From d771708693b6c94017ed57ad40e7d5318978eea4 Mon Sep 17 00:00:00 2001
From: Eduard Urbach <admin@akyoto.dev>
Date: Fri, 5 Jul 2024 16:31:33 +0200
Subject: [PATCH] Improved code generation

---
 src/build/core/ExpressionsToRegisters.go |  1 -
 src/build/core/SaveRegister.go           | 40 ------------------------
 tests/programs/return.q                  | 11 +++++++
 tests/programs_test.go                   |  1 +
 4 files changed, 12 insertions(+), 41 deletions(-)
 delete mode 100644 src/build/core/SaveRegister.go
 create mode 100644 tests/programs/return.q

diff --git a/src/build/core/ExpressionsToRegisters.go b/src/build/core/ExpressionsToRegisters.go
index 6e293e2..64d6816 100644
--- a/src/build/core/ExpressionsToRegisters.go
+++ b/src/build/core/ExpressionsToRegisters.go
@@ -8,7 +8,6 @@ import (
 // ExpressionsToRegisters moves multiple expressions into the specified registers.
 func (f *Function) ExpressionsToRegisters(expressions []*expression.Expression, registers []cpu.Register) error {
 	for i := len(registers) - 1; i >= 0; i-- {
-		f.SaveRegister(registers[i])
 		err := f.ExpressionToRegister(expressions[i], registers[i])
 
 		if err != nil {
diff --git a/src/build/core/SaveRegister.go b/src/build/core/SaveRegister.go
deleted file mode 100644
index 7a23eb8..0000000
--- a/src/build/core/SaveRegister.go
+++ /dev/null
@@ -1,40 +0,0 @@
-package core
-
-import (
-	"fmt"
-
-	"git.akyoto.dev/cli/q/src/build/asm"
-	"git.akyoto.dev/cli/q/src/build/config"
-	"git.akyoto.dev/cli/q/src/build/cpu"
-)
-
-// SaveRegister attempts to move a variable occupying this register to another register.
-func (f *Function) SaveRegister(register cpu.Register) {
-	if f.cpu.IsFree(register) {
-		return
-	}
-
-	var variable *Variable
-
-	for _, v := range f.variables {
-		if v.Register == register {
-			variable = v
-			break
-		}
-	}
-
-	if variable == nil || variable.Alive == 0 {
-		return
-	}
-
-	newRegister := f.cpu.MustFindFree(f.cpu.General)
-	f.cpu.Use(newRegister)
-
-	if config.Comments {
-		f.assembler.Comment(fmt.Sprintf("save %s to %s", register, newRegister))
-	}
-
-	f.assembler.RegisterRegister(asm.MOVE, newRegister, register)
-	f.cpu.Free(register)
-	variable.Register = newRegister
-}
diff --git a/tests/programs/return.q b/tests/programs/return.q
new file mode 100644
index 0000000..13f1e6a
--- /dev/null
+++ b/tests/programs/return.q
@@ -0,0 +1,11 @@
+main() {
+	syscall(60, f(2))
+}
+
+f(x) {
+	return x + 1 + g(x)
+}
+
+g(x) {
+	return x + 1
+}
\ No newline at end of file
diff --git a/tests/programs_test.go b/tests/programs_test.go
index cd70f45..91c483d 100644
--- a/tests/programs_test.go
+++ b/tests/programs_test.go
@@ -20,6 +20,7 @@ var programs = []struct {
 	{"square-sum.q", "", 25},
 	{"chained-calls.q", "", 9},
 	{"nested-calls.q", "", 4},
+	{"return.q", "", 6},
 }
 
 func TestPrograms(t *testing.T) {