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r275981 | rksimon | 2016-07-19 08:07:43 -0700 (Tue, 19 Jul 2016) | 13 lines
[X86][SSE] Reimplement SSE fp2si conversion intrinsics instead of using generic IR
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
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r276740 | rksimon | 2016-07-26 03:41:28 -0700 (Tue, 26 Jul 2016) | 5 lines
[X86][SSE] Fixed issue with memory folding of (v)cvtsd2ss intrinsics
Fixed typo in the intrinsic definitions of (v)cvtsd2ss with memory folding.
This was only unearthed when rL276102 started using the intrinsic again.....
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_39@276990 91177308-0d34-0410-b5e6-96231b3b80d8
We can always pick the passthru value if the mask is undef: we are
permitted to treat the mask as-if it were filled with zeros.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275379 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275345 91177308-0d34-0410-b5e6-96231b3b80d8
A GEPed offset can go negative, the result of getIndexedOffsetInType
should according be a signed type.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275246 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268479 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267211 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265825 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265762 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263501 91177308-0d34-0410-b5e6-96231b3b80d8
Check to see if all operands are constant before calling simplify on them
so that we don't perform wasted simplifications.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263374 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258411 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258391 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258390 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258389 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246194 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246186 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246158 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@243300 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242955 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237377 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237169 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233938 91177308-0d34-0410-b5e6-96231b3b80d8
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...
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233604 91177308-0d34-0410-b5e6-96231b3b80d8
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>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231740 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226078 91177308-0d34-0410-b5e6-96231b3b80d8
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...
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222334 91177308-0d34-0410-b5e6-96231b3b80d8
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*)>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220380 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220341 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218803 91177308-0d34-0410-b5e6-96231b3b80d8
Hans Wennborg