fixed a bug in the register allocator that was rewriting

mov8 mem1 -> mem2
to 
    mov mem1 -> reg
    mov8 reg -> mem2
instead of
    mov8 mem1 reg
    mov reg mem2
which causes unaligned and invalid memory access when the
address mem1 is at a page boundary and the next page is 
unmapped.
This commit is contained in:
Abdulaziz Ghuloum 2010-01-24 00:13:01 +03:00
parent 64aca7c80b
commit 943a72f01f
3 changed files with 34 additions and 27 deletions

View File

@ -2227,6 +2227,23 @@
[else (error 'small-operand? "huh?")]))
(define (mem? x)
(or (disp? x) (fvar? x)))
(define (fix-address x k)
(cond
[(disp? x)
(let ([s0 (disp-s0 x)] [s1 (disp-s1 x)])
(cond
[(not (small-operand? s0))
(let ([u (mku)])
(make-seq
(E (make-asm-instr 'move u s0))
(fix-address (make-disp u s1) k)))]
[(not (small-operand? s1))
(let ([u (mku)])
(make-seq
(E (make-asm-instr 'move u s1))
(fix-address (make-disp s0 u) k)))]
[else (k x)]))]
[else (k x)]))
;;; unspillable effect
(define (E x)
(struct-case x
@ -2235,8 +2252,18 @@
(make-conditional (P e0) (E e1) (E e2))]
[(asm-instr op a b)
(case op
[(load8 load32)
(fix-address b
(lambda (b)
(cond
[(or (register? a) (var? a))
(make-asm-instr op a b)]
[else
(let ([u (mku)])
(make-seq
(make-asm-instr op u b)
(E (make-asm-instr 'move a u))))])))]
[(logor logxor logand int+ int- int* move
load8 load32
int-/overflow int+/overflow int*/overflow)
(cond
[(and (eq? op 'move) (eq? a b))
@ -2256,17 +2283,10 @@
(E (make-asm-instr op u b)))
(E (make-asm-instr 'move a u))))]
[(and (mem? a) (not (small-operand? b)))
(case op
[(load32)
(let ([u (mku)])
(make-seq
(E (make-asm-instr 'load32 u b))
(E (make-asm-instr 'move a u))))]
[else
(let ([u (mku)])
(make-seq
(E (make-asm-instr 'move u b))
(E (make-asm-instr op a u))))])]
(E (make-asm-instr op a u))))]
[(disp? a)
(let ([s0 (disp-s0 a)] [s1 (disp-s1 a)])
(cond

View File

@ -2084,19 +2084,6 @@
(movl (mem (fx- 0 wordsize) fpr) eax)
(ret)))))
SL_values]
[(sl-nonprocedure-error-label)
(define SL_nonprocedure (gensym "SL_nonprocedure"))
(assemble-sources (lambda (x) #f)
(list
(list 0
(label SL_nonprocedure)
(movl cpr (mem (fx- 0 wordsize) fpr)) ; first arg
(movl (obj (primref->symbol '$apply-nonprocedure-error-handler)) cpr)
(movl (mem (- disp-symbol-record-proc record-tag) cpr) cpr)
;(movl (primref-loc '$apply-nonprocedure-error-handler) cpr)
(movl (int (argc-convention 1)) eax)
(tail-indirect-cpr-call))))
SL_nonprocedure]
[(sl-cwv-label)
(define SL_call_with_values (gensym "SL_call_with_values"))
(assemble-sources (lambda (x) #f)

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@ -1 +1 @@
1867
1868