Commit Graph

30 Commits

Author SHA1 Message Date
Sanjay Patel 9ef99b4b11 [InstSimplify] fold fcmp (maxnum, X, C1), C2
This is the sibling transform for rL360899 (D61691):

  maxnum(X, GreaterC) == C --> false
  maxnum(X, GreaterC) <= C --> false
  maxnum(X, GreaterC) <  C --> false
  maxnum(X, GreaterC) >= C --> true
  maxnum(X, GreaterC) >  C --> true
  maxnum(X, GreaterC) != C --> true

llvm-svn: 361118
2019-05-19 14:26:39 +00:00
Sanjay Patel 3413035477 [InstSimplify] add tests for fcmp of maxnum with constants; NFC
Sibling tests for rL360899 (D61691).

llvm-svn: 360905
2019-05-16 15:00:11 +00:00
Sanjay Patel 152f81fae8 [InstSimplify] fold fcmp (minnum, X, C1), C2
minnum(X, LesserC) == C --> false
   minnum(X, LesserC) >= C --> false
   minnum(X, LesserC) >  C --> false
   minnum(X, LesserC) != C --> true
   minnum(X, LesserC) <= C --> true
   minnum(X, LesserC) <  C --> true

maxnum siblings will follow if there are no problems here.

We should be able to perform some other combines when the constants
are equal or greater-than too, but that would go in instcombine.

We might also generalize this by creating an FP ConstantRange
(similar to what we do for integers).

Differential Revision: https://reviews.llvm.org/D61691

llvm-svn: 360899
2019-05-16 14:03:10 +00:00
Sanjay Patel b64c48597f [InstSimplify] add tests for fcmp+minnum; NFC
llvm-svn: 360275
2019-05-08 17:53:18 +00:00
Sanjay Patel e088d03b9c [ValueTracking] add logic for known-never-nan with minnum/maxnum
From the LangRef: "Returns NaN only if both operands are NaN."

llvm-svn: 360206
2019-05-07 22:58:31 +00:00
Sanjay Patel 9a1c2b7776 [InstSimplify] add tests for minnum/maxnum and NaN; NFC
llvm-svn: 360197
2019-05-07 21:50:09 +00:00
Eric Christopher cee313d288 Revert "Temporarily Revert "Add basic loop fusion pass.""
The reversion apparently deleted the test/Transforms directory.

Will be re-reverting again.

llvm-svn: 358552
2019-04-17 04:52:47 +00:00
Eric Christopher a863435128 Temporarily Revert "Add basic loop fusion pass."
As it's causing some bot failures (and per request from kbarton).

This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda.

llvm-svn: 358546
2019-04-17 02:12:23 +00:00
Sanjay Patel 68171e3cd6 [InstSimplify] use any-zero matcher for fcmp folds
The m_APFloat matcher does not work with anything but strict
splat vector constants, so we could miss these folds and then
trigger an assertion in instcombine:
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=13201

The previous attempt at this in rL354406 had a logic bug that
actually triggered a regression test failure, but I failed to
notice it the first time.

llvm-svn: 354467
2019-02-20 14:34:00 +00:00
Sanjay Patel 49f97395ab Revert "[InstSimplify] use any-zero matcher for fcmp folds"
This reverts commit 058bb83513.
Forgot to update another test affected by this change.

llvm-svn: 354408
2019-02-20 00:20:38 +00:00
Sanjay Patel 058bb83513 [InstSimplify] use any-zero matcher for fcmp folds
The m_APFloat matcher does not work with anything but strict
splat vector constants, so we could miss these folds and then
trigger an assertion in instcombine:
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=13201

llvm-svn: 354406
2019-02-20 00:09:50 +00:00
Sanjay Patel 9cf04addf3 [InstSimplify] add vector tests for fcmp+fabs; NFC
llvm-svn: 354404
2019-02-19 23:58:02 +00:00
Sanjay Patel d4dc30c20d [InstSimplify] fold 'fcmp nnan ult X, 0.0' when X is not negative
This is the inverted case for the transform added with D53874 / rL345725.

llvm-svn: 345728
2018-10-31 15:35:46 +00:00
Sanjay Patel 85cba3b6fb [InstSimplify] fold 'fcmp nnan oge X, 0.0' when X is not negative
This re-raises some of the open questions about how to apply and use fast-math-flags in IR from PR38086:
https://bugs.llvm.org/show_bug.cgi?id=38086
...but given the current implementation (no FMF on casts), this is likely the only way to predicate the 
transform.

This is part of solving PR39475:
https://bugs.llvm.org/show_bug.cgi?id=39475

Differential Revision: https://reviews.llvm.org/D53874

llvm-svn: 345725
2018-10-31 14:57:23 +00:00
Sanjay Patel 1cd9917edf [InstSimplify] add tests for fcmp and known positive; NFC
llvm-svn: 345722
2018-10-31 14:29:21 +00:00
Sanjay Patel bcde5afcac [InstSimplify] add tests for fcmp folds; NFC
This is part of a problem noted in PR39475:
https://bugs.llvm.org/show_bug.cgi?id=39475

llvm-svn: 345615
2018-10-30 16:58:43 +00:00
Thomas Lively c339250e12 [InstCombine] InstCombine and InstSimplify for minimum and maximum
Summary: Depends on D52765

Reviewers: aheejin, dschuff

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D52766

llvm-svn: 344799
2018-10-19 19:01:26 +00:00
Sanjay Patel f9a0d593e9 [ValueTracking] fix maxnum miscompile for cannotBeOrderedLessThanZero (PR37776)
This adds the NAN checks suggested in PR37776:
https://bugs.llvm.org/show_bug.cgi?id=37776

If both operands to maxnum are NAN, that should get constant folded, so we don't 
have to handle that case. This is the same assumption as other FP ops in this
function. Returning 'false' is always conservatively correct.

