#3 Nested dotimes leads to infinite loop

[Mark]

Hi,

the following code, when executed in Jatha causes an inifinte loop:

(dotimes (i 3 i)
(dotimes (j 3 j)
(princ j)
)
(princ i)
)

To be more precise, the inner loop is executed once and from then on only the (princ i) statement is looped over eternally.

Mark

[Micheal Hewett]

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Thanks, I'll check into the problem.

Mike

[Mark]

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Hi,

is there any progress on this issue? Is there any help I can offer in solving this? Part of an application I'm building relies on such a nested loop, so I'm quite interested in fixing this issue.

Regards,
Mark

[Micheal Hewett]

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I looked at the compiled code last night and it looks pretty strange.
One thing you can do that would help save me time is to
define a function containing the nested dotimes statements
and then run (grindef) on the function and send me the
output.

Thanks,
Mike Hewett

[Mark]

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I tried to execute the following code in Jatha according to your request:

(defun loop-test ()
(setq sum 0)
(dotimes (i 3)
(dotimes (j 3)
(setq sum (+ sum 1))
)
)
sum
)

(grindef loop-test)

but all I get is an exception "The variable LOOP-TEST is unbound.". If i run it with

(grindef #'loop-test)

I get the exception "java.lang.ClassCastException: org.jatha.dynatype.StandardLispSymbol" in org.jatha.compile.LispPrimitive.printCode(LispPrimitive.java:115)

Further instructions would be appreciated.

Regards,
Mark

[Micheal Hewett]

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Well, bug upon bug...

I fixed grindef temporarily - have to check the fix against all functions.
Here is the compiled output. I will be staring at it this afternoon.
If you see anything, let me know. I tentatively suspect the compiler-generated
variable *AND-DUMMY-VAR* or some similar variable does not work
correctly if used more than once. It may mean just a simple compiler
change to make each *AND_DUMMY-VAR* unique. I'll run some tests to
verify.

FYI, the Javadoc comments in org.jatha.machine.opLD and sibling classes
describe what each machine code instruction does.

