Commit Graph

231 Commits

Author SHA1 Message Date
Neil Henning
7465597060 [IRBuilder] Fixup CreateIntrinsic to allow specifying Types to Mangle.
The IRBuilder CreateIntrinsic method wouldn't allow you to specify the
types that you wanted the intrinsic to be mangled with. To fix this
I've:

- Added an ArrayRef<Type *> member to both CreateIntrinsic overloads.
- Used that array to pass into the Intrinsic::getDeclaration call.
- Added a CreateUnaryIntrinsic to replace the most common use of
  CreateIntrinsic where the type was auto-deduced from operand 0.
- Added a bunch more unit tests to test Create*Intrinsic calls that
  weren't being tested (including the FMF flag that wasn't checked).

This was suggested as part of the AMDGPU specific atomic optimizer
review (https://reviews.llvm.org/D51969).

Differential Revision: https://reviews.llvm.org/D52087

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@343962 91177308-0d34-0410-b5e6-96231b3b80d8
2018-10-08 10:32:33 +00:00
Craig Topper
9461c2135c [InstCombine] Fold (min/max ~X, Y) -> ~(max/min X, ~Y) when Y is freely invertible
Summary: This restores the combine that was reverted in r341883. The infinite loop from the failing test no longer occurs due to changes from r342163.

Reviewers: spatel, dmgreen

Reviewed By: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D52070

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@342797 91177308-0d34-0410-b5e6-96231b3b80d8
2018-09-22 05:53:27 +00:00
Craig Topper
93dcdfe7b7 [InstCombine] Fold (xor (min/max X, Y), -1) -> (max/min ~X, ~Y) when X and Y are freely invertible.
This allows the xor to be removed completely.

This might help with recomitting r341674, but seems good regardless.

Coincidentally fixes PR38915.

Differential Revision: https://reviews.llvm.org/D51964

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@342163 91177308-0d34-0410-b5e6-96231b3b80d8
2018-09-13 18:52:58 +00:00
Sanjay Patel
84c594f387 [InstCombine] remove checks for IsFreeToInvert()
I accidentally committed this diff with rL342147 because
I had applied D51964. We probably do need those checks,
but D51964 has tests and more discussion/motivation,
so they should be re-added with that patch.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@342149 91177308-0d34-0410-b5e6-96231b3b80d8
2018-09-13 16:18:12 +00:00
Sanjay Patel
7cc8ebdc13 [InstCombine] reorder folds to reduce chance of infinite loops
I don't have a test case for this, but it's motivated by
the discussion in D51964, and I've added TODO comments for
the better fix - move simplifications into instsimplify
because that's more efficient and reduces risk of infinite
loops in instcombine caused by transforms trying to do the
opposite folds.

In this case, we know that the transform that tries to move
'not' through min/max can be fooled by the multiple uses
of a value in another min/max, so try to squash the 
foldSPFofSPF() patterns first.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@342147 91177308-0d34-0410-b5e6-96231b3b80d8
2018-09-13 16:04:06 +00:00
Alina Sbirlea
5ec364705c [InstCombine] Partially revert rL341674 due to PR38897.
Summary:
Revert min/max changes in rL341674 dues to high compile times causing timeouts (PR38897).
Checking in to unblock failing builds. Patch available for post-commit review and re-revert once resolved.
Working on a smaller reproducer for PR38897.

Reviewers: craig.topper, spatel

Subscribers: sanjoy, jlebar, llvm-commits

Differential Revision: https://reviews.llvm.org/D51897

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341883 91177308-0d34-0410-b5e6-96231b3b80d8
2018-09-10 23:47:21 +00:00
Craig Topper
189c2c8cb6 [InstCombine] Fold (min/max ~X, Y) -> ~(max/min X, ~Y) when Y is freely invertible
If the ~X wasn't able to simplify above the max/min, we might be able to simplify it by moving it below the max/min.

I had to modify the ~(min/max ~X, Y) transform to prevent getting stuck in a loop when we saw the new ~(max/min X, ~Y) before the ~Y had been folded away to remove the new not.

Differential Revision: https://reviews.llvm.org/D51398

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341674 91177308-0d34-0410-b5e6-96231b3b80d8
2018-09-07 16:19:50 +00:00
Florian Hahn
1b57b3d686 [InstCombine] Do not fold scalar ops over select with vector condition.
If OtherOpT or OtherOpF have scalar types and the condition is a vector,
we would create an invalid select.

