The partitioning logic attempted to handle uses of an alloca with an
offset starting before the alloca so long as the use had some overlap
with the alloca itself. However, there was a bug where we tested
'(uint64_t)Offset >= AllocSize' without first checking whether 'Offset'
was positive. As a consequence, essentially every negative offset (that
is, starting *before* the alloca does) would be thrown out, even if it
was overlapping. The subsequent code to throw out negative offsets which
were actually non-overlapping was essentially dead. The code to *handle*
overlapping negative offsets was actually dead!

I've just removed all of this, and taught SROA to discard any uses which
start prior to the alloca from the beginning. It has the lovely property
of simplifying the code. =] All the tests still pass, and in fact no new
tests are needed as this is already covered by our testsuite. Fixing the
code so that negative offsets work the way the comments indicate they
were supposed to work causes regressions. That's how I found this.

Anyways, this is all progress in the correct direction -- tightening up
SROA to be maximally aggressive. Some day, I really hope to turn
out-of-bounds accesses to an alloca into 'unreachable'.

llvm-svn: 169120

llvm-svn: 169119

Fixes PR14465.

Differential Revision: http://llvm-reviews.chandlerc.com/D148

llvm-svn: 169084

llvm-svn: 169083

Also check in a case to repeat the issue, on which 'opt -globalopt' consumes 1.6GB memory.
The big memory footprint cause is that current GlobalOpt one by one hoists and stores the leaf element constant into the global array, in each iteration, it recreates the global array initializer constant and leave the old initializer alone. This may result in many obsolete constants left.
For example:  we have global array @rom = global [16 x i32] zeroinitializer
After the first element value is hoisted and installed:   @rom = global [16 x i32] [ 1, 0, 0, ... ]
After the second element value is installed:  @rom = global [16 x 32] [ 1, 2, 0, 0, ... ]        // here the previous initializer is obsolete
...
When the transform is done, we have 15 obsolete initializers left useless.

llvm-svn: 169079

reversed the logic of the log2 detection routine to reduce the number of nested ifs

llvm-svn: 169049

llvm-svn: 169048

The original patch removed a bunch of code that the SjLjEHPrepare pass placed
into the entry block if all of the landing pads were removed during the
CodeGenPrepare class. The more natural way of doing things is to run the CGP
*before* we run the SjLjEHPrepare pass.

Make it so!

llvm-svn: 169044

llvm-svn: 169043

reviewed by Michael Ilseman <milseman@apple.com>

llvm-svn: 169025

Remove the use of LPPassManager. We can remove LPM because we dont need to run any additional loop passes on the new vector loop.

llvm-svn: 169016

llvm-svn: 168995

We're iterating over a non-deterministically ordered container looking
for two saturating flags. To do this correctly, we have to saturate
both, and only stop looping if both saturate to their final value.
Otherwise, which flag we see first changes the result.

This is also a micro-optimization of the previous version as now we
don't go into the (possibly expensive) test logic once the first
violation of either constraint is detected.

llvm-svn: 168989

functionality changed.

Evan's commit r168970 moved the code that the primary comment in this
function referred to to the other end of the function without moving the
comment, and there has been a steady creep of "boolean" logic in it that
is simpler if handled via early exit. That way each special case can
have its own comments. I've also made the variable name a bit more
explanatory than "AllFit". This is in preparation to fix the
non-deterministic output of this function.

llvm-svn: 168988

The simplify-libcalls pass maintained a statistic to count the number
of library calls that have been simplified.  Now that library call
simplification is being carried out in instcombine the statistic should
be moved to there.

llvm-svn: 168975

depends on the IR infrastructure, there is no sense in it being off in
Support land.

This is in preparation to start working to expand InstVisitor into more
special-purpose visitors that are still generic and can be re-used
across different passes. The expansion will go into the Analylis tree
though as nothing in VMCore needs it.

llvm-svn: 168972

the tables cannot fit in registers (i.e. bitmap), do not emit the table
if it's using an illegal type.

rdar://12779436

llvm-svn: 168970

This revision attempts to recognize following population-count pattern:

 while(a) { c++; ... ; a &= a - 1; ... },
  where <c> and <a>could be used multiple times in the loop body.

 TODO: On X8664 and ARM, __buildin_ctpop() are not expanded to a efficent 
instruction sequence, which need to be improved in the following commits.

Reviewed by Nadav, really appreciate!

llvm-svn: 168931

the last invoke instruction in the function. This also removes the last landing
pad in an function. This is fine, but with SjLj EH code, we've already placed a
bunch of code in the 'entry' block, which expects the landing pad to stick
around.

When we get to the situation where CGP has removed the last landing pad, go
ahead and nuke the SjLj instructions from the 'entry' block.
<rdar://problem/12721258>

llvm-svn: 168930

llvm-svn: 168928

llvm-svn: 168927

This patch migrates the puts optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

All the simplifiers from simplify-libcalls have now been migrated to
instcombine.  Yay!  Just a few other bits to migrate (prototype attribute
inference and a few statistics) and simplify-libcalls can finally be put
to rest.

llvm-svn: 168925

[ASan] Simplify check added in r168861. Bail out from module pass early if the module is blacklisted.

llvm-svn: 168913

llvm-svn: 168911

llvm-svn: 168910

This patch migrates the fputs optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 168893

This patch migrates the fwrite optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 168892

This patch migrates the fprintf optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 168891

Handle insertelement, extractelement, shufflevector.

llvm-svn: 168889

    
The old version failed on a 3-arg instruction with (-1, 0, 0) shadows (it would
pick the 3rd operand origin irrespective of its shadow).
    
The new version always picks the origin of the rightmost poisoned operand.

llvm-svn: 168887

llvm-svn: 168884

This is a special case of signed relational comparison where result
only depends on the sign of x.

llvm-svn: 168881

This change ensures that shadow memory accesses have the same alignment
as corresponding app memory accesses.

llvm-svn: 168880

    
Rewrite getOriginPtr in a way that lets subsequent optimizations factor out
the common part of Shadow and Origin address calculation. Improves perf by
up to 5%.

llvm-svn: 168879

llvm-svn: 168878

This was already done for memmove, where it is required for correctness.
This change improves performance by avoiding copyingthe same memory twice.
Also, the library functions are given __msan_ prefix to prevent instcombine
pass from converting them back to intrinsics.

llvm-svn: 168876

llvm-svn: 168873

Compiler pass only.

llvm-svn: 168866

[asan/tsan] initialize the asan/tsan callbacks in runOnFunction as opposed to doInitialization. This is required to allow the upcoming changes in PassManager behavior

llvm-svn: 168864

llvm-svn: 168861