From: Luke Lau <luke_lau@icloud.com>
Date: Sat, 27 Jul 2019 22:54:16 +0000 (+0100)
Subject: Fix overwriting preserved base pointer in prolog
X-Git-Url: http://git.lukelau.me/?p=scheme.git;a=commitdiff_plain;h=c3ee0f7639a02371a2d01b39ddca91506c4791c3

Fix overwriting preserved base pointer in prolog

Also fix illegal instruction copying over captives
---

diff --git a/codegen.scm b/codegen.scm
index dda1471..517cc11 100644
--- a/codegen.scm
+++ b/codegen.scm
@@ -124,6 +124,8 @@
   (let* ((heap-offsets (map (lambda (i) (+ 8 (* 8 i)))
 			    (range 0 (length captured))))) ; 4, 12, 20, etc.
 
+    (emit "## creating closure")
+
     (emit "movq heap_start@GOTPCREL(%rip), %rbx")
     
     (emit "movq (%rbx), %rax")          ; %rax = heap addr of closure
@@ -132,16 +134,18 @@
     ; point heap_start to next space
     (emit "addq $~a, (%rbx)" (+ 8 (* 8 (length captured))))
 
+    (emit "## storing address to lambda")
 					; store the address to the lambda code
     (emit "movq ~a@GOTPCREL(%rip), %rbx" label)
     (emit "movq %rbx, 0(%rax)")
 
+    (emit "## storing captives")
 					; store the captured vars
     (for-each
      (lambda (var-name new-offset)
-       (emit "movq ~a(%rbp), ~a(rax)"
-	     (cdr (assoc var-name env))
-	     new-offset))
+       (begin
+	 (emit "movq ~a(%rbp), %rbx" (cdr (assoc var-name env)))
+	 (emit "movq %rbx, ~a(%rax)" new-offset)))
      captured
      heap-offsets)))
 
@@ -206,7 +210,7 @@
 
 	 (stack-offsets (map (lambda (i)
 			       (* (- wordsize) i))
-			     (range 1 (length params))))
+			     (range 0 (length params))))
 
 	 (env (map cons params stack-offsets)))
     (emit "~a:" label)
@@ -222,21 +226,27 @@
     (newline)
     
     (emit "push %rbp") ; preserve caller's base pointer
+    
     (emit "movq %rsp, %rbp") ; set up our own base pointer
+    (emit "subq $8, %rbp")   
 
 					; load the captured vars onto the stack
     (for-each
      (lambda (i)
-       (emit "movq ~a(~a), ~a(%rbp)"
-	     i (param-register 0) (* (- wordsize) i)))
+       (begin
+	 (emit "movq ~a(~a), %rbx" i (param-register 0))
+	 (emit "movq %rbx, ~a(%rbp)" (* (- wordsize) i))))
      (range 0 (length captured)))
 
 					; load the args onto the stack
     (for-each
      (lambda (i)
-       (emit "movq ~a, ~a(%rbp)"
-	     (param-register i) (* (- wordsize) i)))
-     (range 1 (length args)))
+       (begin
+	 (emit "movq ~a, %rbx" (param-register (+ 1 i)))
+	 (emit "movq %rbx, ~a(%rbp)"
+	       (* (- wordsize)
+		  (+ (length captured) i)))))
+     (range 0 (length args)))
     
     (codegen-expr body (* (- wordsize) (+ 1 (length params))) env)
 
@@ -375,7 +385,7 @@
       ('app (append
 					; if a builtin is used as a function, don't generate lambda
 	     (if (eqv? 'builtin (ast-type (car e)))
-		 '()
+		 (list (car e))
 		 (list (extract (car e))))
 	     (map extract (cdr e))))