List.repeat in zig

compiler/builtins/bitcode/src/list.zig

@@ -7,6 +7,9 @@ const Allocator = mem.Allocator;
 const EqFn = fn (?[*]u8, ?[*]u8) callconv(.C) bool;
 const Opaque = ?[*]u8;
 
+const Inc = fn (?[*]u8) callconv(.C) void;
+const Dec = fn (?[*]u8) callconv(.C) void;
+
 pub const RocList = extern struct {
     bytes: ?[*]u8,
     length: usize,
@@ -278,3 +281,30 @@ pub fn listContains(list: RocList, key: Opaque, key_width: usize, is_eq: EqFn) c
 
     return false;
 }
+
+pub fn listRepeat(count: usize, alignment: usize, element: Opaque, element_width: usize, inc_n_element: Inc) callconv(.C) RocList {
+    if (count == 0) {
+        return RocList.empty();
+    }
+
+    const allocator = std.heap.c_allocator;
+    var output = RocList.allocate(allocator, alignment, count, element_width);
+
+    if (output.bytes) |target_ptr| {
+        var i: usize = 0;
+        const source = element orelse unreachable;
+        while (i < count) : (i += 1) {
+            @memcpy(target_ptr + i * element_width, source, element_width);
+        }
+
+        // TODO do all increments at once!
+        i = 0;
+        while (i < count) : (i += 1) {
+            inc_n_element(element);
+        }
+
+        return output;
+    } else {
+        unreachable;
+    }
+}

compiler/builtins/bitcode/src/main.zig

@@ -14,6 +14,7 @@ comptime {
     exportListFn(list.listKeepOks, "keep_oks");
     exportListFn(list.listKeepErrs, "keep_errs");
     exportListFn(list.listContains, "contains");
+    exportListFn(list.listRepeat, "repeat");
 }
 
 // Dict Module

compiler/builtins/src/bitcode.rs

@@ -67,3 +67,4 @@ pub const LIST_KEEP_ERRS: &str = "roc_builtins.list.keep_errs";
 pub const LIST_WALK: &str = "roc_builtins.list.walk";
 pub const LIST_WALK_BACKWARDS: &str = "roc_builtins.list.walk_backwards";
 pub const LIST_CONTAINS: &str = "roc_builtins.list.contains";
+pub const LIST_REPEAT: &str = "roc_builtins.list.repeat";

compiler/gen/src/llvm/bitcode.rs

@@ -207,6 +207,15 @@ fn build_transform_caller_help<'a, 'ctx, 'env>(
     function_value
 }
 
+pub fn build_inc_n_wrapper<'a, 'ctx, 'env>(
+    env: &Env<'a, 'ctx, 'env>,
+    layout_ids: &mut LayoutIds<'a>,
+    layout: &Layout<'a>,
+    n: u64,
+) -> FunctionValue<'ctx> {
+    build_rc_wrapper(env, layout_ids, layout, Mode::Inc(n))
+}
+
 pub fn build_inc_wrapper<'a, 'ctx, 'env>(
     env: &Env<'a, 'ctx, 'env>,
     layout_ids: &mut LayoutIds<'a>,

compiler/gen/src/llvm/build.rs

@@ -3597,7 +3597,15 @@ fn run_low_level<'a, 'ctx, 'env>(
 
             let inplace = get_inplace_from_layout(layout);
 
