#5422: Panic when using lots of registers in cmm code
---------------------------------+------------------------------------------
Reporter: pumpkin | Owner:
Type: bug | Status: new
Priority: normal | Milestone:
Component: Compiler | Version: 7.2.1
Keywords: | Testcase:
Blockedby: | Difficulty:
Os: Unknown/Multiple | Blocking:
Architecture: Unknown/Multiple | Failure: None/Unknown
---------------------------------+------------------------------------------
Comment(by ekmett):
Yes. For a concrete example, calling MPFR's 'add' function in the style of
our use of GMP would take 9.
{{{
type CSign# = Int#
type CPrecision# = Int#
type CExp# = Int#
type CRounding# = Int#
foreign import prim "mpfr_cmm_add" mpfrAdd#
:: CRounding#
-> CPrecision# -> CSign# -> CExp# -> ByteArray#
-> CPrecision# -> CSign# -> CExp# -> ByteArray#
-> (# CPrecision#, CSign#, CExp#, ByteArray# #)
}}}
As a stopgap, we are multiplying sign by precision a priori and unpacking
in C--.
{{{
type CSignPrec# = Int#
foreign import prim "mpfr_cmm_add" mpfrAdd#
:: CRounding#
-> CSignPrec# -> CExp# -> ByteArray#
-> CSignPrec# -> CExp# -> ByteArray#
-> (# CSignPrec#, CExp#, ByteArray# #)
}}}
This gets us down to 7 for most ops, in exchange for a bunch of random bit
twiddling, but there are some bindings that will still push us up against
the limit.
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5422#comment:5>
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
