Commit Graph

416 Commits

Author SHA1 Message Date
Bill Wendling 958b94d679 Correct indentation.
llvm-svn: 348071
2018-12-01 09:06:26 +00:00
Bill Wendling 2a81f6670d Specify constant context in constant emitter
The constant emitter may need to evaluate the expression in a constant context.
For exasmple, global initializer lists.

llvm-svn: 348070
2018-12-01 08:29:36 +00:00
Bill Wendling 90a0563118 Revert r348029. I was git-ing and jumped the gun.
llvm-svn: 348032
2018-11-30 20:44:11 +00:00
Bill Wendling e64fe2abae We're in a constant context in the ConstantEmitter.
llvm-svn: 348029
2018-11-30 20:40:06 +00:00
Bill Wendling 8003edc9aa Compound literals, enums, et al require const expr
Summary:
Compound literals,  enums, file-scoped arrays, etc. require their
initializers and size specifiers to be constant. Wrap the initializer
expressions in a ConstantExpr so that we can easily check for this later
on.

Reviewers: rsmith, shafik

Reviewed By: rsmith

Subscribers: cfe-commits, jyknight, nickdesaulniers

Differential Revision: https://reviews.llvm.org/D53921

llvm-svn: 346455
2018-11-09 00:41:36 +00:00
Erik Pilkington e3b7144e6a [CodeGen] Fix a crash when updating a designated initializer
We need to handle the ConstantAggregateZero case here too.

rdar://45691981

Differential revision: https://reviews.llvm.org/D54010

llvm-svn: 346004
2018-11-02 17:36:58 +00:00
Bruno Ricci 17ff026b73 [AST] Refactor PredefinedExpr
Make the following changes to PredefinedExpr:

1. Move PredefinedExpr below StringLiteral so that it can use its definition.
2. Rename IdentType to IdentKind to be more in line with clang's conventions,
   and propagate the change to its users.
3. Move the location and the IdentKind into the newly available space of
   the bit-fields of Stmt.
4. Only store the function name when needed. When parsing all of Boost,
   of the 1357 PredefinedExpr 919 have no function name.

Differential Revision: https://reviews.llvm.org/D53605

Reviewed By: rjmccall

llvm-svn: 345460
2018-10-27 19:21:19 +00:00
Leonard Chan b4ba467da8 [Fixed Point Arithmetic] Fixed Point to Boolean Cast
This patch is a part of https://reviews.llvm.org/D48456 in an attempt to split
the casting logic up into smaller patches. This contains the code for casting
from fixed point types to boolean types.

Differential Revision: https://reviews.llvm.org/D53308

llvm-svn: 345063
2018-10-23 17:55:35 +00:00
Andrew Savonichev b555b76ed3 [OpenCL][NFC] Unify ZeroToOCL* cast types
Reviewers: Anastasia, yaxunl

Reviewed By: Anastasia

Subscribers: asavonic, cfe-commits

Differential Revision: https://reviews.llvm.org/D52654

llvm-svn: 345038
2018-10-23 15:19:20 +00:00
Leonard Chan 99bda375a1 [Fixed Point Arithmetic] FixedPointCast
This patch is a part of https://reviews.llvm.org/D48456 in an attempt to
split them up. This contains the code for casting between fixed point types
and other fixed point types.

The method for converting between fixed point types is based off the convert()
method in APFixedPoint.

Differential Revision: https://reviews.llvm.org/D50616

llvm-svn: 344530
2018-10-15 16:07:02 +00:00
Balaji V. Iyer 749e8285a5 [CodeGen] IncompleteArray Support
Added code to support ArrayType that is not ConstantArray.

https://reviews.llvm.org/D49952
rdar://42476155

llvm-svn: 339207
2018-08-08 00:01:21 +00:00
Fangrui Song 6907ce2f8f Remove trailing space
sed -Ei 's/[[:space:]]+$//' include/**/*.{def,h,td} lib/**/*.{cpp,h}

llvm-svn: 338291
2018-07-30 19:24:48 +00:00
George Karpenkov 39e5137f43 [AST] Add a convenient getter from QualType to RecordDecl
Differential Revision: https://reviews.llvm.org/D49951

llvm-svn: 338187
2018-07-28 02:16:13 +00:00
Richard Smith 4c6568869e Fix typo causing assert in self-host.
llvm-svn: 337508
2018-07-19 23:24:41 +00:00
Richard Smith 83497d9ead When we choose to use zeroinitializer for a trailing portion of an array
constant, don't convert the rest into a packed struct.

