Can't restart from floating point errors

[Bike]

For example,

(handler-bind ((arithmetic-error #'abort))
  (restart-case
      (integer-decode-float #.ext:short-float-positive-infinity)
    (abort ())))

will signal an out of extent unwind. Something weird with signal handling, probably.

[Bike]

The backtrace as obtained by btcl or c_btcl has the frame for the function that establishes the restart, but it still fails. Don't know how that's possible? The stack being copied? I really have no idea

[Bike]

Seems to be just crashing now.

[kpoeck]

with the change from longjmp to _longjmp I get again: (did also a fprintf in handle_fpe to see if the hander is called

 (handler-bind ((arithmetic-error #'abort))
  (restart-case
      (integer-decode-float #.ext:short-float-positive-infinity)
    (abort ())))
Enter handle_fpe Signo: 8 Errno:0 Code:0

Condition of type: OUT-OF-EXTENT-UNWIND
Attempted to return or go to an expired block or tagbody tag.
Available restarts:
(use :r1 to invoke restart 1, etc.)

1. (ABORT) ABORT
2. (RESTART-TOPLEVEL) Go back to Top-Level REPL. ```` 

[kpoeck]

this is now fixed, isn't it?

[Bike]

With some of the optimizations I've been doing I've gotten a crash as Clasp doesn't seem to recognize its own condition signaled from the SIGFPE handler. Which isn't quite the same, but I'm in general still pretty suspicious of how we handle traps.

[Bike]

To elaborate: On linux I do

(defun foo (x y)
  (declare (single-float x y))
  (ext:with-float-traps-masked () (/ x y)))
(foo 1.0 0.0)

and it crashes while trying to print a backtrace for the division-by-zero.

Note that you can't just do (/ 1.0 0.0), because LLVM will constant fold that into a NaN. (Which is something else we might need to rethink.)

[kpoeck]

If I try this in main on macos I get:

COMMON-LISP-USER> (defun foo (x y)
  (declare (single-float x y))
  (ext:with-float-traps-masked () (/ x y)))
; caught ERROR:
;   BUG: Bad rtype (SINGLE-FLOAT)
;     at unknown location
; 

Condition of type: SIMPLE-ERROR
BUG: Bad rtype (SINGLE-FLOAT)
Available restarts:
(use :r1 to invoke restart 1, etc.)

1. (RESTART-TOPLEVEL) Go back to Top-Level REPL.


