Commit Graph

339 Commits

Author SHA1 Message Date
David Bolvansky
cd93c4ef1a [InstCombine] snprintf optimizations
Reviewers: spatel, efriedma, majnemer, rja, bkramer

Reviewed By: rja, bkramer

Subscribers: mstorsjo, rja, llvm-commits

Differential Revision: https://reviews.llvm.org/D46285

llvm-svn: 332110
2018-05-11 17:50:49 +00:00
Martin Storsjo
86e6742c17 Revert "[InstCombine] snprintf optimizations"
This reverts commit SVN r331889, which could trigger failed
assertions for cases where the snprintf function is declared
with a vaguely differing signature (e.g. being defined as
static inline), see PR37408.

llvm-svn: 332043
2018-05-10 21:23:36 +00:00
David Bolvansky
9b5e6e8288 [InstCombine] snprintf optimizations
Reviewers: spatel, efriedma, majnemer, rja, bkramer

Reviewed By: rja, bkramer

Subscribers: rja, llvm-commits

Differential Revision: https://reviews.llvm.org/D46285

llvm-svn: 331889
2018-05-09 16:09:31 +00:00
Benjamin Kramer
ccb0fbe9a0 Revert "[InstCombine] snprintf optimizations"
This reverts commit r331849. It miscompiles
snprintf(buf, sizeof(buf), "%s", "any constant string); into
memcpy(buf, "%s", sizeof("any constant string"));

llvm-svn: 331866
2018-05-09 11:38:57 +00:00
David Bolvansky
44a37f04b2 [InstCombine] snprintf optimizations
Reviewers: spatel, efriedma, majnemer, rja

Reviewed By: rja

Subscribers: rja, llvm-commits

Differential Revision: https://reviews.llvm.org/D46285

llvm-svn: 331849
2018-05-09 06:34:20 +00:00
Matt Morehouse
1ae1febfde Revert "[SimplifyLibcalls] Replace locked IO with unlocked IO"
This reverts r331002 due to sanitizer bot breakage.

llvm-svn: 331011
2018-04-27 01:48:09 +00:00
David Bolvansky
2c9cc9c731 [SimplifyLibcalls] Replace locked IO with unlocked IO
Summary: If file stream arg is not captured and source is fopen, we could replace IO calls by unlocked IO ("_unlocked" function variants) to gain better speed,

Reviewers: efriedma, RKSimon, spatel, sanjoy, hfinkel, majnemer

Subscribers: lebedev.ri, llvm-commits

Differential Revision: https://reviews.llvm.org/D45736

llvm-svn: 331002
2018-04-26 22:31:43 +00:00
David Bolvansky
cb8ca5f37c [SimplifyLibcalls] Atoi, strtol replacements
Reviewers: spatel, lebedev.ri, xbolva00, efriedma

Reviewed By: xbolva00, efriedma

Subscribers: efriedma, llvm-commits

Differential Revision: https://reviews.llvm.org/D45418

llvm-svn: 330860
2018-04-25 18:58:53 +00:00
Sanjay Patel
b2ab3f28d5 [SimplifyLibcalls] Realloc(null, N) -> Malloc(N)
Patch by Dávid Bolvanský!

Differential Revision: https://reviews.llvm.org/D45413

llvm-svn: 330259
2018-04-18 14:21:31 +00:00
David Blaikie
2be3922807 Fix a couple of layering violations in Transforms
Remove #include of Transforms/Scalar.h from Transform/Utils to fix layering.

Transforms depends on Transforms/Utils, not the other way around. So
remove the header and the "createStripGCRelocatesPass" function
declaration (& definition) that is unused and motivated this dependency.

Move Transforms/Utils/Local.h into Analysis because it's used by
Analysis/MemoryBuiltins.cpp.

llvm-svn: 328165
2018-03-21 22:34:23 +00:00
Craig Topper
2915bc0046 [SimplifyLibCalls] Update an obviously copy and pasted header comment to match this file. NFC
llvm-svn: 326475
2018-03-01 20:05:09 +00:00
Daniel Neilson
8acd8b036c [SimplifyLibCalls] Update from deprecated IRBuilder API for creating memory intrinsics (NFC)
Summary:
This change is part of step five in the series of changes to remove alignment argument from
memcpy/memmove/memset in favour of alignment attributes. In particular, this changes the
SimplifyLibCalls pass to cease using the old IRBuilder createMemCpy/createMemMove
single-alignment APIs in favour of the new API that allows setting source and destination
alignments independently.

Steps:
Step 1) Remove alignment parameter and create alignment parameter attributes for
memcpy/memmove/memset. ( rL322965, rC322964, rL322963 )
Step 2) Expand the IRBuilder API to allow creation of memcpy/memmove with differing
source and dest alignments. ( rL323597 )
Step 3) Update Clang to use the new IRBuilder API. ( rC323617 )
Step 4) Update Polly to use the new IRBuilder API. ( rL323618 )
Step 5) Update LLVM passes that create memcpy/memmove calls to use the new IRBuilder API,
and those that use use MemIntrinsicInst::[get|set]Alignment() to use [get|set]DestAlignment()
and [get|set]SourceAlignment() instead. ( rL323886, rL323891, r3L24148 )
Step 6) Remove the single-alignment IRBuilder API for memcpy/memmove, and the
MemIntrinsicInst::[get|set]Alignment() methods.

Reference
   http://lists.llvm.org/pipermail/llvm-dev/2015-August/089384.html
   http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151109/312083.html

llvm-svn: 324273
2018-02-05 21:23:22 +00:00
Dmitry Venikov
e5fbf591a7 [InstCombine] Missed optimization in math expression: sin(x) / cos(x) => tan(x)
Summary: This patch enables folding sin(x) / cos(x) -> tan(x), cos(x) / sin(x) -> 1 / tan(x) under -ffast-math flag

Reviewers: hfinkel, spatel

Reviewed By: spatel

Subscribers: andrew.w.kaylor, efriedma, scanon, llvm-commits

Differential Revision: https://reviews.llvm.org/D41286

llvm-svn: 322255
2018-01-11 06:33:00 +00:00
Hal Finkel
2ff24731bb [SimplifyLibCalls] Inline calls to cabs when it's safe to do so
When unsafe algerbra is allowed calls to cabs(r) can be replaced by:

  sqrt(creal(r)*creal(r) + cimag(r)*cimag(r))

Patch by Paul Walker, thanks!

Differential Revision: https://reviews.llvm.org/D40069

llvm-svn: 320901
2017-12-16 01:26:25 +00:00
Sanjay Patel
b23e148114 [SimplifyLibCalls] propagate FMF when folding pow(x, -1.0) call
Follow-up for a bug that's similar to:
https://bugs.llvm.org/show_bug.cgi?id=35601

llvm-svn: 320312
2017-12-10 17:25:54 +00:00
Sanjay Patel
09ec34349a [SimplifyLibCalls] propagate FMF when folding pow(x, 2.0) call (PR35601)
This should fix the larger problem with sqrt shown in:
https://bugs.llvm.org/show_bug.cgi?id=35601

llvm-svn: 320310
2017-12-10 16:52:26 +00:00
Sanjay Patel
9771a96f6e [LibCallSimplifier] allow splat vectors for pow(x, 0.5) -> sqrt() transforms
llvm-svn: 318629
2017-11-19 16:42:27 +00:00
Sanjay Patel
fbd3e66b9a [LibCallSimplifier] partly fix pow(x, 0.5) -> sqrt() transforms
As the first test shows, we could transform an llvm intrinsic which never sets errno 
into a libcall which could set errno (even though it's marked readnone?), so that's 
not ideal.

It's possible that we can also transform a libcall which could set errno to an
intrinsic given the fast-math-flags constraint, but that's deferred to determine
exactly which set of FMF are needed.