Reviewers: spatel, john.brawn, mssimpso, craig.topper

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D51781


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341666 91177308-0d34-0410-b5e6-96231b3b80d8
2018-09-07 14:40:06 +00:00
Craig Topper
b8bd0d424e [InstCombine] Replace two calls to getNumUses() with !hasNUsesOrMore
We were calling getNumUses to check for 1 or 2 uses. But getNumUses is linear in the number of uses. We can instead use !hasNUsesOrMore(3) which will stop the linear scan as soon as it determines there are at least 3 uses even if there are more.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@340939 91177308-0d34-0410-b5e6-96231b3b80d8
2018-08-29 17:09:21 +00:00
Sanjay Patel
162b59d303 [InstCombine] fix formatting; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@340790 91177308-0d34-0410-b5e6-96231b3b80d8
2018-08-27 23:01:10 +00:00
David Bolvansky
48d2b81f7a [InstCombine] Fold Select with binary op - FP opcodes
Summary:
Follow up for https://reviews.llvm.org/rL339520 and https://reviews.llvm.org/rL338300

Alive:

```
%A = fcmp oeq float %x, 0.0
%B = fadd nsz float %x, %z
%C = select i1 %A, float %B, float %y
=>
%C = select i1 %A, float %z, float %y
----------                                                                      
  %A = fcmp oeq float %x, 0.0
  %B = fadd nsz float %x, %z
  %C = select %A, float %B, float %y
=>
  %C = select %A, float %z, float %y

Done: 1                                                                         
Optimization is correct

%A = fcmp une float %x, -0.0
%B = fadd nsz float %x, %z
%C = select i1 %A, float %y, float %B
=>
%C = select i1 %A, float %y, float %z
----------                                                                      
  %A = fcmp une float %x, -0.0
  %B = fadd nsz float %x, %z
  %C = select %A, float %y, float %B
=>
  %C = select %A, float %y, float %z

Done: 1                                                                         
Optimization is correct
```


Reviewers: spatel, lebedev.ri

Reviewed By: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D50714

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@340538 91177308-0d34-0410-b5e6-96231b3b80d8
2018-08-23 15:22:15 +00:00
Michael Berg
679b18fd6a extend binop folds for selects to include true and false binops flag intersection
Summary: This change address bug 38641

Reviewers: spatel, wristow

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D50996

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@340222 91177308-0d34-0410-b5e6-96231b3b80d8
2018-08-20 22:26:58 +00:00
Craig Topper
b02c526697 [InstCombine] Move some variable declarations into a more appropriate scope. NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@340150 91177308-0d34-0410-b5e6-96231b3b80d8
2018-08-20 05:35:12 +00:00
Michael Berg
86864df093 add a missed case for binary op FMF propagation under select folds
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@339938 91177308-0d34-0410-b5e6-96231b3b80d8
2018-08-16 20:59:45 +00:00
David Bolvansky
9ff5ab2f4e [InstCombine] Fold Select with binary op - non-commutative opcodes
Summary:
Basic version was merged - https://reviews.llvm.org/D49954

This adds support for FP & non-commutative opcodes

Precommited tests: https://reviews.llvm.org/rL338727

Reviewers: spatel, lebedev.ri

Reviewed By: spatel

Subscribers: jfb

Differential Revision: https://reviews.llvm.org/D50190

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@339520 91177308-0d34-0410-b5e6-96231b3b80d8
2018-08-12 17:30:07 +00:00
Sanjay Patel
c5553c47ec [InstCombine] rearrange code for foldSelectBinOpIdentity; NFCI
This is a retry of rL339439 with a fix for the problem that
caused the original commit to be reverted at rL339446. 

That problem was that the compare can be integer while
the binop is FP or vice-versa, so we need to use the binop 
type when we ask for the identity constant.

A test to guard against the problem was added at rL339453.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@339469 91177308-0d34-0410-b5e6-96231b3b80d8
2018-08-10 20:30:35 +00:00
Sanjay Patel
395e45dbe5 [InstCombine] revert r339439 - rearrange code for foldSelectBinOpIdentity
That was supposed to be NFC, but it exposed a logic hole somewhere that
caused bots to fail.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@339446 91177308-0d34-0410-b5e6-96231b3b80d8
2018-08-10 16:12:19 +00:00
Sanjay Patel
abd8586481 [InstCombine] rearrange code for foldSelectBinOpIdentity; NFCI
This should make it easier to folow and to add the planned enhancements
such as D50190.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@339439 91177308-0d34-0410-b5e6-96231b3b80d8
2018-08-10 15:11:26 +00:00
David Bolvansky
a5603d18b0 [InstCombine] Fold Select with binary op
Summary:
Fold
  %A = icmp eq i8 %x, 0
  %B = xor i8 %x, %z
  %C = select i1 %A, i8 %B, i8 %y
To
  %C = select i1 %A, i8 %z, i8 %y