(CLASP-CLEAVIR::INITIALIZE-IBLOCK-TRANSLATION #<IBLOCK NIL>)
COMMON-LISP-USER>> :b

   4: (CLASP-CLEAVIR::INITIALIZE-IBLOCK-TRANSLATION #<IBLOCK NIL>)
   6: ((LAMBDA (CLASP-CLEAVIR::IB)) #<IBLOCK NIL>)
   7: (CLEAVIR-BIR:MAP-IBLOCKS #<FUNCTION (LAMBDA (CLASP-CLEAVIR::IB))> #<FUNCTION FOO>)
   9: ((LAMBDA NIL))
  11: (LAMBDA (&OPTIONAL CORE:FILE-SCOPE COMPILER::FILE-HANDLE &REST #:G64319))
  12: (COMPILER::DO-DBG-FUNCTION #<FUNCTION (LAMBDA NIL)> 999909 #<FUNCTION-TYPE { i8*, i64 } (i8*, i64, i8*, i8*, i8*, i8*, ...)> #<FUNCTION FOO^COMMON-LISP-USER^FN^^-lcl>)
  14: (CLASP-CLEAVIR::LAYOUT-MAIN-FUNCTION #<FUNCTION FOO> FOO #<CLASP-CLEAVIR::ABI-X86-64>)
  16: (CLASP-CLEAVIR::LAYOUT-PROCEDURE #<FUNCTION FOO> FOO #<CLASP-CLEAVIR::ABI-X86-64> :LINKAGE LLVM-SYS:INTERNAL-LINKAGE)
  17: (CLASP-CLEAVIR::LAYOUT-MODULE #<CLEAVIR-BIR:MODULE> #<CLASP-CLEAVIR::ABI-X86-64> :LINKAGE LLVM-SYS:INTERNAL-LINKAGE)
  19: (CLASP-CLEAVIR::TRANSLATE #<FUNCTION (LAMBDA NIL)> :ABI #<CLASP-CLEAVIR::ABI-X86-64> :LINKAGE LLVM-SYS:INTERNAL-LINKAGE)
  21: (CLASP-CLEAVIR::TRANSLATE-AST #<FUNCTION-AST (LAMBDA NIL) NIL @0x12026dc01>)
  23: ((LAMBDA NIL))
  25: (LITERAL::DO-RTV #<FUNCTION (LAMBDA NIL)>)
  27: (FLET #:G65215)
  28: (CLASP-CLEAVIR::BIR-COMPILE-CST #<CONS-CST raw: (LAMBDA NIL (PROGN #'(LAMBDA (X Y) (DECLARE (CORE:LAMBDA-NAME FOO) (TYPE SINGLE-FLOAT Y) (TYPE SINGLE-FLOAT X)) (BLOCK FOO (EXT:WITH-FLOAT-TRAPS-MASKED NIL (/ X Y)))))) @0x12290a331> NIL "APP-FASL:CCLASP-BOEHM-IMAGE.FASP.NEWEST" :LINKAGE LLVM-SYS:INTERNAL-LINKAGE :NAME NIL)
  30: ((LAMBDA NIL))
  32: (COMPILER::CALL-WITH-COMPILATION-RESULTS #<FUNCTION (LAMBDA NIL)>)
  34: (COMPILER::COMPILE-WITH-HOOK #<FUNCTION CLASP-CLEAVIR::BIR-COMPILE-CST> #<CONS-CST raw: (LAMBDA NIL (PROGN #'(LAMBDA (X Y) (DECLARE (CORE:LAMBDA-NAME FOO) (TYPE SINGLE-FLOAT Y) (TYPE SINGLE-FLOAT X)) (BLOCK FOO (EXT:WITH-FLOAT-TRAPS-MASKED NIL (/ X Y)))))) @0x12290a331> NIL "APP-FASL:CCLASP-BOEHM-IMAGE.FASP.NEWEST" :LINKAGE LLVM-SYS:INTERNAL-LINKAGE :NAME NIL)
  35: ((LAMBDA NIL))
  37: (COMPILER::DO-COMPILATION-UNIT #<FUNCTION (LAMBDA NIL)>)
  39: (COMPILER:COMPILE-IN-ENV #<CONS-CST raw: (LAMBDA NIL (PROGN #'(LAMBDA (X Y) (DECLARE (CORE:LAMBDA-NAME FOO) (TYPE SINGLE-FLOAT Y) (TYPE SINGLE-FLOAT X)) (BLOCK FOO (EXT:WITH-FLOAT-TRAPS-MASKED NIL (/ X Y)))))) @0x12290a331> NIL #<FUNCTION CLASP-CLEAVIR::BIR-COMPILE-CST> LLVM-SYS:INTERNAL-LINKAGE)
  41: (CLASP-CLEAVIR::BIR-COMPILE-CST-IN-ENV #<CONS-CST raw: (LAMBDA NIL (PROGN #'(LAMBDA (X Y) (DECLARE (CORE:LAMBDA-NAME FOO) (TYPE SINGLE-FLOAT Y) (TYPE SINGLE-FLOAT X)) (BLOCK FOO (EXT:WITH-FLOAT-TRAPS-MASKED NIL (/ X Y)))))) @0x12290a331> NIL)
...

slightly puzzeled

[kpoeck]

Did a distclean and full rebuild before

[Bike]

odd. that should be fixed by 867b986

[kpoeck]

Will check whether I have the commit you mentionned

[kpoeck]

and with the really latest that works fine, sorry for the noise

[Bike]

Do you still get the crash?

[kpoeck]

All seem to work fine:

COMMON-LISP-USER>> (defun foo (x y)
  (declare (single-float x y))
  (ext:with-float-traps-masked () (/ x y)))

FOO
COMMON-LISP-USER>> (foo 1.0 0.0)

Debugger received error of type: DIVISION-BY-ZERO
Condition of type DIVISION-BY-ZERO was signaled.
Error flushed.
COMMON-LISP-USER>> :r1

COMMON-LISP-USER> (handler-bind ((arithmetic-error #'abort))
  (restart-case
      (integer-decode-float #.ext:short-float-positive-infinity)
    (abort ())))

Condition of type: SIMPLE-PROGRAM-ERROR
Can't decode NaN or infinity inf
Available restarts:
(use :r1 to invoke restart 1, etc.)

1. (ABORT) ABORT
2. (RESTART-TOPLEVEL) Go back to Top-Level REPL.


(CORE:SIGNAL-SIMPLE-ERROR CORE:SIMPLE-PROGRAM-ERROR NIL "~a" ("Can't decode NaN or infinity inf"))
COMMON-LISP-USER>> :r1

NIL

[Bike]

Huh. Is this on Linux or Mac or what?

[kpoeck]

on mac

[yitzchak]

Fixed by #1619

COMMON-LISP-USER> (handler-bind ((arithmetic-error #'abort))
  (restart-case
      (integer-decode-float #.ext:short-float-positive-infinity)
    (abort ())))

Condition of type: SIMPLE-PROGRAM-ERROR
Can't decode NaN or infinity inf
Available restarts:
(use :r1 to invoke restart 1, etc.)

1. (ABORT) ABORT
2. (RESTART-TOPLEVEL) Go back to Top-Level REPL.

ERROR
COMMON-LISP-USER>> :r2
COMMON-LISP-USER>