Differential Revision: https://reviews.llvm.org/D40150

llvm-svn: 318628
2017-11-19 16:13:14 +00:00
Sanjay Patel
629c411538 [IR] redefine 'UnsafeAlgebra' / 'reassoc' fast-math-flags and add 'trans' fast-math-flag
As discussed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2016-November/107104.html
and again more recently:
http://lists.llvm.org/pipermail/llvm-dev/2017-October/118118.html

...this is a step in cleaning up our fast-math-flags implementation in IR to better match
the capabilities of both clang's user-visible flags and the backend's flags for SDNode.

As proposed in the above threads, we're replacing the 'UnsafeAlgebra' bit (which had the 
'umbrella' meaning that all flags are set) with a new bit that only applies to algebraic 
reassociation - 'AllowReassoc'.

We're also adding a bit to allow approximations for library functions called 'ApproxFunc' 
(this was initially proposed as 'libm' or similar).

...and we're out of bits. 7 bits ought to be enough for anyone, right? :) FWIW, I did 
look at getting this out of SubclassOptionalData via SubclassData (spacious 16-bits), 
but that's apparently already used for other purposes. Also, I don't think we can just 
add a field to FPMathOperator because Operator is not intended to be instantiated. 
We'll defer movement of FMF to another day.

We keep the 'fast' keyword. I thought about removing that, but seeing IR like this:
%f.fast = fadd reassoc nnan ninf nsz arcp contract afn float %op1, %op2
...made me think we want to keep the shortcut synonym.

Finally, this change is binary incompatible with existing IR as seen in the 
compatibility tests. This statement:
"Newer releases can ignore features from older releases, but they cannot miscompile 
them. For example, if nsw is ever replaced with something else, dropping it would be 
a valid way to upgrade the IR." 
( http://llvm.org/docs/DeveloperPolicy.html#ir-backwards-compatibility )
...provides the flexibility we want to make this change without requiring a new IR 
version. Ie, we're not loosening the FP strictness of existing IR. At worst, we will 
fail to optimize some previously 'fast' code because it's no longer recognized as 
'fast'. This should get fixed as we audit/squash all of the uses of 'isFast()'.

Note: an inter-dependent clang commit to use the new API name should closely follow 
commit.

Differential Revision: https://reviews.llvm.org/D39304

llvm-svn: 317488
2017-11-06 16:27:15 +00:00
Vivek Pandya
9590658fb8 [NFC] Convert OptimizationRemarkEmitter old emit() calls to new closure
parameterized emit() calls

Summary: This is not functional change to adopt new emit() API added in r313691.

Reviewed By: anemet

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D38285

llvm-svn: 315476
2017-10-11 17:12:59 +00:00
Adam Nemet
0965da2055 Rename OptimizationDiagnosticInfo.* to OptimizationRemarkEmitter.*
Sync it up with the name of the class actually defined here.  This has been
bothering me for a while...

llvm-svn: 315249
2017-10-09 23:19:02 +00:00
Matthias Braun
cc603ee3d5 TargetLibraryInfo: Stop guessing wchar_t size
Usually the frontend communicates the size of wchar_t via metadata and
we can optimize wcslen (and possibly other calls in the future). In
cases without the wchar_size metadata we would previously try to guess
the correct size based on the target triple; however this is fragile to
keep up to date and may miss users manually changing the size via flags.
Better be safe and stop guessing and optimizing if the frontend didn't
communicate the size.

Differential Revision: https://reviews.llvm.org/D38106

llvm-svn: 314185
2017-09-26 02:36:57 +00:00
Sanjay Patel
82ec872990 [LibCallSimplifier] try harder to fold memcmp with constant arguments (2nd try)
The 1st try was reverted because it could inf-loop by creating a dead instruction.
Fixed that to not happen and added a test case to verify.

Original commit message:

Try to fold:
memcmp(X, C, ConstantLength) == 0 --> load X == *C

Without this change, we're unnecessarily checking the alignment of the constant data,
so we miss the transform in the first 2 tests in the patch.

I noted this shortcoming of LibCallSimpifier in one of the recent CGP memcmp expansion
patches. This doesn't help the example in:
https://bugs.llvm.org/show_bug.cgi?id=34032#c13
...directly, but it's worth short-circuiting more of these simple cases since we're
already trying to do that.

The benefit of transforming to load+cmp is that existing IR analysis/transforms may
further simplify that code. For example, if the load of the variable is common to
multiple memcmp calls, CSE can remove the duplicate instructions.

Differential Revision: https://reviews.llvm.org/D36922

llvm-svn: 311366
2017-08-21 19:13:14 +00:00
Sanjay Patel
707f786cc5 revert r311333: [LibCallSimplifier] try harder to fold memcmp with constant arguments
We're getting lots of compile-timeout bot failures like:
http://lab.llvm.org:8011/builders/clang-native-arm-lnt/builds/7119
http://lab.llvm.org:8011/builders/clang-cmake-x86_64-avx2-linux

llvm-svn: 311340
2017-08-21 15:16:25 +00:00
Sanjay Patel
7756edfa93 [LibCallSimplifier] try harder to fold memcmp with constant arguments
Try to fold:
memcmp(X, C, ConstantLength) == 0 --> load X == *C

Without this change, we're unnecessarily checking the alignment of the constant data, 
so we miss the transform in the first 2 tests in the patch.

I noted this shortcoming of LibCallSimpifier in one of the recent CGP memcmp expansion 
patches. This doesn't help the example in:
https://bugs.llvm.org/show_bug.cgi?id=34032#c13
...directly, but it's worth short-circuiting more of these simple cases since we're 
already trying to do that.

The benefit of transforming to load+cmp is that existing IR analysis/transforms may
further simplify that code. For example, if the load of the variable is common to 
multiple memcmp calls, CSE can remove the duplicate instructions.

Differential Revision: https://reviews.llvm.org/D36922

llvm-svn: 311333
2017-08-21 13:55:49 +00:00
Andrew Kaylor
53a5fbb45f Add strictfp attribute to prevent unwanted optimizations of libm calls
Differential Revision: https://reviews.llvm.org/D34163

llvm-svn: 310885
2017-08-14 21:15:13 +00:00
Adam Nemet
ea06e6e865 Migrate SimplifyLibCalls to new OptimizationRemarkEmitter
Summary:
This changes SimplifyLibCalls to use the new OptimizationRemarkEmitter
API.

In fact, as SimplifyLibCalls is only ever called via InstCombine,
(as far as I can tell) the OptimizationRemarkEmitter is added there,
and then passed through to SimplifyLibCalls later.

I have avoided changing any remark text.

This closes PR33787

Patch by Sam Elliott!

Reviewers: anemet, davide

Reviewed By: anemet

Subscribers: davide, mehdi_amini, eraman, fhahn, llvm-commits

Differential Revision: https://reviews.llvm.org/D35608

llvm-svn: 309158
2017-07-26 19:03:18 +00:00
Craig Topper
79ab643da8 [Constants] If we already have a ConstantInt*, prefer to use isZero/isOne/isMinusOne instead of isNullValue/isOneValue/isAllOnesValue inherited from Constant. NFCI
Going through the Constant methods requires redetermining that the Constant is a ConstantInt and then calling isZero/isOne/isMinusOne.

llvm-svn: 307292
2017-07-06 18:39:47 +00:00
Sanjay Patel
70db424601 [SimplifyLibCalls] fix formatting; NFC
llvm-svn: 305081
2017-06-09 14:22:03 +00:00
Zaara Syeda
3a7578c658 [PPC] Inline expansion of memcmp
This patch does an inline expansion of memcmp.
It changes the memcmp library call into an inline expansion when the size is
known at compile time and is under a target specified threshold.
This expansion is implemented in CodeGenPrepare and expands into straight line
code. The target specifies a maximum load size and the expansion works by using
this size to load the two sources, compare, and exit early if a difference is
found. It also has a special case when the memcmp result is used in a compare
to zero equality.

