From ebfbbd0a1a0f10b6a06b79bb81db235cc65b292e Mon Sep 17 00:00:00 2001
From: Max Wash <mbswash@gmail.com>
Date: Fri, 29 Aug 2025 15:47:42 +0100
Subject: [PATCH] frontend: compile: create and (optionally) show isel graph
 for each block

---
 frontend/cmd/compile.c | 100 ++++++++++++++++++++++++++++++++++-------
 1 file changed, 84 insertions(+), 16 deletions(-)

diff --git a/frontend/cmd/compile.c b/frontend/cmd/compile.c
index 397a665..7849582 100644
--- a/frontend/cmd/compile.c
+++ b/frontend/cmd/compile.c
@@ -1,5 +1,6 @@
 #include "../debug.h"
 #include "cmd.h"
+#include "mie/select/builder.h"
 
 #include <blue/cmd.h>
 #include <blue/term.h>
@@ -11,8 +12,12 @@
 #include <ivy/lang/diag.h>
 #include <ivy/lang/lex.h>
 #include <mie/ctx.h>
+#include <mie/ir/block.h>
 #include <mie/ir/convert.h>
+#include <mie/ir/func.h>
 #include <mie/ir/module.h>
+#include <mie/select/builder.h>
+#include <mie/select/graph.h>
 #include <stdio.h>
 
 enum {
@@ -20,6 +25,8 @@ enum {
 	OPT_SHOW_LEX_TOKENS,
 	OPT_SHOW_AST_NODES,
 	OPT_SHOW_IR,
+	OPT_SHOW_ISEL_PRE,
+	OPT_SHOW_ISEL_POST,
 };
 
 struct codegen_args {
@@ -54,6 +61,9 @@ static int compile_file(const char *path, const b_arglist *args)
 	              > 0;
 	bool show_ir
 		= b_arglist_get_count(args, OPT_SHOW_IR, B_COMMAND_INVALID_ID) > 0;
+	bool show_isel_pre
+		= b_arglist_get_count(args, OPT_SHOW_ISEL_PRE, B_COMMAND_INVALID_ID)
+	        > 0;
 	enum ivy_status status = IVY_OK;
 
 	struct ivy_file *src = NULL;
@@ -123,11 +133,6 @@ static int compile_file(const char *path, const b_arglist *args)
 		if (status != IVY_OK) {
 			ivy_diag_ctx_write(
 				diag, IVY_DIAG_FORMAT_PRETTY, &diag_stream);
-#if 0
-			b_err("failed to parse '%s'", path);
-			b_i("reason: lex error (%s)",
-			    ivy_status_to_string(ivy_lexer_get_status(lex)));
-#endif
 			break;
 		}
 
@@ -172,11 +177,6 @@ static int compile_file(const char *path, const b_arglist *args)
 		ivy_ast_node_iterate(root, &it, print_ast_node, NULL);
 	}
 
-	if (!show_ir) {
-		ivy_parser_destroy(parser, NULL);
-		return 0;
-	}
-
 	ivy_codegen_start_module(codegen);
 
 	struct ivy_ast_node *node = ivy_parser_root_node(parser);
@@ -197,14 +197,64 @@ static int compile_file(const char *path, const b_arglist *args)
 	struct mie_module *mod = NULL;
 	ivy_codegen_end_module(codegen, &mod);
 
-	struct mie_ir_converter *convert
-		= mie_ir_converter_create(ctx, MIE_IR_MEM, MIE_IR_TEXT);
-	mie_ir_converter_set_src_value(convert, MIE_VALUE(mod));
-	mie_ir_converter_set_dest_file(convert, stdout);
-	mie_ir_converter_process(convert);
+	if (show_ir) {
+		struct mie_ir_converter *convert
+			= mie_ir_converter_create(ctx, MIE_IR_MEM, MIE_IR_TEXT);
+		mie_ir_converter_set_src_value(convert, MIE_VALUE(mod));
+		mie_ir_converter_set_dest_file(convert, stdout);
+		mie_ir_converter_process(convert);
+
+		mie_ir_converter_destroy(convert);
+	}
+
+	struct mie_select_builder *builder = mie_select_builder_create(ctx);
+
+	b_queue_iterator func_it;
+	b_queue_foreach (&func_it, &mod->m_func) {
+		struct mie_value *func_v
+			= b_unbox(struct mie_value, func_it.entry, v_entry);
+		struct mie_func *func = (struct mie_func *)func_v;
+
+		b_queue_iterator block_it;
+		b_queue_foreach (&block_it, &func->f_blocks) {
+			struct mie_value *block_v = b_unbox(
+				struct mie_value, block_it.entry, v_entry);
+			struct mie_block *block = (struct mie_block *)block_v;
+
+			b_queue_iterator instr_it;
+			b_queue_foreach (&instr_it, &block->b_phi) {
+				struct mie_value *instr_v = b_unbox(
+					struct mie_value, instr_it.entry, v_entry);
+				mie_select_builder_push_instr(
+					builder, (struct mie_instr *)instr_v);
+			}
+
+			b_queue_foreach (&instr_it, &block->b_instr) {
+				struct mie_value *instr_v = b_unbox(
+					struct mie_value, instr_it.entry, v_entry);
+				mie_select_builder_push_instr(
+					builder, (struct mie_instr *)instr_v);
+			}
+
+			if (block->b_terminator) {
+				mie_select_builder_push_instr(
+					builder, block->b_terminator);
+			}
+
+			struct mie_select_graph *graph
+				= mie_select_builder_finish(builder);
+
+			if (show_isel_pre) {
+				printf("%s.%s instruction graph:\n",
+				       func->f_base.v_name.n_str,
+				       block->b_base.v_name.n_str);
+				mie_select_graph_dump_dot(graph);
+				mie_select_graph_destroy(graph);
+			}
+		}
+	}
 
 	mie_value_destroy(MIE_VALUE(mod));
-	mie_ir_converter_destroy(convert);
 	ivy_codegen_destroy(codegen);
 
 	ivy_parser_destroy(parser, NULL);
@@ -267,6 +317,24 @@ B_COMMAND(CMD_COMPILE, CMD_ROOT)
 			"input files.");
 	}
 
+	B_COMMAND_OPTION(OPT_SHOW_ISEL_PRE)
+	{
+		B_OPTION_LONG_NAME("show-isel-pre");
+		B_OPTION_SHORT_NAME('s');
+		B_OPTION_DESC(
+			"print the instruction selection graph before "
+			"selection has taken place.");
+	}
+
+	B_COMMAND_OPTION(OPT_SHOW_ISEL_POST)
+	{
+		B_OPTION_LONG_NAME("show-isel-post");
+		B_OPTION_SHORT_NAME('m');
+		B_OPTION_DESC(
+			"print the instruction selection graph after "
+			"selection has taken place.");
+	}
+
 	B_COMMAND_ARG(ARG_SOURCE_FILE)
 	{
 		B_ARG_NAME("source file");