Mike

LDC SUM
LDC 0
SETQ
LDC 0
LDC 3
CONST_NIL
CONS
CONS
LDF
LDC (SECD.CONST_NIL SECD.LD (1 . 1) SECD.LD (1 . 2) SECD.LIS 2 #<function < 2...> #<function NOT 1> SECD.SP_BIND *AND-DUMMY-VAR* SECD.LDF (SECD.LD_GLOBAL *AND-DUMMY-VAR* SECD.TEST (SECD.CONST_NIL SECD.LIS 1 SECD.LDC NIL #<function RETURN-FROM 1 2> SECD.RTN) SECD.CONST_NIL SECD.RTN) SECD.AP SECD.SP_UNBIND *AND-DUMMY-VAR* SECD.LDC 0 SECD.LDC 3 SECD.CONST_NIL #<function CONS 2> #<function CONS 2> SECD.LDF (SECD.LDC (SECD.CONST_NIL SECD.LD (1 . 1) SECD.LD (1 . 2) SECD.LIS 2 #<function < 2...> #<function NOT 1> SECD.SP_BIND *AND-DUMMY-VAR* SECD.LDF (SECD.LD_GLOBAL *AND-DUMMY-VAR* SECD.TEST (SECD.CONST_NIL SECD.LIS 1 SECD.LDC NIL #<function RETURN-FROM 1 2> SECD.RTN) SECD.CONST_NIL SECD.RTN) SECD.AP SECD.SP_UNBIND *AND-DUMMY-VAR* SECD.LDC SUM SECD.LD_GLOBAL SUM SECD.LDC 1 SECD.LIS 2 #<function + 0...> #<function SETQ 2> SECD.LDC (1 . 1) SECD.LD (1 . 1) #<function 1+ 1> #<function SETQ 2> SECD.LDC (#:T1) #<function GO 1> #<function TAGBODY 1...> SECD.BLK NIL SECD.RTN) SECD.SP_BIND #:T1 SECD.LDC (SECD.CONST_NIL SECD.LD (1 . 1) SECD.LD (1 . 2) SECD.LIS 2 #<function < 2...> #<function NOT 1> SECD.SP_BIND *AND-DUMMY-VAR* SECD.LDF (SECD.LD_GLOBAL *AND-DUMMY-VAR* SECD.TEST (SECD.CONST_NIL SECD.LIS 1 SECD.LDC NIL #<function RETURN-FROM 1 2> SECD.RTN) SECD.CONST_NIL SECD.RTN) SECD.AP SECD.SP_UNBIND *AND-DUMMY-VAR* SECD.LDC SUM SECD.LD_GLOBAL SUM SECD.LDC 1 SECD.LIS 2 #<function + 0...> #<function SETQ 2> SECD.LDC (1 . 1) SECD.LD (1 . 1) #<function 1+ 1> #<function SETQ 2> SECD.LDC (#:T1) #<function GO 1> #<function TAGBODY 1...> SECD.BLK NIL SECD.RTN) SECD.SP_BIND #:T2 SECD.TAG_B SECD.CONST_NIL SECD.LD (1 . 1) SECD.LD (1 . 2) SECD.LIS 2 #<function < 2...> #<function NOT 1> SECD.SP_BIND *AND-DUMMY-VAR* SECD.LDF (SECD.LD_GLOBAL *AND-DUMMY-VAR* SECD.TEST (SECD.CONST_NIL SECD.LIS 1 SECD.LDC NIL #<function RETURN-FROM 1 2> SECD.RTN) SECD.CONST_NIL SECD.RTN) SECD.AP SECD.SP_UNBIND *AND-DUMMY-VAR* SECD.LDC SUM SECD.LD_GLOBAL SUM SECD.LDC 1 SECD.LIS 2 #<function + 0...> #<function SETQ 2> SECD.LDC (1 . 1) SECD.LD (1 . 1) #<function 1+ 1> #<function SETQ 2> SECD.LDC (#:T2) #<function GO 1> #<function TAGBODY 1...> SECD.TAG_E SECD.SP_UNBIND #:T1 SECD.SP_UNBIND #:T2 SECD.BLK NIL SECD.RTN) SECD.AP SECD.LDC (1 . 1) SECD.LD (1 . 1) #<function 1+ 1> #<function SETQ 2> SECD.LDC (#:T0) #<function GO 1> #<function TAGBODY 1...> SECD.BLK NIL SECD.RTN)
SP_BIND #:T0
LDC (SECD.CONST_NIL SECD.LD (1 . 1) SECD.LD (1 . 2) SECD.LIS 2 #<function < 2...> #<function NOT 1> SECD.SP_BIND *AND-DUMMY-VAR* SECD.LDF (SECD.LD_GLOBAL *AND-DUMMY-VAR* SECD.TEST (SECD.CONST_NIL SECD.LIS 1 SECD.LDC NIL #<function RETURN-FROM 1 2> SECD.RTN) SECD.CONST_NIL SECD.RTN) SECD.AP SECD.SP_UNBIND *AND-DUMMY-VAR* SECD.LDC 0 SECD.LDC 3 SECD.CONST_NIL #<function CONS 2> #<function CONS 2> SECD.LDF (SECD.LDC (SECD.CONST_NIL SECD.LD (1 . 1) SECD.LD (1 . 2) SECD.LIS 2 #<function < 2...> #<function NOT 1> SECD.SP_BIND *AND-DUMMY-VAR* SECD.LDF (SECD.LD_GLOBAL *AND-DUMMY-VAR* SECD.TEST (SECD.CONST_NIL SECD.LIS 1 SECD.LDC NIL #<function RETURN-FROM 1 2> SECD.RTN) SECD.CONST_NIL SECD.RTN) SECD.AP SECD.SP_UNBIND *AND-DUMMY-VAR* SECD.LDC SUM SECD.LD_GLOBAL SUM SECD.LDC 1 SECD.LIS 2 #<function + 0...> #<function SETQ 2> SECD.LDC (1 . 1) SECD.LD (1 . 1) #<function 1+ 1> #<function SETQ 2> SECD.LDC (#:T1) #<function GO 1> #<function TAGBODY 1...> SECD.BLK NIL SECD.RTN) SECD.SP_BIND #:T1 SECD.LDC (SECD.CONST_NIL SECD.LD (1 . 1) SECD.LD (1 . 2) SECD.LIS 2 #<function < 2...> #<function NOT 1> SECD.SP_BIND *AND-DUMMY-VAR* SECD.LDF (SECD.LD_GLOBAL *AND-DUMMY-VAR* SECD.TEST (SECD.CONST_NIL SECD.LIS 1 SECD.LDC NIL #<function RETURN-FROM 1 2> SECD.RTN) SECD.CONST_NIL SECD.RTN) SECD.AP SECD.SP_UNBIND *AND-DUMMY-VAR* SECD.LDC SUM SECD.LD_GLOBAL SUM SECD.LDC 1 SECD.LIS 2 #<function + 0...> #<function SETQ 2> SECD.LDC (1 . 1) SECD.LD (1 . 1) #<function 1+ 1> #<function SETQ 2> SECD.LDC (#:T1) #<function GO 1> #<function TAGBODY 1...> SECD.BLK NIL SECD.RTN) SECD.SP_BIND #:T2 SECD.TAG_B SECD.CONST_NIL SECD.LD (1 . 1) SECD.LD (1 . 2) SECD.LIS 2 #<function < 2...> #<function NOT 1> SECD.SP_BIND *AND-DUMMY-VAR* SECD.LDF (SECD.LD_GLOBAL *AND-DUMMY-VAR* SECD.TEST (SECD.CONST_NIL SECD.LIS 1 SECD.LDC NIL #<function RETURN-FROM 1 2> SECD.RTN) SECD.CONST_NIL SECD.RTN) SECD.AP SECD.SP_UNBIND *AND-DUMMY-VAR* SECD.LDC SUM SECD.LD_GLOBAL SUM SECD.LDC 1 SECD.LIS 2 #<function + 0...> #<function SETQ 2> SECD.LDC (1 . 1) SECD.LD (1 . 1) #<function 1+ 1> #<function SETQ 2> SECD.LDC (#:T2) #<function GO 1> #<function TAGBODY 1...> SECD.TAG_E SECD.SP_UNBIND #:T1 SECD.SP_UNBIND #:T2 SECD.BLK NIL SECD.RTN) SECD.AP SECD.LDC (1 . 1) SECD.LD (1 . 1) #<function 1+ 1> #<function SETQ 2> SECD.LDC (#:T0) #<function GO 1> #<function TAGBODY 1...> SECD.BLK NIL SECD.RTN)
SP_BIND #:T3
TAG_B
CONST_NIL
LD (1 . 1)
LD (1 . 2)
LIS 2
<
NOT
SP_BIND *AND-DUMMY-VAR*
LDF
LD_GLOBAL *AND-DUMMY-VAR*
TEST
CONST_NIL
LIS 1
LDC NIL
RETURN-FROM
RTN

