Commit Graph

203 Commits

Author SHA1 Message Date
Aaron Ballman 5547919280 Fix a crash when casting _Complex and ignoring the results.
Performing a cast where the result is ignored caused Clang to crash when
performing codegen for the conversion:

  _Complex int a;
  void fn1() { (_Complex double) a; }

This patch addresses the crash by not trying to emit the scalar conversions,
causing it to be a noop. Fixes PR44624.
2020-01-28 13:05:56 -05:00
Alexey Bataev a58da1a2ff [OPENMP50]Codegen for lastprivate conditional list items.
Added codegen support for lastprivate conditional. According to the
standard, if  when the conditional modifier appears on the clause, if an
assignment to a list item is encountered in the construct then the
original list item is assigned the value that is assigned to the new
list item in the sequentially last iteration or lexically last section
in which such an assignment is encountered.
We look for the assignment operations and check if the left side
references lastprivate conditional variable. Then the next code is
emitted:
if (last_iv_a <= iv) {
  last_iv_a = iv;
  last_a = lp_a;
}

At the end the implicit barrier is generated to wait for the end of all
threads and then in the check for the last iteration the private copy is
assigned the last value.

if (last_iter) {
  lp_a = last_a; // <--- new code
  a = lp_a;      // <--- store of private value to the original  variable.
}
2020-01-02 16:43:00 -05:00
Akira Hatanaka f139ae3d93 [NFC] Pass a reference to CodeGenFunction to methods of LValue and
AggValueSlot

This reapplies 8a5b7c3570 after a null
dereference bug in CGOpenMPRuntime::emitUserDefinedMapper.

Original commit message:

This is needed for the pointer authentication work we plan to do in the
near future.

a63a81bd99/clang/docs/PointerAuthentication.rst
2019-12-03 15:22:13 -08:00
Akira Hatanaka 9f37c0e703 Revert "[NFC] Pass a reference to CodeGenFunction to methods of LValue and"
This reverts commit 8a5b7c3570. This seems
to have broken UBSan because of a null dereference.
2019-12-03 13:08:01 -08:00
Akira Hatanaka 8a5b7c3570 [NFC] Pass a reference to CodeGenFunction to methods of LValue and
AggValueSlot

This is needed for the pointer authentication work we plan to do in the
near future.

a63a81bd99/clang/docs/PointerAuthentication.rst
2019-12-03 11:30:09 -08:00
Richard Smith 778dc0f1d4 [c++20] Add CXXRewrittenBinaryOperator to represent a comparison
operator that is rewritten as a call to multiple other operators.

No functionality change yet: nothing creates these expressions.

llvm-svn: 375305
2019-10-19 00:04:38 +00:00
Erik Pilkington eee944e7f9 [C++2a] Add __builtin_bit_cast, used to implement std::bit_cast
This commit adds a new builtin, __builtin_bit_cast(T, v), which performs a
bit_cast from a value v to a type T. This expression can be evaluated at
compile time under specific circumstances.

The compile time evaluation currently doesn't support bit-fields, but I'm
planning on fixing this in a follow up (some of the logic for figuring this out
is in CodeGen). I'm also planning follow-ups for supporting some more esoteric
types that the constexpr evaluator supports, as well as extending
__builtin_memcpy constexpr evaluation to use the same infrastructure.

rdar://44987528

Differential revision: https://reviews.llvm.org/D62825

llvm-svn: 364954
2019-07-02 18:28:13 +00:00
Eric Fiselier 708afb56c1 Implement __builtin_LINE() et. al. to support source location capture.
Summary:
This patch implements the source location builtins `__builtin_LINE(), `__builtin_FUNCTION()`, `__builtin_FILE()` and `__builtin_COLUMN()`. These builtins are needed to implement [`std::experimental::source_location`](https://rawgit.com/cplusplus/fundamentals-ts/v2/main.html#reflection.src_loc.creation).

With the exception of `__builtin_COLUMN`, GCC also implements these builtins, and Clangs behavior is intended to match as closely as possible. 

Reviewers: rsmith, joerg, aaron.ballman, bogner, majnemer, shafik, martong

Reviewed By: rsmith

Subscribers: rnkovacs, loskutov, riccibruno, mgorny, kunitoki, alexr, majnemer, hfinkel, cfe-commits

Differential Revision: https://reviews.llvm.org/D37035

llvm-svn: 360937
2019-05-16 21:04:15 +00:00
Leonard Chan 8f7caae00a [Fixed Point Arithmetic] Fixed Point and Integer Conversions
This patch includes the necessary code for converting between a fixed point type and integer.
This also includes constant expression evaluation for conversions with these types.