Differential Revision: https://reviews.llvm.org/D28637

llvm-svn: 304313
2017-05-31 17:12:38 +00:00
Craig Topper
8205a1a9b6 [ValueTracking] Convert most of the calls to computeKnownBits to use the version that returns the KnownBits object.
This continues the changes started when computeSignBit was replaced with this new version of computeKnowBits.

Differential Revision: https://reviews.llvm.org/D33431

llvm-svn: 303773
2017-05-24 16:53:07 +00:00
Matthias Braun
50ec0b5dce SimplifyLibCalls: Optimize wcslen
Refactor the strlen optimization code to work for both strlen and wcslen.

This especially helps with programs in the wild where people pass
L"string"s to const std::wstring& function parameters and the wstring
constructor gets inlined.

This also fixes a lingerind API problem/bug in getConstantStringInfo()
where zeroinitializers would always give you an empty string (without a
length) back regardless of the actual length of the initializer which
did not work well in the TrimAtNul==false causing the PR mentioned
below.

Note that the fixed getConstantStringInfo() needed fixes to SelectionDAG
memcpy lowering and may lead to some cases for out-of-bounds
zeroinitializer accesses not getting optimized anymore. So some code
with UB may produce out of bound memory reads now instead of just
producing zeros.

The refactoring "accidentally" fixes http://llvm.org/PR32124

Differential Revision: https://reviews.llvm.org/D32839

llvm-svn: 303461
2017-05-19 22:37:09 +00:00
Serge Guelton
e38003f839 Suppress all uses of LLVM_END_WITH_NULL. NFC.
Use variadic templates instead of relying on <cstdarg> + sentinel.
This enforces better type checking and makes code more readable.

Differential Revision: https://reviews.llvm.org/D32541

llvm-svn: 302571
2017-05-09 19:31:13 +00:00
Reid Kleckner
a0b45f4bfc [IR] Abstract away ArgNo+1 attribute indexing as much as possible
Summary:
Do three things to help with that:
- Add AttributeList::FirstArgIndex, which is an enumerator currently set
  to 1. It allows us to change the indexing scheme with fewer changes.
- Add addParamAttr/removeParamAttr. This just shortens addAttribute call
  sites that would otherwise need to spell out FirstArgIndex.
- Remove some attribute-specific getters and setters from Function that
  take attribute list indices.  Most of these were only used from
  BuildLibCalls, and doesNotAlias was only used to test or set if the
  return value is malloc-like.

I'm happy to split the patch, but I think they are probably easier to
review when taken together.

This patch should be NFC, but it sets the stage to change the indexing
scheme to this, which is more convenient when indexing into an array:
  0: func attrs
  1: retattrs
  2...: arg attrs

Reviewers: chandlerc, pete, javed.absar

Subscribers: david2050, llvm-commits

Differential Revision: https://reviews.llvm.org/D32811

llvm-svn: 302060
2017-05-03 18:17:31 +00:00
Craig Topper
b45eabcf82 [ValueTracking] Introduce a KnownBits struct to wrap the two APInts for computeKnownBits
This patch introduces a new KnownBits struct that wraps the two APInt used by computeKnownBits. This allows us to treat them as more of a unit.

Initially I've just altered the signatures of computeKnownBits and InstCombine's simplifyDemandedBits to pass a KnownBits reference instead of two separate APInt references. I'll do similar to the SelectionDAG version of computeKnownBits/simplifyDemandedBits as a separate patch.

I've added a constructor that allows initializing both APInts to the same bit width with a starting value of 0. This reduces the repeated pattern of initializing both APInts. Once place default constructed the APInts so I added a default constructor for those cases.

Going forward I would like to add more methods that will work on the pairs. For example trunc, zext, and sext occur on both APInts together in several places. We should probably add a clear method that can be used to clear both pieces. Maybe a method to check for conflicting information. A method to return (Zero|One) so we don't write it out everywhere. Maybe a method for (Zero|One).isAllOnesValue() to determine if all bits are known. I'm sure there are many other methods we can come up with.

Differential Revision: https://reviews.llvm.org/D32376

llvm-svn: 301432
2017-04-26 16:39:58 +00:00
Matthias Braun
c36a78c3f3 SimplifyLibCalls: Fix crash on memset(notmalloc())
rdar://31520787

llvm-svn: 301352
2017-04-25 19:44:25 +00:00
Andrew Ng
1606fc0bf9 [SimplifyLibCalls] Fix infinite loop with fast-math optimization.
One of the fast-math optimizations is to replace calls to standard double
functions with their float equivalents, e.g. exp -> expf. However, this can
cause infinite loops for the following:

  float expf(float val) { return (float) exp((double) val); }

A similar inline declaration exists in the MinGW-w64 math.h header file which
when compiled with -O2/3 and fast-math generates infinite loops.

So this fix checks that the calling function to the standard double function
that is being replaced does not match the float equivalent.

Differential Revision: https://reviews.llvm.org/D31806

llvm-svn: 301304
2017-04-25 12:36:14 +00:00
Davide Italiano
5b65f12bfa [SimplifyLibCalls] Remove a cl::opt that's been true for a long time.
llvm-svn: 301288
2017-04-25 03:48:47 +00:00
Serge Guelton
59a2d7b909 Module::getOrInsertFunction is using C-style vararg instead of variadic templates.
From a user prospective, it forces the use of an annoying nullptr to mark the end of the vararg, and there's not type checking on the arguments.
The variadic template is an obvious solution to both issues.

Differential Revision: https://reviews.llvm.org/D31070

llvm-svn: 299949
2017-04-11 15:01:18 +00:00
Diana Picus
b050c7fbe0 Revert "Turn some C-style vararg into variadic templates"
This reverts commit r299925 because it broke the buildbots. See e.g.
http://lab.llvm.org:8011/builders/clang-cmake-armv7-a15/builds/6008

llvm-svn: 299928
2017-04-11 10:07:12 +00:00
Serge Guelton
5fd75fb72e Turn some C-style vararg into variadic templates
Module::getOrInsertFunction is using C-style vararg instead of
variadic templates.

From a user prospective, it forces the use of an annoying nullptr
to mark the end of the vararg, and there's not type checking on the
arguments. The variadic template is an obvious solution to both
issues.

llvm-svn: 299925
2017-04-11 08:36:52 +00:00
Mehdi Amini
db11fdfda5 Revert "Turn some C-style vararg into variadic templates"
This reverts commit r299699, the examples needs to be updated.

llvm-svn: 299702
2017-04-06 20:23:57 +00:00
Mehdi Amini
579540a8f7 Turn some C-style vararg into variadic templates
Module::getOrInsertFunction is using C-style vararg instead of
variadic templates.

From a user prospective, it forces the use of an annoying nullptr
to mark the end of the vararg, and there's not type checking on the
arguments. The variadic template is an obvious solution to both
issues.

Patch by: Serge Guelton <serge.guelton@telecom-bretagne.eu>

Differential Revision: https://reviews.llvm.org/D31070

llvm-svn: 299699
2017-04-06 20:09:31 +00:00
Joerg Sonnenberger
28bed106e0 Do not translate rint into nearbyint, but truncate it like nearbyint.
A common way to implement nearbyint is by fiddling with the floating
point environment and calling rint. This is used at least by the BSD
libm and musl. As such, canonicalizing the latter to the former will
create infinite loops for libm and generally pessimize performance, at
least when the generic C versions are used.

This change preserves the rint in the libcall translation and also
handles the domain truncation logic, so that rint with float argument
will be reduced to rintf etc.

llvm-svn: 299247
2017-03-31 19:58:07 +00:00
Reid Kleckner
b518054b87 Rename AttributeSet to AttributeList
Summary:
This class is a list of AttributeSetNodes corresponding the function
prototype of a call or function declaration. This class used to be
called ParamAttrListPtr, then AttrListPtr, then AttributeSet. It is
typically accessed by parameter and return value index, so
"AttributeList" seems like a more intuitive name.

