Summary:
When moving add and sub to memory operand instructions,
aarch64-ldst-opt would prematurally pop the stack pointer,
before memory instructions that do access the stack using
indirect loads.
e.g.
```
int foo(int offset){
int local[4] = {0};
return local[offset];
}
```
would generate:
```
sub sp, sp, #16 ; Push the stack
mov x8, sp ; Save stack in register
stp xzr, xzr, [sp], #16 ; Zero initialize stack, and post-increment, making it invalid
------ If an exception goes here, the stack value might be corrupted
ldr w0, [x8, w0, sxtw #2] ; Access correct position, but it is not guarded by SP
```
Reviewers: fhahn, foad, thegameg, eli.friedman, efriedma
Reviewed By: efriedma
Subscribers: efriedma, kristof.beyls, hiraditya, danielkiss, llvm-commits, simon_tatham
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75755
This is a little more complicated than I'd like it to be. We have
to manually match a trunc+srl+load pattern that generic DAG
combine won't do for us due to isTypeDesirableForOp.
Because we have to use a ConstantExpr at some point, the canonical form
isn't set in stone, but this seems reasonable.
The pretty sizeof(<vscale x 4 x i32>) dumping is a relic of ancient
LLVM; I didn't have to touch that code. :)
Differential Revision: https://reviews.llvm.org/D75887
Patch based on https://reviews.llvm.org/D75912 by Alexander Shishkin. Thanks
Alexander!
To minimize disruption to existing clients, who may be relying on the fact that
unused references to unresolved symbols do not generate an error, this patch
makes error checking opt-in: Clients can call ExecutionEngine::hasError or
LLVMExecutionEngineGetError to check whether and error has occurred.
Differential revision: https://reviews.llvm.org/D75912
Summary:
Add FORCE_ON option to LLVM_ENABLE_ZLIB, which causes a configuration
error if zlib is not found.
Similar to https://reviews.llvm.org/D40050.
Reviewers: hans, thakis, rnk
Subscribers: mgorny, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76110
a tail call
This reapplies the patch in https://reviews.llvm.org/rG1f5b471b8bf4,
which was reverted because it was causing crashes.
https://bugs.chromium.org/p/chromium/issues/detail?id=1061289#c2
Check that HasSafePathToCall is true before checking the call is a tail
call.
Original commit message:
Previosly ARC optimizer removed the autoreleaseRV/retainRV pair in the
following code, which caused the object returned by @something to be
placed in the autorelease pool because the call to @something isn't a
tail call:
```
%call = call i8* @something(...)
%2 = call i8* @objc_retainAutoreleasedReturnValue(i8* %call)
%3 = call i8* @objc_autoreleaseReturnValue(i8* %2)
ret i8* %3
```
Fix the bug by checking whether @something is a tail call.
rdar://problem/59275894
Only collapse inner endcf if the outer one belongs to SI_IF.
If it does belong to SI_ELSE then mask being restored in fact
a partial inverse of what we need.
Differential Revision: https://reviews.llvm.org/D76154
These symbols need to be external (MSVC tools error out if a weak
external points at a symbol that isn't external; this was tried before
but had to be reverted in bc5b7217dceecd3eec69593026a9e38dfbfd6908,
and this was originally explicitly fixed in
732eeaf2a930ad2755cb4eb5d99a3deae0de4a72).
If multiple object files have weak symbols with defaults, their
defaults could cause linker errors due to duplicate definitions,
unless the names of the defaults are unique.
GNU binutils handles this by appending the name of another symbol
from the same object file to the name of the default symbol. Try
to implement something similar; before writing the object file,
locate a symbol that should have a unique name and use the name of
that one for making the weak defaults unique.
Differential Revision: https://reviews.llvm.org/D75989
There are some functional regressions and I suspect our
scopes are not as perfectly enclosed as I expected.
Disable it for now.
Differential Revision: https://reviews.llvm.org/D76148
This reverts commit 5c3117b0a98dd11717eaffd7fb583985d39544b2
This should not be necessary after
7593a480dbce4e26f7dda4aa8f15bffd03acbfdb, and Florian Hahn has confirmed
that the problem no longer reproduces with this patch.
I happened to notice this code because the FIXME talks about
OrderedBasicBlock.
Reviewed By: fhahn, dexonsmith
Differential Revision: https://reviews.llvm.org/D76075
If we're extracting the 0'th index of a v16i8 vector we're better off using MOVD than PEXTRB, unless we're storing the value or we require the implicit zero extension of PEXTRB.
