No test case. Noticed by inspection and I doubt it ever affects the
outcome of the overall heuristic, let alone final codegen.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140431 91177308-0d34-0410-b5e6-96231b3b80d8
No tests; these changes aren't really interesting in the sense that the logic is the same for volatile and atomic.
I believe this completes all of the changes necessary for the optimizer to handle loads and stores correctly. I'm going to try and come up with some additional testing, though.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139533 91177308-0d34-0410-b5e6-96231b3b80d8
better.
Don't immediately give up when an add operation can't be trivially
sign/zero-extended within a loop. If it has NSW/NUW flags, generate a
new expression with sign extended (non-recurrent) operand. As before,
if SCEV says that all sign extends are loop invariant, then we can
widen the operation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139453 91177308-0d34-0410-b5e6-96231b3b80d8
This changes loop unrolling to use the same mechanism for trip count
computation as indvars. This is a stronger check that tends to unroll
more loops. A very common side-effect is that many single iteration
loops will be removed sooner. The real goal was simply to remove
dependence on canonical IVs.
x86 is break even.
ARM performance changes to expect (+ is good):
External/SPEC/CFP2000/183.equake/183.equake +13%
SingleSource/Benchmarks/Dhrystone/fldry +21%
MultiSource/Applications/spiff/spiff +3%
SingleSource/Benchmarks/Stanford/Puzzle -14%
The Puzzle regression is actually an improvement in loop optimization
that defeats GVN: rdar://problem/10065079.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139009 91177308-0d34-0410-b5e6-96231b3b80d8
The landingpad instruction is required in the landing pad block. Because we're
not deleting terminating instructions, the invoke may still jump to here (see
Transforms/SCCP/2004-11-16-DeadInvoke.ll). Remove all uses of the landingpad
instruction, but keep it around until code-gen can remove the basic block.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138890 91177308-0d34-0410-b5e6-96231b3b80d8
ssa, so it has to be run really early in the pipeline. Any replacement
should probably use the SSAUpdater.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138841 91177308-0d34-0410-b5e6-96231b3b80d8
known-incremented level, because the two concepts can be used
to prove the saftey of a retain+release removal in different
ways.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138016 91177308-0d34-0410-b5e6-96231b3b80d8
PRE needs the landing pads to have their critical edges split. Doing this for a
landing pad is non-trivial. Abandon the attempt to perform PRE when we come
across a landing pad. (Reviewed by Owen!)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137876 91177308-0d34-0410-b5e6-96231b3b80d8
making random bad assumptions about instructions which are not explicitly listed.
Includes fix for rdar://9956541, a version of "undef ^ undef should return
0 because it's easier than arguing with users".
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137777 91177308-0d34-0410-b5e6-96231b3b80d8
This implements the 'landingpad' instruction. It's used to indicate that a basic
block is a landing pad. There are several restrictions on its use (see
LangRef.html for more detail). These restrictions allow the exception handling
code to gather the information it needs in a much more sane way.
This patch has the definition, implementation, C interface, parsing, and bitcode
support in it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137501 91177308-0d34-0410-b5e6-96231b3b80d8
the retains and releases all use the same SSA pointer value.
Also, don't let CFG hazards disrupt nested retain+release pair
optimizations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137399 91177308-0d34-0410-b5e6-96231b3b80d8
rather than plain postorder, so that CFG constructs like single-exit loops
are reliably visited in a sensible order.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137398 91177308-0d34-0410-b5e6-96231b3b80d8
SCEV unrolling can unroll loops with arbitrary induction variables. It
is a prerequisite for -disable-iv-rewrite performance. It is also
easily handles loops of arbitrary structure including multiple exits
and is generally more robust.
This is under a temporary option to avoid affecting default
behavior for the next couple of weeks. It is needed so that I can
checkin unit tests for updateUnloop.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137384 91177308-0d34-0410-b5e6-96231b3b80d8
based on ScalarEvolution without changing the induction variable phis.
