From c24e1eb5d396104bb783ddcff22bfe80466d5eba Mon Sep 17 00:00:00 2001
From: dibyendumajumdar <mobile@majumdar.org.uk>
Date: Sat, 19 Mar 2022 21:49:34 +0000
Subject: [PATCH] #77 simple optimization phase to replace upvalues that
 reference literals with those literals

---
 include/ravi_compiler.h | 8 ++++++++
 src/linearizer.c        | 4 ++++
 src/ravi_binding.c      | 1 +
 tests/tcommon.c         | 3 +++
 tests/tcommon.h         | 2 +-
 tests/trun.c            | 6 ++++++
 6 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/include/ravi_compiler.h b/include/ravi_compiler.h
index 9cd3b60..cc1d6b4 100644
--- a/include/ravi_compiler.h
+++ b/include/ravi_compiler.h
@@ -248,6 +248,14 @@ RAVICOMP_EXPORT LinearizerState *raviX_init_linearizer(CompilerState *compiler_s
  * Returns 0 on success.
  */
 RAVICOMP_EXPORT int raviX_ast_linearize(LinearizerState *linearizer);
+
+/*
+ * Attempts to replace use of upvalues with constants where the upvalue
+ * points to a local that was initialized with a literal and the local
+ * has no other assignments.
+ */
+RAVICOMP_EXPORT void raviX_optimize_upvalues(LinearizerState *linearizer);
+
 /* Prints out the content of the linear IR */
 RAVICOMP_EXPORT void raviX_output_linearizer(LinearizerState *linearizer, FILE *fp);
 /* Cleanup the linearizer */
diff --git a/src/linearizer.c b/src/linearizer.c
index ffe7ef8..791d853 100644
--- a/src/linearizer.c
+++ b/src/linearizer.c
@@ -3001,6 +3001,10 @@ static void replace_literal_upvalues(Proc *proc)
 	END_FOR_EACH_PTR(childproc)
 }
 
+void raviX_optimize_upvalues(LinearizerState *linearizer) {
+	replace_literal_upvalues(linearizer->main_proc);
+}
+
 ////////////// end of optimization of upvalues
 
 static const char *op_codenames[] = {
diff --git a/src/ravi_binding.c b/src/ravi_binding.c
index 25f5134..4e758b0 100644
--- a/src/ravi_binding.c
+++ b/src/ravi_binding.c
@@ -68,6 +68,7 @@ int raviX_compile(struct Ravi_CompilerInterface *compiler_interface)
 	}
 	raviX_construct_cfg(linearizer->main_proc);
 	raviX_remove_unreachable_blocks(linearizer);
+	raviX_optimize_upvalues(linearizer);
 
 	TextBuffer buf;
 	raviX_buffer_init(&buf, 4096);
diff --git a/tests/tcommon.c b/tests/tcommon.c
index cb2a29e..9c95f78 100644
--- a/tests/tcommon.c
+++ b/tests/tcommon.c
@@ -40,6 +40,7 @@ void parse_arguments(struct arguments *args, int argc, const char *argv[])
 	args->simplify_ast = 0;
 	args->remove_unreachable_blocks = 0;
 	args->gen_C = 0;
+	args->opt_upvalue = 0;
 	args->mainfunc = "setup";
 	for (int i = 1; i < argc; i++) {
 		if (strcmp(argv[i], "--notypecheck") == 0) {
@@ -60,6 +61,8 @@ void parse_arguments(struct arguments *args, int argc, const char *argv[])
 			args->remove_unreachable_blocks = 1;
 		} else if (strcmp(argv[i], "--gen-C") == 0) {
 			args->gen_C = 1;
+		} else if (strcmp(argv[i], "--opt-upvalues") == 0) {
+			args->opt_upvalue = 1;
 		} else if (strcmp(argv[i], "-main") == 0) {
 			if (i < argc - 1) {
 				i++;
diff --git a/tests/tcommon.h b/tests/tcommon.h
index 57040ee..5f582d1 100644
--- a/tests/tcommon.h
+++ b/tests/tcommon.h
@@ -30,7 +30,7 @@ struct arguments {
 	const char *filename;
 	const char *code;
 	unsigned typecheck : 1, linearize : 1, astdump : 1, irdump : 1, cfgdump : 1, codump : 1, simplify_ast : 1,
-	    remove_unreachable_blocks: 1, gen_C: 1;
+	    remove_unreachable_blocks: 1, gen_C: 1, opt_upvalue: 1;
 	const char *mainfunc; /* name of the main function in generated code, only applies if gen_C is on */
 };
 extern void parse_arguments(struct arguments *args, int argc, const char *argv[]);
diff --git a/tests/trun.c b/tests/trun.c
index d580da6..6b9fdf5 100644
--- a/tests/trun.c
+++ b/tests/trun.c
@@ -179,6 +179,12 @@ static int do_code(C_MemoryAllocator *allocator, const char *code, const struct
 			raviX_output_cfg(linearizer->main_proc, stdout);
 		}
 	}
+	if (args->opt_upvalue) {
+		raviX_optimize_upvalues(linearizer);
+		if (args->irdump) {
+			raviX_output_linearizer(linearizer, stdout);
+		}
+	}
 	if (args->gen_C) {
 		fprintf(stdout, "\n#endif\n");
 		raviX_generate_C_tofile(linearizer, args->mainfunc, stdout);