#8867: newArray# fails to initialize card table correctly
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Reporter: tibbe | Owner: simonmar
Type: bug | Status: new
Priority: normal | Milestone:
Component: Runtime System | Version: 7.6.3
Resolution: | Keywords:
Operating System: Unknown/Multiple | Architecture: Unknown/Multiple
Type of failure: None/Unknown | Difficulty: Unknown
Test Case: | Blocked By:
Blocking: | Related Tickets:
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Comment (by Johan Tibell ):
In [changeset:"46d05ba03d1491cade4a3fe33f0b8c404ad3c760/ghc"]:
{{{
#!CommitTicketReference repository="ghc"
revision="46d05ba03d1491cade4a3fe33f0b8c404ad3c760"
Fix two issues in stg_newArrayzh
The implementations of newArray# and newArrayArray#, stg_newArrayzh
and stg_newArrayArrayzh, had three issues:
* The condition for the loop that fills the array with the initial
element was incorrect. It would write into the card table as
well. The condition for the loop that filled the card table was
never executed, as its condition was also wrong. In the end this
didn't lead to any disasters as the value of the card table doesn't
matter for newly allocated arrays.
* The card table was unnecessarily initialized. The card table is
only used when the array isn't copied, which new arrays always
are. By not writing the card table at all we save some cycles.
* The ticky allocation accounting was wrong. The second argument to
TICK_ALLOC_PRIM is the size of the closure excluding the header
size, but the header size was incorrectly included.
Fixes #8867.
}}}
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Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8867#comment:3
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The Glasgow Haskell Compiler
