This fixes https://bugs.llvm.org/show_bug.cgi?id=40110.
This implements handling of undef operands for integer intrinsics in
ConstantFolding, in particular for the bitcounting intrinsics (ctpop,
cttz, ctlz), the with.overflow intrinsics, the saturating math
intrinsics and the funnel shift intrinsics.
The undef behavior follows what InstSimplify does for the general cas
e of non-constant operands. For the bitcount intrinsics (where
InstSimplify doesn't do undef handling -- there cannot be a combination
of an undef + non-constant operand) I'm using a 0 result if the intrinsic
is defined for zero and undef otherwise.
Differential Revision: https://reviews.llvm.org/D55950
llvm-svn: 350971
Struct types may have leading zero-size elements like [0 x i32], in
which case the "real" element at offset 0 will not necessarily coincide
with the 0th element of the aggregate. ConstantFoldLoadThroughBitcast()
wants to drill down the element at offset 0, but currently always picks
the 0th aggregate element to do so. This patch changes the code to find
the first non-zero-size element instead, for the struct case.
The motivation behind this change is https://github.com/rust-lang/rust/issues/48627.
Rust is fond of emitting [0 x iN] separators between struct elements to
enforce alignment, which prevents constant folding in this particular case.
The additional tests with [4294967295 x [0 x i32]] check that we don't
end up unnecessarily looping over a large number of zero-size elements
of a zero-size array.
Differential Revision: https://reviews.llvm.org/D55169
llvm-svn: 348895
Support saturating add/sub in constant folding, based on the APInt methods introduced in D54332.
Patch by: @nikic (Nikita Popov)
Differential Revision: https://reviews.llvm.org/D54531
llvm-svn: 347328
This adds the llvm-side support for post-inlining evaluation of the
__builtin_constant_p GCC intrinsic.
Also fixed SCCPSolver::visitCallSite to not blow up when seeing a call
to a function where canConstantFoldTo returns true, and one of the
arguments is a struct.
Updated from patch initially by Janusz Sobczak.
Differential Revision: https://reviews.llvm.org/D4276
llvm-svn: 346322
This patch does the following things:
1. update SymbolicallyEvaluateGEP so that it bails out if it cannot preserve inrange arribute;
2. update llvm/test/Analysis/ConstantFolding/gep.ll to remove UB in it;
3. remove inaccurate comment above ConstantFoldInstOperandsImpl in llvm/lib/Analysis/ConstantFolding.cpp;
4. add a new regression test that makes sure that no optimizations change an inrange GEP in an unexpected way.
Patch by Zhaomo Yang!
Differential Revision: https://reviews.llvm.org/D51698
llvm-svn: 341888
This is another step towards being able to canonicalize to the funnel shift
intrinsics in IR (see D49242 for the initial patch).
We should not have any loss of simplification power in IR between these and
the equivalent IR constructs.
Differential Revision: https://reviews.llvm.org/D50848
llvm-svn: 340022
Summary:
We've supported constant folding for sse versions for many years. This patch adds support for the avx512 versions including unsigned with the default rounding mode. We could probably do more with other roundings modes and SAE in the future.
The test cases are largely based on the sse.ll test cases. But I did add some test cases to ensure the unsigned versions don't accept negative values. Also checked the bounds of f64->i32 conversions to make sure unsigned has a larger positive range than signed.
Reviewers: RKSimon, spatel, chandlerc
Reviewed By: RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D50553
llvm-svn: 339529
Summary:
Check if the parent basic block and caller exists
before calling CS.getCaller when constant folding
strip.invariant.group instrinsic.
This avoids a crash when the function containing the intrinsic
is being inlined. The instruction is checked for any simplifiction
but has not yet been added to a basic block.
Reviewers: Prazek, rsmith, efriedma
Reviewed By: efriedma
Subscribers: eraman, llvm-commits
Differential Revision: https://reviews.llvm.org/D49690
llvm-svn: 337742
Summary:
Support for this option is needed for building Linux kernel.
This is a very frequently requested feature by kernel developers.
More details : https://lkml.org/lkml/2018/4/4/601
GCC option description for -fdelete-null-pointer-checks:
This Assume that programs cannot safely dereference null pointers,
and that no code or data element resides at address zero.