Rename AttributeSetImpl to AttributeListImpl to follow suit.

It's useful to rename this class so that we can rename AttributeSetNode
to AttributeSet later. AttributeSet is the set of attributes that apply
to a single function, argument, or return value.

Reviewers: sanjoy, javed.absar, chandlerc, pete

Reviewed By: pete

Subscribers: pete, jholewinski, arsenm, dschuff, mehdi_amini, jfb, nhaehnle, sbc100, void, llvm-commits

Differential Revision: https://reviews.llvm.org/D31102

llvm-svn: 298393
2017-03-21 16:57:19 +00:00
Justin Lebar
cb9b41dd76 [LangRef] Make @llvm.sqrt(x) return undef, rather than have UB, for negative x.
Summary:
Some frontends emit a speculate-and-select idiom for sqrt, wherein they compute
sqrt(x), check if x is negative, and select NaN if it is:

  %cmp = fcmp olt double %a, -0.000000e+00
  %sqrt = call double @llvm.sqrt.f64(double %a)
  %ret = select i1 %cmp, double 0x7FF8000000000000, double %sqrt

This is technically UB as the LangRef is written today if %a is ever less than
-0.  But emitting code that's compliant with the current definition of sqrt
would require a branch, which would then prevent us from matching this idiom in
SelectionDAG (which we do today -- ISD::FSQRT has defined behavior on negative
inputs), because SelectionDAG looks at one BB at a time.

Nothing in LLVM takes advantage of this undefined behavior, as far as we can
tell, and the fact that llvm.sqrt has UB dates from its initial addition to the
LangRef.

Reviewers: arsenm, mehdi_amini, hfinkel

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D28797

llvm-svn: 293242
2017-01-27 00:58:03 +00:00
Matt Arsenault
954a624fb9 SimplifyLibCalls: Replace more unary libcalls with intrinsics
llvm-svn: 292855
2017-01-23 23:55:08 +00:00
David L. Jones
d21529fa0d [Analysis] Add LibFunc_ prefix to enums in TargetLibraryInfo. (NFC)
Summary:
The LibFunc::Func enum holds enumerators named for libc functions.
Unfortunately, there are real situations, including libc implementations, where
function names are actually macros (musl uses "#define fopen64 fopen", for
example; any other transitively visible macro would have similar effects).

Strictly speaking, a conforming C++ Standard Library should provide any such
macros as functions instead (via <cstdio>). However, there are some "library"
functions which are not part of the standard, and thus not subject to this
rule (fopen64, for example). So, in order to be both portable and consistent,
the enum should not use the bare function names.

The old enum naming used a namespace LibFunc and an enum Func, with bare
enumerators. This patch changes LibFunc to be an enum with enumerators prefixed
with "LibFFunc_". (Unfortunately, a scoped enum is not sufficient to override
macros.)

There are additional changes required in clang.

Reviewers: rsmith

Subscribers: mehdi_amini, mzolotukhin, nemanjai, llvm-commits

Differential Revision: https://reviews.llvm.org/D28476

llvm-svn: 292848
2017-01-23 23:16:46 +00:00
Matt Arsenault
b948b4d8df SimplifyLibCalls: Remove checks for fabs
Use the intrinsic instead of emitting the libcall which
will be replaced by the intrinsic.

llvm-svn: 292176
2017-01-17 00:30:31 +00:00
Matt Arsenault
7233344c28 SimplifyLibCalls: Replace fabs libcalls with intrinsics
Add missing fabs(fpext) optimzation that worked with the call,
and also fixes it creating a second fpext when there were multiple
uses.

llvm-svn: 292172
2017-01-17 00:10:40 +00:00
Davide Italiano
f8711f093e [SimplifyLibCalls] Propagate fast math flags while optimizing pow().
llvm-svn: 291577
2017-01-10 18:02:05 +00:00
Davide Italiano
472684eaf5 [SimplifyLibCalls] pow(x, -0.5) -> 1.0 / sqrt(x).
Differential Revision:  https://reviews.llvm.org/D28479

llvm-svn: 291486
2017-01-09 21:55:23 +00:00
Matt Arsenault
a7d2194168 SimplifyLibCalls: Remove incorrect optimization of fabs
fabs(x * x) is not generally safe to assume x is positive if x is a NaN.
This is also less general than it could be, so this will be replaced
with a transformation on the intrinsic.

llvm-svn: 291359
2017-01-07 19:55:12 +00:00
Daniel Jasper
aec2fa352f Revert @llvm.assume with operator bundles (r289755-r289757)
This creates non-linear behavior in the inliner (see more details in
r289755's commit thread).

llvm-svn: 290086
2016-12-19 08:22:17 +00:00
Davide Italiano
f024a56cb8 [SimplifyLibCalls] Use a lambda. NFCI.
llvm-svn: 289911
2016-12-16 02:28:38 +00:00
Davide Italiano
85ad36b0e0 [SimplifyLibCalls] Lower fls() to llvm.ctlz().
Differential Revision:  https://reviews.llvm.org/D14590

llvm-svn: 289894
2016-12-15 23:45:11 +00:00
Davide Italiano
890e850348 [SimplifyLibCalls] Remove redundant folding logic for ffs().
Lowering to llvm.cttz() will result in constant folding anyway
if the argument to ffs is a constant. Pointed out by Eli for
fls() in D14590.

llvm-svn: 289888
2016-12-15 23:11:00 +00:00
Hal Finkel
3ca4a6bcf1 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...

llvm-svn: 289756
2016-12-15 03:02:15 +00:00
Stephan Bergmann
17c7f70362 Replace APFloatBase static fltSemantics data members with getter functions
At least the plugin used by the LibreOffice build
(<https://wiki.documentfoundation.org/Development/Clang_plugins>) indirectly
uses those members (through inline functions in LLVM/Clang include files in turn
using them), but they are not exported by utils/extract_symbols.py on Windows,
and accessing data across DLL/EXE boundaries on Windows is generally
problematic.

Differential Revision: https://reviews.llvm.org/D26671

llvm-svn: 289647
2016-12-14 11:57:17 +00:00
Sam Parker
214f7bf5cc Enable simplify libcalls for ARM PCS
Teach SimplifyLibcalls that in can treat functions annotated with
apcs, aapcs or aapcs_vfp like normal C functions if they only take
and return integer or pointer values, and the target is not iOS.

Differential Revision: https://reviews.llvm.org/D24453

llvm-svn: 281322
2016-09-13 12:10:14 +00:00
David Majnemer
0a16c22846 Use range algorithms instead of unpacking begin/end
No functionality change is intended.

llvm-svn: 278417
2016-08-11 21:15:00 +00:00
Davide Italiano
873219c406 [SimplifyLibCalls] Restore the old behaviour, emit a libcall.
Hal pointed out that the semantic of our intrinsic and the libc
call are slightly different. Add a comment while I'm here to
explain why we can't emit an intrinsic. Thanks Hal!

llvm-svn: 278200
2016-08-10 06:33:32 +00:00
Davide Italiano
e3b916d164 [SimplifyLibCalls] Emit sqrt intrinsic instead of a libcall.
llvm-svn: 277972
2016-08-08 03:23:01 +00:00
Davide Italiano
27da131f32 [SLC] Emit an intrinsic instead of a libcall for pow.
Differential Revision:  https://reviews.llvm.org/D22104

llvm-svn: 277963
2016-08-07 20:27:03 +00:00
Sjoerd Meijer
7435a910b5 Addressing post-commit comments for not rewriting fputs:
moved the optimise for size check inside function optimizeFPuts.

llvm-svn: 274758
2016-07-07 14:31:19 +00:00
Sjoerd Meijer
17c08dc701 Code size optimisation: don't rewrite fputs to fwrite when optimising for size
because fwrite requires more arguments and thus extra MOVs are required.

llvm-svn: 274753
2016-07-07 13:56:23 +00:00
Joerg Sonnenberger
8ffe7ab7c2 Optimize a printf with a double procent to putchar.
llvm-svn: 268922
2016-05-09 14:36:16 +00:00
Ahmed Bougacha
d765a82b54 [TLI] Unify LibFunc signature checking. NFCI.
I tried to be as close as possible to the strongest check that
existed before; cleaning these up properly is left for future work.

