Two or more identical assumes are occasionally next to each other in a
basic block.
While our generic machinery will turn a redundant assume into a no-op,
it is not super cheap.
We can perform a simpler check to achieve the same result for this case.
llvm-svn: 265801
InstCombine cannot effectively remove redundant assumptions without them
registered in the assumption cache. The vectorizer can create identical
assumptions but doesn't register them with the cache, resulting in
slower compile times because InstCombine tries to reason about a lot
more assumptions.
Fix this by registering the cloned assumptions.
llvm-svn: 265800
virtual registers.
Generic virtual registers:
- May not have a register class
- May not have a register bank
- If they do not have a register class they must have a size
- If they have a register bank, the size of the register bank must be
greater or equal to the size of the virtual register (basically check
that the virtual register will fit into that register class)
llvm-svn: 265798
For now, we put the register bank in the Class field since a register
may only have one of those at a given time. The downside of that
representation is that if a register class and a register bank have the
same name, we will not be able to distinguish them.
llvm-svn: 265796
The way to get the elements size with getPrimitiveSizeInBits() is not
the same as used in other parts of Polly which should use
DataLayout::getTypeAllocSize(). Its use only queries the size of the
pointer and getPrimitiveSizeInBits returns 0 for types that require a
DataLayout object such as pointers.
Together with r265379, this should fix PR27195.
llvm-svn: 265795
Added ISelDAGToDAG functions to enable selection of the smlawb, smlawt,
smulwb and smulwt instructions for the ARM backend. Also updated the smul
CodeGen test and removed the smulw one.
Differential Revision: http://reviews.llvm.org/D18892
llvm-svn: 265793
The spec says:
If a symbol definition with STV_PROTECTED visibility from a shared
object is taken as resolving a reference from an executable or another
shared object, the SHN_UNDEF symbol table entry created has STV_DEFAULT
visibility.
llvm-svn: 265792
It caused PR27275: "ARM: Bad machine code: Using an undefined physical register"
Also reverting the following commits that were landed on top:
r265610 "Fix the compare-clang diff error introduced by r265547."
r265639 "Fix the sanitizer bootstrap error in r265547."
r265657 "InlineSpiller.cpp: Escap \@ in r265547. [-Wdocumentation]"
llvm-svn: 265790
This re-commits r265535 which was reverted in r265541 because it
broke the windows bots. The problem was that we had a PointerIntPair
which took a pointer to a struct allocated with new. The problem
was that new doesn't provide sufficient alignment guarantees.
This pattern was already present before r265535 and it just happened
to work. To fix this, we now separate the PointerToIntPair from the
ExitNotTakenInfo struct into a pointer and a bool.
Original commit message:
Summary:
When the backedge taken codition is computed from an icmp, SCEV can
deduce the backedge taken count only if one of the sides of the icmp
is an AddRecExpr. However, due to sign/zero extensions, we sometimes
end up with something that is not an AddRecExpr.
However, we can use SCEV predicates to produce a 'guarded' expression.
This change adds a method to SCEV to get this expression, and the
SCEV predicate associated with it.
In HowManyGreaterThans and HowManyLessThans we will now add a SCEV
predicate associated with the guarded backedge taken count when the
analyzed SCEV expression is not an AddRecExpr. Note that we only do
this as an alternative to returning a 'CouldNotCompute'.
We use new feature in Loop Access Analysis and LoopVectorize to analyze
and transform more loops.
Reviewers: anemet, mzolotukhin, hfinkel, sanjoy
Subscribers: flyingforyou, mcrosier, atrick, mssimpso, sanjoy, mzolotukhin, llvm-commits
Differential Revision: http://reviews.llvm.org/D17201
llvm-svn: 265786
As discussed on D18441 - auto brief is used so we don't need /brief, we don't need to include the function name and added some missing descriptions.
llvm-svn: 265785
This patch fixes dynamic relocation creation from GOT access in dynamic
objects on aarch64. Current code creates a plt relative one
(R_AARCH64_JUMP_SLOT) instead of a got relative (R_AARCH64_GLOB_DAT).
It leads the programs fails with:
$ cat t.cc
std::string test = "hello...\n";
int main ()
{
printf ("%s\n", test.c_str());
return 0;
}
$ clang++ t.cc -fpic -o t
$ ./t
hello...
Segmentation fault (core dumped)
Due the fact it will try to access the plt instead of the got for
__cxa_atexit registration for the std::string destruction. It will
lead in a bogus function address in atexit.
llvm-svn: 265784
I. Current implementation of images is not conformant to spec in the following points:
1. It makes no distinction with respect to access qualifiers and therefore allows to use images with different access type interchangeably. The following code would compile just fine:
void write_image(write_only image2d_t img);
kernel void foo(read_only image2d_t img) { write_image(img); } // Accepted code
which is disallowed according to s6.13.14.