-            list_repeat(env, inplace, parent, list_len, elem, elem_layout)
+            list_repeat(
+                env,
+                layout_ids,
+                inplace,
+                parent,
+                list_len,
+                elem,
+                elem_layout,
+            )
         }
         ListReverse => {
             // List.reverse : List elem -> List elem

compiler/gen/src/llvm/build_list.rs

@@ -1,6 +1,7 @@
 #![allow(clippy::too_many_arguments)]
 use crate::llvm::bitcode::{
-    build_eq_wrapper, build_transform_caller, call_bitcode_fn, call_void_bitcode_fn,
+    build_eq_wrapper, build_inc_wrapper, build_transform_caller, call_bitcode_fn,
+    call_void_bitcode_fn,
 };
 use crate::llvm::build::{
     allocate_with_refcount_help, build_num_binop, cast_basic_basic, complex_bitcast, Env, InPlace,
@@ -53,90 +54,45 @@ pub fn list_single<'a, 'ctx, 'env>(
 /// List.repeat : Int, elem -> List elem
 pub fn list_repeat<'a, 'ctx, 'env>(
     env: &Env<'a, 'ctx, 'env>,
+    layout_ids: &mut LayoutIds<'a>,
     inplace: InPlace,
     parent: FunctionValue<'ctx>,
     list_len: IntValue<'ctx>,
-    elem: BasicValueEnum<'ctx>,
-    elem_layout: &Layout<'a>,
+    element: BasicValueEnum<'ctx>,
+    element_layout: &Layout<'a>,
 ) -> BasicValueEnum<'ctx> {
     let builder = env.builder;
-    let ctx = env.context;
 
-    // list_len > 0
-    // We have to do a loop below, continuously adding the `elem`
-    // to the output list `List elem` until we have reached the
-    // number of repeats. This `comparison` is used to check
-    // if we need to do any looping; because if we dont, then we
-    // dont need to allocate memory for the index or the check
-    // if index != 0
-    let comparison = builder.build_int_compare(
-        IntPredicate::UGT,
-        list_len,
-        ctx.i64_type().const_int(0, false),
-        "atleastzero",
-    );
+    let u8_ptr = env.context.i8_type().ptr_type(AddressSpace::Generic);
 
-    let build_then = || {
-        // Allocate space for the new array that we'll copy into.
-        let list_ptr = allocate_list(env, inplace, elem_layout, list_len);
-        // TODO check if malloc returned null; if so, runtime error for OOM!
+    let element_ptr = builder.build_alloca(element.get_type(), "element_ptr");
+    env.builder.build_store(element_ptr, element);
 
-        let index_name = "#index";
-        let start_alloca = builder.build_alloca(ctx.i64_type(), index_name);
+    let element_width = env
+        .ptr_int()
+        .const_int(element_layout.stack_size(env.ptr_bytes) as u64, false);
 
-        // Start at the last element in the list.
-        let last_elem_index = builder.build_int_sub(
-            list_len,
-            ctx.i64_type().const_int(1, false),
-            "lastelemindex",
-        );
-        builder.build_store(start_alloca, last_elem_index);
+    let alignment = element_layout.alignment_bytes(env.ptr_bytes);
+    let alignment_iv = env.ptr_int().const_int(alignment as u64, false);
+    let inc_element_fn = build_inc_wrapper(env, layout_ids, element_layout);
 
-        let loop_bb = ctx.append_basic_block(parent, "loop");
-        builder.build_unconditional_branch(loop_bb);
-        builder.position_at_end(loop_bb);
-
-        // #index = #index - 1
-        let curr_index = builder
-            .build_load(start_alloca, index_name)
-            .into_int_value();
-        let next_index =
-            builder.build_int_sub(curr_index, ctx.i64_type().const_int(1, false), "nextindex");
-
-        builder.build_store(start_alloca, next_index);
-        let elem_ptr =
-            unsafe { builder.build_in_bounds_gep(list_ptr, &[curr_index], "load_index") };
-
-        // Mutate the new array in-place to change the element.
-        builder.build_store(elem_ptr, elem);
-
-        // #index != 0
-        let end_cond = builder.build_int_compare(
-            IntPredicate::NE,
-            ctx.i64_type().const_int(0, false),
-            curr_index,
-            "loopcond",
-        );
-
-        let after_bb = ctx.append_basic_block(parent, "afterloop");
-
-        builder.build_conditional_branch(end_cond, loop_bb, after_bb);
-        builder.position_at_end(after_bb);
-
-        store_list(env, list_ptr, list_len)
-    };
-
-    let build_else = || empty_polymorphic_list(env);
-
-    let struct_type = collection(ctx, env.ptr_bytes);
-
-    build_basic_phi2(
+    let output = call_bitcode_fn(
         env,
-        parent,
-        comparison,
-        build_then,
-        build_else,
-        BasicTypeEnum::StructType(struct_type),
+        &[
+            list_len.into(),
+            alignment_iv.into(),
+            env.builder.build_bitcast(element_ptr, u8_ptr, "to_u8_ptr"),
+            element_width.into(),
+            inc_element_fn.as_global_value().as_pointer_value().into(),
+        ],
+        bitcode::LIST_REPEAT,
+    );
+
+    complex_bitcast(
+        env.builder,
+        output,
+        collection(env.context, env.ptr_bytes).into(),
+        "from_i128",
     )
 }
 