Fixes https://bugs.llvm.org/show_bug.cgi?id=38345
Proof: https://rise4fun.com/Alive/43J

Reviewers: lebedev.ri, spatel

Reviewed By: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D49954

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338300 91177308-0d34-0410-b5e6-96231b3b80d8
2018-07-30 20:38:53 +00:00
Chen Zheng
976b9f9f2d [InstCombine] canonicalize abs pattern
Differential Revision: https://reviews.llvm.org/D48754



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338092 91177308-0d34-0410-b5e6-96231b3b80d8
2018-07-27 01:49:51 +00:00
Chen Zheng
d27cef10a8 [InstCombine] add more SPFofSPF folding
Differential Revision: https://reviews.llvm.org/D49238


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337143 91177308-0d34-0410-b5e6-96231b3b80d8
2018-07-16 02:23:00 +00:00
John Brawn
ebe751f980 [InstCombine] Correct the cmp operand type used when canonicalizing abs/nabs
When adjusting a cmp in order to canonicalize an abs/nabs select pattern we need
to use the type of the existing operand when creating a new operand not the
type of a select operand, as the two may be different.

This fixes PR37686.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334019 91177308-0d34-0410-b5e6-96231b3b80d8
2018-06-05 14:10:55 +00:00
Sanjay Patel
4495104b59 [InstCombine] narrow select to match condition operands' size
This is the planned enhancement to D47163 / rL333611.
We want to match cmp/select sizes because that will be recognized
as min/max more easily and lead to better codegen (especially for
vector types).

As mentioned in D47163, this improves some of the tests that would
also be folded by D46380, so we may want to adjust that patch to
match the new patterns where the extend op occurs after the select.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333689 91177308-0d34-0410-b5e6-96231b3b80d8
2018-05-31 19:55:27 +00:00
Sanjay Patel
42ebf193bc [InstCombine] choose 1 form of abs and nabs as canonical
We already do this for min/max (see the blob above the diff), 
so we should do the same for abs/nabs.
A sign-bit check (<s 0) is used as a predicate for other IR 
transforms and it's likely the best for codegen.

This might solve the motivating cases for D47037 and D47041, 
but I think those patches still make sense. We can't guarantee 
this canonicalization if the icmp has more than one use.

Differential Revision: https://reviews.llvm.org/D47076


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@332819 91177308-0d34-0410-b5e6-96231b3b80d8
2018-05-20 14:23:23 +00:00
Craig Topper
e24d17420c [InstCombine] Qualify a select pattern based transform to restrct to only min/max and ignore abs/nabs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@332770 91177308-0d34-0410-b5e6-96231b3b80d8
2018-05-18 21:21:56 +00:00
Sanjay Patel
b841e3b947 [InstCombine] refine select-of-constants to bitwise ops
Add logic for the special case when a cmp+select can clearly be
reduced to just a bitwise logic instruction, and remove an 
over-reaching chunk of general purpose bit magic. The primary goal 
is to remove cases where we are not improving the IR instruction 
count when doing these select transforms, and in all cases here that 
is true.

In the motivating 3-way compare tests, there are further improvements
because we can combine/propagate select values (not sure if that
belongs in instcombine, but it's there for now).

DAGCombiner has folds to turn some of these selects into bit magic,
so there should be no difference in the end result in those cases.
Not all constant combinations are handled there yet, however, so it
is possible that some targets will see more cmov/csel codegen with
this change in IR canonicalization. 

Ideally, we'll go further to *not* turn selects into multiple 
logic/math ops in instcombine, and we'll canonicalize to selects.
But we should make sure that this step does not result in regressions
first (and if it does, we should fix those in the backend).