2. It discards access qualifier on generated code, which leads to generated code for the above example:
call void @write_image(%opencl.image2d_t* %img);
In OpenCL2.0 however we can have different calls into write_image with read_only and wite_only images.
Also generally following compiler steps have no easy way to take different path depending on the image access: linking to the right implementation of image types, performing IR opts and backend codegen differently.
3. Image types are language keywords and can't be redeclared s6.1.9, which can happen currently as they are just typedef names.
4. Default access qualifier read_only is to be added if not provided explicitly.
II. This patch corrects the above points as follows:
1. All images are encapsulated into a separate .def file that is inserted in different points where image handling is required. This avoid a lot of code repetition as all images are handled the same way in the code with no distinction of their exact type.
2. The Cartesian product of image types and image access qualifiers is added to the builtin types. This simplifies a lot handling of access type mismatch as no operations are allowed by default on distinct Builtin types. Also spec intended access qualifier as special type qualifier that are combined with an image type to form a distinct type (see statement above - images can't be created w/o access qualifiers).
3. Improves testing of images in Clang.
Author: Anastasia Stulova
Reviewers: bader, mgrang.
Subscribers: pxli168, pekka.jaaskelainen, yaxunl.
Differential Revision: http://reviews.llvm.org/D17821
llvm-svn: 265783
This is the same change on PPC64 as r255821 on AArch64. I have even borrowed
his commit message.
The access function has a short entry and a short exit, the initialization
block is only run the first time. To improve the performance, we want to
have a short frame at the entry and exit.
We explicitly handle most of the CSRs via copies. Only the CSRs that are not
handled via copies will be in CSR_SaveList.
Frame lowering and prologue/epilogue insertion will generate a short frame
in the entry and exit according to CSR_SaveList. The majority of the CSRs will
be handled by register allcoator. Register allocator will try to spill and
reload them in the initialization block.
We add CSRsViaCopy, it will be explicitly handled during lowering.
1> we first set FunctionLoweringInfo->SplitCSR if conditions are met (the target
supports it for the given machine function and the function has only return
exits). We also call TLI->initializeSplitCSR to perform initialization.
2> we call TLI->insertCopiesSplitCSR to insert copies from CSRsViaCopy to
virtual registers at beginning of the entry block and copies from virtual
registers to CSRsViaCopy at beginning of the exit blocks.
3> we also need to make sure the explicit copies will not be eliminated.
Author: Tom Jablin (tjablin)
Reviewers: hfinkel kbarton cycheng
http://reviews.llvm.org/D17533
llvm-svn: 265781
If we build the domains for error blocks and later remove them we lose
the information that they are not executed. Thus, in the SCoP it looks
like the control will always reach the statement S:
for (i = 0 ... N)
if (*valid == 0)
doSth(&ptr);
S: A[i] = *ptr;
Consequently, we would have assumed "ptr" to be always accessed and
preloaded it unconditionally. However, only if "*valid != 0" we would
execute the optimized version of the SCoP. Nevertheless, we would have
hoisted and accessed "ptr"regardless of "*valid". This changes the
semantic of the program as the value of "*valid" can cause a change of
"ptr" and control if it is executed or not.
To fix this problem we adjust the execution context of hoisted loads
wrt. error domains. To this end we introduce an ErrorDomainCtxMap that
maps each basic block to the error context under which it might be
executed. Thus, to the context under which it is executed but an error
block would have been executed to. To fill this map one traversal of
the blocks in the SCoP suffices. During this traversal we do also
"remove" error statements and those that are only reachable via error
statements. This was previously done by the removeErrorBlockDomains
function which is therefor not needed anymore.
This fixes bug PR26683 and thereby several SPEC miscompiles.
Differential Revision: http://reviews.llvm.org/D18822
llvm-svn: 265778
If ScalarEvolution cannot look through some expression but we do, it
might happen that a multiplication will arrive at the
SCEVAffinator::visitMulExpr. While we could always try to improve the
extractConstantFactor function we might still miss something, thus we
reintroduce the code to generate multiplicative piecewise-affine
functions as a fall-back.
llvm-svn: 265777
The findValues() function did not look through div & srem instructions
that were part of the argument SCEV. However, in different other
places we already look through it. This mismatch caused us to preload
values in the wrong order.
llvm-svn: 265775
Summary:
This check flags initializers of globals that access extern objects, and therefore can lead to order-of-initialization problems (this recommandation is part of CPP core guidelines).
Note that this only checks half of the guideline for now (it does not enforce using constexpr functions).
Reviewers: aaron.ballman, alexfh
Subscribers: aaron.ballman, etienneb, Eugene.Zelenko, cfe-commits
Patch by Clement Courbet!
