Commit Graph

62 Commits

Author SHA1 Message Date
Sanjay Patel 03da6e6a62 [ValueTracking] add tests for fmin/fmax; NFC
llvm-svn: 345777
2018-10-31 21:11:59 +00:00
Thomas Lively 30f1d69115 [NFC] Rename minnan and maxnan to minimum and maximum
Summary:
Changes all uses of minnan/maxnan to minimum/maximum
globally. These names emphasize that the semantic difference between
these operations is more than just NaN-propagation.

Reviewers: arsenm, aheejin, dschuff, javed.absar

Subscribers: jholewinski, sdardis, wdng, sbc100, jgravelle-google, jrtc27, atanasyan, llvm-commits

Differential Revision: https://reviews.llvm.org/D53112

llvm-svn: 345218
2018-10-24 22:49:55 +00:00
Thomas Lively d47b5c7bed [ValueTracking] Allow select patterns to work on FP vectors
Summary:
This CL allows constant vectors of floats to be recognized as non-NaN
and non-zero in select patterns. This change makes
`matchSelectPattern` more powerful generally, but was motivated
specifically because I wanted fminnan and fmaxnan to be created for
vector versions of the scalar patterns they are created for.

Tested with check-all on all targets. A testcase in the WebAssembly
backend that tests the non-nan codepath is in an upcoming CL.

Reviewers: aheejin, dschuff

Subscribers: sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D52324

llvm-svn: 343364
2018-09-28 21:36:43 +00:00
Simon Dardis 70dbd5fbd0 Infer lowest bits of an integer Multiply when the low bits of the operands are known
When the lowest bits of the operands to an integer multiply are known, the low bits of the result are deducible.
Code to deduce known-zero bottom bits already existed, but this change improves on that by deducing known-ones.

Patch by: Pedro Ferreira

Reviewers: craig.topper, sanjoy, efriedma

Differential Revision: https://reviews.llvm.org/D34029

llvm-svn: 320269
2017-12-09 23:25:57 +00:00
Craig Topper 8580cd4e1a [ValueTracking] Avoid undefined behavior in unittest by not making a named ArrayRef from a std::initializer_list
One of the ValueTracking unittests creates a named ArrayRef initialized by a std::initializer_list. The underlying array for an std::initializer_list is only guaranteed to have a lifetime as long as the initializer_list object itself. So this can leave the ArrayRef pointing at an array that no long exists.

This fixes this to just create an explicit array instead of an ArrayRef.

Differential Revision: https://reviews.llvm.org/D32089

llvm-svn: 300354
2017-04-14 17:59:19 +00:00
Sanjoy Das 4897cea4ed Fix signed-unsigned comparison warning
llvm-svn: 296274
2017-02-25 22:25:48 +00:00
Sanjoy Das 39a684d117 [ValueTracking] Don't do an unchecked shift in ComputeNumSignBits
Summary:
Previously we used to return a bogus result, 0, for IR like `ashr %val,
-1`.

I've also added an assert checking that `ComputeNumSignBits` at least
returns 1.  That assert found an already checked in test case where we
were returning a bad result for `ashr %val, -1`.

Fixes PR32045.

Reviewers: spatel, majnemer

Reviewed By: spatel, majnemer

Subscribers: efriedma, mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D30311

llvm-svn: 296273
2017-02-25 20:30:45 +00:00
Sanjoy Das 3bb2dbd665 Fix an issue with isGuaranteedToTransferExecutionToSuccessor
I'm not sure if this was intentional, but today
isGuaranteedToTransferExecutionToSuccessor returns true for readonly and
argmemonly calls that may throw.  This commit changes the function to
not implicitly infer nounwind this way.

Even if we eventually specify readonly calls as not throwing,
isGuaranteedToTransferExecutionToSuccessor is not the best place to
infer that.  We should instead teach FunctionAttrs or some other such
pass to tag readonly functions / calls as nounwind instead.

llvm-svn: 290794
2016-12-31 22:12:34 +00:00
Mehdi Amini 03b42e41bf Remove every uses of getGlobalContext() in LLVM (but the C API)
At the same time, fixes InstructionsTest::CastInst unittest: yes
you can leave the IR in an invalid state and exit when you don't
destroy the context (like the global one), no longer now.

This is the first part of http://reviews.llvm.org/D19094

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266379
2016-04-14 21:59:01 +00:00
James Molloy 687a8448f4 [ValueTracking] Minor comment change in test
This test was updated in r246678 - fix a copypasta in a comment noticed post-commit.

llvm-svn: 246679
2015-09-02 17:29:54 +00:00
James Molloy 569cea65f0 [ValueTracking] Look through casts when both operands are casts.
We only looked through casts when one operand was a constant. We can also look through casts when both operands are non-constant, but both are in fact the same cast type. For example:

%1 = icmp ult i8 %a, %b
%2 = zext i8 %a to i32
%3 = zext i8 %b to i32
%4 = select i1 %1, i32 %2, i32 %3

llvm-svn: 246678
2015-09-02 17:25:25 +00:00
James Molloy 134bec2722 Add support for floating-point minnum and maxnum
The select pattern recognition in ValueTracking (as used by InstCombine
and SelectionDAGBuilder) only knew about integer patterns. This teaches
it about minimum and maximum operations.

matchSelectPattern() has been extended to return a struct containing the
existing Flavor and a new enum defining the pattern's behavior when
given one NaN operand.

C minnum() is defined to return the non-NaN operand in this case, but
the idiomatic C "a < b ? a : b" would return the NaN operand.

ARM and AArch64 at least have different instructions for these different cases.

llvm-svn: 244580
2015-08-11 09:12:57 +00:00