Create wrapper methods in the Function class for the OptimizeForSize and MinSize
attributes. We want to hide the logic of "or'ing" them together when optimizing
just for size (-Os).
Currently, we are not consistent about this and rely on a front-end to always set
OptimizeForSize (-Os) if MinSize (-Oz) is on. Thus, there are 18 FIXME changes here
that should be added as follow-on patches with regression tests.
This patch is NFC-intended: it just replaces existing direct accesses of the attributes
by the equivalent wrapper call.
Differential Revision: http://reviews.llvm.org/D11734
llvm-svn: 243994
If we don't have sys/wait.h and we're on a unix system there's no way
that several of the llvm tools work at all. This includes clang.
Just remove the configure and cmake checks entirely - we'll get a
build error instead of building something broken now.
llvm-svn: 243957
Summary: This patch adds enum value for an existing metadata type -- make.implicit. Using preassigned enum will be helpful to get compile time type checking and avoid string construction and comparison. The patch also changes uses of make.implicit from string metadata to enum metadata. There is no functionality change.
Reviewers: reames
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D11698
llvm-svn: 243954
This happens to work, but is not guaranteed to work. Indeed, most memcpy
interfaces in Linux-land annotate these arguments as nonnull, and GCC
and LLVM both can and do optimized based upon that. When they do so,
they might legitimately have miscompiled code calling this routine with
two valid iterators, 'nullptr' and 'nullptr'. There was even code doing
precisely this because StringRef().begin() and StringRef().end() both
produce null pointers.
This was found by UBSan.
llvm-svn: 243927
Various value handles needed to be copy constructible and copy
assignable (mostly for their use in DenseMap). But to avoid an API that
might allow accidental slicing, make these members protected in the base
class and make derived classes final (the special members become
implicitly public there - but disallowing further derived classes that
might be sliced to the intermediate type).
Might be worth having a warning a bit like -Wnon-virtual-dtor that
catches public move/copy assign/ctors in classes with virtual functions.
(suppressable in the same way - by making them protected in the base,
and making the derived classes final) Could be fancier and only diagnose
them when they're actually called, potentially.
Also allow a few default implementations where custom implementations
(especially with non-standard return types) were implemented.
llvm-svn: 243909
This fixes a bug found while working on the bitcode reader. In
particular, the method BitstreamReader::AtEndOfStream doesn't always
behave correctly when processing a data streamer. The method
fillCurWord doesn't properly set CurWord/BitsInCurWord if the data
streamer was already at eof, but GetBytes had not yet set the
ObjectSize field of the streaming memory object.
This patch fixes this problem, and provides a test to show that
this problem has been fixed.
Patch by Karl Schimpf.
Differential Revision: http://reviews.llvm.org/D11391
llvm-svn: 243890
Since r241097, `DIBuilder` has only created distinct `DICompileUnit`s.
The backend is liable to start relying on that (if it hasn't already),
so make uniquable `DICompileUnit`s illegal and automatically upgrade old
bitcode. This is a nice cleanup, since we can remove an unnecessary
`DenseSet` (and the associated uniquing info) from `LLVMContextImpl`.
Almost all the testcases were updated with this script:
git grep -e '= !DICompileUnit' -l -- test |
grep -v test/Bitcode |
xargs sed -i '' -e 's,= !DICompileUnit,= distinct !DICompileUnit,'
I imagine something similar should work for out-of-tree testcases.
llvm-svn: 243885
Instead of cloning distinct `MDNode`s when linking in a module, just
move them over. The module linker destroys the source module, so the
old node would otherwise just be leaked on the context. Create the new
node in place. This also reduces the number of cloned uniqued nodes
(since it's less likely their operands have changed).
This mapping strategy is only correct when we're discarding the source,
so the linker turns it on via a ValueMapper flag, `RF_MoveDistinctMDs`.
There's nothing observable in terms of `llvm-link` output here: the
linked module should be semantically identical.
I'll be adding more 'distinct' nodes to the debug info metadata graph in
order to break uniquing cycles, so the benefits of this will partly come
in future commits. However, we should get some gains immediately, since
we have a fair number of 'distinct' `DILocation`s being linked in.
llvm-svn: 243883
Instead of always showing/printing all functions, a class derived from
the DOTViewer class can overwrite the set of functions that will be
processed.
