From 195cfbd2486f75d6bf309eb6f1b5f16af661f39e Mon Sep 17 00:00:00 2001
From: Enrico Lumetti <enrico.lumetti@gmail.com>
Date: Sun, 21 Aug 2022 01:35:30 +0200
Subject: [PATCH] wip: Improve register allocations and its test coverage

---
 allocate-regs.rkt            | 19 +++++++++++++------
 tests/test-allocate-regs.rkt | 12 ++++++++++--
 2 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/allocate-regs.rkt b/allocate-regs.rkt
index 55b253c..4df77d7 100644
--- a/allocate-regs.rkt
+++ b/allocate-regs.rkt
@@ -34,20 +34,27 @@
      (define reg-dest (generate-regs (length instr-args) (length instr-dest)))
      (append (generate-ldr instr-args stack-map)
              (list (AArch64-instr-from-dest-args instr reg-dest reg-args))
-             (generate-str instr-dest stack-map))))
+             (if (empty? instr-dest)
+                 '()
+                 (generate-str (generate-reg-n (length instr-args))
+                             (car instr-dest)
+                             stack-map)))))
 
 (define (generate-regs start len)
-  (map (lambda (i)
-           (Reg (string->symbol (string-append "x" (number->string i)))))
+  (map generate-reg-n
        (range start (+ start len))))
-     
+
+(define (generate-reg-n n)
+  (Reg (string->symbol (string-append "x" (number->string n)))))
+
 (define (generate-ldr var-list stack-map)
   (for/list ([var var-list]
              [reg (generate-regs 0 (length var-list))])
      (Ldr (AMOffset 'sp (hash-ref stack-map (Var-var-name var))) reg)))
 
-(define (generate-str var-list stack-map)
-  (list))
+(define (generate-str reg dest-var stack-map)
+  (list
+    (Str reg (AMOffset 'sp (hash-ref stack-map (Var-var-name dest-var))))))
 
 
 ; generate stack read/writes and allocate registers for
diff --git a/tests/test-allocate-regs.rkt b/tests/test-allocate-regs.rkt
index 0e98939..c937120 100644
--- a/tests/test-allocate-regs.rkt
+++ b/tests/test-allocate-regs.rkt
@@ -30,5 +30,13 @@
                                   -16)
         (list (Ldr (AMOffset 'sp 0) (Reg 'x0))
               (Ldr (AMOffset 'sp -8) (Reg 'x1))
-              (Add (Reg 'x0) (Reg 'x1) (Reg 'x2))))))))
-
+              (Add (Reg 'x0) (Reg 'x1) (Reg 'x2))
+              (Str (Reg 'x2) (AMOffset 'sp -16)))))
+    (test-case
+      "RetDefault"
+      (check-equal?
+        (allocate-regs-std-instr! (RetDefault)
+                                  (make-hash)
+                                  0)
+        (list (RetDefault)))))))
+