Differential Revision: https://reviews.llvm.org/D56900

llvm-svn: 355462
2019-03-06 00:28:43 +00:00
James Y Knight 751fe286dc [opaque pointer types] Cleanup CGBuilder's Create*GEP.
The various EltSize, Offset, DataLayout, and StructLayout arguments
are all computable from the Address's element type and the DataLayout
which the CGBuilder already has access to.

After having previously asserted that the computed values are the same
as those passed in, now remove the redundant arguments from
CGBuilder's Create*GEP functions.

Differential Revision: https://reviews.llvm.org/D57767

llvm-svn: 353629
2019-02-09 22:22:28 +00:00
James Y Knight 9871db064d [opaque pointer types] Pass function types for runtime function calls.
Emit{Nounwind,}RuntimeCall{,OrInvoke} have been modified to take a
FunctionCallee as an argument, and CreateRuntimeFunction has been
modified to return a FunctionCallee. All callers have been updated.

Additionally, CreateBuiltinFunction is removed, as it was redundant
with CreateRuntimeFunction after some previous changes.

Differential Revision: https://reviews.llvm.org/D57668

llvm-svn: 353184
2019-02-05 16:42:33 +00:00
James Y Knight 3933addd30 Cleanup: replace uses of CallSite with CallBase.
llvm-svn: 352595
2019-01-30 02:54:28 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +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
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
Adrian Prantl 9fc8faf9e6 Remove \brief commands from doxygen comments.
This is similar to the LLVM change https://reviews.llvm.org/D46290.

We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

for i in $(git grep -l '\@brief'); do perl -pi -e 's/\@brief //g' $i & done
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46320

llvm-svn: 331834
2018-05-09 01:00:01 +00:00
Alexander Kornienko 2a8c18d991 Fix typos in clang
Found via codespell -q 3 -I ../clang-whitelist.txt
Where whitelist consists of:

  archtype
  cas
  classs
  checkk
  compres
  definit
  frome
  iff
  inteval
  ith
  lod
  methode
  nd
  optin
  ot
  pres
  statics
  te
  thru

Patch by luzpaz! (This is a subset of D44188 that applies cleanly with a few
files that have dubious fixes reverted.)

Differential revision: https://reviews.llvm.org/D44188

llvm-svn: 329399
2018-04-06 15:14:32 +00:00
Rafael Espindola f4ec803cac Delete BuiltinCC. NFC.
It is always identical to RuntimeCC.

llvm-svn: 328050
2018-03-20 22:02:57 +00:00
Akira Hatanaka 797afe3a4e [CodeGen] Ignore OpaqueValueExprs that are unique references to their
source expressions when iterating over a PseudoObjectExpr's semantic
subexpression list.

Previously the loop in emitPseudoObjectExpr would emit the IR for each
OpaqueValueExpr that was in a PseudoObjectExpr's semantic-form
expression list and use the result when the OpaqueValueExpr later
appeared in other expressions. This caused an assertion failure when
AggExprEmitter tried to copy the result of an OpaqueValueExpr and the
copied type didn't have trivial copy/move constructors or assignment
operators.

This patch adds flag IsUnique to OpaqueValueExpr which indicates it is a
unique reference to its source expression (it is not used in multiple
places). The loop in emitPseudoObjectExpr ignores OpaqueValueExprs that
are unique and CodeGen visitors simply traverse the source expressions
of such OpaqueValueExprs.

rdar://problem/34363596

Differential Revision: https://reviews.llvm.org/D39562

llvm-svn: 327939
2018-03-20 01:47:58 +00:00
Florian Hahn b1c9dbdd7d [Complex] Don't use __div?c3 when building with fast-math.
Summary: Plant an inline version of "((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))" instead.

Patch by Paul Walker.

Reviewed By: hfinkel

Differential Revision: https://reviews.llvm.org/D40299

llvm-svn: 321183
2017-12-20 15:50:52 +00:00
Benjamin Kramer 16610028ea Remove unused variables. No functionality change.
llvm-svn: 315185
2017-10-08 19:11:02 +00:00
Alex Lorenz 6cc8317c38 [IRGen] Evaluate constant static variables referenced through member
expressions

C++ allows us to reference static variables through member expressions. Prior to
this commit, non-integer static variables that were referenced using a member
expression were always emitted using lvalue loads. The old behaviour introduced
an inconsistency between regular uses of static variables and member expressions
uses. For example, the following program compiled and linked successfully:

struct Foo {
   constexpr static const char *name = "foo";
};
int main() {
  return Foo::name[0] == 'f';
}

but this program failed to link because "Foo::name" wasn't found:

struct Foo {
   constexpr static const char *name = "foo";
};
int main() {
  Foo f;
  return f.name[0] == 'f';
}

This commit ensures that constant static variables referenced through member
expressions are emitted in the same way as ordinary static variable references.