If an array constant has a large non-zero portion and a large zero
portion, we want to emit the first part as an array and the rest as a
zeroinitializer if possible. This fixes a memory usage regression from
r333141 when compiling PHP.

llvm-svn: 337498
2018-07-19 21:38:56 +00:00
Richard Smith 3e268632cf Use zeroinitializer for (trailing zero portion of) large array initializers
more reliably.

This re-commits r333044 with a fix for PR37560.

llvm-svn: 333141
2018-05-23 23:41:38 +00:00
Hans Wennborg 156349fa10 Revert r333044 "Use zeroinitializer for (trailing zero portion of) large array initializers"
It caused asserts, see PR37560.

> Use zeroinitializer for (trailing zero portion of) large array initializers
> more reliably.
>
> Clang has two different ways it emits array constants (from InitListExprs and
> from APValues), and both had some ability to emit zeroinitializer, but neither
> was able to catch all cases where we could use zeroinitializer reliably. In
> particular, emitting from an APValue would fail to notice if all the explicit
> array elements happened to be zero. In addition, for large arrays where only an
> initial portion has an explicit initializer, we would emit the complete
> initializer (which could be huge) rather than emitting only the non-zero
> portion. With this change, when the element would have a suffix of more than 8
> zero elements, we emit the array constant as a packed struct of its initial
> portion followed by a zeroinitializer constant for the trailing zero portion.
>
> In passing, I found a bug where SemaInit would sometimes walk the entire array
> when checking an initializer that only covers the first few elements; that's
> fixed here to unblock testing of the rest.
>
> Differential Revision: https://reviews.llvm.org/D47166

llvm-svn: 333067
2018-05-23 08:24:01 +00:00
Richard Smith 9062bbf419 Use zeroinitializer for (trailing zero portion of) large array initializers
more reliably.

Clang has two different ways it emits array constants (from InitListExprs and
from APValues), and both had some ability to emit zeroinitializer, but neither
was able to catch all cases where we could use zeroinitializer reliably. In
particular, emitting from an APValue would fail to notice if all the explicit
array elements happened to be zero. In addition, for large arrays where only an
initial portion has an explicit initializer, we would emit the complete
initializer (which could be huge) rather than emitting only the non-zero
portion. With this change, when the element would have a suffix of more than 8
zero elements, we emit the array constant as a packed struct of its initial
portion followed by a zeroinitializer constant for the trailing zero portion.

In passing, I found a bug where SemaInit would sometimes walk the entire array
when checking an initializer that only covers the first few elements; that's
fixed here to unblock testing of the rest.

Differential Revision: https://reviews.llvm.org/D47166

llvm-svn: 333044
2018-05-23 00:09:29 +00:00
Richard Smith 3f1d6de4f7 Revert r332847; it caused us to miscompile certain forms of reference initialization.
llvm-svn: 332886
2018-05-21 20:36:58 +00:00
Serge Pavlov 9f8068420a [CodeGen] Recognize more cases of zero initialization
If a variable has an initializer, codegen tries to build its value. If
the variable is large in size, building its value requires substantial
resources. It causes strange behavior from user viewpoint: compilation
of huge zero initialized arrays like:

    char data_1[2147483648u] = { 0 };

consumes enormous amount of time and memory.

With this change codegen tries to determine if variable initializer is
equivalent to zero initializer. In this case variable value is not
constructed.

This change fixes PR18978.

Differential Revision: https://reviews.llvm.org/D46241

llvm-svn: 332847
2018-05-21 16:09:54 +00:00
Matt Davis 2930d7662e [CodeGen] Use the zero initializer instead of storing an all zero representation.
Summary:
This change avoids the overhead of storing, and later crawling,
an initializer list of all zeros for arrays. When LLVM
visits this (llvm/IR/Constants.cpp) ConstantArray::getImpl()
it will scan the list looking for an array of all zero.

We can avoid the store, and short-cut the scan, by detecting
all zeros when clang builds-up the initialization representation.