-fno-delete-null-pointer-checks is the inverse of this implying that
null pointer dereferencing is not undefined.
This feature is implemented in LLVM IR in this CL as the function attribute
"null-pointer-is-valid"="true" in IR (Under review at D47894).
The CL updates several passes that assumed null pointer dereferencing is
undefined to not optimize when the "null-pointer-is-valid"="true"
attribute is present.
Reviewers: t.p.northover, efriedma, jyknight, chandlerc, rnk, srhines, void, george.burgess.iv
Reviewed By: efriedma, george.burgess.iv
Subscribers: eraman, haicheng, george.burgess.iv, drinkcat, theraven, reames, sanjoy, xbolva00, llvm-commits
Differential Revision: https://reviews.llvm.org/D47895
llvm-svn: 336613
Summary:
This patch introduce new intrinsic -
strip.invariant.group that was described in the
RFC: Devirtualization v2
Reviewers: rsmith, hfinkel, nlopes, sanjoy, amharc, kuhar
Subscribers: arsenm, nhaehnle, JDevlieghere, hiraditya, xbolva00, llvm-commits
Differential Revision: https://reviews.llvm.org/D47103
Co-authored-by: Krzysztof Pszeniczny <krzysztof.pszeniczny@gmail.com>
llvm-svn: 336073
Making a width of GEP Index, which is used for address calculation, to be one of the pointer properties in the Data Layout.
p[address space]:size:memory_size:alignment:pref_alignment:index_size_in_bits.
The index size parameter is optional, if not specified, it is equal to the pointer size.
Till now, the InstCombiner normalized GEPs and extended the Index operand to the pointer width.
It works fine if you can convert pointer to integer for address calculation and all registered targets do this.
But some ISAs have very restricted instruction set for the pointer calculation. During discussions were desided to retrieve information for GEP index from the Data Layout.
http://lists.llvm.org/pipermail/llvm-dev/2018-January/120416.html
I added an interface to the Data Layout and I changed the InstCombiner and some other passes to take the Index width into account.
This change does not affect any in-tree target. I added tests to cover data layouts with explicitly specified index size.
Differential Revision: https://reviews.llvm.org/D42123
llvm-svn: 325102
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.
I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.
This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.
Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).
llvm-svn: 304787
This is actually NFC because the next case starts with the same if statement as this case did. So the result will be the same and it will fallthrough to the end of the switch. But there's no reason to rely on that so we should just break.
llvm-svn: 304680
Summary:
The constant folding code currently assumes that the constant expression will always be on the left and the simple null will be on the right. But that's not true at least on the path from InstSimplify.
This patch adds support to ConstantFolding to detect the reversed case.
Reviewers: spatel, dberlin, majnemer, davide, joey
Reviewed By: joey
Subscribers: joey, llvm-commits
Differential Revision: https://reviews.llvm.org/D33801
llvm-svn: 304559
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
This patch adds isConstant and getConstant for determining if KnownBits represents a constant value and to retrieve the value. Use them to simplify code.
Differential Revision: https://reviews.llvm.org/D32785
llvm-svn: 302091
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
After the loop unroll threshold was increased in r295538, very
large constant expressions can be created. This prevents them
from having to be recursively scanned, leading to a compile
time blow-up.
Differential Revision: https://reviews.llvm.org/D30689
llvm-svn: 298356
Summary:
The reverse of an artbitrary bitpattern is also an arbitrary
bitpattern.
Reviewers: trentxintong, arsenm, majnemer
Reviewed By: majnemer
Subscribers: majnemer, wdng, llvm-commits
Differential Revision: https://reviews.llvm.org/D31118
llvm-svn: 298201
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
Summary:
Currently we return undef, but we're in the process of changing the
LangRef so that llvm.sqrt behaves like the other math intrinsics,
matching the return value of the standard libcall but not setting errno.
This change is legal even without the LangRef change because currently
calling llvm.sqrt(x) where x is negative is spec'ed to be UB. But in
practice it's also safe because we're simply constant-folding fewer
inputs: Inputs >= -0 get constant-folded as before, but inputs < -0 now
aren't constant-folded, because ConstantFoldFP aborts if the host math
function raises an fp exception.
