368 Commits

Author SHA1 Message Date
Sanjay Patel
f6e615cc84 [ValueTracking] emit a remark when we detect a conflicting assumption (PR31809)
This is a follow-up to D29395 where we try to be good citizens and let the user know that
we've probably gone off the rails.

This should allow us to resolve:
https://llvm.org/bugs/show_bug.cgi?id=31809

Differential Revision: https://reviews.llvm.org/D29404


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@294208 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-06 18:26:06 +00:00
Sanjay Patel
b44cec60e3 [InstSimplify] try to eliminate icmp Pred (add nsw X, C1), C2
I was surprised to see that we're missing icmp folds based on 'add nsw' in InstCombine, 
but we should handle the InstSimplify cases first because that could make the InstCombine
code simpler.

Here are Alive-based proofs for the logic:

Name: add_neg_constant
Pre: C1 < 0 && (C2 > ((1<<(width(C1)-1)) + C1))
%a = add nsw i7 %x, C1
%b = icmp sgt %a, C2
  =>
%b = false

Name: add_pos_constant
Pre: C1 > 0 && (C2 < ((1<<(width(C1)-1)) + C1 - 1))
%a = add nsw i6 %x, C1
%b = icmp slt %a, C2
  =>
%b = false

Name: nuw
Pre: C1 u>= C2
%a = add nuw i11 %x, C1
%b = icmp ult %a, C2
  =>
%b = false

Differential Revision: https://reviews.llvm.org/D29053



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292952 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-24 17:03:24 +00:00
Sanjay Patel
f2f72bf178 [InstSimplify] refactor finding limits for icmp with binop; NFCI
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292812 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-23 18:22:26 +00:00
Marcello Maggioni
99dc11c166 Removing potentially error-prone fallthrough. NFC
This fallthrough if other cases are added between fabs and default
could cause fabs to fall to the next case resulting in a bug.
Better getting rid of it immediately just to be sure.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292003 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-14 07:28:47 +00:00
Matt Arsenault
5499c1d786 InstSimplify: Refactor function to use more switches
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291634 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-11 00:57:54 +00:00
Matt Arsenault
1f4353fb62 InstSimplify: Eliminate fabs on known positive
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291624 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-11 00:33:24 +00:00
David Majnemer
dae3654635 [InstSimplify] Optimize away udivs in the presence of range metadata
We know that udiv %V, C can be optimized away to 0 if %V is ult C.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291296 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-06 22:58:02 +00:00
David Majnemer
ef654a7ee6 [InstSimplify] Optimize away urems in the presence of range metadata
We know that urem %V, C can be optimized away to %V if %V is ult C.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291282 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-06 21:23:51 +00:00
Daniel Jasper
8de3a54f07 Revert @llvm.assume with operator bundles (r289755-r289757)
This creates non-linear behavior in the inliner (see more details in
r289755's commit thread).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290086 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-19 08:22:17 +00:00
Hal Finkel
bffeba468d Remove the AssumptionCache
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
2016-12-15 03:02:15 +00:00
Sanjay Patel
0fb6860f37 [InstSimplify] improve function name; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289332 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-10 17:40:47 +00:00
Zia Ansari
ea5455c788 [InstSimplify] Add "X / 1.0" to SimplifyFDivInst.
Differential Revision: https://reviews.llvm.org/D27587


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289153 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-08 23:27:40 +00:00
Sanjay Patel
43179a0fbb [InstSimplify] fixed (?) to not mutate icmps
As Eli noted in the post-commit thread for r288833, the use of
swapOperands() may not be allowed in InstSimplify, so I'm 
removing those calls here pending further review. 

The swap mutates the icmp, and there doesn't appear to be precedent
for instruction mutation in InstSimplify.

I didn't actually have any tests for those cases, so I'm adding
a few here. 



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288855 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-06 22:09:52 +00:00
Sanjay Patel
02d83470ab [InstSimplify] add folds for and-of-icmps with same operands
All of these (and a few more) are already handled by InstCombine,
but we shouldn't have to wait until then to simplify these because
they're cheap to deal with here in InstSimplify.

This is the 'and' sibling of the earlier 'or' patch:
https://reviews.llvm.org/rL288833


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288841 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-06 19:05:46 +00:00
Sanjay Patel
b4824c6afa [InstSimplify] add folds for or-of-icmps with same operands
All of these (and a few more) are already handled by InstCombine,
but we shouldn't have to wait until then to simplify these because
they're cheap to deal with here in InstSimplify.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288833 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-06 18:09:37 +00:00
Sanjay Patel
d4ddede406 [InstSimplify] add more helper functions for SimplifyICmpInst; NFCI
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288589 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-03 18:03:53 +00:00
Sanjay Patel
b7a44fa355 [InstSimplify] add helper functions for SimplifyICmpInst; NFCI
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288588 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-03 17:30:22 +00:00
Sanjay Patel
ded092b053 [InstSimplify] allow integer vector types to use computeKnownBits
Note that the non-splat lshr+lshr test folded, but that does not
work in general. Something is missing or wrong in computeKnownBits
as the non-splat shl+shl test still shows.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288005 91177308-0d34-0410-b5e6-96231b3b80d8
2016-11-27 21:07:28 +00:00
Sanjoy Das
cf6e9a81f6 Simplify x >=u x >> y and x >=u x udiv y
Summary:
Extends InstSimplify to handle both `x >=u x >> y` and `x >=u x udiv y`.

