#4391: forkIO threads do not properly save/restore the floating point
environment
---------------------------------+------------------------------------------
Reporter: draconx | Owner:
Type: bug | Status: new
Priority: normal | Milestone: 7.2.1
Component: Runtime System | Version: 6.12.3
Keywords: | Testcase:
Blockedby: | Difficulty:
Os: Unknown/Multiple | Blocking:
Architecture: x86_64 (amd64) | Failure: None/Unknown
---------------------------------+------------------------------------------
Comment(by duncan):
I've occasionally thought about what it would take to do full IEEE
floating point in Haskell. Assuming one can come up with a high level pure
API (e.g. modeling rounding mode etc as extra input parameters) then the
next big problem is at the ABI / codegen layer. With lazy evaluation
you're calling unknown functions all the time and these expect the default
FP state. I think you'd have to make the FP state part of the function
call ABI. That is, for normal calls to normal functions you'd have to
save/restore the FP state around the call. For functions that take the
rounding/exception mode as a parameter then you can call them without
save/restore. The danger is that it'd be rather expensive.
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/4391#comment:11>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
_______________________________________________
Glasgow-haskell-bugs mailing list
[email protected]
http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