This will be used (and tested) by Polly's scop viewers, but other users
can be imagined as well.
llvm-svn: 243881
Summary:
This is useful for PNaCl's `RewriteAtomics` pass. NaCl intrinsics don't exist for some of the more exotic RMW instructions, so by refactoring this function into its own, `RewriteAtomics` can share code rewriting those atomics with `AtomicExpand` while additionally saving a few cycles by generating the `cmpxchg` NaCl-specific intrinsic with the callback. Without this patch, `RewriteAtomics` would require two extra passes over functions, by first requiring use of the full `AtomicExpand` pass to just expand the leftover exotic RMWs and then running itself again to expand resulting `cmpxchg`s.
NFC
Reviewers: jfb
Subscribers: jfb, llvm-commits
Differential Revision: http://reviews.llvm.org/D11422
llvm-svn: 243880
Summary:
Modify the cost calculation function for interleaved accesses
to use the target-specific costs for insert/extract element and
memory operations.
This better models the case where the backend can't match
the interleaved group, and we are forced to use a wide load
and shuffle vectors.
Interleaved accesses are not enabled by default, so this shouldn't
cause a performance change.
Reviewers: jmolloy
Subscribers: jmolloy, llvm-commits
Differential Revision: http://reviews.llvm.org/D11718
llvm-svn: 243875
Adjust the GlobalMergeOnExternal option so that the default behaviour is to
do whatever the Target thinks is best. Explicitly enabled or disabling the
option will override this default.
Differential Revision: http://reviews.llvm.org/D10965
llvm-svn: 243873
Change `DIELoc` and `DIEBlock` to stop inheriting from `DIE`, instead
inheriting from `DIEValueList` to share the value storage API. This
awkward bit of code-sharing was also fairly confusing: neither `DIELoc`
nor `DIEBlock` represents a `DIE`, so why would they inherit from it?
Aside from the API cleanup, this should improve debug info memory usage
in the backend, since it shaves five pointers off of every `DIELoc` and
`DIEBlock`. I haven't bothered to measure the savings, though.
llvm-svn: 243858
Rewrite `DIEValueList` as a subclass of `DIE`, renaming its API to match
`DIE`'s. This is preparation for changing `DIEBlock` and `DIELoc` to
stop inheriting from `DIE` and inherit directly from `DIEValueList`.
I thought about leaving this as a has-a relationship (and changing
`DIELoc` and `DIEBlock` to also have-a `DIEValueList`), but that seemed
to require a fair bit more boilerplate and I think it needed more
changes to the `DwarfUnit` API than this will.
No functionality change intended here.
llvm-svn: 243854
Various targets use std::swap on specific MCAsmOperands (ARM and
possibly Hexagon as well). It might be helpful to mark those subclasses
as final, to ensure that the availability of move/copy operations can't
lead to slicing. (same sort of requirements as the non-vitual dtor -
protected or a final class)
llvm-svn: 243820
This commit fixes a bug in the class 'SIInstrInfo' where the implicit register
machine operands were added to a machine instruction in an incorrect order -
the implicit uses were added before the implicit defs.
I found this bug while working on moving the implicit register operand
verification code from the MIR parser to the machine verifier.
This commit also makes the method 'addImplicitDefUseOperands' in the machine
instruction class public so that it can be reused in the 'SIInstrInfo' class.
Reviewers: Matt Arsenault
Differential Revision: http://reviews.llvm.org/D11689
llvm-svn: 243799
Remove the fake `DW_TAG_auto_variable` and `DW_TAG_arg_variable` tags,
using `DW_TAG_variable` in their place Stop exposing the `tag:` field at
all in the assembly format for `DILocalVariable`.
Most of the testcase updates were generated by the following sed script:
find test/ -name "*.ll" -o -name "*.mir" |
xargs grep -l 'DILocalVariable' |
xargs sed -i '' \
-e 's/tag: DW_TAG_arg_variable, //' \
-e 's/tag: DW_TAG_auto_variable, //'
There were only a handful of tests in `test/Assembly` that I needed to
update by hand.
(Note: a follow-up could change `DILocalVariable::DILocalVariable()` to
set the tag to `DW_TAG_formal_parameter` instead of `DW_TAG_variable`
(as appropriate), instead of having that logic magically in the backend
in `DbgVariable`. I've added a FIXME to that effect.)
llvm-svn: 243774
This introduces new instructions neccessary to implement MSVC-compatible
exception handling support. Most of the middle-end and none of the
back-end haven't been audited or updated to take them into account.