Reviewers: hfinkel, efriedma, sanjoy
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D28929
llvm-svn: 292692
For vector GEPs, CastGEPIndices can end up in an infinite recursion, because
we compare the vector type to the scalar pointer type, find them different,
and then try to cast a type to itself.
Differential Revision: https://reviews.llvm.org/D28009
llvm-svn: 290260
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
ConstantFolding tried to cast one of the scalar indices to a vector
type. Instead, use the vector type only for the first index (which
is the only one allowed to be a vector) and use its scalar type
otherwise.
Fixes PR31250.
Reviewers: majnemer
Differential Revision: https://reviews.llvm.org/D27389
llvm-svn: 289073
If the inrange keyword is present before any index, loading from or
storing to any pointer derived from the getelementptr has undefined
behavior if the load or store would access memory outside of the bounds of
the element selected by the index marked as inrange.
This can be used, e.g. for alias analysis or to split globals at element
boundaries where beneficial.
As previously proposed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2016-July/102472.html
Differential Revision: https://reviews.llvm.org/D22793
llvm-svn: 286514
The constant folder didn't know how to always fold bitcasts of constant integer
vectors. In particular, it was unable to handle the case where a constant vector
had some undef elements, and the resulting (i.e. bitcasted) vector type had more
elements than the original vector type.
Example:
%cast = bitcast <2 x i64><i64 undef, i64 2> to <4 x i32>
On a little endian target, %cast could have been folded to:
<4 x i32><i32 undef, i32 undef, i32 2, i32 0>
This patch improves the folding logic by teaching how to correctly propagate
undef elements in the folded vector.
Differential Revision: https://reviews.llvm.org/D24301
llvm-svn: 281343
An undef vector element can be treated as if it had any value. Folding
such a vector element to 0 in a bitcast can open up further folding
opportunities.
llvm-svn: 277104
ConstantExpr::getWithOperands does much of the hard work that
ConstantFoldInstOperandsImpl tries to do but more completely.
This lets us fold ExtractValue/InsertValue expressions.
llvm-svn: 277100
A ConstantVector can have ConstantExpr operands and vice versa.
However, the folder had no ability to fold ConstantVectors which, in
some cases, was an optimization barrier.
Instead, rephrase the folder in terms of Constants instead of
ConstantExprs and teach callers how to deal with failure.
llvm-svn: 277099
When folding an expression, we run ConstantFoldConstantExpression on
each operand of that expression.
However, ConstantFoldConstantExpression can fail and retur nullptr.
Previously, we would bail on further refining the expression.
Instead, use the original operand and see if we can refine a later
operand.
llvm-svn: 276959
D20859 and D20860 attempted to replace the SSE (V)CVTTPS2DQ and VCVTTPD2DQ truncating conversions with generic IR instead.
It turns out that the behaviour of these intrinsics is different enough from generic IR that this will cause problems, INF/NAN/out of range values are guaranteed to result in a 0x80000000 value - which plays havoc with constant folding which converts them to either zero or UNDEF. This is also an issue with the scalar implementations (which were already generic IR and what I was trying to match).
This patch changes both scalar and packed versions back to using x86-specific builtins.
It also deals with the other scalar conversion cases that are runtime rounding mode dependent and can have similar issues with constant folding.
A companion clang patch is at D22105
Differential Revision: https://reviews.llvm.org/D22106
llvm-svn: 275981
Treat loads which clip before the start of a global initializer the same
way we treat clipping beyond the end of the initializer: use zeros.
llvm-svn: 275345
We assumed that ConstantVectors would be rather uninteresting from the
perspective of analysis. However, this is not the case due to a quirk
of how LLVM handles vectors of i1. Vectors of i1 are not
ConstantDataVectors like vectors of i8, i16, i32 or i64 because i1's
SizeInBits differs from it's StoreSizeInBytes. This leads to it being
categorized as a ConstantVector instead of a ConstantDataVector.
Instead, treat ConstantVector more uniformly.
This fixes PR27591.
llvm-svn: 268479
The relative vtable ABI (PR26723) needs PLT relocations to refer to virtual
functions defined in other DSOs. The unnamed_addr attribute means that the
function's address is not significant, so we're allowed to substitute it
with the address of a PLT entry.
Also includes a bonus feature: addends for COFF image-relative references.