This utility is the main tool of IndVarSimplifyPass, but the pass also
restructures induction variables in strange ways that are sensitive to
pass ordering. This provides a way for other loop passes to simplify
new uses of induction variables created during transformation. The
utility may be used by any pass that preserves ScalarEvolution. Soon
LoopUnroll will use it.
The net effect in this checkin is to cleanup the IndVarSimplify pass
by factoring out the SimplifyIndVar algorithm into a standalone utility.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137197 91177308-0d34-0410-b5e6-96231b3b80d8
recurrence, the initial values low bits can sometimes be ignored.
To take advantage of this, added FoldIVUser to IndVarSimplify to fold
an IV operand into a udiv/lshr if the operator doesn't affect the
result.
-indvars -disable-iv-rewrite now transforms
i = phi i4
i1 = i0 + 1
idx = i1 >> (2 or more)
i4 = i + 4
into
i = phi i4
idx = i0 >> ...
i4 = i + 4
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137013 91177308-0d34-0410-b5e6-96231b3b80d8
This adds the 'resume' instruction class, IR parsing, and bitcode reading and
writing. The 'resume' instruction resumes propagation of an existing (in-flight)
exception whose unwinding was interrupted with a 'landingpad' instruction (to be
added later).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136589 91177308-0d34-0410-b5e6-96231b3b80d8
working on x86 (at least for trivial testcases); other architectures will
need more work so that they actually emit the appropriate instructions for
orderings stricter than 'monotonic'. (As far as I can tell, the ARM, PPC,
Mips, and Alpha backends need such changes.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136457 91177308-0d34-0410-b5e6-96231b3b80d8
specified in the same file that the library itself is created. This is
more idiomatic for CMake builds, and also allows us to correctly specify
dependencies that are missed due to bugs in the GenLibDeps perl script,
or change from compiler to compiler. On Linux, this returns CMake to
a place where it can relably rebuild several targets of LLVM.
I have tried not to change the dependencies from the ones in the current
auto-generated file. The only places I've really diverged are in places
where I was seeing link failures, and added a dependency. The goal of
this patch is not to start changing the dependencies, merely to move
them into the correct location, and an explicit form that we can control
and change when necessary.
This also removes a serialization point in the build because we don't
have to scan all the libraries before we begin building various tools.
We no longer have a step of the build that regenerates a file inside the
source tree. A few other associated cleanups fall out of this.
This isn't really finished yet though. After talking to dgregor he urged
switching to a single CMake macro to construct libraries with both
sources and dependencies in the arguments. Migrating from the two macros
to that style will be a follow-up patch.
Also, llvm-config is still generated with GenLibDeps.pl, which means it
still has slightly buggy dependencies. The internal CMake
'llvm-config-like' macro uses the correct explicitly specified
dependencies however. A future patch will switch llvm-config generation
(when using CMake) to be based on these deps as well.
This may well break Windows. I'm getting a machine set up now to dig
into any failures there. If anyone can chime in with problems they see
or ideas of how to solve them for Windows, much appreciated.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136433 91177308-0d34-0410-b5e6-96231b3b80d8
so that a declaration for objc_retain is created when needed if it doesn't
already exist. rdar://9825114.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135821 91177308-0d34-0410-b5e6-96231b3b80d8
size but different element types, so that it filters out the cases
that CreateShuffleVectorCast doesn't handle. This fixes rdar://9786827.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135721 91177308-0d34-0410-b5e6-96231b3b80d8
For -disable-iv-rewrite, perform LFTR without generating a new
"canonical" induction variable. Instead find the "best" existing
induction variable for use in the loop exit test and compute the final
value of that IV for use in the new loop exit test. In short,
convert to a simple eq/ne exit test as long as it's cheap to do so.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135420 91177308-0d34-0410-b5e6-96231b3b80d8