This is a folloup of rL258422 and
https://github.com/rust-lang/rust/pull/30917 where llvm failed to
optimize away the bounds checking in a binary search.

Patch by Arthur Silva!

Reviewers: sanjoy

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D25941

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285228 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-26 19:18:43 +00:00
Sanjay Patel
bac9c437ae [InstSimplify] fold negation of sign-bit
0 - X --> X, if X is 0 or the minimum signed value
0 - X --> 0, if X is 0 or the minimum signed value and the sub is NSW

I noticed this pattern might be created in the backend after the change from D25485, 
so we'll want to add a similar fold for the DAG.

The use of computeKnownBits in InstSimplify may be something to investigate if the
compile time of InstSimplify is noticeable. We could replace computeKnownBits with 
specific pattern matchers or limit the recursion.

Differential Revision: https://reviews.llvm.org/D25785


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284649 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-19 21:23:45 +00:00
Sanjoy Das
f6a95d4da8 Remove duplicated code; NFC
ICmpInst::makeConstantRange does exactly the same thing as
ConstantRange::makeExactICmpRegion.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283059 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-02 00:09:57 +00:00
Sanjay Patel
435dd3c7ec [InstSimplify] allow or-of-icmps folds with vector splat constants
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282592 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-28 14:27:21 +00:00
Sanjay Patel
c17583a507 [InstSimplify] allow and-of-icmps folds with vector splat constants
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282590 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-28 13:53:13 +00:00
Sanjay Patel
c091990663 move variables closer to their uses; add FIXMEs; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281972 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-20 14:36:14 +00:00
Andrea Di Biagio
341f684093 Simplify code a bit. No functional change intended.
We don't need to call `GetCompareTy(LHS)' every single time true or false is
returned from function SimplifyFCmpInst as suggested by Sanjay in review D24142.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280491 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-02 15:55:25 +00:00
Andrea Di Biagio
74f53f3812 [instsimplify] Fix incorrect folding of an ordered fcmp with a vector of all NaN.
This patch fixes a crash caused by an incorrect folding of an ordered comparison
between a packed floating point vector and a splat vector of NaN.

An ordered comparison between a vector and a constant vector of NaN, should
always be folded into a constant vector where each element is i1 false.

Since revision 266175, SimplifyFCmpInst folds the ordered fcmp into a scalar
'false'. Later on, this would cause an assertion failure, since the value type
of the folded value doesn't match the expected value type of the uses of the
original instruction: "Assertion failed: New->getType() == getType() &&
"replaceAllUses of value with new value of different type!".

This patch fixes the issue and adds a test case to the already existing test
InstSimplify/floating-point-compares.ll.

Differential Revision: https://reviews.llvm.org/D24143


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280488 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-02 14:47:43 +00:00
Sanjay Patel
d439a66862 [InstSimplify] allow icmp with constant folds for splat vectors, part 2
Completes the m_APInt changes for simplifyICmpWithConstant().

Other commits in this series:
https://reviews.llvm.org/rL279492
https://reviews.llvm.org/rL279530
https://reviews.llvm.org/rL279534
https://reviews.llvm.org/rL279538