Differential Revision: http://reviews.llvm.org/D11097
llvm-svn: 243766
Replace the general `createLocalVariable()` with two more specific
functions: `createParameterVariable()` and `createAutoVariable()`, and
rewrite the documentation.
Besides cleaning up the API, this avoids exposing the fake DWARF tags
`DW_TAG_arg_variable` and `DW_TAG_auto_variable` to frontends, and is
preparation for removing them completely.
llvm-svn: 243764
This patch is a follow up from r240560 and is a step further into
mitigating the compile time performance issues in CaptureTracker.
By providing the CaptureTracker with a "cached ordered basic block"
instead of computing it every time, MemDepAnalysis can use this cache
throughout its calls to AA->callCapturesBefore, avoiding to recompute it
for every scanned instruction. In the same testcase used in r240560,
compile time is reduced from 2min to 30s.
This also fixes PR22348.
rdar://problem/19230319
Differential Revision: http://reviews.llvm.org/D11364
llvm-svn: 243750
Summary: Also provide the associated assertion when CodeGen starts.
Reviewers: echristo
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D11654
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 243682
Before, we were passing the pointer partitions to LAA. Now, we get all
the checks from LAA and filter out the checks within partitions in
LoopDistribution.
This effectively concludes the steps to move filtering memchecks from
LAA into its clients. There is still some cleanup left to remove the
unused interfaces in LAA that still take PtrPartition.
(Moving this functionality to LoopDistribution also requires
needsChecking on pointers to be made public.)
llvm-svn: 243613
This avoids stack overflows when the the compiler does not perform tail call
elimination. Apparently this happens for MSVC with the /Ob2 switch which
may be used by external code including this header.
Reported by and based on a patch from Jean-Francois Riendeau.
Related to rdar://21900756
llvm-svn: 243590
Bonus change to remove emacs major mode marker from SystemZMachineFunctionInfo.cpp because emacs already knows it's C++ from the extension. Also fix typo "appeary" in AMDGPUMCAsmInfo.h.
llvm-svn: 243585
This reverts commit r243567, which ultimately reapplies r243563.
The fix here was to use std::enable_if for overload resolution. Thanks to David
Blaikie for lots of help on this, and for the extra tests!
Original commit message follows:
For cases where we needed a foreach loop in reverse over a container,
we had to do something like
for (const GlobalValue *GV : make_range(TypeInfos.rbegin(),
TypeInfos.rend())) {
This provides a convenience method which shortens this to
for (const GlobalValue *GV : reverse(TypeInfos)) {
There are 2 versions of this, with a preference to the rbegin() version.
The first uses rbegin() and rend() to construct an iterator_range.
The second constructs an iterator_range from the begin() and end() methods
wrapped in std::reverse_iterator's.
Reviewed by David Blaikie.
llvm-svn: 243581
This reverts commit r243563.
The GCC buildbots were extremely unhappy about this. Reverting while
we discuss a better way of doing overload resolution.
llvm-svn: 243567
For cases where we needed a foreach loop in reverse over a container,
we had to do something like
for (const GlobalValue *GV : make_range(TypeInfos.rbegin(),
TypeInfos.rend())) {
This provides a convenience method which shortens this to
for (const GlobalValue *GV : reverse(TypeInfos)) {
There are 2 versions of this, with a preference to the rbegin() version.
The first uses rbegin() and rend() to construct an iterator_range.
The second constructs an iterator_range from the begin() and end() methods
wrapped in std::reverse_iterator's.
Reviewed by David Blaikie.
llvm-svn: 243563
Making allowableAlignment() more accessible was suggested as a predecessor patch
for D10662, so I've pulled it into TargetLowering. This let's us remove 4 instances
of duplicate logic in LegalizeDAG.
There's a subtle functional change in the implementation: the existing
allowableAlignment() code was using getPrefTypeAlignment() when checking
alignment with the DataLayout and assumed that was fast. In this implementation,
we use getABITypeAlignment() and assume that is fast. See the TODO comment or the
discussion in the Phab review for future improvements in this implementation
(don't use the data layout at all).
