From d3436b13a572722e1493fec2c527d6e4fea16b17 Mon Sep 17 00:00:00 2001
From: Eduard Urbach <admin@akyoto.dev>
Date: Wed, 10 Jul 2024 10:48:15 +0200
Subject: [PATCH] Reduced usage of temporary registers

---
 src/build/core/CompileDefinition.go    | 6 ++----
 src/build/core/ExpressionToRegister.go | 5 +++++
 src/build/core/Function.go             | 7 -------
 src/build/core/Instructions.go         | 6 ++++--
 src/build/core/SaveRegister.go         | 5 +----
 src/build/core/UsesRegister.go         | 9 +--------
 6 files changed, 13 insertions(+), 25 deletions(-)

diff --git a/src/build/core/CompileDefinition.go b/src/build/core/CompileDefinition.go
index f2fd234..c23ac56 100644
--- a/src/build/core/CompileDefinition.go
+++ b/src/build/core/CompileDefinition.go
@@ -1,8 +1,6 @@
 package core
 
 import (
-	"fmt"
-
 	"git.akyoto.dev/cli/q/src/build/ast"
 	"git.akyoto.dev/cli/q/src/build/config"
 	"git.akyoto.dev/cli/q/src/build/errors"
@@ -43,7 +41,7 @@ func (f *Function) CompileDefinition(node *ast.Define) error {
 
 func (f *Function) AddVariable(variable *Variable) {
 	if config.Comments {
-		f.Comment(fmt.Sprintf("%s = %s (%s, %d uses)", variable.Name, variable.Value, variable.Register, variable.Alive))
+		f.Comment("%s = %s (%s, %d uses)", variable.Name, variable.Value, variable.Register, variable.Alive)
 	}
 
 	f.variables[variable.Name] = variable
@@ -60,7 +58,7 @@ func (f *Function) useVariable(variable *Variable) {
 
 	if variable.Alive == 0 {
 		if config.Comments {
-			f.Comment(fmt.Sprintf("%s died (%s)", variable.Name, variable.Register))
+			f.Comment("%s died (%s)", variable.Name, variable.Register)
 		}
 
 		f.cpu.Free(variable.Register)
diff --git a/src/build/core/ExpressionToRegister.go b/src/build/core/ExpressionToRegister.go
index 793403c..acc211d 100644
--- a/src/build/core/ExpressionToRegister.go
+++ b/src/build/core/ExpressionToRegister.go
@@ -3,6 +3,7 @@ package core
 import (
 	"git.akyoto.dev/cli/q/src/build/asm"
 	"git.akyoto.dev/cli/q/src/build/ast"
+	"git.akyoto.dev/cli/q/src/build/config"
 	"git.akyoto.dev/cli/q/src/build/cpu"
 	"git.akyoto.dev/cli/q/src/build/errors"
 	"git.akyoto.dev/cli/q/src/build/expression"
@@ -34,6 +35,10 @@ func (f *Function) ExpressionToRegister(node *expression.Expression, register cp
 
 	if f.UsesRegister(right, register) {
 		register = f.cpu.MustFindFree(f.cpu.General)
+
+		if config.Comments {
+			f.Comment("temporary register %s", register)
+		}
 	}
 
 	f.cpu.Reserve(register)
diff --git a/src/build/core/Function.go b/src/build/core/Function.go
index 0af8d06..7e57da2 100644
--- a/src/build/core/Function.go
+++ b/src/build/core/Function.go
@@ -1,8 +1,6 @@
 package core
 
 import (
-	"fmt"
-
 	"git.akyoto.dev/cli/q/src/build/arch/x64"
 	"git.akyoto.dev/cli/q/src/build/asm"
 	"git.akyoto.dev/cli/q/src/build/ast"
@@ -102,11 +100,6 @@ func (f *Function) CompileASTNode(node ast.Node) error {
 	}
 }
 
-// Logf formats a message for verbose output.
-func (f *Function) Logf(format string, data ...any) {
-	fmt.Printf("[%s @ %d] %s\n", f, len(f.assembler.Instructions), fmt.Sprintf(format, data...))
-}
-
 // String returns the function name.
 func (f *Function) String() string {
 	return f.Name
diff --git a/src/build/core/Instructions.go b/src/build/core/Instructions.go
index d9bae49..e6764ca 100644
--- a/src/build/core/Instructions.go
+++ b/src/build/core/Instructions.go
@@ -1,6 +1,8 @@
 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"
@@ -17,8 +19,8 @@ func (f *Function) Call(label string) {
 	f.postInstruction()
 }
 
-func (f *Function) Comment(comment string) {
-	f.assembler.Comment(comment)
+func (f *Function) Comment(format string, args ...any) {
+	f.assembler.Comment(fmt.Sprintf(format, args...))
 	f.postInstruction()
 }
 
diff --git a/src/build/core/SaveRegister.go b/src/build/core/SaveRegister.go
index 17f16cb..30e3c33 100644
--- a/src/build/core/SaveRegister.go
+++ b/src/build/core/SaveRegister.go
@@ -1,8 +1,6 @@
 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"
@@ -37,10 +35,9 @@ func (f *Function) SaveRegister(register cpu.Register) {
 	f.cpu.Reserve(newRegister)
 
 	if config.Comments {
-		f.Comment(fmt.Sprintf("save %s to %s", register, newRegister))
+		f.Comment("save %s to %s", register, newRegister)
 	}
 
 	f.RegisterRegister(asm.MOVE, newRegister, register)
-	f.cpu.Free(register)
 	variable.Register = newRegister
 }
diff --git a/src/build/core/UsesRegister.go b/src/build/core/UsesRegister.go
index 5090f63..9a10a85 100644
--- a/src/build/core/UsesRegister.go
+++ b/src/build/core/UsesRegister.go
@@ -4,19 +4,12 @@ import (
 	"git.akyoto.dev/cli/q/src/build/ast"
 	"git.akyoto.dev/cli/q/src/build/cpu"
 	"git.akyoto.dev/cli/q/src/build/expression"
-	"git.akyoto.dev/cli/q/src/build/token"
 )
 
 // UsesRegister returns true if evaluating the expression would write or read the given register.
 func (f *Function) UsesRegister(expr *expression.Expression, register cpu.Register) bool {
 	if expr.IsLeaf() {
-		if expr.Token.Kind == token.Number {
-			return false
-		}
-
-		name := expr.Token.Text()
-		variable := f.variables[name]
-		return register == variable.Register
+		return false
 	}
 
 	if ast.IsFunctionCall(expr) {