The general direction for this change was discussed here:
http://lists.llvm.org/pipermail/llvm-dev/2016-September/105373.html
http://lists.llvm.org/pipermail/llvm-dev/2017-July/114885.html

Alive proofs for the new bit magic:
https://rise4fun.com/Alive/XG7

Differential Revision: https://reviews.llvm.org/D46086


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@331486 91177308-0d34-0410-b5e6-96231b3b80d8
2018-05-03 21:58:44 +00:00
Sanjay Patel
3d8c29de7b [InstCombine] clean up foldSelectICmpAnd(); NFC
As discussed in D45862, we want to delete parts of
this code because it can create more instructions
than it removes. But we also want to preserve some 
folds that are winners, so tidy up what's here to
make splitting the good from bad a bit easier.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@330841 91177308-0d34-0410-b5e6-96231b3b80d8
2018-04-25 16:34:01 +00:00
Roman Lebedev
9f6d594268 [InstCombine]: foldSelectICmpAndAnd(): and is commutative
Summary:
The fold added in D45108 did not account for the fact that
the and instruction is commutative, and if the mask is a variable,
the mask variable and the fold variable may be swapped.

I have noticed this by accident when looking into [[ https://bugs.llvm.org/show_bug.cgi?id=6773 | PR6773 ]]

This extends/generalizes that fold, so it is handled too.

Reviewers: spatel, craig.topper

Reviewed By: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D45539

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@330001 91177308-0d34-0410-b5e6-96231b3b80d8
2018-04-13 09:57:57 +00:00
Roman Lebedev
93f6735875 [InstCombine] Get rid of select of bittest (PR36950 / PR17564)
Summary:
See [[ https://bugs.llvm.org/show_bug.cgi?id=36950 | PR36950 ]], [[ https://bugs.llvm.org/show_bug.cgi?id=17564 | PR17564 ]], D45065, D45107
https://godbolt.org/g/iAYRup

Alive proof: https://rise4fun.com/Alive/uiH

Testing: `ninja check-llvm`

Reviewers: spatel, craig.topper

Reviewed By: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D45108

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@329492 91177308-0d34-0410-b5e6-96231b3b80d8
2018-04-07 10:37:24 +00:00
Sanjay Patel
1017678677 [PatternMatch] allow undef elements when matching vector FP +0.0
This continues the FP constant pattern matching improvements from:
https://reviews.llvm.org/rL327627
https://reviews.llvm.org/rL327339
https://reviews.llvm.org/rL327307

Several integer constant matchers also have this ability. I'm
separating matching of integer/pointer null from FP positive zero
and renaming/commenting to make the functionality clearer.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@328461 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-25 21:16:33 +00:00
Sanjay Patel
bf1689531a [InstCombine] canonicalize fcmp+select to fabs
This is complicated by -0.0 and nan. This is based on the DAG patterns 
as shown in D44091. I'm hoping that we can just remove those DAG folds 
and always rely on IR canonicalization to handle the matching to fabs.

We would still need to delete the broken code from DAGCombiner to fix 
PR36600:
https://bugs.llvm.org/show_bug.cgi?id=36600

Differential Revision: https://reviews.llvm.org/D44550


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@327858 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-19 15:14:30 +00:00
Craig Topper
c4689888d6 [InstCombine] Replace calls to getNumUses with hasNUses or hasNUsesOrMore
getNumUses is a linear time operation. It traverses the user linked list to the end and counts as it goes. Since we are only interested in small constant counts, we should use hasNUses or hasNUsesMore more that terminate the traversal as soon as it can provide the answer.

There are still two other locations in InstCombine, but changing those would force a rebase of D44266 which if accepted would remove them.

Differential Revision: https://reviews.llvm.org/D44398

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@327315 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-12 18:46:05 +00:00
Sanjay Patel
a05c22c9e8 [InstCombine] simplify min/max canonicalization; NFCI
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@326828 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-06 19:01:18 +00:00
Sanjay Patel
3c992c643c [ValueTracking] move helpers for SelectPatterns from InstCombine to ValueTracking
Most of the folds based on SelectPatternResult belong in InstSimplify rather than
InstCombine, so the helper code should be available to other passes/analysis.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@326812 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-06 16:57:55 +00:00
Craig Topper
29dc0262df [InstCombine] Don't fold select(C, Z, binop(select(C, X, Y), W)) -> select(C, Z, binop(Y, W)) if the binop is rem or div.
The select may have been preventing a division by zero or INT_MIN/-1 so removing it might not be safe.

Fixes PR36362.

