the active loop. This is generally desirable, and it avoids trouble
in situations such as the testcase in PR9123, though the failure
mode depends on use-list order, so it is infeasible to test.

llvm-svn: 125065

SimplifyCFG: Track the number of used icmps when turning a icmp chain into a switch. If we used only one icmp, don't turn it into a switch.

Also prevent the switch-to-icmp transform from creating identity adds, noticed by Marius Wachtler.

llvm-svn: 125056

instcombine xform to exercise this.

Nothing forms exact udivs yet though.  This is progress on PR8862

llvm-svn: 124992

llvm-svn: 124977

now, and this wasn't comparing some of their relevant bits anyhow.

llvm-svn: 124976

SimplifyCFG: Also transform switches that represent a range comparison but are not sorted into sub+icmp.

This transforms another 1000 switches in gcc.c.

llvm-svn: 124826

This makes the job of the later optzn passes easier, allowing the vast amount of
icmp transforms to chew on it.

We transform 840 switches in gcc.c, leading to a 16k byte shrink of the resulting
binary on i386-linux.

The testcase from README.txt now compiles into
  decl  %edi
  cmpl  $3, %edi
  sbbl  %eax, %eax
  andl  $1, %eax
  ret

llvm-svn: 124724

that might have changed been affected by a merge elsewhere will have been
removed from the function set, and it isn't needed for performance because we
call grow() ahead of time to prevent reallocations.

llvm-svn: 124717

reassociation. No testcase, because I wasn't able to create a testcase
which actually demonstrates a problem.

llvm-svn: 124713

llvm-svn: 124712

(A+B) == A  ->  B == 0
A == (A+B)  ->  B == 0

llvm-svn: 124567

The DEBUG() call at line 606 demands to see raw_ostream's definition. I have no idea why this seems to only break MSVC.

llvm-svn: 124545

llvm-svn: 124535

llvm-svn: 124534

llvm-svn: 124527

llvm-svn: 124526

llvm-svn: 124522

Re-commit r124462 with fixes. Tail recursion elim will now dup ret into unconditional predecessor to enable TCE on demand.

llvm-svn: 124518

Modified patch by Adam Preuss.

This builds on the existing framework for block tracing, edge profiling and optimal edge profiling.
See -help-hidden for new flags.
For documentation, see the technical report "Implementation of Path Profiling..." in llvm.org/pubs.

llvm-svn: 124515

benchmarks, and that it can be simplified to X/Y.  (In general you can only
simplify (Z*Y)/Y to Z if the multiplication did not overflow; if Z has the
form "X/Y" then this is the case).  This patch implements that transform and
moves some Div logic out of instcombine and into InstructionSimplify.
Unfortunately instcombine gets in the way somewhat, since it likes to change
(X/Y)*Y into X-(X rem Y), so I had to teach instcombine about this too.
Finally, thanks to the NSW/NUW flags, sometimes we know directly that "Z*Y"
does not overflow, because the flag says so, so I added that logic too.  This
eliminates a bunch of divisions and subtractions in 447.dealII, and has good
effects on some other benchmarks too.  It seems to have quite an effect on
tramp3d-v4 but it's hard to say if it's good or bad because inlining decisions
changed, resulting in massive changes all over.

llvm-svn: 124487

functionality change.

llvm-svn: 124482

llvm-svn: 124480

llvm-svn: 124479

llvm-svn: 124478

the function equality set.

llvm-svn: 124475

llvm-svn: 124469

  branches. PR8575, rdar://5134905, rdar://8911460.
- Allow codegen tail duplication to dup small return blocks after register
  allocation is done.

llvm-svn: 124462

llvm-svn: 124426

llvm-svn: 124406

llvm-svn: 124404

that relationships like "i8* null" is equivalent to "i32* null".

llvm-svn: 124368

operand being factorized (and erased) could occur several times in Ops,
resulting in freed memory being used when the next occurrence in Ops was
analyzed.

llvm-svn: 124287

it. No functionality change!

llvm-svn: 124286

merge vector<intptr_t>::push_back() and vector<void*>::push_back() because
Enumerate() doesn't realize that "i64* null" and "i8** null" are equivalent.

llvm-svn: 124285

elements for type equivalence.

llvm-svn: 124284

for now. It's controlled by the HasGlobalAliases variable which is not attached
to any flag yet.

llvm-svn: 124182

with BasicAA's DecomposeGEPExpression, which recently began
using a TargetData. This fixes PR8968, though the testcase
is awkward to reduce.

Also, update several off GetUnderlyingObject's users
which happen to have a TargetData handy to pass it in.

llvm-svn: 124134

code.

llvm-svn: 124100

llvm-svn: 124099

occurs because instcombine sinks loads and inserts phis.  This kicks in 
on such apps as 175.vpr, eon, 403.gcc, xalancbmk and a bunch of times in
spec2006 in some app that uses std::deque.

This resolves the last of rdar://7339113.

llvm-svn: 124090