llvm-svn: 53730

llvm-svn: 53715

llvm-svn: 53705

could cause problems for memdep when it breaks critical edges.

llvm-svn: 53691

FindInsertedValue, it now performs a number of simple transformations that
should result in the same effect when applied iteratively.

llvm-svn: 53673

llvm-svn: 53666

llvm-svn: 53627

llvm-svn: 53616

Have GVN do a pre-pass over the CFG that folds away unconditional branches where possible.  This allows local PRE to be more aggressive.

llvm-svn: 53615

llvm-svn: 53564

disproving a condition.  This actually compiles the existing testcase
(udiv_select_to_select_shift) to:

define i64 @test(i64 %X, i1 %Cond) {
entry:
	%divisor1.t = lshr i64 %X, 3		; <i64> [#uses=1]
	%quotient2 = lshr i64 %X, 3		; <i64> [#uses=1]
	%sum = add i64 %divisor1.t, %quotient2		; <i64> [#uses=1]
	ret i64 %sum
}

instead of:

define i64 @test(i64 %X, i1 %Cond) {
entry:
	%quotient1.v = select i1 %Cond, i64 3, i64 4		; <i64> [#uses=1]
	%quotient1 = lshr i64 %X, %quotient1.v		; <i64> [#uses=1]
	%quotient2 = lshr i64 %X, 3		; <i64> [#uses=1]
	%sum = add i64 %quotient1, %quotient2		; <i64> [#uses=1]
	ret i64 %sum
}

llvm-svn: 53534

Remove dead code analyzing urem. 'urem' of power-of-2 is canonicalized to an
'and' instruction.

llvm-svn: 53506

llvm-svn: 53470

llvm-svn: 53454

llvm-svn: 53452

similar.

llvm-svn: 53451

llvm-svn: 53449

llvm-svn: 53448

llvm-svn: 53447

the min/max values for an integer type, compare against the min/max
values we can prove contain the input.  This might be a tighter bound,
so this is general goodness.

llvm-svn: 53446

handle them in some code.

llvm-svn: 53445

was using the algorithm for folding unsigned comparisons which is
completely wrong.  This has been broken since the signless types change.

llvm-svn: 53444

This cause a regression in InstCombine/JavaCompare, which was doing the right
thing on accident.  To handle the missed case, generalize the comparisons based
on masked bits a little bit to handle comparisons against the max value. For 
example, we can now xform (slt i32 (and X, 4), 4) -> (setne i32 (and X, 4), 4)

llvm-svn: 53443

llvm-svn: 53393

llvm-svn: 53283

llvm-svn: 53282

llvm-svn: 53276

llvm-svn: 53271

llvm-svn: 53265

into phis.  This is actually the same bug as PR2262 /
2008-04-29-VolatileLoadDontMerge.ll, but I missed checking the first 
predecessor for multiple successors.  Testcase here:
InstCombine/2008-07-08-VolatileLoadMerge.ll

llvm-svn: 53240

1. LSR runOnLoop is always returning false regardless if any transformation is made.
2. AddUsersIfInteresting can create new instructions that are added to DeadInsts. But there is a later early exit which prevents them from being freed.

llvm-svn: 53193

llvm-svn: 53177

llvm-svn: 53151

Use information already present in the ValueTable to fast-fail when we know there won't be a value number match.  This speeds up GVN on a case where there are very few redundancies by ~25%.

llvm-svn: 53108

Do not try to update dominator info while manipulating CFG.  This code does not handle all cases and keeps invalid dom info around some cases, which misleads other passes down stream.

Right now, dom info is recaluclated in the end if the loop is switched.

llvm-svn: 53106

Remove the ability for ADCE to remove unreachable blocks in loop nests, because, as Eli pointed out, SimplifyCFG already does this.

llvm-svn: 53104

llvm-svn: 53090

llvm-svn: 53089

llvm-svn: 53087

llvm-svn: 53086