This was brought to my attention when investigating PR36030


Reviewers: majnemer, rjmccall

Reviewed By: rjmccall

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D42549

llvm-svn: 324776
2018-02-09 22:10:09 +00:00
Akira Hatanaka 502775a2ee [CodeGen][X86] Fix handling of __fp16 vectors.
This commit fixes a bug in IRGen where it generates completely broken
code for __fp16 vectors on X86. For example when the following code is
compiled:

half4 hv0, hv1, hv2; // these are vectors of __fp16.

void foo221() {
  hv0 = hv1 + hv2;
}

clang generates the following IR, in which two i16 vectors are added:

@hv1 = common global <4 x i16> zeroinitializer, align 8
@hv2 = common global <4 x i16> zeroinitializer, align 8
@hv0 = common global <4 x i16> zeroinitializer, align 8

define void @foo221() {
  %0 = load <4 x i16>, <4 x i16>* @hv1, align 8
  %1 = load <4 x i16>, <4 x i16>* @hv2, align 8
  %add = add <4 x i16> %0, %1
  store <4 x i16> %add, <4 x i16>* @hv0, align 8
  ret void
}

To fix the bug, this commit uses the code committed in r314056, which
modified clang to promote and truncate __fp16 vectors to and from float
vectors in the AST. It also fixes another IRGen bug where a short value
is assigned to an __fp16 variable without any integer-to-floating-point
conversion, as shown in the following example:

__fp16 a;
short b;

void foo1() {
  a = b;
}

@b = common global i16 0, align 2
@a = common global i16 0, align 2

define void @foo1() #0 {
  %0 = load i16, i16* @b, align 2
  store i16 %0, i16* @a, align 2
  ret void
}

rdar://problem/20625184

Differential Revision: https://reviews.llvm.org/D40112

llvm-svn: 320215
2017-12-09 00:02:37 +00:00
Alexander Richardson 6d989436d0 Convert clang::LangAS to a strongly typed enum
Summary:
Convert clang::LangAS to a strongly typed enum

Currently both clang AST address spaces and target specific address spaces
are represented as unsigned which can lead to subtle errors if the wrong
type is passed. It is especially confusing in the CodeGen files as it is
not possible to see what kind of address space should be passed to a
function without looking at the implementation.
I originally made this change for our LLVM fork for the CHERI architecture
where we make extensive use of address spaces to differentiate between
capabilities and pointers. When merging the upstream changes I usually
run into some test failures or runtime crashes because the wrong kind of
address space is passed to a function. By converting the LangAS enum to a
C++11 we can catch these errors at compile time. Additionally, it is now
obvious from the function signature which kind of address space it expects.

I found the following errors while writing this patch:

- ItaniumRecordLayoutBuilder::LayoutField was passing a clang AST address
  space to  TargetInfo::getPointer{Width,Align}()
- TypePrinter::printAttributedAfter() prints the numeric value of the
  clang AST address space instead of the target address space.
  However, this code is not used so I kept the current behaviour
- initializeForBlockHeader() in CGBlocks.cpp was passing
  LangAS::opencl_generic to TargetInfo::getPointer{Width,Align}()
- CodeGenFunction::EmitBlockLiteral() was passing a AST address space to
  TargetInfo::getPointerWidth()
- CGOpenMPRuntimeNVPTX::translateParameter() passed a target address space
  to Qualifiers::addAddressSpace()
- CGOpenMPRuntimeNVPTX::getParameterAddress() was using
  llvm::Type::getPointerTo() with a AST address space
- clang_getAddressSpace() returns either a LangAS or a target address
  space. As this is exposed to C I have kept the current behaviour and
  added a comment stating that it is probably not correct.

Other than this the patch should not cause any functional changes.

Reviewers: yaxunl, pcc, bader

Reviewed By: yaxunl, bader

Subscribers: jlebar, jholewinski, nhaehnle, Anastasia, cfe-commits

Differential Revision: https://reviews.llvm.org/D38816

llvm-svn: 315871
2017-10-15 18:48:14 +00:00
John McCall 99e5e98eec Further refactoring of the constant emitter. NFC.
llvm-svn: 311065
2017-08-17 05:03:55 +00:00
John McCall de0fe07eef Extract IRGen's constant-emitter into its own helper class and clean up
the interface.

The ultimate goal here is to make it easier to do some more interesting
things in constant emission, like emit constant initializers that have
ignorable side-effects, or doing the majority of an initialization
in-place and then patching up the last few things with calls.  But for
now this is mostly just a refactoring.

llvm-svn: 310964
2017-08-15 21:42:52 +00:00
Serge Guelton 1d993270b3 Suppress all uses of LLVM_END_WITH_NULL. NFC.
Use variadic templates instead of relying on <cstdarg> + sentinel.