Differential Revision: https://reviews.llvm.org/D43276

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@325148 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-14 18:08:33 +00:00
Sanjay Patel
50b49991b4 [InstCombine] add unsigned saturation subtraction canonicalizations
This is the instcombine part of unsigned saturation canonicalization.
Backend patches already commited: 
https://reviews.llvm.org/D37510
https://reviews.llvm.org/D37534

It converts unsigned saturated subtraction patterns to forms recognized 
by the backend:
(a > b) ? a - b : 0 -> ((a > b) ? a : b) - b)
(b < a) ? a - b : 0 -> ((a > b) ? a : b) - b)
(b > a) ? 0 : a - b -> ((a > b) ? a : b) - b)
(a < b) ? 0 : a - b -> ((a > b) ? a : b) - b)
((a > b) ? b - a : 0) -> - ((a > b) ? a : b) - b)
((b < a) ? b - a : 0) -> - ((a > b) ? a : b) - b)
((b > a) ? 0 : b - a) -> - ((a > b) ? a : b) - b)
((a < b) ? 0 : b - a) -> - ((a > b) ? a : b) - b)

Patch by Yulia Koval!

Differential Revision: https://reviews.llvm.org/D41480


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324255 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-05 17:53:29 +00:00
John Brawn
9fcafd067a [InstCombine] Make foldSelectOpOp able to handle two-operand getelementptr
Three (or more) operand getelementptrs could plausibly also be handled, but
handling only two-operand fits in easily with the existing BinaryOperator
handling.

Differential Revision: https://reviews.llvm.org/D39958


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@322930 91177308-0d34-0410-b5e6-96231b3b80d8
2018-01-19 10:05:15 +00:00
Sanjay Patel
ae612d7dfd [InstCombine] fold min/max tree with common operand (PR35717)
There is precedence for factorization transforms in instcombine for FP ops with fast-math. 
We also have similar logic in foldSPFofSPF().

It would take more work to add this to reassociate because that's specialized for binops, 
and min/max are not binops (or even single instructions). Also, I don't have evidence that 
larger min/max trees than this exist in real code, but if we find that's true, we might
want to reorganize where/how we do this optimization.

In the motivating example from https://bugs.llvm.org/show_bug.cgi?id=35717 , we have:

int test(int xc, int xm, int xy) {
  int xk;
  if (xc < xm)
    xk = xc < xy ? xc : xy;
  else
    xk = xm < xy ? xm : xy;
  return xk;
}

This patch solves that problem because we recognize more min/max patterns after rL321672

https://rise4fun.com/Alive/Qjne
https://rise4fun.com/Alive/3yg

Differential Revision: https://reviews.llvm.org/D41603


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@321998 91177308-0d34-0410-b5e6-96231b3b80d8
2018-01-08 15:05:34 +00:00
Sanjay Patel
536ffae2c4 [InstCombine] relax use constraint for min/max (~a, ~b) --> ~min/max(a, b)
In the minimal case, this won't remove instructions, but it still improves
uses of existing values.

In the motivating example from PR35834, it does remove instructions, and
sets that case up to be optimized by something like D41603:
https://reviews.llvm.org/D41603


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@321936 91177308-0d34-0410-b5e6-96231b3b80d8
2018-01-06 17:34:22 +00:00
Sanjay Patel
d4ca29bfda [InstCombine] add folds for min(~a, b) --> ~max(a, b)
Besides the bug of omitting the inverse transform of max(~a, ~b) --> ~min(a, b),
the use checking and operand creation were off. We were potentially creating 
repeated identical instructions of existing values. This led to infinite
looping after I added the extra folds.

By using the simpler m_Not matcher and not creating new 'not' ops for a and b,
we avoid that problem. It's possible that not using IsFreeToInvert() here is
more limiting than the simpler matcher, but there are no tests for anything
more exotic. It's also possible that we should relax the use checking further
to handle a case like PR35834:
https://bugs.llvm.org/show_bug.cgi?id=35834
...but we can make that a follow-up if it is needed. 


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@321882 91177308-0d34-0410-b5e6-96231b3b80d8
2018-01-05 19:01:17 +00:00
Craig Topper
0612ed0350 [InstCombine] Simplify binops that are only used by a select and are fed by a select with the same condition.
Summary:
This patch optimizes a binop sandwiched between 2 selects with the same condition. Since we know its only used by the select we can propagate the appropriate input value from the earlier select.

As I'm writing this I realize I may need to avoid doing this for division in case the select was protecting a divide by zero?

