Commit Graph

6 Commits

Author SHA1 Message Date
David Majnemer 9930398c5c GlobalOpt: Fix constantfold-initializers.ll test
The test added in r211762 was sloppy, the correct initializer wasn't
added to @llvm.global_ctors

Spotted by Pasi Parviainen!

llvm-svn: 211879
2014-06-27 07:36:26 +00:00
David Majnemer 6098b2f519 GlobalOpt: Don't optimize thread_local for initializers
Folding a reference to a thread_local variable into another global
variable's initializer is very problematic, there is no relocation that
exists to represent such an access.

llvm-svn: 211762
2014-06-26 03:02:19 +00:00
David Majnemer 23fc9afa4d GlobalOpt: Don't optimize dllimport for initializers
Referencing a dllimport variable requires actually instructions, not
just a relocation.  This fixes PR19955.

Differential Revision: http://reviews.llvm.org/D4249

llvm-svn: 211571
2014-06-24 06:53:45 +00:00
Chandler Carruth aacb8a5809 Fix a crash on valid (if UB) bitcode that is produced for some global
constants in C++11 mode. I have no idea why it required such particular
circumstances to get here, the code seems clearly to rely upon unchecked
assumptions.

Specifically, when we decide to form an index into a struct type, we may
have gone through (at least one) zero-length array indexing round, which
would have left the offset un-adjusted, and thus not necessarily valid
for use when indexing the struct type.

This is just an canonicalization step, so the correct thing is to refuse
to canonicalize nonsensical GEPs of this form. Implemented, and test
case added.

Fixes PR12642. Pair debugged and coded with Richard Smith. =] I credit
him with most of the debugging, and preventing me from writing the wrong
code.

llvm-svn: 155466
2012-04-24 18:42:47 +00:00
Nick Lewycky 9d0da18597 Use the target-aware constant folder on expressions to improve the chance
they'll be simple enough to simulate, and to reduce the chance we'll encounter
equal but different simple pointer constants.

This removes the symptoms from PR11352 but is not a full fix. A proper fix would
either require a guarantee that two constant objects we simulate are folded
when equal, or a different way of handling equal pointers (ie., trying a
constantexpr icmp on them to see whether we know they're equal or non-equal or
unsure).

llvm-svn: 151093
2012-02-21 22:08:06 +00:00
Dan Gohman 580b80d6d9 Make ConstantFoldConstantExpression recursively visit the entire
ConstantExpr, not just the top-level operator. This allows it to
fold many more constants.

Also, make GlobalOpt call ConstantFoldConstantExpression on
GlobalVariable initializers.

llvm-svn: 89659
2009-11-23 16:22:21 +00:00