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279543 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-23 18:00:51 +00:00
Sanjay Patel
405b046cb5 [InstSimplify] allow icmp with constant folds for splat vectors, part 1
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279538 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-23 17:30:56 +00:00
Sanjay Patel
a28b29b8db [InstSimplify] add helper function for SimplifyICmpInst(); NFCI
And add a FIXME because the helper excludes folds for vectors. It's
not clear yet how many of these are actually testable (and therefore
necessary?) because later analysis uses computeKnownBits and other
methods to catch many of these cases.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279492 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-22 23:12:02 +00:00
Justin Bogner
6673ea81f6 Replace "fallthrough" comments with LLVM_FALLTHROUGH
This is a mechanical change of comments in switches like fallthrough,
fall-through, or fall-thru to use the LLVM_FALLTHROUGH macro instead.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278902 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-17 05:10:15 +00:00
David Majnemer
0bf24e0333 [InstSimplify] Fold gep (gep V, C), (xor V, -1) to C-1
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278779 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-16 06:13:46 +00:00
David Majnemer
dc9c737666 Use range algorithms instead of unpacking begin/end
No functionality change is intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278417 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-11 21:15:00 +00:00
David Majnemer
7428509ec4 [InstSimplify] Fold gep (gep V, C), (sub 0, V) to C
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277952 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-07 07:58:12 +00:00
David Majnemer
2a07d9fdb3 [InstSimplify] Try hard to simplify pointer comparisons
Simplify ptrtoint comparisons involving operands with different source
types.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277951 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-07 07:58:10 +00:00
Sanjay Patel
47b6d6791b [InstCombine] use m_APInt to allow icmp eq (op X, Y), C folds for splat constant vectors
I'm removing a misplaced pair of more specific folds from InstCombine in this patch as well,
so we know where those folds are happening in InstSimplify.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277738 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-04 17:48:04 +00:00
David Majnemer
8da786cb44 Reinstate "[CloneFunction] Don't remove side effecting calls"
This reinstates r277611 + r277614 and reverts r277642.  A cast_or_null
should have been a dyn_cast_or_null.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277691 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-04 04:24:02 +00:00
Reid Kleckner
8c1e5c7a43 Revert "[CloneFunction] Don't remove side effecting calls"
This reverts commit r277611 and the followup r277614.

Bootstrap builds and chromium builds are crashing during inlining after
this change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277642 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-03 20:01:01 +00:00
David Majnemer
406cfb6253 [CloneFunction] Don't remove side effecting calls
We were able to figure out that the result of a call is some constant.
While propagating that fact, we added the constant to the value map.
This is problematic because it results in us losing the call site when
processing the value map.

This fixes PR28802.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277611 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-03 17:12:47 +00:00
David Majnemer
5d321c1c3e [InstSimplify] Cast folding can be made more generic
Use isEliminableCastPair to determine if a pair of casts are foldable.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276777 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-26 17:58:05 +00:00
David Majnemer
e37fa0be6d Reapply: [InstSimplify] Add support for bitcasts"
This reverts commit r276700 and reapplies r276698.
The relevant clang tests have been updated.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276727 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-26 05:52:29 +00:00
David Majnemer
f6fdf20c5f Revert "[InstSimplify] Add support for bitcasts"
This reverts commit r276698.  Clang has tests which rely on the
optimizer :(

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276700 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-25 22:24:59 +00:00
David Majnemer
66e75f38d9 [InstSimplify] Add support for bitcasts
BitCasts of BitCasts can be folded away as can BitCasts which don't
change the type of the operand.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276698 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-25 22:04:58 +00:00
David Majnemer
3d0336e163 [InstSimplify] Fold trunc([zs]ext(%V)) -> %V
Truncates can completely cancel out a zext or sext instruction.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276604 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-25 03:39:21 +00:00
Sanjay Patel
366a2caf93 [InstSimplify] don't crash handling a pointer or aggregate type
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276345 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-21 21:56:00 +00:00
Sanjay Patel
32995b5eb3 [InstSimplify] recognize trunc + icmp sgt/slt variants of select simplifications (PR28466)
rL245171 exposed a hole in InstSimplify that manifested in a strange way in PR28466:
https://llvm.org/bugs/show_bug.cgi?id=28466

It's possible to use trunc + icmp sgt/slt in place of an and + icmp eq/ne, so we need to
recognize that pattern to eliminate selects that are choosing between some value and some
bitmasked version of that value.

Note that there is significant room for improvement (refactoring) and enhancement (more
patterns, possibly in InstCombine rather than here).

Differential Revision: https://reviews.llvm.org/D22537



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276341 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-21 21:26:45 +00:00
Sanjay Patel
4c8b3b4588 [InstSimplify][InstCombine] don't crash when folding vector selects of icmp
Differential Revision: https://reviews.llvm.org/D22602


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276209 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-20 23:40:01 +00:00
Sanjay Patel
dba9c3285e refactor SimplifySelectInst; NFCI
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275911 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-18 20:56:53 +00:00
David Majnemer
6d67ce109b Simplify llvm.masked.load w/ undef masks
We can always pick the passthru value if the mask is undef: we are
permitted to treat the mask as-if it were filled with zeros.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275379 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-14 06:58:37 +00:00
David Majnemer
d2dd1e2fd6 Move a transform from InstCombine to InstSimplify.
This transform doesn't require any new instructions, it can safely live
in InstSimplify.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275344 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-13 23:32:53 +00:00
Hal Finkel
b0d67723f0 Pointer-comparison folding should look through returned-argument functions
For functions which are known to return a specific argument, pointer-comparison
folding can look through the function calls as part of its analysis.

Differential Revision: http://reviews.llvm.org/D9387

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275039 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-11 03:37:59 +00:00