diff --git a/mie/pass/builtin/builtin.c b/mie/pass/builtin/builtin.c
index 19fa546..8b98b75 100644
--- a/mie/pass/builtin/builtin.c
+++ b/mie/pass/builtin/builtin.c
@@ -4,4 +4,5 @@
 
 MIE_PASS_GROUP_BEGIN(mie_builtin)
 	MIE_PASS_GROUP_ADD_PASS(prefix_func_with_underscore);
+	MIE_PASS_GROUP_ADD_PASS(convert_scf_to_cf);
 MIE_PASS_GROUP_END()
diff --git a/mie/pass/builtin/convert-scf-to-cf.c b/mie/pass/builtin/convert-scf-to-cf.c
new file mode 100644
index 0000000..27750e9
--- /dev/null
+++ b/mie/pass/builtin/convert-scf-to-cf.c
@@ -0,0 +1,136 @@
+#include <mie/ctx.h>
+#include <mie/dialect/builtin.h>
+#include <mie/dialect/cf.h>
+#include <mie/dialect/dialect.h>
+#include <mie/ir/block.h>
+#include <mie/ir/op-definition.h>
+#include <mie/ir/op.h>
+#include <mie/ir/region.h>
+#include <mie/ir/walk.h>
+#include <mie/macros.h>
+#include <mie/pass/pass-definition.h>
+#include <mie/pass/pass.h>
+#include <mie/rewrite/convert.h>
+#include <mie/rewrite/pattern.h>
+#include <mie/rewrite/rewriter.h>
+
+static bool op_is_flat(const struct mie_op *op)
+{
+	return false;
+}
+
+static enum mie_match_result if_match(const struct mie_op *op)
+{
+	if (!mie_op_is(op, "scf", "if")) {
+		return MIE_NO_MATCH_FOUND;
+	}
+
+	return MIE_MATCH_FOUND;
+}
+
+static struct mie_rewrite_result if_rewrite(
+	struct mie_op *op, struct mie_rewriter *rewriter)
+{
+	printf("if: rewriting %p %s.%s\n", op, op->op_dialect->d_name,
+	       op->op_info->op_name);
+
+	struct mie_register *cond = mie_op_get_arg(op, 0);
+	struct mie_region *parent_region = op->op_container->b_parent;
+
+	struct mie_region *if_region = mie_op_get_first_region(op);
+	struct mie_block *if_start = mie_region_get_first_block(if_region);
+	struct mie_block *if_end = mie_region_get_last_block(if_region);
+	struct mie_region *else_region = mie_op_get_next_region(op, if_region);
+	struct mie_block *else_start = mie_region_get_first_block(else_region);
+
+	struct mie_block *pre_block = op->op_container;
+	struct mie_block *end_block
+		= mie_rewriter_split_block(rewriter, pre_block, op, "if.end");
+
+	for (size_t i = 0; i < MIE_VECTOR_COUNT(op->op_result); i++) {
+		struct mie_register *old_reg = &op->op_result.items[i];
+		struct mie_register *new_reg = mie_block_add_param(end_block);
+		new_reg->reg_type = old_reg->reg_type;
+		char *name = b_strdup(old_reg->reg_name.n_str);
+
+		mie_name_destroy(&old_reg->reg_name);
+		mie_rewriter_rename_register(rewriter, new_reg, name);
+		mie_rewriter_replace_register(rewriter, old_reg, new_reg);
+		free(name);
+	}
+
+	struct mie_walker walker;
+	mie_walker_begin(&walker, op, MIE_WALKER_F_INCLUDE_OPS);
+
+	do {
+		const struct mie_walk_item *item = mie_walker_get(&walker);
+		if (!mie_op_is(item->i_op, "scf", "yield")) {
+			continue;
+		}
+
+		printf("if: found scf.yield %p\n", item->i_op);
+
+		struct mie_op *br = mie_rewriter_replace_op(
+			rewriter, item->i_op, "cf", "br");
+		struct mie_op_successor *s = mie_rewriter_add_op_successor(
+			rewriter, br, end_block, NULL, 0);
+		mie_rewriter_move_op_args_to_successor(rewriter, br, s);
+
+	} while (mie_walker_step(&walker) == MIE_SUCCESS);
+
+	mie_walker_end(&walker);
+
+	mie_rewriter_move_blocks_after(
+		rewriter, if_region, parent_region, pre_block);
+	mie_rewriter_rename_block(rewriter, if_start, "if.then");
+
+	if (else_region) {
+		mie_rewriter_move_blocks_after(
+			rewriter, else_region, parent_region, if_end);
+		mie_rewriter_rename_block(rewriter, else_start, "if.else");
+	}
+
+	mie_rewriter_erase_op(rewriter, op);
+
+	mie_rewriter_set_insertion_block(rewriter, pre_block);
+	mie_rewriter_set_insertion_point(rewriter, NULL);
+	mie_cf_br_cond_put(
+		MIE_EMITTER(rewriter), cond, if_start, NULL, 0, else_start,
+		NULL, 0);
+
+	return MIE_REWRITE_RESULT(MIE_REWRITE_SUCCESS, MIE_SUCCESS);
+}
+
+MIE_REWRITE_PATTERN_BEGIN(if_pattern)
+	MIE_REWRITE_PATTERN_ROOT("scf", "if");
+	MIE_REWRITE_PATTERN_MATCH(if_match);
+	MIE_REWRITE_PATTERN_REWRITE(if_rewrite);
+MIE_REWRITE_PATTERN_END()
+
+static struct mie_pass_result transform(
+	struct mie_pass *pass, struct mie_op *op, struct mie_pass_args *args)
+{
+	printf("%s: taking a look at %p %s.%s\n", mie_pass_get_name(pass), op,
+	       op->op_dialect->d_name, op->op_info->op_name);
+
+	struct mie_convert_config *cfg = mie_convert_config_create(args->p_ctx);
+	mie_convert_config_add_illegal_op(cfg, "scf", "if");
+
+	struct mie_pattern_set patterns = {};
+	if_pattern_create(&patterns);
+	mie_convert_apply(op, cfg, &patterns);
+
+	mie_pattern_set_cleanup(&patterns);
+	mie_convert_config_destroy(cfg);
+
+	return MIE_PASS_CONTINUE;
+}
+
+MIE_PASS_DEFINITION_BEGIN(convert_scf_to_cf)
+	MIE_PASS_NAME("convert-scf-to-cf");
+	MIE_PASS_DESCRIPTION(
+		"Convert high-level SCF constructs to low-level CF operations "
+		"and blocks.");
+	MIE_PASS_TRANSFORM(transform);
+	MIE_PASS_FILTER_OP("func", "func");
+MIE_PASS_DEFINITION_END()