This enforces better type checking and makes code more readable.

Differential revision: https://reviews.llvm.org/D32550

llvm-svn: 302572
2017-05-09 19:31:30 +00:00
Craig Topper 73daaa8fb2 [CodeGen] Use APInt::lshrInPlace instead of APInt::lshr. NFC
llvm-svn: 300658
2017-04-19 05:17:33 +00:00
George Burgess IV 1a39b86d0f [CodeGen] Unique constant CompoundLiterals.
Our newly aggressive constant folding logic makes it possible for
CGExprConstant to see the same CompoundLiteralExpr more than once. So,
emitting a new GlobalVariable every time we see a CompoundLiteral is no
longer correct.

We had a similar issue with BlockExprs that was caught while testing
said aggressive folding, so I applied the same style of fix (see D26410)
here. If we find yet another case where this needs to happen, we should
probably refactor this so we don't have a third DenseMap+getter+setter.

As a design note: getAddrOfConstantCompoundLiteralIfEmitted is really
only intended to be called by ConstExprEmitter::EmitLValue. So,
returning a GlobalVariable* instead of a ConstantAddress costs us
effectively nothing, and saves us either a few bytes per entry in our
map or a bit of code duplication.

llvm-svn: 290661
2016-12-28 07:27:40 +00:00
Egor Churaev 89831421af Fix problems in "[OpenCL] Enabling the usage of CLK_NULL_QUEUE as compare operand."
Summary: Fixed warnings in commit: https://reviews.llvm.org/rL290171

Reviewers: djasper, Anastasia

Subscribers: yaxunl, cfe-commits, bader

Differential Revision: https://reviews.llvm.org/D27981

llvm-svn: 290431
2016-12-23 14:55:49 +00:00
Yaxun Liu 402804b6d6 Re-commit r289252 and r289285, and fix PR31374
llvm-svn: 289787
2016-12-15 08:09:08 +00:00
Nico Weber 7849eeb035 Revert 289252 (and follow-up 289285), it caused PR31374
llvm-svn: 289713
2016-12-14 21:38:18 +00:00
Stephan Bergmann 17c7f70362 Replace APFloatBase static fltSemantics data members with getter functions
At least the plugin used by the LibreOffice build
(<https://wiki.documentfoundation.org/Development/Clang_plugins>) indirectly
uses those members (through inline functions in LLVM/Clang include files in turn
using them), but they are not exported by utils/extract_symbols.py on Windows,
and accessing data across DLL/EXE boundaries on Windows is generally
problematic.

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

llvm-svn: 289647
2016-12-14 11:57:17 +00:00
Simon Pilgrim e4600d330f Fix unused variable warnings. NFCI.
llvm-svn: 289285
2016-12-09 22:45:21 +00:00
Yaxun Liu 8f66b4b44a Add support for non-zero null pointer for C and OpenCL
In amdgcn target, null pointers in global, constant, and generic address space take value 0 but null pointers in private and local address space take value -1. Currently LLVM assumes all null pointers take value 0, which results in incorrectly translated IR. To workaround this issue, instead of emit null pointers in local and private address space, a null pointer in generic address space is emitted and casted to local and private address space.

Tentative definition of global variables with non-zero initializer will have weak linkage instead of common linkage since common linkage requires zero initializer and does not have explicit section to hold the non-zero value.

Virtual member functions getNullPointer and performAddrSpaceCast are added to TargetCodeGenInfo which by default returns ConstantPointerNull and emitting addrspacecast instruction. A virtual member function getNullPointerValue is added to TargetInfo which by default returns 0. Each target can override these virtual functions to get target specific null pointer and the null pointer value for specific address space, and perform specific translations for addrspacecast.

Wrapper functions getNullPointer is added to CodegenModule and getTargetNullPointerValue is added to ASTContext to facilitate getting the target specific null pointers and their values.

This change has no effect on other targets except amdgcn target. Other targets can provide support of non-zero null pointer in a similar way.

This change only provides support for non-zero null pointer for C and OpenCL. Supporting for other languages will be added later incrementally.