There are no regression test changes from this difference, and I'm not sure how to
expose it via a test. I think we actually do want to provide the 'Fast' param when
checking this from DAGCombiner::MergeConsecutiveStores(). Ie, we shouldn't merge
stores if the new stores are not going to be fast. But that change will require
fixing allowsMisalignedMemoryAccess() overrides as noted in D10662.
Differential Revision: http://reviews.llvm.org/D10905
llvm-svn: 243549
This fix was suggested as part of D11345 and is part of fixing PR24141.
With this change, we can avoid walking the uses of a divisor node if the target
doesn't want the combineRepeatedFPDivisors transform in the first place.
There is no NFC-intended other than that.
Differential Revision: http://reviews.llvm.org/D11531
llvm-svn: 243498
Reapply 243271 with more fixes; although we are not handling multiple
sources with coalescable copies, we were not properly skipping this
case.
- Teaches the ValueTracker in the PeepholeOptimizer to look through PHI
instructions.
- Add findNextSourceAndRewritePHI method to lookup into multiple sources
returnted by the ValueTracker and rewrite PHIs with new sources.
With these changes we can find more register sources and rewrite more
copies to allow coaslescing of bitcast instructions. Hence, we eliminate
unnecessary VR64 <-> GR64 copies in x86, but it could be extended to
other archs by marking "isBitcast" on target specific instructions. The
x86 example follows:
A:
psllq %mm1, %mm0
movd %mm0, %r9
jmp C
B:
por %mm1, %mm0
movd %mm0, %r9
jmp C
C:
movd %r9, %mm0
pshufw $238, %mm0, %mm0
Becomes:
A:
psllq %mm1, %mm0
jmp C
B:
por %mm1, %mm0
jmp C
C:
pshufw $238, %mm0, %mm0
Differential Revision: http://reviews.llvm.org/D11197
rdar://problem/20404526
llvm-svn: 243486
Summary:
Make Scalar Evolution able to propagate NSW and NUW flags from instructions to SCEVs in some cases. This is based on reasoning about when poison from instructions with these flags would trigger undefined behavior. This gives a 13% speed-up on some Eigen3-based Google-internal microbenchmarks for NVPTX.
There does not seem to be clear agreement about when poison should be considered to propagate through instructions. In this analysis, poison propagates only in cases where that should be uncontroversial.
This change makes LSR able to create induction variables for expressions like &ptr[i + offset] for loops like this:
for (int i = 0; i < limit; ++i) {
sum += ptr[i + offset];
}
Here ptr is a 64 bit pointer and offset is a 32 bit integer. For NVPTX, LSR currently creates an induction variable for i + offset instead, which is not as fast. Improving this situation is what brings the 13% speed-up on some Eigen3-based Google-internal microbenchmarks for NVPTX.
There are more details in this discussion on llvmdev.
June: http://lists.cs.uiuc.edu/pipermail/llvmdev/2015-June/thread.html#87234
July: http://lists.cs.uiuc.edu/pipermail/llvmdev/2015-July/thread.html#87392
Patch by Bjarke Roune
Reviewers: eliben, atrick, sanjoy
Subscribers: majnemer, hfinkel, jingyue, meheff, llvm-commits
Differential Revision: http://reviews.llvm.org/D11212
llvm-svn: 243460
The 'common' section TLS is not implemented.
Current C/C++ TLS variables are not placed in common section.
DWARF debug info to get the address of TLS variables is not generated yet.
clang and driver changes in http://reviews.llvm.org/D10524
Added -femulated-tls flag to select the emulated TLS model,
which will be used for old targets like Android that do not
support ELF TLS models.
Added TargetLowering::LowerToTLSEmulatedModel as a target-independent
function to convert a SDNode of TLS variable address to a function call
to __emutls_get_address.
Added into lib/Target/*/*ISelLowering.cpp to call LowerToTLSEmulatedModel
for TLSModel::Emulated. Although all targets supporting ELF TLS models are
enhanced, emulated TLS model has been tested only for Android ELF targets.
Modified AsmPrinter.cpp to print the emutls_v.* and emutls_t.* variables for
emulated TLS variables.
Modified DwarfCompileUnit.cpp to skip some DIE for emulated TLS variabls.
TODO: Add proper DIE for emulated TLS variables.
Added new unit tests with emulated TLS.
Differential Revision: http://reviews.llvm.org/D10522
llvm-svn: 243438
Object: add IMAGE_FILE_MACHINE_ARM64
The official specifications state that the value of IMAGE_FILE_MACHINE_ARM64
is 0xAA64 (as per the Microsoft Portable Executable and Common Object Format
Specification v8.3).
