For targets with no itinerary (x86) it is a nop by default. For
targets with issue width already expressed in the itinerary (ARM) it
bypasses a scoreboard check but otherwise does not affect the
schedule. It does make the code more consistent and complete and
allows new targets to specify their issue width in an arbitrary way.
llvm-svn: 132385
turns out that it could cause an infinite loop in some situations. If this code
is triggered and it converts a cleanup into a catchall, but that cleanup was in
already in a cleanup, then the _Unwind_SjLj_Resume could infinite loop. I.e.,
the code doesn't consume the exception object and passes it on to
_Unwind_SjLj_Resume. But _USjLjR expects it to be consumed (since it's landing
at a catchall instead of a cleanup). So it uses the values that are presently
there, which are the values that tell it to jump to the fake landing pad.
<rdar://problem/9508402>
llvm-svn: 132381
When assigned ranges are evicted, they are put in the RS_Evicted stage and are
not allowed to evict anything else. That prevents looping automatically.
When evicting ranges just to get a cheaper register, use only spill weights to
find the possible candidates. Avoid breaking hints for this purpose, it is not
worth it.
Start implementing more complex eviction heuristics, guarded by the temporary
-complex-eviction flag. The initial version permits a heavier range to be
evicted if it doesn't have any uses where the evicting range is live. This makes
it a good candidate for live ranfge splitting.
llvm-svn: 132358
nand), atomic.swap and atomic.cmp.swap, all in i8, i16 and i32 versions.
The intrinsics are implemented by creating pseudo-instructions, which are
then expanded in the method MipsTargetLowering::EmitInstrWithCustomInserter.
Patch by Sasa Stankovic.
llvm-svn: 132323
same dwarf number. This will be used for creating a dwarf number to register
mapping.
The only case that needs this so far is the XMM/YMM registers that unfortunately
do have the same numbers.
llvm-svn: 132314
This only affects targets like Mips where branch instructions may kill virtual
registers. Most other targets branch on flag values, so virtual registers are
not involved.
The problem is that MachineBasicBlock::updateTerminator deletes branches and
inserts new ones while LiveVariables keeps a list of pointers to instructions
that kill virtual registers. That list wasn't properly updated in
MBB::SplitCriticalEdge.
llvm-svn: 132298
This is important for the correct lowering of unwind instructions
(which doesn't matter at all) and llvm.eh.resume calls (which does).
Take 2, now with more basic competence.
llvm-svn: 132295
This is important for the correct lowering of unwind instructions
(which doesn't matter at all) and llvm.eh.resume calls (which does).
llvm-svn: 132291
variable. Noticed by inspection.
Simulate memset in EvaluateFunction where the target of the memset and the
value we're setting are both the null value. Fixes PR10047!
llvm-svn: 132288
handler.
At this moment, only GCC-style exceptions are supported. Other kinds
of exceptions, including "traditional" SEH and Microsoft Visual C++ exceptions,
need more work--and an compiler exception model that isn't specific to
GCC-style exceptions!
In particular, I imagine that it would be possible to mix "traditional" SEH
with GCC-style EH or Microsoft C++ EH. Currently LLVM has no way (beyond some
target-specific defaults and whole-module compiler switches) of knowing which
scheme to use when.
llvm-svn: 132283
This patch does not change the behavior of the type legalizer. The codegen
produces the same code.
This infrastructural change is needed in order to enable complex decisions
for vector types (needed by the vector-select patch).
llvm-svn: 132263
transformed by the inliner into a branch to the enclosing landing pad
(when inlined through an invoke). If not so optimized, it is lowered
DWARF EH preparation into a call to _Unwind_Resume (or _Unwind_SjLj_Resume
as appropriate). Its chief advantage is that it takes both the
exception value and the selector value as arguments, meaning that there
is zero effort in recovering these; however, the frontend is required
to pass these down, which is not actually particularly difficult.
Also document the behavior of landing pads a bit better, and make it
clearer that it's okay that personality functions don't always land at
landing pads. This is just a fact of life. Don't write optimizations that
rely on pushing things over an unwind edge.
llvm-svn: 132253
to load/store i64 values. Since there's no current support to explicitly
declare such restrictions, implement it by using specific hardcoded register
pairs during isel.
llvm-svn: 132248