rdar://33942261

Differential Revision: https://reviews.llvm.org/D36876

llvm-svn: 311772
2017-08-25 10:07:00 +00:00
Gor Nishanov 5eb585836a [coroutines] Add codegen for await and yield expressions
Details:

Emit suspend expression which roughly looks like:

auto && x = CommonExpr();
if (!x.await_ready()) {
   llvm_coro_save();
   x.await_suspend(...);     (*)
   llvm_coro_suspend(); (**)
}
x.await_resume();
where the result of the entire expression is the result of x.await_resume()

(*) If x.await_suspend return type is bool, it allows to veto a suspend:
if (x.await_suspend(...))
   llvm_coro_suspend();
(**) llvm_coro_suspend() encodes three possible continuations as a switch instruction:

%where-to = call i8 @llvm.coro.suspend(...)
switch i8 %where-to, label %coro.ret [ ; jump to epilogue to suspend
  i8 0, label %yield.ready   ; go here when resumed
  i8 1, label %yield.cleanup ; go here when destroyed
]

llvm-svn: 298784
2017-03-26 02:18:05 +00:00
Reid Kleckner 092d065265 Don't assume cleanup emission preserves dominance in expr evaluation
Summary:
Because of the existence branches out of GNU statement expressions, it
is possible that emitting cleanups for a full expression may cause the
new insertion point to not be dominated by the result of the inner
expression. Consider this example:

  struct Foo { Foo(); ~Foo(); int x; };
  int g(Foo, int);
  int f(bool cond) {
    int n = g(Foo(), ({ if (cond) return 0; 42; }));
    return n;
  }

Before this change, result of the call to 'g' did not dominate its use
in the store to 'n'. The early return exit from the statement expression
branches to a shared cleanup block, which ends in a switch between the
fallthrough destination (the assignment to 'n') or the function exit
block.

This change solves the problem by spilling and reloading expression
evaluation results when any of the active cleanups have branches.

I audited the other call sites of enterFullExpression, and they don't
appear to keep and Values live across the site of the cleanup, except in
ARC code. I wasn't able to create a test case for ARC that exhibits this
problem, though.

Reviewers: rjmccall, rsmith

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D30590

llvm-svn: 297084
2017-03-06 22:18:34 +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
Daniel Jasper 9068938eb0 Revert "[OpenCL] Enabling the usage of CLK_NULL_QUEUE as compare operand."
This reverts commit r290171. It triggers a bunch of warnings, because
the new enumerator isn't handled in all switches. We want a warning-free
build.

Replied on the commit with more details.

llvm-svn: 290173
2016-12-20 10:05:04 +00:00
Egor Churaev 67c3f3ec68 [OpenCL] Enabling the usage of CLK_NULL_QUEUE as compare operand.
Summary: Enabling the compression of CLK_NULL_QUEUE to variable of type queue_t.

Reviewers: Anastasia

Subscribers: cfe-commits, yaxunl, bader

Differential Revision: https://reviews.llvm.org/D27569

llvm-svn: 290171
2016-12-20 09:15:21 +00:00
John McCall b92ab1afd5 Refactor call emission to package the function pointer together with
abstract information about the callee.  NFC.

The goal here is to make it easier to recognize indirect calls and
trigger additional logic in certain cases.  That logic will come in
a later patch; in the meantime, I felt that this was a significant
improvement to the code.

llvm-svn: 285258
2016-10-26 23:46:34 +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
Mehdi Amini 9670f847b8 [NFC] Header cleanup
Summary: Removed unused headers, replaced some headers with forward class declarations

Patch by: Eugene <claprix@yandex.ru>

Differential Revision: https://reviews.llvm.org/D20100

llvm-svn: 275882
2016-07-18 19:02:11 +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
Samuel Antao 798f11cfb7 Preserve exceptions information during calls code generation.
This patch changes the generation of CGFunctionInfo to contain 
the FunctionProtoType if it is available. This enables the code 
generation for call instructions to look into this type for 
exception information and therefore generate better quality 
IR - it will not create invoke instructions for functions that 
are know not to throw.

llvm-svn: 253926
2015-11-23 22:04:44 +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
Charles Davis c7d5c94f78 Support __builtin_ms_va_list.
Summary:
This change adds support for `__builtin_ms_va_list`, a GCC extension for
variadic `ms_abi` functions. The existing `__builtin_va_list` support is
inadequate for this because `va_list` is defined differently in the Win64
ABI vs. the System V/AMD64 ABI.

Depends on D1622.