Differential Revision: http://reviews.llvm.org/D19469

llvm-svn: 267758
2016-04-27 19:04:35 +00:00
David Majnemer
abb9f55c80 Revert "[SimplifyLibCalls] sprintf doesn't copy null bytes"
The destination buffer that sprintf uses is restrict qualified, we do
not need to worry about derived pointers referenced via format
specifiers.

This reverts commit r267580.

llvm-svn: 267605
2016-04-26 21:04:47 +00:00
David Majnemer
8cd77baebc [SimplifyLibCalls] sprintf doesn't copy null bytes
sprintf doesn't read or copy the terminating null byte from it's string
operands.  sprintf will append it's own after processing all of the
format specifiers.

This fixes PR27526.

llvm-svn: 267580
2016-04-26 18:16:49 +00:00
Mehdi Amini
b550cb1750 [NFC] Header cleanup
Removed some unused headers, replaced some headers with forward class declarations.

Found using simple scripts like this one:
clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap'

Patch by Eugene Kosov <claprix@yandex.ru>

Differential Revision: http://reviews.llvm.org/D19219

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266595
2016-04-18 09:17:29 +00:00
David L Kreitzer
752c1448fe Simplify strlen to a subtraction for certain cases.
Patch by Li Huang (li1.huang@intel.com)

Differential Revision: http://reviews.llvm.org/D18230

llvm-svn: 266200
2016-04-13 14:31:06 +00:00
Davide Italiano
d4f5a059e0 [SimplifyLibCalls] Garbage collect dead code.
We already skip optimizations if the return value
of printf() is used, so CI->use_empty() is always
true.

Differential Revision:  http://reviews.llvm.org/D18656

llvm-svn: 265253
2016-04-03 01:46:52 +00:00
Davide Italiano
6db1dcbf6b [SimplifyLibCalls] Transform printf("%s", "a") -> putchar('a').
llvm-svn: 264588
2016-03-28 15:54:01 +00:00
David Majnemer
abae6b588b [SimplifyLibCalls] Only consider sinpi/cospi functions within the same function
The sinpi/cospi can be replaced with sincospi to remove unnecessary
computations.  However, we need to make sure that the calls are within
the same function!

This fixes PR26993.

llvm-svn: 263875
2016-03-19 04:53:02 +00:00
Sanjay Patel
980b280f50 [LibCallSimplifier] fold memset(malloc(x), 0, x) --> calloc(1, x)
This is a step towards solving PR25892:
https://llvm.org/bugs/show_bug.cgi?id=25892

It won't handle the reported case. As noted by the 'TODO' comments in the patch, 
we need to relax the hasOneUse() constraint and also match patterns that include
memset_chk() and the llvm.memset() intrinsic in addition to memset().

Differential Revision: http://reviews.llvm.org/D16337

llvm-svn: 258816
2016-01-26 16:17:24 +00:00
Sanjay Patel
577472141c move function definitions so we don't need separate declarations ; NFCI
llvm-svn: 258455
2016-01-21 23:38:43 +00:00
Sanjay Patel
9beec21fcf [LibCallSimplifier] refactor FP function signature checks ; NFCI
Use the helper function added in r258428.

The check should really be hoisted to the caller of all of these
optimize* functions, but that's another step.

llvm-svn: 258446
2016-01-21 22:58:01 +00:00
Sanjay Patel
042aed90ab avoid variable shadowing; NFC
llvm-svn: 258445
2016-01-21 22:41:16 +00:00
Sanjay Patel
0e603fc3a7 remove unnecessary variable; NFC
llvm-svn: 258444
2016-01-21 22:31:18 +00:00
Sanjay Patel
fcc7c1a0ba [LibCallSimplifier] don't get fooled by a fake fmin()
This is similar to the bug/fix:
https://llvm.org/bugs/show_bug.cgi?id=26211
http://reviews.llvm.org/rL258325

The fmin() test case reveals another bug caused by sloppy
code duplication. It will crash without this patch because
fp128 is a valid floating-point type, but we would think
that we had matched a function that used doubles.

The new helper function can be used to replace similar
checks that are used in several other places in this file.

llvm-svn: 258428
2016-01-21 20:19:54 +00:00
Sanjay Patel
4e971da272 make helper functions static; NFCI
llvm-svn: 258416
2016-01-21 18:01:57 +00:00
Sanjay Patel
bd2dc67142 [LibCallSimplifier] don't get fooled by a fake sqrt()
The test case will crash without this patch because the subsequent call to
hasUnsafeAlgebra() assumes that the call instruction is an FPMathOperator
(ie, returns an FP type).

This part of the function signature check was omitted for the sqrt() case, 
but seems to be in place for all other transforms.

Before:
http://reviews.llvm.org/rL257400
...we would have needlessly continued execution in optimizeSqrt(), but the
bug was harmless because we'd eventually fail some other check and return
without damage.

This should fix:
https://llvm.org/bugs/show_bug.cgi?id=26211

Differential Revision: http://reviews.llvm.org/D16198

llvm-svn: 258325
2016-01-20 17:41:14 +00:00
Sanjay Patel
d3112a5bcc function names start with a lowercase letter; NFC
Note: There are no uses of these functions outside of
SimplifyLibCalls, so they could be static functions in
that file.

llvm-svn: 258172
2016-01-19 19:46:10 +00:00
Sanjay Patel
d1f4f03f5e [LibCallSimplifier] use instruction-level fast-math-flags to shrink calls
This is a continuation of adding FMF to call instructions:
http://reviews.llvm.org/rL255555

llvm-svn: 258158
2016-01-19 18:38:52 +00:00
Sanjay Patel
81a63cd11f [LibCallSimplifier] use instruction-level fast-math-flags to transform pow(x, [small integer]) calls
This is a continuation of adding FMF to call instructions:
http://reviews.llvm.org/rL255555

As with D15937, the intent of the patch is to preserve the current behavior of the transform
except that we use the pow call's 'fast' attribute as a trigger rather than a function-level
attribute.

The TODO comment notes a potential follow-on patch that would propagate FMF to the new
instructions.

Differential Revision: http://reviews.llvm.org/D16122

llvm-svn: 258153
2016-01-19 18:15:12 +00:00
Sanjay Patel
53ba88dbb0 [LibCallSimplifier] use instruction-level fast-math-flags to transform pow(x, 0.5) calls
Also, propagate the FMF to the newly created sqrt() call.

llvm-svn: 257503
2016-01-12 19:06:35 +00:00
Sanjay Patel
a252815bc1 function names start with a lower case letter ; NFC
llvm-svn: 257496
2016-01-12 18:03:37 +00:00
Sanjay Patel
6002e78a06 [LibCallSimplifier] use instruction-level fast-math-flags to transform pow(exp(x)) calls
See also:
http://reviews.llvm.org/rL255555
http://reviews.llvm.org/rL256871
http://reviews.llvm.org/rL256964
http://reviews.llvm.org/rL257400
http://reviews.llvm.org/rL257404
http://reviews.llvm.org/rL257414

llvm-svn: 257491
2016-01-12 17:30:37 +00:00
Sanjay Patel
e896ede7f1 [LibCallSimplifier] use instruction-level fast-math-flags to transform log calls
Also, add tests to verify that we're checking 'fast' on both calls of each transform pair,
tighten the CHECK lines, and give the tests more meaningful names.