Reviewers: rnk
Subscribers: llvm-commits, compnerd, ruiu
Differential Revision: http://reviews.llvm.org/D11511
llvm-svn: 243434
This path add the aarch64 lowering of __builtin_thread_pointer. It uses
the already implemented AArch64ISD::THREAD_POINTER used in TLS generation.
llvm-svn: 243412
Summary:
The previous way of overriding it was relying on calling "setDefault"
on the global registry, which implies global mutable state.
Reviewers: echristo, atrick
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D11538
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 243388
Before the patch, the checks were generated internally in
addRuntimeCheck. Now, we use the new overloaded version of
addRuntimeCheck that takes the ready-made set of checks as a parameter.
The checks are now generated by the client (LoopDistribution) with the
new RuntimePointerChecking::generateChecks API.
Also the new printChecks API is used to print out the checks for
debugging.
This is to continue the transition over to the new model whereby clients
will get the full set of checks from LAA, filter it and then pass it to
LoopVersioning and in turn to addRuntimeCheck.
llvm-svn: 243382
Swift has a custom calling convention that also requires some new flags
on arguments and one new attribute on alloca instructions. This patch
does not include the implementation of that calling convention - that
will be provided as part of the open-source release of Swift; this only
reserves the bitcode constant values so that they are not used for
other purposes.
llvm-svn: 243379
As a stop-gap, retrieving the InlineAsm's function type was done via the
pointee type of its (pointer) Value type.
Instead, pass down and store the FunctionType in the InlineAsm object.
The only wrinkle with this is the ConstantUniqueMap, which then needs to
ferry the FunctionType down through the InlineAsmKeyType. This could be
done a bit differently if the ConstantInfo trait were broadened a bit to
provide an extension point for access to the TypeClass object from the
ValType objects, so that the ConstantUniqueMap<InlineAsm> would then be
keyed on FunctionTypes instead of PointerTypes that point to
FunctionTypes.
This drops the number of IR tests that don't roundtrip through bitcode*
without calling PointerType::getElementType from 416 to 8 (out of
10733). 3 of those crash when roundtripping at ToT anyway.
* modulo various unavoidable uses of pointer types when validating IR
(for now) and in the way globals are parsed, unfortunately. These
cases will either go away (because such validation will no longer be
necessary or possible when pointee types are opaque), or have to be
made simultaneously with the removal of pointee types.
llvm-svn: 243356
This is effectively an NFC but we can no longer print the index of the
pointer group so instead I print its address. This still lets us
cross-check the section that list the checks against the section that
list the groups (see how I modified the test).
E.g. before we printed this:
Run-time memory checks:
Check 0:
Comparing group 0:
%arrayidxC = getelementptr inbounds i16, i16* %c, i64 %store_ind
%arrayidxC1 = getelementptr inbounds i16, i16* %c, i64 %store_ind_inc
Against group 1:
%arrayidxA = getelementptr i16, i16* %a, i64 %ind
%arrayidxA1 = getelementptr i16, i16* %a, i64 %add
...
Grouped accesses:
Group 0:
(Low: %c High: (78 + %c))
Member: {%c,+,4}<%for.body>
Member: {(2 + %c),+,4}<%for.body>
Now we print this (changes are underlined):
Run-time memory checks:
Check 0:
Comparing group (0x7f9c6040c320):
~~~~~~~~~~~~~~
%arrayidxC1 = getelementptr inbounds i16, i16* %c, i64 %store_ind_inc
%arrayidxC = getelementptr inbounds i16, i16* %c, i64 %store_ind
Against group (0x7f9c6040c358):
~~~~~~~~~~~~~~
%arrayidxA1 = getelementptr i16, i16* %a, i64 %add
%arrayidxA = getelementptr i16, i16* %a, i64 %ind
...
Grouped accesses:
Group 0x7f9c6040c320:
~~~~~~~~~~~~~~
(Low: %c High: (78 + %c))
Member: {(2 + %c),+,4}<%for.body>
Member: {%c,+,4}<%for.body>
llvm-svn: 243354
Summary:
This function is not used in this change but will be used in a
subsequent change.
Reviewers: mcrosier, chandlerc
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9180
llvm-svn: 243347
This commit serializes the references from the machine basic blocks to the
unnamed basic blocks.