Differential Revision: http://reviews.llvm.org/D17938
llvm-svn: 267211
Summary:
The llvm cos intrinsic currently does not propagate undef's. This change
transforms cos(undef) to null value or 0.
There are 2 test cases added as well.
Patch by Anna Thomas!
Reviewers: sanjoy
Subscribers: majnemer, llvm-commits
Differential Revision: http://reviews.llvm.org/D18863
llvm-svn: 265825
Summary:
Fixes PR26774.
If you're aware of the issue, feel free to skip the "Motivation"
section and jump directly to "This patch".
Motivation:
I define "refinement" as discarding behaviors from a program that the
optimizer has license to discard. So transforming:
```
void f(unsigned x) {
unsigned t = 5 / x;
(void)t;
}
```
to
```
void f(unsigned x) { }
```
is refinement, since the behavior went from "if x == 0 then undefined
else nothing" to "nothing" (the optimizer has license to discard
undefined behavior).
Refinement is a fundamental aspect of many mid-level optimizations done
by LLVM. For instance, transforming `x == (x + 1)` to `false` also
involves refinement since the expression's value went from "if x is
`undef` then { `true` or `false` } else { `false` }" to "`false`" (by
definition, the optimizer has license to fold `undef` to any non-`undef`
value).
Unfortunately, refinement implies that the optimizer cannot assume
that the implementation of a function it can see has all of the
behavior an unoptimized or a differently optimized version of the same
function can have. This is a problem for functions with comdat
linkage, where a function can be replaced by an unoptimized or a
differently optimized version of the same source level function.
For instance, FunctionAttrs cannot assume a comdat function is
actually `readnone` even if it does not have any loads or stores in
it; since there may have been loads and stores in the "original
function" that were refined out in the currently visible variant, and
at the link step the linker may in fact choose an implementation with
a load or a store. As an example, consider a function that does two
atomic loads from the same memory location, and writes to memory only
if the two values are not equal. The optimizer is allowed to refine
this function by first CSE'ing the two loads, and the folding the
comparision to always report that the two values are equal. Such a
refined variant will look like it is `readonly`. However, the
unoptimized version of the function can still write to memory (since
the two loads //can// result in different values), and selecting the
unoptimized version at link time will retroactively invalidate
transforms we may have done under the assumption that the function
does not write to memory.
Note: this is not just a problem with atomics or with linking
differently optimized object files. See PR26774 for more realistic
examples that involved neither.
This patch:
This change introduces a new set of linkage types, predicated as
`GlobalValue::mayBeDerefined` that returns true if the linkage type
allows a function to be replaced by a differently optimized variant at
link time. It then changes a set of IPO passes to bail out if they see
such a function.
Reviewers: chandlerc, hfinkel, dexonsmith, joker.eph, rnk
Subscribers: mcrosier, llvm-commits
Differential Revision: http://reviews.llvm.org/D18634
llvm-svn: 265762
Summary:
This form was replaced by a form taking an instruction instead of opcode and
return type in r258391. After committing this change (and some depending,
follow-up changes) it turned out in the review thread to be controversial. The
discussion didn't come to a conclusion yet. I'm re-adding the old form to fix
the API regression and to provide a better base for discussion, possibly on
llvm-dev.
A difference to the original function is that it can't be called with GEPs
(similarly to how it was already the case for compares). In order to support
opaque pointers in the future, folding GEPs needs to be passed the source
element type, which is not possible with the current API.
Reviewers: dberlin, reames
Subscribers: dblaikie, eddyb
Differential Revision: http://reviews.llvm.org/D17901
llvm-svn: 263501
This undoes the change made in r258163. The assertion fails if `Ptr` is of a
vector type. The previous code doesn't look completely correct either, so I'll
investigate this more.
llvm-svn: 258411
Summary:
The previous form, taking opcode and type, is moved to an internal
helper and the new form, taking an instruction, is a wrapper around this
helper.
Although this is a slight cleanup on its own, the main motivation is to
refactor the constant folding API to ease migration to opaque pointers.
This will be follow-up work.
Reviewers: eddyb
Subscribers: dblaikie, llvm-commits
Differential Revision: http://reviews.llvm.org/D16383
llvm-svn: 258391
Summary:
Although this is a slight cleanup on its own, the main motivation is to
refactor the constant folding API to ease migration to opaque pointers.
