Summary:
In case the function was called with a desired read size *and* the file
was not an "mmap()" candidate, the function was falling back to a
"pread()", but it was failing to check the result of that system call.
This meant that the function would return "success" even though the read
operation failed, and it returned a buffer full of uninitialized memory.
Reviewers: rnk, dblaikie
Subscribers: kristina, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66224
llvm-svn: 368977
assume_safety implies that loads under "if's" can be safely executed
speculatively (unguarded, unmasked). However this assumption holds only for the
original user "if's", not those introduced by the compiler, such as the
fold-tail "if" that guards us from loading beyond the original loop trip-count.
Currently the combination of fold-tail and assume-safety pragmas results in
ignoring the fold-tail predicate that guards the loads, generating unmasked
loads. This patch fixes this behavior.
Differential Revision: https://reviews.llvm.org/D66106
Reviewers: Ayal, hsaito, fhahn
llvm-svn: 368973
We already had the pattern for just the scalar to vector and bitcast,
but not the case where we wanted zeroes in the high half of the xmm.
llvm-svn: 368972
fp_to_sint is turned into X86cvttp2si during isel preprocessing.
The other redundant isel patterns were removed previously, but I
missed this one because its in the MMX td file.
llvm-svn: 368968
Remove the @return to fix the warning: '@returns' command used in a
comment that is attached to a function returning void [-Wdocumentation]
llvm-svn: 368957
If the width is 256 bits, then we must have AVX so the else here
was unnecessary. Once that's removed then the >= 256 bit code is
identical to the 128 bit code with a different VT so combine them.
llvm-svn: 368956
Summary:
Fixes https://bugs.llvm.org/show_bug.cgi?id=36578 and https://bugs.llvm.org/show_bug.cgi?id=36296.
Supersedes: https://reviews.llvm.org/D55966
One of the fundamental transformation that CoroSplit pass performs before splitting the coroutine is to find which values need to survive between suspend and resume and provide a slot for them in the coroutine frame to spill and restore the value as needed.
Coroutine frame becomes available once the storage for it was allocated and that point is marked in the pre-split coroutine with a llvm.coro.begin intrinsic.
FE normally puts all of the user-authored code that would be accessing those values after llvm.coro.begin, however, sometimes instructions accessing those values would end up prior to coro.begin. For example, writing out a value of the parameter into the alloca done by the FE or instructions that are added by the optimization passes such as SROA when it rewrites allocas.
Prior to this change, CoroSplit pass would try to move instructions that may end up accessing the values in the coroutine frame after CoroBegin. However it would run into problems (report_fatal_error) if some of the values would be used both in the allocation function (for example allocator is passed as a parameter to a coroutine) and in the use-authored body of the coroutine.
To handle this case and to simplify the instruction moving logic, this change removes all of the instruction moving. Instead, we only change the uses of the spilled values that are dominated by coro.begin and leave other instructions intact.
Before:
```
%var = alloca i32
%1 = getelementptr .. %var; ; will move this one after coro.begin
%f = call i8* @llvm.coro.begin(
```
After:
```
%var = alloca i32
%1 = getelementptr .. %var; stays put
%f = call i8* @llvm.coro.begin(
```
If we discover that there is a potential write into an alloca, prior to coro.begin we would copy its value from the alloca into the spill slot in the coroutine frame.
Before:
```
%var = alloca i32
store .. %var ; will move this one after coro.begin
%f = call i8* @llvm.coro.begin(
```
After:
```
%var = alloca i32
store .. %var ;stays put
%f = call i8* @llvm.coro.begin(
%tmp = load %var
store %tmp, %spill.slot.for.var
```
Note: This change does not handle array allocas as that is something that C++ FE does not produce, but, it can be added in the future if need arises
Reviewers: llvm-commits, modocache, ben-clayton, tks2103, rjmccall
Reviewed By: modocache
Subscribers: bartdesmet
Differential Revision: https://reviews.llvm.org/D66230
llvm-svn: 368949
Summary: This exposes `CallInst`'s tail call kind via new `LLVMGetTailCallKind` and `LLVMSetTailCallKind` functions. The motivation for this is to be able to see `musttail` for languages that require mandatory tail calls for correctness. Today only the weaker `LLVMSetTail` is exposed and there is no way to set `GuaranteedTailCallOpt` via the C API.