Differential Revision: http://reviews.llvm.org/D18649
llvm-svn: 265774
It seems that llc cannot be called used in assembler tests so test that
checks asm for particular target needs to be moved to codegen.
llvm-svn: 265770
This reverts commit r265765, reapplying r265759 after changing a call from
LocalAsMetadata::get to ValueAsMetadata::get (and adding a unit test). When a
local value is mapped to a constant (like "i32 %a" => "i32 7"), the new debug
intrinsic operand may no longer be pointing at a local.
http://lab.llvm.org:8080/green/job/clang-stage1-configure-RA_build/19020/
The previous coommit message follows:
--
This is a partial re-commit -- maybe more of a re-implementation -- of
r265631 (reverted in r265637).
This makes RF_IgnoreMissingLocals behave (almost) consistently between
the Value and the Metadata hierarchy. In particular:
- MapValue returns nullptr or "metadata !{}" for missing locals in
MetadataAsValue/LocalAsMetadata bridging paris, depending on
the RF_IgnoreMissingLocals flag.
- MapValue doesn't memoize LocalAsMetadata-related results.
- MapMetadata no longer deals with LocalAsMetadata or
RF_IgnoreMissingLocals at all. (This wasn't in r265631 at all, but
I realized during testing it would make the patch simpler with no
loss of generality.)
r265631 went too far, making both functions universally ignore
RF_IgnoreMissingLocals. This broke building (e.g.) compiler-rt.
Reassociate (and possibly other passes) don't currently maintain
dominates-use invariants for metadata operands, resulting in IR like
this:
define void @foo(i32 %arg) {
call void @llvm.some.intrinsic(metadata i32 %x)
%x = add i32 1, i32 %arg
}
If the inliner chooses to inline @foo into another function, then
RemapInstruction will call `MapValue(metadata i32 %x)` and assert that
the return is not nullptr.
I've filed PR27273 to add a Verifier check and fix the underlying
problem in the optimization passes.
As a workaround, return `!{}` instead of nullptr for unmapped
LocalAsMetadata when RF_IgnoreMissingLocals is unset. Otherwise, match
the behaviour of r265631.
Original commit message:
ValueMapper: Make LocalAsMetadata match function-local Values
Start treating LocalAsMetadata similarly to function-local members of
the Value hierarchy in MapValue and MapMetadata.
- Don't memoize them.
- Return nullptr if they are missing.
This also cleans up ConstantAsMetadata to stop listening to the
RF_IgnoreMissingLocals flag.
llvm-svn: 265768
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
This patch closes a gap in the DWARF backend that caused LLVM to drop
debug info for floating point variables that were constant for part of
their scope. Floating point constants are emitted as one or more
DW_OP_constu joined via DW_OP_piece.
This fixes a regression caught by the LLDB testsuite that I introduced
in r262247 when we stopped blindly expanding the range of singular
DBG_VALUEs to span the entire scope and started to emit location lists
with accurate ranges instead.
Also deletes a now-impossible testcase (debug-loc-empty-entries).
<rdar://problem/25448338>
llvm-svn: 265760
This is a partial re-commit -- maybe more of a re-implementation -- of
r265631 (reverted in r265637).
This makes RF_IgnoreMissingLocals behave (almost) consistently between
the Value and the Metadata hierarchy. In particular:
- MapValue returns nullptr or "metadata !{}" for missing locals in
MetadataAsValue/LocalAsMetadata bridging paris, depending on
the RF_IgnoreMissingLocals flag.
- MapValue doesn't memoize LocalAsMetadata-related results.
- MapMetadata no longer deals with LocalAsMetadata or
RF_IgnoreMissingLocals at all. (This wasn't in r265631 at all, but
I realized during testing it would make the patch simpler with no
loss of generality.)
r265631 went too far, making both functions universally ignore
RF_IgnoreMissingLocals. This broke building (e.g.) compiler-rt.
Reassociate (and possibly other passes) don't currently maintain
dominates-use invariants for metadata operands, resulting in IR like
this:
define void @foo(i32 %arg) {
call void @llvm.some.intrinsic(metadata i32 %x)
%x = add i32 1, i32 %arg
}
If the inliner chooses to inline @foo into another function, then
RemapInstruction will call `MapValue(metadata i32 %x)` and assert that
the return is not nullptr.
I've filed PR27273 to add a Verifier check and fix the underlying
problem in the optimization passes.
As a workaround, return `!{}` instead of nullptr for unmapped
LocalAsMetadata when RF_IgnoreMissingLocals is unset. Otherwise, match
the behaviour of r265631.
Original commit message:
ValueMapper: Make LocalAsMetadata match function-local Values
Start treating LocalAsMetadata similarly to function-local members of
the Value hierarchy in MapValue and MapMetadata.
- Don't memoize them.
- Return nullptr if they are missing.
This also cleans up ConstantAsMetadata to stop listening to the
RF_IgnoreMissingLocals flag.
llvm-svn: 265759
Quentin Colombet