Reviewers: spatel, majnemer

Reviewed By: majnemer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D39999

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318267 91177308-0d34-0410-b5e6-96231b3b80d8
2017-11-15 05:23:02 +00:00
Matthew Simpson
4f7d658ee0 [InstCombine] Simplify selects that test cmpxchg instructions
If a select instruction tests the returned flag of a cmpxchg instruction and
selects between the returned value of the cmpxchg instruction and its compare
operand, the result of the select will always be equal to its false value.

Differential Revision: https://reviews.llvm.org/D39383

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316994 91177308-0d34-0410-b5e6-96231b3b80d8
2017-10-31 12:34:02 +00:00
Eugene Zelenko
26ee77f253 [Transforms] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316503 91177308-0d34-0410-b5e6-96231b3b80d8
2017-10-24 21:24:53 +00:00
Craig Topper
783862083c [InstCombine] Move foldSelectICmpAnd helper function earlier in the file to enable reuse in a future patch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312518 91177308-0d34-0410-b5e6-96231b3b80d8
2017-09-05 05:26:37 +00:00
Craig Topper
f10caaa503 [InstCombine] In foldSelectIntoOp, avoid creating a Constant before we know for sure we're going to use it and avoid an unnecessary call to m_APInt.
Instead of creating a Constant and then calling m_APInt with it (which will always return true). Just create an APInt initially, and use that for the checks in isSelect01 function. If it turns out we do need the Constant, create it from the APInt.

This is a refactor for a future patch that will do some more checks of the constant values here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312517 91177308-0d34-0410-b5e6-96231b3b80d8
2017-09-05 05:26:36 +00:00
Craig Topper
85fcd3487c [InstCombine][InstSimplify] Teach decomposeBitTestICmp to look through truncate instructions
This patch teaches decomposeBitTestICmp to look through truncate instructions on the input to the compare. If a truncate is found it will now return the pre-truncated Value and appropriately extend the APInt mask.

This allows some code to be removed from InstSimplify that was doing this functionality.

This allows InstCombine's bit test combining code to match a pre-truncate Value with the same Value appear with an 'and' on another icmp. Or it allows us to combine a truncate to i16 and a truncate to i8. This also required removing the type check from the beginning of getMaskedTypeForICmpPair, but I believe that's ok because we still have to find two values from the input to each icmp that are equal before we'll do any transformation. So the type check was really just serving as an early out.

There was one user of decomposeBitTestICmp that didn't want to look through truncates, so I've added a flag to prevent that behavior when necessary.

Differential Revision: https://reviews.llvm.org/D37158

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312382 91177308-0d34-0410-b5e6-96231b3b80d8
2017-09-01 21:27:34 +00:00
Sanjay Patel
17f4bfb8d0 [InstCombine] remove unnecessary vector select fold; NFCI
This code is double-dead:
1. We simplify all selects with constant true/false condition in InstSimplify.
   I've minimized/moved the tests to show that works as expected.
2. All remaining vector selects with a constant condition are canonicalized to
   shufflevector, so we really can't see this pattern.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312123 91177308-0d34-0410-b5e6-96231b3b80d8
2017-08-30 14:04:57 +00:00
Craig Topper
93198099d3 [InstCombine] Teach foldSelectICmpAndOr to handle vector splats
This was pretty close to working already. While I was here I went ahead and passed the ICmpInst pointer from the caller instead of doing a dyn_cast that can never fail.

Differential Revision: https://reviews.llvm.org/D37237

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@311960 91177308-0d34-0410-b5e6-96231b3b80d8
2017-08-29 00:13:49 +00:00
Craig Topper
ccba49dfc2 [InstCombine] Teach select01 helper of foldSelectIntoOp to handle vector splats
We were handling some vectors in foldSelectIntoOp, but not if the operand of the bin op was any kind of vector constant. This patch fixes it to treat vector splats the same as scalars.

Differential Revision: https://reviews.llvm.org/D37232

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@311940 91177308-0d34-0410-b5e6-96231b3b80d8
2017-08-28 22:00:27 +00:00
Craig Topper
bbbb2f573f [InstCombine] Teach foldSelectICmpAnd to recognize a (icmp slt X, 0) and (icmp sgt X, -1) as equivalent to an and with the sign bit of the truncated type
This is similar to what was already done in foldSelectICmpAndOr. Ultimately I'd like to see if we can call foldSelectICmpAnd from foldSelectIntoOp if we detect a power of 2 constant. This would allow us to remove foldSelectICmpAndOr entirely.

Differential Revision: https://reviews.llvm.org/D36498

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@311362 91177308-0d34-0410-b5e6-96231b3b80d8
2017-08-21 19:02:06 +00:00