This will be follow-up work.
Reviewers: eddyb
Subscribers: zzheng, dblaikie, llvm-commits
Differential Revision: http://reviews.llvm.org/D16380
llvm-svn: 258390
Summary:
Although this is a slight cleanup on its own, the main motivation is to
refactor the constant folding API to ease migration to opaque pointers.
This will be follow-up work.
Reviewers: eddyb
Subscribers: dblaikie, llvm-commits
Differential Revision: http://reviews.llvm.org/D16378
llvm-svn: 258389
Constant propagation for single precision math functions (such as
tanf) is already working, but was not enabled. This patch enables
these for many single-precision functions, and adds respective test
cases.
Newly handled functions: acosf asinf atanf atan2f ceilf coshf expf
exp2f fabsf floorf fmodf logf log10f powf sinhf tanf tanhf
llvm-svn: 246194
Constant propagation for single precision math functions (such as
tanf) is already working, but was not enabled. This patch enables
these for many single-precision functions, and adds respective test
cases.
Newly handled functions: acosf asinf atanf atan2f ceilf coshf expf
exp2f fabsf floorf fmodf logf log10f powf sinhf tanf tanhf
llvm-svn: 246186
Constant propagation for single precision math functions (such as
tanf) is already working, but was not enabled. This patch enables
these for many single-precision functions, and adds respective test
cases.
Newly handled functions: acosf asinf atanf atan2f ceilf coshf expf
exp2f fabsf floorf fmodf logf log10f powf sinhf tanf tanhf
llvm-svn: 246158
The pointer size of the addrspacecasted pointer might not have matched,
so this would have hit an assert in accumulateConstantOffset.
I think this was here to allow constant folding of a load of an
addrspacecasted constant. Accumulating the offset through the
addrspacecast doesn't make much sense, so something else is necessary
to allow folding the load through this cast.
llvm-svn: 243300
The MSVC ABI requires that we generate an alias for the vtable which
means looking through a GlobalAlias which cannot be overridden improves
our ability to devirtualize.
Found while investigating PR20801.
Patch by Andrew Zhogin!
Differential Revision: http://reviews.llvm.org/D11306
llvm-svn: 242955
A patch by Chakshu Grover!
This patch allows constfolding of trunc,rint,nearbyint,ceil and floor intrinsics using APFloat class.
Differential Revision: http://reviews.llvm.org/D11144
llvm-svn: 242763
Function 'ConstantFoldScalarCall' (in ConstantFolding.cpp) works under the
wrong assumption that a call to 'convert.from.fp16' returns a value of
type 'float'.
However, intrinsic 'convert.from.fp16' can be overloaded; for example, we
can call 'convert.from.fp16.f64' to convert from half to double; etc.
Before this patch, the following example would have triggered an assertion
failure in opt (with -constprop):
```
define double @foo() {
entry:
%0 = call double @llvm.convert.from.fp16.f64(i16 0)
ret double %0
}
```
This patch fixes the problem in ConstantFolding.cpp. When folding a call to
convert.from.fp16, we perform a different kind of conversion based on the call
return type.
Added test 'Transform/ConstProp/convert-from-fp16.ll'.
Differential Revision: http://reviews.llvm.org/D9771
llvm-svn: 237377
We already had a method to iterate over all the incoming values of a PHI. This just changes all eligible code to use it.
Ineligible code included anything which cared about the index, or was also trying to get the i'th incoming BB.
llvm-svn: 237169
Created an abstraction for log2, llvm::Log2 in Support/MathExtras.h
Hid Android problems inside of it
Differential Revision: http://reviews.llvm.org/D9467
llvm-svn: 236680
Require the pointee type to be passed explicitly and assert that it is
correct. For now it's possible to pass nullptr here (and I've done so in
a few places in this patch) but eventually that will be disallowed once
all clients have been updated or removed. It'll be a long road to get
all the way there... but if you have the cahnce to update your callers
to pass the type explicitly without depending on a pointer's element
type, that would be a good thing to do soon and a necessary thing to do
eventually.
llvm-svn: 233938
This pushes the use of PointerType::getElementType up into several
callers - I'll essentially just have to keep pushing that up the stack
until I can eliminate every call to it...
llvm-svn: 233604
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
While the term "Target" is in the name, it doesn't really have to do
with the LLVM Target library -- this isn't an abstraction which LLVM
targets generally need to implement or extend. It has much more to do
with modeling the various runtime libraries on different OSes and with
different runtime environments. The "target" in this sense is the more
general sense of a target of cross compilation.
