Fix the the ceiling-division used in computing the MaxBECount so that it doesn't
have trouble with an intermediate add overflowing. Also, be more conservative
about the case where the induction varia

Fix the the ceiling-division used in computing the MaxBECount so that it doesn't
have trouble with an intermediate add overflowing. Also, be more conservative
about the case where the induction variable in an SLT loop exit can step past
the RHS of the SLT and overflow in a single step.

Make getSignedRange more aggressive, to recover for some common cases which
the above fixes pessimized.

This addresses rdar://7561161.

llvm-svn: 94512

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Re-implement the main strength-reduction portion of LoopStrengthReduction.
This new version is much more aggressive about doing "full" reduction in
cases where it reduces register pressure, and also

Re-implement the main strength-reduction portion of LoopStrengthReduction.
This new version is much more aggressive about doing "full" reduction in
cases where it reduces register pressure, and also more aggressive about
rewriting induction variables to count down (or up) to zero when doing so
reduces register pressure.

It currently uses fairly simplistic algorithms for finding reuse
opportunities, but it introduces a new framework allows it to combine
multiple strategies at once to form hybrid solutions, instead of doing
all full-reduction or all base+index.

llvm-svn: 94061

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Add a comment and tidy up some whitespace.

llvm-svn: 93932

Give ScalarEvolution access to the DominatorTree. It'll need this
to make more intellegent AddRec folding decisions.

llvm-svn: 93930

Use WriteAsOperand instead of getName() to print loop header names,
so that unnamed blocks are handled.

llvm-svn: 93059

Remove dump routine and the associated Debug.h from a header. Patch up
other files to compensate.

llvm-svn: 92075

Convert debug messages to use dbgs(). Generally this means
s/errs/dbgs/g except for certain special cases.

llvm-svn: 92067

Fix a spello in a comment that Nick spotted.

llvm-svn: 91742

Make this comment more precise.

llvm-svn: 91722

Revert this use of NUW/NSW also. Overflow-undefined multiplication isn't
associative either.

llvm-svn: 91701

Revert this use of NSW; this one isn't actually safe. NSW addition
is not reassociative.

llvm-svn: 91667

Delete an unused variable.

llvm-svn: 91659

Preserve NSW information in more places.

llvm-svn: 91656

Add Loop contains utility methods for testing whether a loop
contains another loop, or an instruction. The loop form is
substantially more efficient on large loops than the typical
code it replaces.

Add Loop contains utility methods for testing whether a loop
contains another loop, or an instruction. The loop form is
substantially more efficient on large loops than the typical
code it replaces.

llvm-svn: 91654

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Whitespace cleanups.

llvm-svn: 91651

Remove dead LLVMContext argument.

llvm-svn: 89641

Pass the (optional) TargetData object to ConstantFoldInstOperands
and ConstantFoldCompareInstOperands.

llvm-svn: 86626

fix ConstantFoldCompareInstOperands to take the LHS/RHS as
individual operands instead of taking a temporary array

llvm-svn: 86619

remove a bunch of extraneous LLVMContext arguments
from various APIs, addressing PR5325.

llvm-svn: 86231

Reverting 85714, 85715, 85716, which are breaking the build

llvm-svn: 85717

Add a function to Passes.h to allow clients to create instances
of the ScalarEvolution pass without needing to #include ScalarEvolution.h.

llvm-svn: 85716

Rename forgetLoopBackedgeTakenCount to forgetLoop, because it
clears out more information than just the stored backedge taken count.

llvm-svn: 85664

Remove includes of Support/Compiler.h that are no longer needed after the
VISIBILITY_HIDDEN removal.

llvm-svn: 85043

Remove VISIBILITY_HIDDEN from class/struct found inside anonymous namespaces.
Chris claims we should never have visibility_hidden inside any .cpp file but
that's still not true even after this commit

Remove VISIBILITY_HIDDEN from class/struct found inside anonymous namespaces.
Chris claims we should never have visibility_hidden inside any .cpp file but
that's still not true even after this commit.

llvm-svn: 85042

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Revert r83606 and add comments explaining why it isn't safe.

llvm-svn: 83649