This commit adds a new attribute to the machine basic block's YAML mapping
called 'ir-block'. This attribute contains the actual reference to the
basic block.
Reviewers: Duncan P. N. Exon Smith
llvm-svn: 243340
This commit publicly exposes the method 'getLocalSlot' in the
'ModuleSlotTracker' class.
This change is useful for MIR serialization, to serialize the unnamed basic
block and unnamed alloca references.
Reviewers: Duncan P. N. Exon Smith
llvm-svn: 243336
Summary:
Was D9784: "Remove loop variant range check when induction variable is
strictly increasing"
This change re-implements D9784 with the two differences:
1. It does not use SCEVExpander and does not generate new
instructions. Instead, it does a quick local search for existing
`llvm::Value`s that it needs when modifying the `icmp`
instruction.
2. It is more general -- it deals with both increasing and decreasing
induction variables.
I've added all of the tests included with D9784, and two more.
As an example on what this change does (copied from D9784):
Given C code:
```
for (int i = M; i < N; i++) // i is known not to overflow
if (i < 0) break;
a[i] = 0;
}
```
This transformation produces:
```
for (int i = M; i < N; i++)
if (M < 0) break;
a[i] = 0;
}
```
Which can be unswitched into:
```
if (!(M < 0))
for (int i = M; i < N; i++)
a[i] = 0;
}
```
I went back and forth on whether the top level logic should live in
`SimplifyIndvar::eliminateIVComparison` or be put into its own
routine. Right now I've put it under `eliminateIVComparison` because
even though the `icmp` is not *eliminated*, it no longer is an IV
comparison. I'm open to putting it in its own helper routine if you
think that is better.
Reviewers: reames, nicholas, atrick
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D11278
llvm-svn: 243331
This reverts commit r243135.
Feedback from Craig Topper and David Blaikie was that we don't put const on Type as it has no mutable state.
llvm-svn: 243283
Reapply r242295 with fixes in the implementation.
- Teaches the ValueTracker in the PeepholeOptimizer to look through PHI
instructions.
- Add findNextSourceAndRewritePHI method to lookup into multiple sources
returnted by the ValueTracker and rewrite PHIs with new sources.
With these changes we can find more register sources and rewrite more
copies to allow coaslescing of bitcast instructions. Hence, we eliminate
unnecessary VR64 <-> GR64 copies in x86, but it could be extended to
other archs by marking "isBitcast" on target specific instructions. The
x86 example follows:
A:
psllq %mm1, %mm0
movd %mm0, %r9
jmp C
B:
por %mm1, %mm0
movd %mm0, %r9
jmp C
C:
movd %r9, %mm0
pshufw $238, %mm0, %mm0
Becomes:
A:
psllq %mm1, %mm0
jmp C
B:
por %mm1, %mm0
jmp C
C:
pshufw $238, %mm0, %mm0
Differential Revision: http://reviews.llvm.org/D11197
rdar://problem/20404526
llvm-svn: 243271
r243250 appeared to break clang/test/Analysis/dead-store.c on one of the build
slaves, but I couldn't reproduce this failure locally. Probably a false
positive as I saw this test was broken by r243246 or r243247 too but passed
later without people fixing anything.
llvm-svn: 243253
Summary:
This patch updates TargetTransformInfoImplCRTPBase::getGEPCost to consider
addressing modes. It now returns TCC_Free when the GEP can be completely folded
to an addresing mode.
I started this patch as I refactored SLSR. Function isGEPFoldable looks common
and is indeed used by some WIP of mine. So I extracted that logic to getGEPCost.
Furthermore, I noticed getGEPCost wasn't directly tested anywhere. The best
testing bed seems CostModel, but its getInstructionCost method invokes
getAddressComputationCost for GEPs which provides very coarse estimation. So
this patch also makes getInstructionCost call the updated getGEPCost for GEPs.
This change inevitably breaks some tests because the cost model changes, but
nothing looks seriously wrong -- if we believe the new cost model is the right
way to go, these tests should be updated.
This patch is not perfect yet -- the comments in some tests need to be updated.
I want to know whether this is a right approach before fixing those details.
Reviewers: chandlerc, hfinkel
Subscribers: aschwaighofer, llvm-commits, aemerson
Differential Revision: http://reviews.llvm.org/D9819
llvm-svn: 243250