This is a continuation of:
http://reviews.llvm.org/rL255555
http://reviews.llvm.org/rL256871
http://reviews.llvm.org/rL256964
http://reviews.llvm.org/rL257400
http://reviews.llvm.org/rL257404

llvm-svn: 257414
2016-01-11 23:31:48 +00:00
Sanjay Patel
6c1ddbb7b6 [LibCallSimplifier] don't allow sqrt transform unless all ops are unsafe
Fix the FIXME added with:
http://reviews.llvm.org/rL257400

llvm-svn: 257404
2016-01-11 22:50:36 +00:00
Sanjay Patel
9f67dadea2 more space; NFC
llvm-svn: 257401
2016-01-11 22:35:39 +00:00
Sanjay Patel
683f29735f [LibCallSimplifier] use instruction-level fast-math-flags to transform sqrt calls
This is a continuation of adding FMF to call instructions:
http://reviews.llvm.org/rL255555

The intent of the patch is to preserve the current behavior of the transform except
that we use the sqrt instruction's 'fast' attribute as a trigger rather than the
function-level attribute.

But this raises a bug noted by the new FIXME comment.

In order to do this transform:
sqrt((x * x) * y) ---> fabs(x) * sqrt(y)

...we need all of the sqrt, the first fmul, and the second fmul to be 'fast'. 
If any of those ops is strict, we should bail out.

Differential Revision: http://reviews.llvm.org/D15937

llvm-svn: 257400
2016-01-11 22:34:19 +00:00
Sanjay Patel
c2d6461a4a [LibCallSimplifier] less indenting; NFCI
llvm-svn: 256973
2016-01-06 20:52:21 +00:00
Sanjay Patel
cddcd7256c [LibCallSimplifier] use instruction-level fast-math-flags for tan/atan transform
llvm-svn: 256964
2016-01-06 19:23:35 +00:00
David Majnemer
b70e23c390 [SimplifyLibCalls] Teach SimplifyLibCalls about operand bundles
If we replace one call-site with another, be sure to move over any
operand bundles that lingered on the old call-site.

This fixes PR26036.

llvm-svn: 256912
2016-01-06 05:01:34 +00:00
Sanjay Patel
c7ddb7fcdb A (B + C) = A B + A C ; NFCI
llvm-svn: 256884
2016-01-06 00:32:15 +00:00
Sanjay Patel
29095ea1b0 [LibCallSimplfier] use instruction-level fast-math-flags for fmin/fmax transforms
llvm-svn: 256871
2016-01-05 20:46:19 +00:00
Sanjay Patel
bee05caa6b [LibCallSimplifier] propagate FMF when shrinking binary calls
llvm-svn: 256682
2015-12-31 23:40:59 +00:00
Sanjay Patel
aa23114cb4 [LibCallSimplifier] propagate FMF when shrinking unary calls
llvm-svn: 256679
2015-12-31 21:52:31 +00:00
Sanjay Patel
96475cbd22 Variable names start with an upper case letter; NFC
llvm-svn: 256676
2015-12-31 16:16:58 +00:00
Sanjay Patel
d707db97a9 fix formatting; NFC
llvm-svn: 256675
2015-12-31 16:10:49 +00:00
Sanjay Patel
af674fbfd9 getParent() ^ 3 == getModule() ; NFCI
llvm-svn: 255511
2015-12-14 17:24:23 +00:00
Weiming Zhao
8213072a45 [SimplifyLibCalls] Optimization for pow(x, n) where n is some constant
Summary:
    In order to avoid calling pow function we generate repeated fmul when n is a
    positive or negative whole number.
    
    For each exponent we pre-compute Addition Chains in order to minimize the no.
    of fmuls.
    Refer: http://wwwhomes.uni-bielefeld.de/achim/addition_chain.html
    
    We pre-compute addition chains for exponents upto 32 (which results in a max of
    7 fmuls).

    For eg:
    4 = 2+2
    5 = 2+3
    6 = 3+3 and so on
    
    Hence,
    pow(x, 4.0) ==> y = fmul x, x
                    x = fmul y, y
                    ret x

    For negative exponents, we simply compute the reciprocal of the final result.
    
    Note: This transformation is only enabled under fast-math.
    
    Patch by Mandeep Singh Grang <mgrang@codeaurora.org>

Reviewers: weimingz, majnemer, escha, davide, scanon, joerg

Subscribers: probinson, escha, llvm-commits

Differential Revision: http://reviews.llvm.org/D13994

llvm-svn: 254776
2015-12-04 22:00:47 +00:00
Davide Italiano
1aeed6a955 [SimplifyLibCalls] Transform log(exp2(y)) to y*log(2) under fast-math.
llvm-svn: 254317
2015-11-30 19:36:35 +00:00
Davide Italiano
0b14f29285 [SimplifyLibCalls] Don't crash if the function doesn't have a name.
llvm-svn: 254265
2015-11-29 21:58:56 +00:00
Davide Italiano
e2db58cfb8 [SimplifyLibCalls] Cross out implemented transformations.
llvm-svn: 254264
2015-11-29 21:00:43 +00:00
Davide Italiano
b8b7133c94 [SimplifyLibCalls] Tranform log(pow(x, y)) -> y*log(x).
This one is enabled only under -ffast-math. There are cases where the
difference between the value computed and the correct value is huge
even for ffast-math, e.g. as Steven pointed out:

x = -1, y = -4
log(pow(-1), 4) = 0
4*log(-1) = NaN

I checked what GCC does and apparently they do the same optimization
(which result in the dramatic difference). Future work might try to
make this (slightly) less worse.

Differential Revision:	http://reviews.llvm.org/D14400

llvm-svn: 254263
2015-11-29 20:58:04 +00:00
Davide Italiano
da3beebad1 [SimplifyLibCalls] Use any_of(). Suggested by David Blaikie!
llvm-svn: 254239
2015-11-28 22:27:48 +00:00
Benjamin Kramer
89766e5b1d [SimplifyLibCalls] Fix inverted condition that lead to an uninitialized memory read below.
Found by msan!

llvm-svn: 254238
2015-11-28 21:43:12 +00:00
Davide Italiano
ac0953a2e6 [SimplifyLibCalls] Use range-based loop. NFC.
llvm-svn: 254193
2015-11-27 08:05:40 +00:00
Benjamin Kramer
fb419e71f4 [SimplifyLibCalls] Don't depend on a called function having a name, it might be an indirect call.
Fixes the crasher in PR25651 and related crashers using the same pattern.

llvm-svn: 254145
2015-11-26 09:51:17 +00:00
Weiming Zhao
45d4cb9a14 [Utils] Put includes in correct order. NFC.
Summary:
    Followed the guidelines in:
    http://llvm.org/docs/CodingStandards.html#include-style
    
    However, I noticed that uppercase named headers come before lowercase ones
    throughout the codebase. So kept them as is.
    
    Patch by Mandeep Singh Grang <mgrang@codeaurora.org>

Reviewers: majnemer, davide, jmolloy, atrick

Subscribers: sanjoy

Differential Revision: http://reviews.llvm.org/D14939

llvm-svn: 254005
2015-11-24 18:57:06 +00:00
Weiming Zhao
8d5c08f591 [SimplifyLibCalls] Removed some TODOs which are already implemented. NFC.
Summary:
D14302 implements tan(atan(x)) -> x
D14045 implements pow(exp(x), y) -> exp(x*y)

Patch by Mandeep Singh Grang <mgrang@codeaurora.org>

Reviewers: majnemer, davide

Differential Revision: http://reviews.llvm.org/D14882

llvm-svn: 253768
2015-11-21 06:10:20 +00:00
Pete Cooper
67cf9a723b Revert "Change memcpy/memset/memmove to have dest and source alignments."
This reverts commit r253511.