Differential Revision: https://reviews.llvm.org/D26196

llvm-svn: 289252
2016-12-09 19:01:11 +00:00
Richard Smith 122f88d481 [c++17] P0135R1: Guaranteed copy elision.
When an object of class type is initialized from a prvalue of the same type
(ignoring cv qualifications), use the prvalue to initialize the object directly
instead of inserting a redundant elidable call to a copy constructor.

llvm-svn: 288866
2016-12-06 23:52:28 +00:00
George Burgess IV 70d15b36e5 [CodeGen] Use StringRef. NFC.
Looks like CurFn's name outlives FunctionName, so we can just pass
StringRefs around rather than going from a StringRef to a std::string
to a const char* to a StringRef.

llvm-svn: 285873
2016-11-03 02:21:43 +00:00
Akira Hatanaka 255abad9b1 [CodeGen] Fix an assert in EmitNullConstant.
r235815 changed CGRecordLowering::accumulateBases to ignore non-virtual
bases of size 0, which prevented adding those non-virtual bases to
CGRecordLayout's NonVirtualBases. This caused clang to assert when
CGRecordLayout::getNonVirtualBaseLLVMFieldNo was called in
EmitNullConstant. This commit fixes the bug by ignoring zero-sized
non-virtual bases in EmitNullConstant.

rdar://problem/28100139

Differential Revision: https://reviews.llvm.org/D24312

llvm-svn: 281405
2016-09-13 22:13:02 +00:00
Yaxun Liu 0bc4b2d337 [OpenCL] Generate opaque type for sampler_t and function call for the initializer
Currently Clang use int32 to represent sampler_t, which have been a source of issue for some backends, because in some backends sampler_t cannot be represented by int32. They have to depend on kernel argument metadata and use IPA to find the sampler arguments and global variables and transform them to target specific sampler type.

This patch uses opaque pointer type opencl.sampler_t* for sampler_t. For each use of file-scope sampler variable, it generates a function call of __translate_sampler_initializer. For each initialization of function-scope sampler variable, it generates a function call of __translate_sampler_initializer.

Each builtin library can implement its own __translate_sampler_initializer(). Since the real sampler type tends to be architecture dependent, allowing it to be initialized by a library function simplifies backend design. A typical implementation of __translate_sampler_initializer could be a table lookup of real sampler literal values. Since its argument is always a literal, the returned pointer is known at compile time and easily optimized to finally become some literal values directly put into image read instructions.

This patch is partially based on Alexey Sotkin's work in Khronos Clang (3d4eec6162).

Differential Revision: https://reviews.llvm.org/D21567

llvm-svn: 277024
2016-07-28 19:26:30 +00:00
Tim Shen 4a05bb8d8d Re-commit "[Temporary] Add an ExprWithCleanups for each C++ MaterializeTemporaryExpr."
Since D21243 fixes relative clang-tidy tests.

This reverts commit a71d9fbd41e99def9159af2b01ef6509394eaeed.

llvm-svn: 273312
2016-06-21 20:29:17 +00:00
David Majnemer 3370c20c7e [CodeGen] Use pointer-sized integers for ptrtoint sources
Given something like:
void *v = (void *)100;

We need to synthesize a ptrtoint operation from 100.  During constant
emission, we choose i64 as the type for our constant because it
guaranteed not to drop any bits from our CharUnits representation of the
value.  However, this is suboptimal for 32-bit targets: LLVM passes like
GlobalOpt will get confused by these sorts of casts resulting in
pessimization.

Instead, make sure the ptrtoint operand has a pointer-sized integer
type.

llvm-svn: 273020
2016-06-17 17:47:24 +00:00
Tim Shen 17b3deeff3 Revert "[Temporary] Add an ExprWithCleanups for each C++ MaterializeTemporaryExpr."
This reverts r272296, since there are clang-tidy failures that appear to
be caused by this change.

llvm-svn: 272310
2016-06-09 21:13:39 +00:00
Tim Shen f120a7b6a3 [Temporary] Add an ExprWithCleanups for each C++ MaterializeTemporaryExpr.
These ExprWithCleanups are added for holding a RunCleanupsScope not
for destructor calls; rather, they are for lifetime marks. This requires
ExprWithCleanups to keep a bit to indicate whether it have cleanups with
side effects (e.g. dtor calls).