Reviewers: CodaFi, jyknight, deadalnix, rnk
Reviewed By: CodaFi
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66061
llvm-svn: 368945
Summary: This modification was put in place so the `ReduceMetadata` pass doesn't have to consider debug functions
Reviewers: dblaikie
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66257
llvm-svn: 368934
Summary:
Instead of constantly keeping track of the nonnull status with the
dereferenceable information we can simply query the nonnull attribute
whenever we need the information (debug + manifest).
Reviewers: sstefan1, uenoku
Subscribers: hiraditya, bollu, jfb, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66113
llvm-svn: 368924
Implement this single atomic load instruction so that we can compile stack
protector code.
Differential Revision: https://reviews.llvm.org/D66245
llvm-svn: 368923
Summary:
As one of the first attributes, and one of the complex ones,
AAReturnedValues was not using liveness but we filtered the result after
the fact. This change adds liveness usage during the creation. The
algorithm is also improved and shorter.
The new algorithm will collect returned values over time using the
generic facilities that work with liveness already, e.g.,
genericValueTraversal which does not look at dead PHI node predecessors.
A test to show how this leads to better results is included.
Note: Unresolved calls and resolved calls are now tracked explicitly.
Reviewers: uenoku, sstefan1
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66120
llvm-svn: 368922
Summary:
If the associated context instruction is assumed dead we do not need to
update or manifest the state.
Reviewers: sstefan1, uenoku
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66116
llvm-svn: 368921
Summary:
The next attempt to clean up the Attributor interface before we grow it
further.
Before, we used a combination of two values (associated + anchor) and an
argument number (or -1) to determine a location. This was very fragile.
The new system uses exclusively IR positions and we restrict the
generation of IR positions to special constructor methods that verify
internal constraints we have. This will catch misuse early.
The auto-conversion, e.g., in getAAFor, is now performed through the
SubsumingPositionIterator. This iterator takes an IR position and allows
to visit all IR positions that "subsume" the given one, e.g., function
attributes "subsume" argument attributes of that function. For a
detailed breakdown see the class comment of SubsumingPositionIterator.
This patch also introduces the IRPosition::getAttrs() to extract IR
attributes at a certain position. The method knows how to look up in
different positions that are equivalent, e.g., the argument position for
call site arguments. We also introduce three new positions kinds such
that we have all IR positions where attributes can be placed and one for
"floating" values.
Reviewers: sstefan1, uenoku
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65977
llvm-svn: 368919
Summary:
This pass tries to remove Global Variables, as well as their derived uses. For example if a variable `@x` is used by `%call1` and `%call2`, both these uses and the definition of `@x` are deleted. Moreover if `%call1` or `%call2` are used elsewhere those uses are also deleted, and so on recursively.
I'm still uncertain if this pass should remove derived uses, I'm open to suggestions.
Subscribers: mgorny, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64176
llvm-svn: 368918
Summary: This diff also changed the check in `Delta.cpp` to verify interesting-ness, so it exits when the input isn't interesting
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66251
llvm-svn: 368915
It is sometimes useful to have the C++ standard library linked into the
assembly when compiling clang, particularly when distributing a compiler
onto systems that don't have a copy of stdlibc++ or libc++ installed.
This functionality should work with either GCC or Clang as the host
compiler, though statically linking libc++ (as may be required for
licensing purposes) is only possible if the host compiler is Clang with
a copy of libc++ available.
Differential Revision: https://reviews.llvm.org/D65603
llvm-svn: 368907
We already supported rewriting loop exit values for multiple exit loops, but if any of the loop exits were not computable, we gave up on all loop exit values. This patch generalizes the existing code to handle individual computable loop exits where possible.
As discussed in the review, this is a starting point for figuring out a better API. The code is a bit ugly, but getting it in lets us test as we go.
Differential Revision: https://reviews.llvm.org/D65544
llvm-svn: 368898
I'm planning on handling intrinsics that will benefit from checking
the address space enums. Don't bother moving the address collection
for now, since those won't need th enums.
llvm-svn: 368895
Florian Hahn