CONST_NIL
RTN

AP
SP_UNBIND *AND-DUMMY-VAR*
LDC 0
LDC 3
CONST_NIL
CONS
CONS
LDF
LDC (SECD.CONST_NIL SECD.LD (1 . 1) SECD.LD (1 . 2) SECD.LIS 2 #<function < 2...> #<function NOT 1> SECD.SP_BIND *AND-DUMMY-VAR* SECD.LDF (SECD.LD_GLOBAL *AND-DUMMY-VAR* SECD.TEST (SECD.CONST_NIL SECD.LIS 1 SECD.LDC NIL #<function RETURN-FROM 1 2> SECD.RTN) SECD.CONST_NIL SECD.RTN) SECD.AP SECD.SP_UNBIND *AND-DUMMY-VAR* SECD.LDC SUM SECD.LD_GLOBAL SUM SECD.LDC 1 SECD.LIS 2 #<function + 0...> #<function SETQ 2> SECD.LDC (1 . 1) SECD.LD (1 . 1) #<function 1+ 1> #<function SETQ 2> SECD.LDC (#:T4) #<function GO 1> #<function TAGBODY 1...> SECD.BLK NIL SECD.RTN)
SP_BIND #:T5
LDC (SECD.CONST_NIL SECD.LD (1 . 1) SECD.LD (1 . 2) SECD.LIS 2 #<function < 2...> #<function NOT 1> SECD.SP_BIND *AND-DUMMY-VAR* SECD.LDF (SECD.LD_GLOBAL *AND-DUMMY-VAR* SECD.TEST (SECD.CONST_NIL SECD.LIS 1 SECD.LDC NIL #<function RETURN-FROM 1 2> SECD.RTN) SECD.CONST_NIL SECD.RTN) SECD.AP SECD.SP_UNBIND *AND-DUMMY-VAR* SECD.LDC SUM SECD.LD_GLOBAL SUM SECD.LDC 1 SECD.LIS 2 #<function + 0...> #<function SETQ 2> SECD.LDC (1 . 1) SECD.LD (1 . 1) #<function 1+ 1> #<function SETQ 2> SECD.LDC (#:T4) #<function GO 1> #<function TAGBODY 1...> SECD.BLK NIL SECD.RTN)
SP_BIND #:T4
TAG_B
CONST_NIL
LD (1 . 1)
LD (1 . 2)
LIS 2
<
NOT
SP_BIND *AND-DUMMY-VAR*
LDF
LD_GLOBAL *AND-DUMMY-VAR*
TEST
CONST_NIL
LIS 1
LDC NIL
RETURN-FROM
RTN

CONST_NIL
RTN

AP
SP_UNBIND *AND-DUMMY-VAR*
LDC SUM
LD_GLOBAL SUM
LDC 1
LIS 2
+
SETQ
LDC (1 . 1)
LD (1 . 1)
1+
SETQ
LDC (#:T5)
GO
TAGBODY
TAG_E
SP_UNBIND #:T5
SP_UNBIND #:T4
BLK NIL
RTN

AP
LDC (1 . 1)
LD (1 . 1)
1+
SETQ
LDC (#:T3)
GO
TAGBODY
TAG_E
SP_UNBIND #:T0
SP_UNBIND #:T3
BLK NIL
RTN

AP
BLK LOOP-TEST
RTN

[Micheal Hewett]

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Mark,

I'm making progress on this. The dotimes code is
being compiled incorrectly, even for a single dotimes
and especially for a nested dotimes. I have figured out where
it is happening, but not why it is happening. I will
continue working on it.

Mike

[Mark]

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Originator: YES

Mike,

thank you very much. I have had a look at the compiler output, but my compiler creation classes are quite some time back and I haven't made much progress. If I come up with anything, I'll let you know.

Mark