@@ -1532,7 +1488,7 @@ where
         "bounds_check",
     );
 
-    let after_loop_bb = ctx.append_basic_block(parent, "after_outer_loop");
+    let after_loop_bb = ctx.append_basic_block(parent, "after_outer_loop_1");
 
     builder.build_conditional_branch(condition, loop_bb, after_loop_bb);
     builder.position_at_end(after_loop_bb);
@@ -1599,7 +1555,7 @@ where
     // #index < end
     let loop_end_cond = bounds_check_comparison(builder, next_index, end);
 
-    let after_loop_bb = ctx.append_basic_block(parent, "after_outer_loop");
+    let after_loop_bb = ctx.append_basic_block(parent, "after_outer_loop_2");
 
     builder.build_conditional_branch(loop_end_cond, loop_bb, after_loop_bb);
     builder.position_at_end(after_loop_bb);

compiler/mono/src/borrow.rs

@@ -635,7 +635,7 @@ pub fn lowlevel_borrow_signature(arena: &Bump, op: LowLevel) -> &[bool] {
         ListConcat | StrConcat => arena.alloc_slice_copy(&[owned, borrowed]),
         StrSplit => arena.alloc_slice_copy(&[borrowed, borrowed]),
         ListSingle => arena.alloc_slice_copy(&[irrelevant]),
-        ListRepeat => arena.alloc_slice_copy(&[irrelevant, irrelevant]),
+        ListRepeat => arena.alloc_slice_copy(&[irrelevant, borrowed]),
         ListReverse => arena.alloc_slice_copy(&[owned]),
         ListPrepend => arena.alloc_slice_copy(&[owned, owned]),
         StrJoinWith => arena.alloc_slice_copy(&[irrelevant, irrelevant]),

compiler/mono/src/ir.rs

@@ -17,7 +17,7 @@ use roc_types::subs::{Content, FlatType, Subs, Variable};
 use std::collections::HashMap;
 use ven_pretty::{BoxAllocator, DocAllocator, DocBuilder};
 
-pub const PRETTY_PRINT_IR_SYMBOLS: bool = false;
+pub const PRETTY_PRINT_IR_SYMBOLS: bool = true;
 
 macro_rules! return_on_layout_error {
     ($env:expr, $layout_result:expr) => {

examples/benchmarks/AStarTests.roc

@@ -9,14 +9,15 @@ fromList = \list -> List.walk list (\x, a -> Set.insert a x) Set.empty
 
 main : Task.Task {} []
 main =
-    Task.after Task.getInt \n ->
-        when n is
-            1 -> 
     Task.putLine (showBool test1)
-
-            _ -> 
-                ns = Str.fromInt n
-                Task.putLine "No test \(ns)"
+#     Task.after Task.getInt \n ->
+#         when n is
+#             1 -> 
+#                 Task.putLine (showBool test1)
+# 
+#             _ -> 
+#                 ns = Str.fromInt n
+#                 Task.putLine "No test \(ns)"
 
 showBool : Bool -> Str
 showBool = \b ->