This likely broke the bots in
http://lab.llvm.org:8011/builders/clang-ppc64-elf-linux2/builds/20202
http://bb.pgr.jp/builders/clang-3stage-i686-linux/builds/3787

llvm-svn: 253543
2015-11-19 05:56:52 +00:00
Davide Italiano
c5cedd195a [SimplifyLibCalls] New trick: pow(x, 0.5) -> sqrt(x) under -ffast-math.
Differential Revision:	http://reviews.llvm.org/D14466

llvm-svn: 253521
2015-11-18 23:21:32 +00:00
Pete Cooper
72bc23ef02 Change memcpy/memset/memmove to have dest and source alignments.
Note, this was reviewed (and more details are in) http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151109/312083.html

These intrinsics currently have an explicit alignment argument which is
required to be a constant integer.  It represents the alignment of the
source and dest, and so must be the minimum of those.

This change allows source and dest to each have their own alignments
by using the alignment attribute on their arguments.  The alignment
argument itself is removed.

There are a few places in the code for which the code needs to be
checked by an expert as to whether using only src/dest alignment is
safe.  For those places, they currently take the minimum of src/dest
alignments which matches the current behaviour.

For example, code which used to read:
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* %src, i32 500, i32 8, i1 false)
will now read:
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 8 %dest, i8* align 8 %src, i32 500, i1 false)

For out of tree owners, I was able to strip alignment from calls using sed by replacing:
  (call.*llvm\.memset.*)i32\ [0-9]*\,\ i1 false\)
with:
  $1i1 false)

and similarly for memmove and memcpy.

I then added back in alignment to test cases which needed it.

A similar commit will be made to clang which actually has many differences in alignment as now
IRBuilder can generate different source/dest alignments on calls.

In IRBuilder itself, a new argument was added.  Instead of calling:
  CreateMemCpy(Dst, Src, getInt64(Size), DstAlign, /* isVolatile */ false)
you now call
  CreateMemCpy(Dst, Src, getInt64(Size), DstAlign, SrcAlign, /* isVolatile */ false)

There is a temporary class (IntegerAlignment) which takes the source alignment and rejects
implicit conversion from bool.  This is to prevent isVolatile here from passing its default
parameter to the source alignment.

Note, changes in future can now be made to codegen.  I didn't change anything here, but this
change should enable better memcpy code sequences.

Reviewed by Hal Finkel.

llvm-svn: 253511
2015-11-18 22:17:24 +00:00
Davide Italiano
ed5cc95d22 [SimplifyLibCalls] Generalize a comment. This doesn't apply only to sqrt.
llvm-svn: 253224
2015-11-16 16:54:28 +00:00
Davide Italiano
b883b01a8e [SimplifyLibCalls] Make a function shorter. NFC.
llvm-svn: 252970
2015-11-12 23:39:00 +00:00
Davide Italiano
d9f87b4642 [SimplifyLibCalls] Don't hardcode the function name.
llvm-svn: 252342
2015-11-06 21:05:07 +00:00
Davide Italiano
a345877ce8 [SimplifyLibCalls] Use hasFloatVersion(). NFCI.
llvm-svn: 252186
2015-11-05 19:18:23 +00:00
Davide Italiano
51507d2ad8 [SimplifyLibCalls] New transformation: tan(atan(x)) -> x
This is enabled only under -ffast-math.
So, instead of emitting:
  4007b0:       50                      push   %rax
  4007b1:       e8 8a fd ff ff          callq  400540 <atanf@plt>
  4007b6:       58                      pop    %rax
  4007b7:       e9 94 fd ff ff          jmpq   400550 <tanf@plt>
  4007bc:       0f 1f 40 00             nopl   0x0(%rax)

for:
float mytan(float x) {
  return tanf(atanf(x));
}
we emit a single retq.

Differential Revision:	 http://reviews.llvm.org/D14302

llvm-svn: 252098
2015-11-04 23:36:56 +00:00
Davide Italiano
c8a7913f23 [SimplifyLibCalls] Add a new transformation: pow(exp(x), y) -> exp(x*y)
This one is enabled only under -ffast-math (due to rounding/overflows)
but allows us to emit shorter code.

Before (on FreeBSD x86-64):
4007f0:       50                      push   %rax
4007f1:       f2 0f 11 0c 24          movsd  %xmm1,(%rsp)
4007f6:       e8 75 fd ff ff          callq  400570 <exp2@plt>
4007fb:       f2 0f 10 0c 24          movsd  (%rsp),%xmm1
400800:       58                      pop    %rax
400801:       e9 7a fd ff ff          jmpq   400580 <pow@plt>
400806:       66 2e 0f 1f 84 00 00    nopw   %cs:0x0(%rax,%rax,1)
40080d:       00 00 00

After:
4007b0:       f2 0f 59 c1             mulsd  %xmm1,%xmm0
4007b4:       e9 87 fd ff ff          jmpq   400540 <exp2@plt>
4007b9:       0f 1f 80 00 00 00 00    nopl   0x0(%rax)

Differential Revision:	http://reviews.llvm.org/D14045

llvm-svn: 251976
2015-11-03 20:32:23 +00:00
Davide Italiano
b7487e6b8d [SimplifyLibCalls] Remove variables that are not used. NFC.
llvm-svn: 251852
2015-11-02 23:07:14 +00:00
Davide Italiano
e84d4da234 [SimplifyLibCalls] Merge two if statements. NFC.
llvm-svn: 251845
2015-11-02 22:33:26 +00:00
Davide Italiano
5cdf915191 Simplify a check. NFC.
llvm-svn: 251757
2015-11-01 00:09:16 +00:00
Davide Italiano
396f3eeafb [SimplifyLibCalls] Factor out other common code.
llvm-svn: 251754
2015-10-31 23:17:45 +00:00
Davide Italiano
3817486c47 [SimplifyLibCalls] Remove dead code.
llvm-svn: 251737
2015-10-31 08:28:10 +00:00
Davide Italiano
a904e520c2 [SimplifyLibCalls] Factor out common unsafe-math checks.
llvm-svn: 251595
2015-10-29 02:58:44 +00:00
Davide Italiano
c692688cbd [SimplifyLibCalls] Use range-based loop. No functional change.
llvm-svn: 251383
2015-10-27 04:17:51 +00:00
Duncan P. N. Exon Smith
5b4c837c58 TransformUtils: Remove implicit ilist iterator conversions, NFC
Continuing the work from last week to remove implicit ilist iterator
conversions.  First related commit was probably r249767, with some more
motivation in r249925.  This edition gets LLVMTransformUtils compiling
without the implicit conversions.

No functional change intended.

llvm-svn: 250142
2015-10-13 02:39:05 +00:00
Bruno Cardoso Lopes
b491a2d641 [SimplifyLibCalls] Fix instruction misplacement in string/memory libcall optimization
When trying to optimize fortified library functions use the right
location to insert new instructions in order to preserve correct
def-use order.

This fixes an issue where a misplaced instruction definition would
happen to be *after* one of its use after a RAUW, forming invalid IR.
This behavior was introduced by r227250.

Differential Revision: http://reviews.llvm.org/D13301

rdar://problem/22802369

llvm-svn: 249092
2015-10-01 22:43:53 +00:00
NAKAMURA Takumi
0d72539d5a Prune utf8 chars in comments.
llvm-svn: 246953
2015-09-07 00:26:54 +00:00
Chad Rosier
dc65532fd9 Optimize memcmp(x,y,n)==0 for small n and suitably aligned x/y.
http://reviews.llvm.org/D6952
PR20673

llvm-svn: 246313
2015-08-28 18:30:18 +00:00
David Majnemer
3354fe473f [SimplifyLibCalls] Fix a typo
cbrt(sqrt(x)) calculates the sixth root, not the ninth root.
cbrt(cbrt(x)) calculates the ninth root.

llvm-svn: 246046
2015-08-26 18:30:16 +00:00
Benjamin Kramer
bb70d751de [SimplifyLibCalls] Drop default template args. No functional change.
llvm-svn: 245189
2015-08-16 21:16:37 +00:00
Sanjay Patel
57fd1dc5db transform fmin/fmax calls when possible (PR24314)
If we can ignore NaNs, fmin/fmax libcalls can become compare and select
(this is what we turn std::min / std::max into).

