Allows LLVM to optimize sequences like the following:
%add = add nuw i32 %x, 1
%cmp = icmp ugt i32 %add, %y
Into:
%cmp = icmp uge i32 %x, %y
Previously, only signed comparisons were being handled.
Decrements could also be handled, but 'sub nuw %x, 1' is currently canonicalized to
'add %x, -1' in InstCombineAddSub, losing the nuw flag. Removing that canonicalization
seems like it might have far-reaching ramifications so I kept this simple for now.
Patch by Matti Niemenmaa!
Differential Revision: https://reviews.llvm.org/D24700
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291975 91177308-0d34-0410-b5e6-96231b3b80d8
Min/max canonicalization (r287585) exposes the fact that we're missing combines for min/max patterns.
This patch won't solve the example that was attached to that thread, so something else still needs fixing.
The line between InstCombine and InstSimplify gets blurry here because sometimes the icmp instruction that
we want to fold to already exists, but sometimes it's the swapped form of what we want.
Corresponding changes for smax/umin/umax to follow.
Differential Revision: https://reviews.llvm.org/D27531
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289855 91177308-0d34-0410-b5e6-96231b3b80d8
After r289755, the AssumptionCache is no longer needed. Variables affected by
assumptions are now found by using the new operand-bundle-based scheme. This
new scheme is more computationally efficient, and also we need much less
code...
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289756 91177308-0d34-0410-b5e6-96231b3b80d8
Instead, expose whether the current type is an array or a struct, if an array
what the upper bound is, and if a struct the struct type itself. This is
in preparation for a later change which will make PointerType derive from
Type rather than SequentialType.
Differential Revision: https://reviews.llvm.org/D26594
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288458 91177308-0d34-0410-b5e6-96231b3b80d8
These 2 helper functions were already using APInt internally, so just
change the API and caller to allow folds for splats. The scalar
regression tests look quite thorough, so I just added a couple of
tests to prove that vectors are handled too.
These folds should be grouped with the other cmp+shift folds though.
That can be an NFC follow-up.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281663 91177308-0d34-0410-b5e6-96231b3b80d8
This pattern is matched in foldICmpBinOpEqualityWithConstant() and already works
with vectors too. I changed some comments over there to point out the current
location. The tests for this transform are currently in 'sub.ll'.
Note that the remaining folds in this block all require a sub too, so they should
get grouped with the other icmp(sub) patterns.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281627 91177308-0d34-0410-b5e6-96231b3b80d8
This is a big glob of transforms that probably should work for vectors,
but currently they are disallowed because of ConstantInt guards.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281614 91177308-0d34-0410-b5e6-96231b3b80d8
1. Rename variables to be consistent with related/preceding code (may want to reorganize).
2. Fix comments/formatting.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281140 91177308-0d34-0410-b5e6-96231b3b80d8
Everything under foldICmpInstWithConstant() should now be working for
splat vectors via m_APInt matchers. Ie, I've removed all of the FIXMEs
that I added while cleaning that section up. Note that not all of the
associated FIXMEs in the regression tests are gone though, because some
of the tests require earlier folds that are still scalar-only.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281139 91177308-0d34-0410-b5e6-96231b3b80d8
I introduced this potential bug by missing this diff in:
https://reviews.llvm.org/rL280873
...however, I'm not sure how to reach this code path with a regression test.
We may be able to remove this code and assume that the transform to a constant
is always handled by InstSimplify?
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280964 91177308-0d34-0410-b5e6-96231b3b80d8
This is a revert of r280676 which was a revert of r280637;
ie, this is r280637 again. It was speculatively reverted to
help debug buildbot failures.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280861 91177308-0d34-0410-b5e6-96231b3b80d8
The transform in question:
icmp (and (trunc W), C2), C1 -> icmp (and W, C2'), C1'
...is still not enabled for vectors, thus no functional change intended.
It's not clear to me if this is a good transform for vectors or even
scalars in general. Changing that behavior may be a follow-on patch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280627 91177308-0d34-0410-b5e6-96231b3b80d8
While removing a scalar shackle from an icmp fold, I noticed that I couldn't find any tests to trigger
this code path.
The 'and' shrinking transform should be handled by InstCombiner::foldCastedBitwiseLogic()
or eliminated with InstSimplify. The icmp narrowing is part of InstCombiner::foldICmpWithCastAndCast().
Differential Revision: https://reviews.llvm.org/D24031
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280370 91177308-0d34-0410-b5e6-96231b3b80d8
This is prep work before changing the callers to also use APInt which will
allow folds for splat vectors. Currently, the callers have ConstantInt
guards in place, so no functional change intended with this commit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280282 91177308-0d34-0410-b5e6-96231b3b80d8
These folds already have tests for scalar and vector types, except
for the vector div-by-0 case, so I'm adding tests for that.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280115 91177308-0d34-0410-b5e6-96231b3b80d8
1. Fix comments to match variable names
2. Remove redundant CmpRHS variable
3. Add FIXME to replace some checks with asserts
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280112 91177308-0d34-0410-b5e6-96231b3b80d8