Differential Revision: http://reviews.llvm.org/D20498

llvm-svn: 272296
2016-06-09 19:54:46 +00:00
Richard Smith 872307e2ac P0017R1: In C++1z, an aggregate class can have (public non-virtual) base classes; these are initialized as if they were data members.
llvm-svn: 262963
2016-03-08 22:17:41 +00:00
Rui Ueyama 83aa97941f Update for LLVM function name change.
llvm-svn: 257802
2016-01-14 21:00:27 +00:00
George Burgess IV df1ed0099b [Bugfix] Fix ICE on constexpr vector splat.
In {CG,}ExprConstant.cpp, we weren't treating vector splats properly.
This patch makes us treat splats more properly.

Additionally, this patch adds a new cast kind which allows a bool->int
cast to result in -1 or 0, instead of 1 or 0 (for true and false,
respectively), so we can sanely model OpenCL bool->int casts in the AST.

Differential Revision: http://reviews.llvm.org/D14877

llvm-svn: 257559
2016-01-13 01:52:39 +00:00
George Burgess IV 533ff009ff Clean ExprConstant/CGExprConstant up a bit. NFC.
llvm-svn: 255314
2015-12-11 00:23:35 +00:00
Richard Smith d0637bd1c6 PR25368: Replace workaround for build failure with modules enabled with a fix
for the root cause. The 'using llvm::isa;' declaration in Basic/LLVM.h only
pulls the declarations of llvm::isa that were declared prior to it into
namespace clang. In a modules build, this is a hermetic set of just the
declarations from LLVM. In a non-modules build, we happened to also pull the
declaration from lib/CodeGen/Address.h into namespace clang, which made the
code in question accidentally compile.

llvm-svn: 252211
2015-11-05 21:16:22 +00:00
NAKAMURA Takumi b2978da715 CGExprConstant.cpp: Appease Modules.
llvm-svn: 251713
2015-10-30 16:37:27 +00:00
Alexey Bataev 2bf9b4c0d1 [DEBUG INFO] Emit debug info for type used in explicit cast only.
Currently debug info for types used in explicit cast only is not emitted. It happened after a patch for better alignment handling. This patch fixes this bug.
Differential Revision: http://reviews.llvm.org/D13582

llvm-svn: 250795
2015-10-20 04:24:12 +00:00
John McCall 7f416cc426 Compute and preserve alignment more faithfully in IR-generation.
Introduce an Address type to bundle a pointer value with an
alignment.  Introduce APIs on CGBuilderTy to work with Address
values.  Change core APIs on CGF/CGM to traffic in Address where
appropriate.  Require alignments to be non-zero.  Update a ton
of code to compute and propagate alignment information.

As part of this, I've promoted CGBuiltin's EmitPointerWithAlignment
helper function to CGF and made use of it in a number of places in
the expression emitter.

The end result is that we should now be significantly more correct
when performing operations on objects that are locally known to
be under-aligned.  Since alignment is not reliably tracked in the
type system, there are inherent limits to this, but at least we
are no longer confused by standard operations like derived-to-base
conversions and array-to-pointer decay.  I've also fixed a large
number of bugs where we were applying the complete-object alignment
to a pointer instead of the non-virtual alignment, although most of
these were hidden by the very conservative approach we took with
member alignment.

Also, because IRGen now reliably asserts on zero alignments, we
should no longer be subject to an absurd but frustrating recurring
bug where an incomplete type would report a zero alignment and then
we'd naively do a alignmentAtOffset on it and emit code using an
alignment equal to the largest power-of-two factor of the offset.

We should also now be emitting much more aggressive alignment
attributes in the presence of over-alignment.  In particular,
field access now uses alignmentAtOffset instead of min.

Several times in this patch, I had to change the existing
code-generation pattern in order to more effectively use
the Address APIs.  For the most part, this seems to be a strict
improvement, like doing pointer arithmetic with GEPs instead of
ptrtoint.  That said, I've tried very hard to not change semantics,
but it is likely that I've failed in a few places, for which I
apologize.

ABIArgInfo now always carries the assumed alignment of indirect and
indirect byval arguments.  In order to cut down on what was already
a dauntingly large patch, I changed the code to never set align
attributes in the IR on non-byval indirect arguments.  That is,
we still generate code which assumes that indirect arguments have
the given alignment, but we don't express this information to the
backend except where it's semantically required (i.e. on byvals).
This is likely a minor regression for those targets that did provide
this information, but it'll be trivial to add it back in a later
patch.

I partially punted on applying this work to CGBuiltin.  Please
do not add more uses of the CreateDefaultAligned{Load,Store}
APIs; they will be going away eventually.

llvm-svn: 246985
2015-09-08 08:05:57 +00:00