This is in preparation for porting this analysis to the new pass
manager.
No functionality changed, and updates inbound for Clang and Polly.
llvm-svn: 226078
This is to be consistent with StringSet and ultimately with the standard
library's associative container insert function.
This lead to updating SmallSet::insert to return pair<iterator, bool>,
and then to update SmallPtrSet::insert to return pair<iterator, bool>,
and then to update all the existing users of those functions...
llvm-svn: 222334
ConstantFolding crashes when trying to InstSimplify the following load:
@a = private unnamed_addr constant %mst {
i8* inttoptr (i64 -1 to i8*),
i8* inttoptr (i64 -1 to i8*)
}, align 8
%x = load <2 x i8*>* bitcast (%mst* @a to <2 x i8*>*), align 8
This patch fix this by adding support to this type of folding:
%x = load <2 x i8*>* bitcast (%mst* @a to <2 x i8*>*), align 8
==> gets folded to:
%x = <2 x i8*> <i8* inttoptr (i64 -1 to i8*), i8* inttoptr (i64 -1 to i8*)>
llvm-svn: 220380
These are named following the IEEE-754 names for these
functions, rather than the libm fmin / fmax to avoid
possible ambiguities. Some languages may implement something
resembling fmin / fmax which return NaN if either operand is
to propagate errors. These implement the IEEE-754 semantics
of returning the other operand if either is a NaN representing
missing data.
llvm-svn: 220341
As discussed here:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20140609/220598.html
And again here:
http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-September/077168.html
The sqrt of a negative number when using the llvm intrinsic is undefined.
We should return undef rather than 0.0 to match the definition in the LLVM IR lang ref.
This change should not affect any code that isn't using "no-nans-fp-math";
ie, no-nans is a requirement for generating the llvm intrinsic in place of a sqrt function call.
Unfortunately, the behavior introduced by this patch will not match current gcc, xlc, icc, and
possibly other compilers. The current clang/llvm behavior of returning 0.0 doesn't either.
We knowingly approve of this difference with the other compilers in an attempt to flag code
that is invoking undefined behavior.
A front-end warning should also try to convince the user that the program will fail:
http://llvm.org/bugs/show_bug.cgi?id=21093
Differential Revision: http://reviews.llvm.org/D5527
llvm-svn: 218803
Tested and works fine with clang using libstdc++.
All indications are that this was fixed some time ago and isn't a problem with
any clang version we support.
I've added a note in PR6907 which is still open for some reason.
llvm-svn: 210485
Support headers shouldn't use config.h definitions, and they should never be
undefined like this.
ConstantFolding.cpp was the only user of this facility and already includes
config.h for other math features, so it makes sense to move the checks there at
point of use.
(The implicit config.h was also quite dangerous -- removing the FEnv.h include
would have silently disabled math constant folding without causing any tests to
fail. Need to investigate -Wundef once the cleanup is done.)
This eliminates the last config.h include from LLVM headers, paving the way for
more consistent configuration checks.
llvm-svn: 210483
much more effectively when trying to constant fold a load of a constant.
Previously, we only handled bitcasts by trying to find a totally generic
byte representation of the constant and use that. Now, we look through
the bitcast to see what constant we might fold the load into, and then
try to form a constant expression cast of the found value that would be
equivalent to loading the value.
You might wonder why on earth this actually matters. Well, turns out
that the Itanium ABI causes us to create a single array for a vtable
where the first elements are virtual base offsets, followed by the
virtual function pointers. Because the array is homogenous the element
type is consistently i8* and we inttoptr the virtual base offsets into
the initial elements.
Then constructors bitcast these pointers to i64 pointers prior to
loading them. Boom, no more constant folding of virtual base offsets.
This is the first fix to LLVM to address the *insane* performance Eric
Niebler discovered with Clang on his range comprehensions[1]. There is
more to come though, this doesn't *really* fix the problem fully.