Reviewers: rsmith, rnk, rjmccall

CC: cfe-commits

Differential Revision: http://reviews.llvm.org/D1623

llvm-svn: 247941
2015-09-17 20:55:33 +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
Filipe Cabecinhas 7af183d841 Propagate SourceLocations through to get a Loc on float_cast_overflow
Summary:
float_cast_overflow is the only UBSan check without a source location attached.
This patch propagates SourceLocations where necessary to get them to the
EmitCheck() call.

Reviewers: rsmith, ABataev, rjmccall

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D11757

llvm-svn: 244568
2015-08-11 04:19:28 +00:00
Filipe Cabecinhas 650d7f7dd5 Don't repeat function names in comments. NFC.
llvm-svn: 244018
2015-08-05 06:19:26 +00:00
Justin Bogner 66242d6c5e InstrProf: Stop using RegionCounter outside of CodeGenPGO (NFC)
The RegionCounter type does a lot of legwork, but most of it is only
meaningful within the implementation of CodeGenPGO. The uses elsewhere
in CodeGen generally just want to increment or read counters, so do
that directly.

llvm-svn: 235664
2015-04-23 23:06:47 +00:00
David Blaikie 1ed728c499 [opaque pointer type] More GEP API migrations
Looks like the VTable code in particular will need some work to pass
around the pointee type explicitly.

llvm-svn: 234128
2015-04-05 22:45:47 +00:00
David Majnemer ced8bdf74a Sema: Parenthesized bound destructor member expressions can be called
We would wrongfully reject (a.~A)() in both the destructor and
pseudo-destructor cases.

This fixes PR22668.

llvm-svn: 230512
2015-02-25 17:36:15 +00:00
David Majnemer ce27e42d47 CodeGen: _Atomic(_Complex) shouldn't crash
We could be a little kinder if we did a compare-exchange loop instead of
an atomic-load/store pair.

llvm-svn: 229212
2015-02-14 01:48:17 +00:00
David Majnemer a5b195a1dc Revert "Revert r229082 for a bit, it caused PR22577."
This reverts commit r229123.  It was a red herring, the bug was present
without r229082.

llvm-svn: 229205
2015-02-14 01:35:12 +00:00
Nico Weber 7ce96b853d Revert r229082 for a bit, it caused PR22577.
llvm-svn: 229123
2015-02-13 16:27:00 +00:00
David Majnemer abc482effc MS ABI: Implement /volatile:ms
The /volatile:ms semantics turn volatile loads and stores into atomic
acquire and release operations.  This distinction is important because
volatile memory operations do not form a happens-before relationship
with non-atomic memory.  This means that a volatile store is not
sufficient for implementing a mutex unlock routine.

Differential Revision: http://reviews.llvm.org/D7580

llvm-svn: 229082
2015-02-13 07:55:47 +00:00
Richard Smith 527473df0d Fix typoo.
llvm-svn: 228963
2015-02-12 21:23:20 +00:00
David Blaikie 38b2591469 DebugInfo: Refactor default arg handling into a common place (instead of handling in repeatedly for aggregate, complex, and scalar types)
llvm-svn: 228591
2015-02-09 19:13:51 +00:00
David Blaikie 20937be183 DebugInfo: Suppress the location of instructions in complex default arguments.
llvm-svn: 228589
2015-02-09 18:55:57 +00:00
David Blaikie 9b47966615 DebugInfo: Use the preferred location rather than the start location for expression line info
This causes things like assignment to refer to the '=' rather than the
LHS when attributing the store instruction, for example.

There were essentially 3 options for this:

* The beginning of an expression (this was the behavior prior to this
  commit). This meant that stepping through subexpressions would bounce
  around from subexpressions back to the start of the outer expression,
  etc. (eg: x + y + z would go x, y, x, z, x (the repeated 'x's would be
  where the actual addition occurred)).

* The end of an expression. This seems to be what GCC does /mostly/, and
  certainly this for function calls. This has the advantage that
  progress is always 'forwards' (never jumping backwards - except for
  independent subexpressions if they're evaluated in interesting orders,
  etc). "x + y + z" would go "x y z" with the additions occurring at y
  and z after the respective loads.
  The problem with this is that the user would still have to think
  fairly hard about precedence to realize which subexpression is being
  evaluated or which operator overload is being called in, say, an asan
  backtrace.

* The preferred location or 'exprloc'. In this case you get sort of what
  you'd expect, though it's a bit confusing in its own way due to going
  'backwards'. In this case the locations would be: "x y + z +" in
  lovely postfix arithmetic order. But this does mean that if the op+
  were an operator overload, say, and in a backtrace, the backtrace will
  point to the exact '+' that's being called, not to the end of one of
  its operands.

(actually the operator overload case doesn't work yet for other reasons,
but that's being fixed - but this at least gets scalar/complex
assignments and other plain operators right)

llvm-svn: 227027
2015-01-25 01:19:10 +00:00