Copying from the bug report:

Currently, we have this for "when is cannotBeOrderedLessThanZero 
(mustBePositiveOrNaN) true for maxnum":
               L
        -------------------
        | Pos | Neg | NaN |
   ------------------------
   |Pos |  x  |  x  |  x  |
   ------------------------
 R |Neg |  x  |     |  x  |
   ------------------------
   |NaN |  x  |  x  |  x  |
   ------------------------


The cases with (Neg & NaN) are wrong. We should have:

                L
        -------------------
        | Pos | Neg | NaN |
   ------------------------
   |Pos |  x  |  x  |  x  |
   ------------------------
 R |Neg |  x  |     |     |
   ------------------------
   |NaN |  x  |     |  x  |
   ------------------------

Differential Revision: https://reviews.llvm.org/D50081

llvm-svn: 338716
2018-08-02 13:46:20 +00:00
Sanjay Patel fae8ed0104 [InstSimplify] add fixme comment for PR37776; NFC
llvm-svn: 337129
2018-07-15 16:13:58 +00:00
Sanjay Patel 1dbb6b7282 [PatternMatch] enhance m_NaN() to ignore undef elements in vectors
llvm-svn: 327339
2018-03-12 22:18:47 +00:00
Sanjay Patel 5b034c83d6 [InstSimplify] add fcmp tests for constant NaN vector with undef elt; NFC
llvm-svn: 327335
2018-03-12 21:44:17 +00:00
Florian Hahn 30932a3c16 [InstSimplify] More fcmp cases when comparing against negative constants.
Summary:
For known positive non-zero value X:
    fcmp uge X, -C => true
    fcmp ugt X, -C => true
    fcmp une X, -C => true
    fcmp oeq X, -C => false
    fcmp ole X, -C => false
    fcmp olt X, -C => false


Patch by Paul Walker.

Reviewers: majnemer, t.p.northover, spatel, RKSimon

Reviewed By: spatel

Subscribers: fhahn, llvm-commits

Differential Revision: https://reviews.llvm.org/D40012

llvm-svn: 319538
2017-12-01 12:34:16 +00:00
Sanjay Patel 178b70a3de [InstSimplify] add fcmp with negative constant tests; NFC
This is a superset of the tests proposed with D40012 to show another potential improvement.

llvm-svn: 319041
2017-11-27 16:08:34 +00:00
Sanjay Patel 69ac66cf8b [InstSimplify] regenerate checks; NFC
llvm-svn: 312413
2017-09-02 14:38:15 +00:00
Sanjay Patel 16019c5a68 [InstSimplify] move fcmp simplification tests from InstCombine
These are all tests that result in a constant, so moving the tests over to where they are actually handled.

llvm-svn: 312411
2017-09-02 14:27:00 +00:00
Andrea Di Biagio 805815f407 [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

llvm-svn: 280488
2016-09-02 14:47:43 +00:00
Sanjay Patel 69632447b1 [InstSimplify] regenerate checks using a script
I didn't notice any significant changes in the actual checks here;
all of these tests already used FileCheck, so a script can batch
update them in one shot.

This commit is just to show the value of automating this process: 
We have uniform formatting as opposed to a mish-mash of check
structure that changes based on individual prefs and the current
fashion. This makes it simpler to update when we find a bug or
make an enhancement.

llvm-svn: 264457
2016-03-25 20:12:25 +00:00
Fiona Glaser db7824f0c1 CannotBeOrderedLessThanZero: add some missing cases
llvm-svn: 257542
2016-01-12 23:37:30 +00:00
Benjamin Kramer f4ebfa3ae1 [InstSimplify] Fold away ord/uno fcmps when nnan is present.
This is important to fold away the slow case of complex multiplies
emitted by clang.

llvm-svn: 241911
2015-07-10 14:02:02 +00:00
Elena Demikhovsky 45f0448081 Fold fcmp in cases where value is provably non-negative. By Arch Robison.
This patch folds fcmp in some cases of interest in Julia. The patch adds a function CannotBeOrderedLessThanZero that returns true if a value is provably not less than zero. I.e. the function returns true if the value is provably -0, +0, positive, or a NaN. The patch extends InstructionSimplify.cpp to fold instances of fcmp where:
 - the predicate is olt or uge
 - the first operand is provably not less than zero
 - the second operand is zero
The motivation for handling these cases optimizing away domain checks for sqrt in Julia for common idioms such as sqrt(x*x+y*y)..

http://reviews.llvm.org/D6972

llvm-svn: 227298
2015-01-28 08:03:58 +00:00