[1]: http://ericniebler.com/2014/04/27/range-comprehensions/
llvm-svn: 208856
name might indicate, it is an iterator over the types in an instruction
in the IR.... You see where this is going.
Another step of modularizing the support library.
llvm-svn: 202815
This is basically the same fix in three different places. We use a set to avoid
walking the whole tree of a big ConstantExprs multiple times.
For example: (select cmp, (add big_expr 1), (add big_expr 2))
We don't want to visit big_expr twice here, it may consist of thousands of
nodes.
The testcase exercises this by creating an insanely large ConstantExprs out of
a loop. It's questionable if the optimizer should ever create those, but this
can be triggered with real C code. Fixes PR15714.
llvm-svn: 179458
We use constant folding to see if an intrinsic evaluates to the same value as a
constant that we know. If we don't take the undefinedness into account we get a
value that doesn't match the actual implementation, and miscompiled code.
This was uncovered by Chandler's simplifycfg changes.
llvm-svn: 173356
Previously we tried to infer it from the bit width size, with an added
IsIEEE argument for the PPC/IEEE 128-bit case, which had a default
value. This default value allowed bugs to creep in, where it was
inappropriate.
llvm-svn: 173138
into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.
There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.
The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.
I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).
I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.
llvm-svn: 171366
Aside from moving the actual files, this patch only updates the build
system and the source file comments under lib/... that are relevant.
I'll be updating other docs and other files in smaller subsequnet
commits.
While I've tried to test this, but it is entirely possible that there
will still be some build system fallout.
Also, note that I've not changed the library name itself: libLLVMCore.a
is still the library name. I'd be interested in others' opinions about
whether we should rename this as well (I think we should, just not sure
what it might break)
llvm-svn: 171359
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.
Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]
llvm-svn: 169131
r165941: Resubmit the changes to llvm core to update the functions to
support different pointer sizes on a per address space basis.
Despite this commit log, this change primarily changed stuff outside of
VMCore, and those changes do not carry any tests for correctness (or
even plausibility), and we have consistently found questionable or flat
out incorrect cases in these changes. Most of them are probably correct,
but we need to devise a system that makes it more clear when we have
handled the address space concerns correctly, and ideally each pass that
gets updated would receive an accompanying test case that exercises that
pass specificaly w.r.t. alternate address spaces.
However, from this commit, I have retained the new C API entry points.
Those were an orthogonal change that probably should have been split
apart, but they seem entirely good.
In several places the changes were very obvious cleanups with no actual
multiple address space code added; these I have not reverted when
I spotted them.
In a few other places there were merge conflicts due to a cleaner
solution being implemented later, often not using address spaces at all.
In those cases, I've preserved the new code which isn't address space
dependent.
This is part of my ongoing effort to clean out the partial address space
code which carries high risk and low test coverage, and not likely to be
finished before the 3.2 release looms closer. Duncan and I would both
like to see the above issues addressed before we return to these
changes.
llvm-svn: 167222
getIntPtrType support for multiple address spaces via a pointer type,
and also introduced a crasher bug in the constant folder reported in
PR14233.
These commits also contained several problems that should really be
addressed before they are re-committed. I have avoided reverting various
cleanups to the DataLayout APIs that are reasonable to have moving
forward in order to reduce the amount of churn, and minimize the number
of commits that were reverted. I've also manually updated merge
conflicts and manually arranged for the getIntPtrType function to stay
in DataLayout and to be defined in a plausible way after this revert.
Thanks to Duncan for working through this exact strategy with me, and
Nick Lewycky for tracking down the really annoying crasher this
triggered. (Test case to follow in its own commit.)
After discussing with Duncan extensively, and based on a note from
Micah, I'm going to continue to back out some more of the more
problematic patches in this series in order to ensure we go into the
LLVM 3.2 branch with a reasonable story here. I'll send a note to
llvmdev explaining what's going on and why.
Summary of reverted revisions:
r166634: Fix a compiler warning with an unused variable.
r166607: Add some cleanup to the DataLayout changes requested by
Chandler.
r166596: Revert "Back out r166591, not sure why this made it through
since I cancelled the command. Bleh, sorry about this!
r166591: Delete a directory that wasn't supposed to be checked in yet.
r166578: Add in support for getIntPtrType to get the pointer type based
on the address space.
llvm-svn: 167221
Nikita Popov