llvm-svn: 88864

which implements GCC PR18046.  This also gets us 360 more
jump threads on 176.gcc.

llvm-svn: 86953

llvm-svn: 86952

making the new LVI stuff smart enough to subsume some special
cases in the old code.  Disable them when LVI is around, the
testcase still passes.

llvm-svn: 86951

allows us to handle the test10 testcase.

llvm-svn: 86924

llvm-svn: 86923

llvm-svn: 86920

uses LVI info when -enable-jump-threading-lvi is passed.

llvm-svn: 86886

start using them in a trivial way when -enable-jump-threading-lvi
is passed.  enable-jump-threading-lvi will be my playground for 
awhile.

llvm-svn: 86789

llvm-svn: 86766

llvm-svn: 86739

into libanalysis and transformutils.

llvm-svn: 86735

llvm-svn: 86723

debug intrinsics, and an unconditional branch when possible.  This
reuses the TryToSimplifyUncondBranchFromEmptyBlock function split
out of simplifycfg.

llvm-svn: 86722

just one level deep.  On the testcase we go from getting this:

F1:                                               ; preds = %T2
  %F = and i1 true, %cond                         ; <i1> [#uses=1]
  br i1 %F, label %X, label %Y

to a fully threaded:

F1:                                               ; preds = %T2
  br label %Y


This changes gets us to the point where we're forming (too many) switch 
instructions on doug's strswitch testcase.

llvm-svn: 86646

llvm-svn: 86639

except that the result may not be a constant.  Switch jump threading to 
use it so that it gets things like (X & 0) -> 0, which occur when phi preds
are deleted and the remaining phi pred was a zero.

llvm-svn: 86637

Simplify[IF]Cmp pieces.  Add some predicates to CmpInst to 
determine whether a predicate is fp or int.

llvm-svn: 86624

llvm-svn: 86616

simplifies instruction users of PHIs when the phi is eliminated.  This
will be moved to transforms/utils after some other refactoring.

llvm-svn: 86603

llvm-svn: 86497

(making pred factoring only happen if threading is guaranteed
to be successful).

This now survives an X86-64 bootstrap of llvm-gcc.

llvm-svn: 86355

86289, 86278, 86270, 86267, 86266 & 86264
Chris, please take a look.

llvm-svn: 86321

llvm-svn: 86314

set only once even if it has multiple edges to BB.

llvm-svn: 86299

llvm-svn: 86289

llvm-svn: 86278

llvm-svn: 86270

llvm-svn: 86267

llvm-svn: 86266

predicates.  This allows us to jump thread things like:

_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit119:
  %tmp1.i24166 = phi i8 [ 1, %bb5.i117 ], [ %tmp1.i24165, %_Z....exit ], [ %tmp1.i24165, %bb4.i114 ] 
  %toBoolnot.i87 = icmp eq i8 %tmp1.i24166, 0     ; <i1> [#uses=1]
  %tmp4.i90 = icmp eq i32 %tmp2.i, 6              ; <i1> [#uses=1]
  %or.cond173 = and i1 %toBoolnot.i87, %tmp4.i90  ; <i1> [#uses=1]
  br i1 %or.cond173, label %bb4.i96, label %_ZN12...

Where it is "obvious" that when coming from %bb5.i117 that the 'and' is always 
false.  This triggers a surprisingly high number of times in the testsuite, 
and gets us closer to generating good code for doug's strswitch testcase.

This also make a bunch of other code in jump threading redundant, I'll rip
out in the next patch.  This survived an enable-checking llvm-gcc bootstrap.

llvm-svn: 86264

from various APIs, addressing PR5325.

llvm-svn: 86231

Hans Wennborg!

llvm-svn: 86067

now-probably-dead instruction tree feeding it.

llvm-svn: 83778

done by condprop, but do it in a much more general form.  The
basic idea is that we can do a limited form of tail duplication
in the case when we have a branch on a phi.  Moving the branch
up in to the predecessor block makes instruction selection
much easier and encourages chained jump threadings.

llvm-svn: 83759

llvm-svn: 83756

llvm-svn: 83755

llvm-svn: 83754

DemoteRegToStack.  This makes it more efficient (because it isn't
creating a ton of load/stores that are eventually removed by a later
mem2reg), and more slightly more effective (because those load/stores
don't get in the way of threading).

llvm-svn: 83706

update all the callers.

llvm-svn: 82889