".%d");
- enum qbe_instr load = load_for_type(ctx, &builtin_type_uint);
- pushi(ctx->current, &tag, load, &qval, NULL);
- struct qbe_value expected = constl(secondary->id);
- struct gen_value result = mktemp(ctx, &builtin_type_bool, ".%d");
- struct qbe_value qr = mkqval(ctx, &result);
- pushi(ctx->current, &qr, Q_CEQW, &tag, &expected, NULL);
- return result;
+ const struct type *to = expr->result, *from = expr->cast.value->result;
+ if (expr->cast.kind == C_TEST) {
+ return false;
+ }
+ // * => tagged
+ if (type_dealias(to)->storage == STORAGE_TAGGED) {
+ return true;
+ }
+ // array => slice
+ if (type_dealias(from)->storage == STORAGE_ARRAY &&
+ type_dealias(to)->storage == STORAGE_SLICE) {
+ return true;
+ }
+ return false;
}
static void
-gen_type_assertion(struct gen_context *ctx,
- const struct expression *expr,
- struct qbe_value base)
+gen_expr_cast_at(struct gen_context *ctx,
+ const struct expression *expr, struct gen_value out)
{
- const struct type *want = expr->result;
- struct qbe_value tag = mkqtmp(ctx,
- qtype_lookup(ctx, &builtin_type_uint, false),
- ".%d");
- enum qbe_instr load = load_for_type(ctx, &builtin_type_uint);
- pushi(ctx->current, &tag, load, &base, NULL);
- struct qbe_value expected = constl(want->id);
- struct gen_value result = mktemp(ctx, &builtin_type_bool, ".%d");
- struct qbe_value qr = mkqval(ctx, &result);
- pushi(ctx->current, &qr, Q_CEQW, &tag, &expected, NULL);
-
- struct qbe_statement failedl, passedl;
- struct qbe_value bfailed = mklabel(ctx, &failedl, "failed.%d");
- struct qbe_value bpassed = mklabel(ctx, &passedl, "passed.%d");
- pushi(ctx->current, NULL, Q_JNZ, &qr, &bpassed, &bfailed, NULL);
- push(&ctx->current->body, &failedl);
-
- gen_fixed_abort(ctx, expr->loc, ABORT_TYPE_ASSERTION);
+ if (!cast_prefers_at(expr)) {
+ struct gen_value result = gen_expr_cast(ctx, expr);
+ if (!expr->terminates) {
+ gen_store(ctx, out, result);
+ }
+ return;
+ }
- push(&ctx->current->body, &passedl);
+ const struct type *to = expr->result;
+ switch (type_dealias(to)->storage) {
+ case STORAGE_SLICE:
+ gen_expr_cast_slice_at(ctx, expr, out);
+ break;
+ case STORAGE_TAGGED:
+ gen_expr_cast_tagged_at(ctx, expr, out);
+ break;
+ default: abort(); // Invariant
+ }
}
static struct gen_value
@@ -593,8 +647,7 @@ gen_expr_cast(struct gen_context *ctx, const struct expression *expr)
break;
}
- // Casting to tagged union uses _at form
- if (type_dealias(to)->storage == STORAGE_TAGGED) {
+ if (cast_prefers_at(expr)) {
struct gen_value out = mktemp(ctx, expr->result, "object.%d");
struct qbe_value base = mkqval(ctx, &out);
struct qbe_value sz = constl(expr->result->size);
@@ -604,7 +657,7 @@ gen_expr_cast(struct gen_context *ctx, const struct expression *expr)
return out;
}
- // Casting from tagged union to non-tagged union
+ // Special case: tagged => non-tagged
if (type_dealias(from)->storage == STORAGE_TAGGED) {
struct gen_value value = gen_expr(ctx, expr->cast.value);
struct qbe_value base = mkcopy(ctx, &value, ".%d");
@@ -622,7 +675,7 @@ gen_expr_cast(struct gen_context *ctx, const struct expression *expr)
return gen_load(ctx, storage);
}
- // No conversion required
+ // Special case: no conversion required
if (type_dealias(to)->storage == type_dealias(from)->storage
&& to->size == from->size) {
struct gen_value value = gen_expr(ctx, expr->cast.value);
@@ -630,7 +683,7 @@ gen_expr_cast(struct gen_context *ctx, const struct expression *expr)
return value;
}
- // Special cases
+ // Other special cases
switch (type_dealias(to)->storage) {
case STORAGE_POINTER:
if (type_dealias(from)->storage == STORAGE_SLICE) {
@@ -727,8 +780,13 @@ gen_expr_cast(struct gen_context *ctx, const struct expression *expr)
pushi(ctx->current, &qresult, Q_COPY, &qvalue, NULL);
break;
case STORAGE_ARRAY:
+ assert(from->storage == STORAGE_ARRAY);
+ pushi(ctx->current, &qresult, Q_COPY, &qvalue, NULL);
+ break;
case STORAGE_SLICE:
- assert(0); // TODO
+ assert(from->storage == STORAGE_SLICE);
+ pushi(ctx->current, &qresult, Q_COPY, &qvalue, NULL);
+ break;
case STORAGE_ALIAS:
case STORAGE_BOOL:
case STORAGE_FCONST:
diff --git a/tests/911-slices.ha b/tests/911-slices.ha
@@ -0,0 +1,18 @@
+fn castarray() void = {
+ let a: [_]int = [1, 2, 3];
+ let x: []int = a;
+ let p = &x: *struct {
+ data: *[3]int,
+ length: size,
+ capacity: size,
+ };
+ assert(p.data == &a);
+ assert(p.length == len(a));
+ assert(p.capacity == len(a));
+};
+
+export fn main() int = {
+ castarray();
+ // TODO: slicing, indexing, slice assignment
+ return 0;
+};
diff --git a/tests/configure b/tests/configure
@@ -14,7 +14,8 @@ tests() {
907-casts \
908-loops \
909-defer \
- 910-tagged
+ 910-tagged \
+ 911-slices
do
cat <<EOF
tests/$t: harec tests/$t.ha tests/rt.o
