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Code Issues 87 Pull Requests 3 Releases Wiki Activity

core: Remove redundant for.cond BB for iterable loops

David Mak 2023-09-05 17:07:48 +08:00
parent 74034fe473
commit f46140d74a
1 changed files with 10 additions and 16 deletions
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26
nac3core/src/codegen/stmt.rs
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@ -247,7 +247,6 @@ pub fn gen_for<'ctx, 'a, G: CodeGenerator>(
let size_t = generator.get_size_type(ctx.ctx);
let zero = int32.const_zero();
let current = ctx.builder.get_insert_block().and_then(|bb| bb.get_parent()).unwrap();
let test_bb = ctx.ctx.append_basic_block(current, "for.cond");
let body_bb = ctx.ctx.append_basic_block(current, "for.body");
let cont_bb = ctx.ctx.append_basic_block(current, "for.end");
// if there is no orelse, we just go to cont_bb
@ -257,13 +256,16 @@ pub fn gen_for<'ctx, 'a, G: CodeGenerator>(
// Whether the iterable is a range() expression
let is_iterable_range_expr = ctx.unifier.unioned(iter.custom.unwrap(), ctx.primitives.range);
// store loop bb information and restore it later
let loop_bb = if is_iterable_range_expr {
ctx.loop_target.replace((body_bb, cont_bb))
// The target BB of the loop backedge
let backedge_bb_target = if is_iterable_range_expr {
body_bb
} else {
ctx.loop_target.replace((test_bb, cont_bb))
ctx.ctx.append_basic_block(current, "for.cond")
};
// store loop bb information and restore it later
let loop_bb = ctx.loop_target.replace((backedge_bb_target, cont_bb));
let iter_val = generator.gen_expr(ctx, iter)?.unwrap().to_basic_value_enum(
ctx,
generator,
@ -316,6 +318,8 @@ pub fn gen_for<'ctx, 'a, G: CodeGenerator>(
ctx.builder.position_at_end(cond_cont_bb);
ctx.builder.build_store(i, next_i);
} else {
let test_bb = backedge_bb_target;
let counter = generator.gen_var_alloc(ctx, size_t.into())?;
// counter = -1
ctx.builder.build_store(counter, size_t.const_int(u64::max_value(), true));
@ -352,11 +356,7 @@ pub fn gen_for<'ctx, 'a, G: CodeGenerator>(
}
if !ctx.is_terminated() {
if is_iterable_range_expr {
ctx.builder.build_unconditional_branch(body_bb);
} else {
ctx.builder.build_unconditional_branch(test_bb);
}
ctx.builder.build_unconditional_branch(backedge_bb_target);
}
if !orelse.is_empty() {
@ -374,12 +374,6 @@ pub fn gen_for<'ctx, 'a, G: CodeGenerator>(
}
}
// Clear test_bb if unused
if is_iterable_range_expr {
ctx.builder.position_at_end(test_bb);
ctx.builder.build_unreachable();
}
ctx.builder.position_at_end(cont_bb);
ctx.loop_target = loop_bb;
} else {