Teach GetMinSignBits about SCEVAddExprs.

llvm-svn: 74045

Move the special cases for constants out of getUnknown and into
createSCEV. Also, recognize UndefValue in createSCEV.

Change getIntegerSCEV's comment to avoid mentioning FP types,
and re-implement i

Move the special cases for constants out of getUnknown and into
createSCEV. Also, recognize UndefValue in createSCEV.

Change getIntegerSCEV's comment to avoid mentioning FP types,
and re-implement it in terms of getConstant instead of getUnknown.

llvm-svn: 74041

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Use ScalarEvolution::getConstant instead of getUnknown to create
SCEVConstants. This cleanup is a step toward letting getUnknown
be simpler.

llvm-svn: 74037

Include the maximum trip count expression in ScalarEvolution's print output.

llvm-svn: 74035

Add an isAllOnesValue utility function, similar to isZero and isOne.

llvm-svn: 74032

Fix a bug in the trip-count computation with And/Or. If either of the
sides is CouldNotCompute, the resulting exact count must be CouldNotCompute.

llvm-svn: 73920

Remove the parent pointer from SCEV, since it did not end up being needed.

llvm-svn: 73907

SCEVHandle is no more!

llvm-svn: 73906

Fix some typos that Duncan noticed.

llvm-svn: 73903

Banish global state from ScalarEvolution! SCEV uniquing is now done by tables attached to the ScalarEvolution pass.
This also throws out the SCEV reference counting scheme, as the the SCEVs now have

Banish global state from ScalarEvolution! SCEV uniquing is now done by tables attached to the ScalarEvolution pass.
This also throws out the SCEV reference counting scheme, as the the SCEVs now have a lifetime controlled by the
ScalarEvolution pass.

Note that SCEVHandle is now a no-op, and will be remove in a future commit.

llvm-svn: 73892

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Make use of getUMinFromMismatchedTypes when computing backedge-taken
counts for loops with multiple exits, replacing more conservative code
which only handled constants. This is derived from a patch

Make use of getUMinFromMismatchedTypes when computing backedge-taken
counts for loops with multiple exits, replacing more conservative code
which only handled constants. This is derived from a patch by
Nick Lewycky.

This also fixes llc aborts in ClamAV and others, as
getUMinFromMismatchedTypes takes care of balancing the types before
working with them.

llvm-svn: 73884

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Add a getUMinFromMismatchedTypes helper function.

llvm-svn: 73883

Factor out code for computing umin and smin for SCEV expressions into
helper functions. Based on a patch by Nick Lewycky.

llvm-svn: 73869

Teach ScalarEvolution how to analyze loops with multiple exit
blocks, and also exit blocks with multiple conditions (combined
with (bitwise) ands and ors). It's often infeasible to compute an
exact t

Teach ScalarEvolution how to analyze loops with multiple exit
blocks, and also exit blocks with multiple conditions (combined
with (bitwise) ands and ors). It's often infeasible to compute an
exact trip count in such cases, but a useful upper bound can often
be found.

llvm-svn: 73866

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Delete an unused variable.

llvm-svn: 73865

Fix ScalarEvolution's backedge-taken count computations to check for
overflow when computing a integer division to round up.

Thanks to Nick Lewycky for noticing this!

llvm-svn: 73862

Generalize isLoopGuardedByCond's checking to consider two
SCEVUnknowns with identical Instructions to be equal. This allows
it to analze cases such as the attached testcase, where the front-end
has c

Generalize isLoopGuardedByCond's checking to consider two
SCEVUnknowns with identical Instructions to be equal. This allows
it to analze cases such as the attached testcase, where the front-end
has cloned the loop controlling expression. Along with r73805, this
lets IndVarSimplify eliminate all the sign-extend casts in the
loop in the attached testcase.

llvm-svn: 73807

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Use ScalarEvolution's new GetMinSignBits and GetMinLeadingZeros
in the loop backedge-taken count computation of the maximum
possible trip count.

llvm-svn: 73805

Make GetMinTrailingZeros a member function of ScalarEvolution,
so that it can access the TargetData member (when available) and
use ValueTracking.h information to compute information for
SCEVUnknown

Make GetMinTrailingZeros a member function of ScalarEvolution,
so that it can access the TargetData member (when available) and
use ValueTracking.h information to compute information for
SCEVUnknown Values.

Also add GetMinLeadingZeros and GetMinSignBits functions,
with minimal implementations.

llvm-svn: 73794

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Make ScalarEvolution::print print getSCEVAtScope values for
expressions, when interesting.

llvm-svn: 73776

Add a parent pointer to SCEV, in preparation for getting rid of the global uniquing tables. No functionality change.

llvm-svn: 73728

Recognize n != 0 ? n : 1 as umax(n, 1). Previously only ULT/UGT/ULE/UGE
comparisons were recognized for umax, but instcombine canonicalizes
unsigned comparisons with zero to this simpler form.

llvm-

Recognize n != 0 ? n : 1 as umax(n, 1). Previously only ULT/UGT/ULE/UGE
comparisons were recognized for umax, but instcombine canonicalizes
unsigned comparisons with zero to this simpler form.

llvm-svn: 73717

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Update a comment to reflect the code.

llvm-svn: 73704

Fix trailing whitespace from ScalarEvolution::print.

llvm-svn: 73666

Teach ScalarEvolution how to recognize another xor(and(x, C), C) case.
If C is a single bit and the and gets analyzed as a truncate and
zero-extend, the xor can be represnted as an add.

llvm-svn: 73

Teach ScalarEvolution how to recognize another xor(and(x, C), C) case.
If C is a single bit and the and gets analyzed as a truncate and
zero-extend, the xor can be represnted as an add.

llvm-svn: 73664

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