This IR should then be optimized in the backend to whatever is best for
any given target. Eg, x86 can use minss/maxss instructions.

This should solve PR24314:
https://llvm.org/bugs/show_bug.cgi?id=24314

Differential Revision: http://reviews.llvm.org/D11866

llvm-svn: 245187
2015-08-16 20:18:19 +00:00
Davide Italiano
a195386ca1 [SimplifyLibCalls] Correctly set the is_zero_undef flag for llvm.cttz
If <src> is non-zero we can safely set the flag to true, and this
results in less code generated for, e.g. ffs(x) + 1 on FreeBSD.
Thanks to majnemer for suggesting the fix and reviewing.

Code generated before the patch was applied:


 0:   0f bc c7                bsf    %edi,%eax
 3:   b9 20 00 00 00          mov    $0x20,%ecx
 8:   0f 45 c8                cmovne %eax,%ecx
 b:   83 c1 02                add    $0x2,%ecx
 e:   b8 01 00 00 00          mov    $0x1,%eax
13:   85 ff                   test   %edi,%edi
15:   0f 45 c1                cmovne %ecx,%eax
18:   c3                      retq

Code generated after the patch was applied:

 0:   0f bc cf                bsf    %edi,%ecx
 3:   83 c1 02                add    $0x2,%ecx
 6:   85 ff                   test   %edi,%edi
 8:   b8 01 00 00 00          mov    $0x1,%eax
 d:   0f 45 c1                cmovne %ecx,%eax
10:   c3                      retq

It seems we can still use cmove and save another 'test' instruction, but
that can be tackled separately.

Differential Revision:  http://reviews.llvm.org/D11989	

llvm-svn: 244947
2015-08-13 20:34:26 +00:00
Sanjay Patel
e24c60eb54 fix typo; NFC
llvm-svn: 244805
2015-08-12 20:36:18 +00:00
Pete Cooper
9e1d335697 Change Function::getIntrinsicID() to return an Intrinsic::ID. NFC.
Now that Intrinsic::ID is a typed enum, we can forward declare it and so return it from this method.

This updates all users which were either using an unsigned to store it, or had a now unnecessary cast.

llvm-svn: 237810
2015-05-20 17:16:39 +00:00
David Blaikie
ff6409d096 Simplify IRBuilder::CreateCall* by using ArrayRef+initializer_list/braced init only
llvm-svn: 237624
2015-05-18 22:13:54 +00:00
David Blaikie
aa41cd57e0 [opaque pointer type] More GEP IRBuilder API migrations...
llvm-svn: 234058
2015-04-03 21:33:42 +00:00
David Blaikie
65fab6d896 Use early returns to reduce indentation.
llvm-svn: 234057
2015-04-03 21:32:06 +00:00
Ahmed Bougacha
408d010a7c [SimplifyLibCalls] Ignore nobuiltin/unavailable fortified libcalls.
We used to do this before refactorings around r225640.
Some clang users checked for _chk libcall availability using:
  __has_builtin(__builtin___memcpy_chk)
When compiling with -fno-builtin, this is always true.
When passing -ffreestanding/-mkernel, which both imply -fno-builtin, we
end up with fortified libcalls, which isn't acceptable in a freestanding
environment which only provides their non-fortified counterparts.

Until we change clang and/or teach external users to check for availability
differently, disregard the "nobuiltin" attribute and TLI::has.

Workaround for PR23093.

llvm-svn: 233776
2015-04-01 00:45:09 +00:00
David Blaikie
3909da7f4b [opaque pointer type] More IRBuilder::createGEP (non-inbounds) migrations: CodeGenPrepare and SimplifyLibCalls
llvm-svn: 233596
2015-03-30 20:42:56 +00:00
Benjamin Kramer
d6aa0ec737 [SimplifyLibCalls] Fix negative shifts being produced by the memchr -> bitfield transform.
llvm-svn: 232903
2015-03-21 22:04:26 +00:00
Benjamin Kramer
7857d723f1 [SimplifyLibCalls] Turn memchr(const, C, const) into a bitfield check.
strchr("123!", C) != nullptr is a common pattern to check if C is one
of 1, 2, 3 or !. If the largest element of the string is smaller than
the target's register size we can easily create a bitfield and just
do a simple test for set membership.

int foo(char C) { return strchr("123!", C) != nullptr; } now becomes

	cmpl	$64, %edi ## range check
	sbbb	%al, %al
	movabsq	$0xE000200000001, %rcx
	btq	%rdi, %rcx ## bit test
	sbbb	%cl, %cl
	andb	%al, %cl ## and the two conditions
	andb	$1, %cl
	movzbl	%cl, %eax ## returning an int
	ret

(imho the backend should expand this into a series of branches, but
that's a different story)

The code is currently limited to bit fields that fit in a register, so
usually 64 or 32 bits. Sadly, this misses anything using alpha chars
or {}. This could be fixed by just emitting a i128 bit field, but that
can generate really ugly code so we have to find a better way. To some
degree this is also recreating switch lowering logic, but we can't
simply emit a switch instruction and thus change the CFG within
instcombine.

llvm-svn: 232902
2015-03-21 21:09:33 +00:00
Benjamin Kramer
691363e7f2 SimplifyLibCalls: Add basic optimization of memchr calls.
This is just memchr(x, y, 0) -> nullptr and constant folding.

llvm-svn: 232896
2015-03-21 15:36:21 +00:00
Mehdi Amini
a28d91d81b DataLayout is mandatory, update the API to reflect it with references.
Summary:
Now that the DataLayout is a mandatory part of the module, let's start
cleaning the codebase. This patch is a first attempt at doing that.

This patch is not exactly NFC as for instance some places were passing
a nullptr instead of the DataLayout, possibly just because there was a
default value on the DataLayout argument to many functions in the API.
Even though it is not purely NFC, there is no change in the
validation.

I turned as many pointer to DataLayout to references, this helped
figuring out all the places where a nullptr could come up.

I had initially a local version of this patch broken into over 30
independant, commits but some later commit were cleaning the API and
touching part of the code modified in the previous commits, so it
seemed cleaner without the intermediate state.

Test Plan:

Reviewers: echristo

Subscribers: llvm-commits

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 231740
2015-03-10 02:37:25 +00:00
Ahmed Bougacha
1ac9356524 [SimplifyLibCalls] Don't confuse strcpy_chk for stpcpy_chk.
This was introduced in a faulty refactoring (r225640, mea culpa):
the tests weren't testing the return values, so, for both
__strcpy_chk and __stpcpy_chk, we would return the end of the
buffer (matching stpcpy) instead of the beginning (for strcpy).

The root cause was the prefix "__" being ignored when comparing,
which made us always pick LibFunc::stpcpy_chk.
Pass the LibFunc::Func directly to avoid this kind of error.
Also, make the testcases as explicit as possible to prevent this.

The now-useful testcases expose another, entangled, stpcpy problem,
with the further simplification.  This was introduced in a
refactoring (r225640) to match the original behavior.

However, this leads to problems when successive simplifications
generate several similar instructions, none of which are removed
by the custom replaceAllUsesWith.

For instance, InstCombine (the main user) doesn't erase the
instruction in its custom RAUW.  When trying to simplify say
__stpcpy_chk:
- first, an stpcpy is created (fortified simplifier),
- second, a memcpy is created (normal simplifier), but the
  stpcpy call isn't removed.
- third, InstCombine later revisits the instructions,
  and simplifies the first stpcpy to a memcpy.  We now have
  two memcpys.

llvm-svn: 227250
2015-01-27 21:52:16 +00:00