The biggest perf diff is on SLM targets where MOVD (uops=1, lat=3 tp=1) is notably faster than PEXTRB (uops=2, lat=5, tp=4).
This matches what we already do for PEXTRW.
Differential Revision: https://reviews.llvm.org/D76138
Summary:
SLPVectorizer try to vectorize list of scalar instructions of the same type,
instructions already vectorized are rejected through isValidElementType().
Without this patch, tryToVectorizeList() will first try to determine vectorization
factor of a list of Instructions before checking whether each instruction has unsupported
type or not. For instructions already vectorized for SVE, it will crash at getVectorElementSize(),
where it try to return a fixed size.
This patch make sure invalid element types are rejected before trying to get vectorization
factor. This make sure we are not trying to vectorize instructions already vectorized.
Reviewers: sdesmalen, efriedma, spatel, RKSimon, ABataev, apazos, rengolin
Reviewed By: efriedma
Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76017
Back in D42616, we switched our default nop length from 15 to 10 bytes because some platforms have painful decode stalls when encountering multiple instruction prefixes. (10 byte long nops come from the fact that prefixes are used to pad after 8 bytes, and some platforms have issues w/more than two prefixes.)
Based on Agner's guides, it appears to be the case that modern Intel (SandyBridge and later) can decode an arbitrary number of prefixes without issue. Intel's guide only provides up to 9 bytes; I read that as providing a safe default for all their chips. Older chips and Atom series have serious decode stalls. I can't find a conclusive reference beyond those two.
Differential Revision: https://reviews.llvm.org/D75945
For context, the proposed RISC-V bit manipulation extension has a subset
of instructions which require one of two SubtargetFeatures to be
enabled, 'zbb' or 'zbp', and there is no defined feature which both of
these can imply to use as a constraint either (see comments in D65649).
AssemblerPredicates allow multiple SubtargetFeatures to be declared in
the "AssemblerCondString" field, separated by commas, and this means
that the two features must both be enabled. There is no equivalent to
say that _either_ feature X or feature Y must be enabled, short of
creating a dummy SubtargetFeature for this purpose and having features X
and Y imply the new feature.
To solve the case where X or Y is needed without adding a new feature,
and to better match a typical TableGen style, this replaces the existing
"AssemblerCondString" with a dag "AssemblerCondDag" which represents the
same information. Two operators are defined for use with
AssemblerCondDag, "all_of", which matches the current behaviour, and
"any_of", which adds the new proposed ORing features functionality.
This was originally proposed in the RFC at
http://lists.llvm.org/pipermail/llvm-dev/2020-February/139138.html
Changes to all current backends are mechanical to support the replaced
functionality, and are NFCI.
At this stage, it is illegal to combine features with ands and ors in a
single AssemblerCondDag. I suspect this case is sufficiently rare that
adding more complex changes to support it are unnecessary.
Differential Revision: https://reviews.llvm.org/D74338
Summary:
This patch will filter attributes to only preserve those that are usefull.
In the case of NoAlias it is filtered out not because it isn't usefull
but because it is incorrect to preserve it as it is only valdi for the
duration of the function.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: jdoerfert, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75828
Summary:
during inling Create and insert an llvm.assume with attributes to preserve them.
to prevent any changes for now generation of llvm.assume is under a flag disabled by default.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75825
When emitting PDBs, the TypeStreamMerger class is used to merge .debug$T records from the input .OBJ files into the output .PDB stream.
Records in .OBJs are not required to be aligned on 4-bytes, and "The Netwide Assembler 2.14" generates non-aligned records.
When compiling with -DLLVM_ENABLE_ASSERTIONS=ON, an assert was triggered in MergingTypeTableBuilder when non-ghash merging was used.
With ghash merging there was no assert.
As a result, LLD could potentially generate a non-aligned TPI stream.
We now align records on 4-bytes when record indices are remapped, in TypeStreamMerger::remapIndices().
Differential Revision: https://reviews.llvm.org/D75081
This patch add mayContainUnboundedCycle helper function which checks whether a function has any cycle which we don't know if it is bounded or not.
Loops with maximum trip count are considered bounded, any other cycle not.
It also contains some fixed tests and some added tests contain bounded and
unbounded loops and non-loop cycles.
Reviewed By: jdoerfert, uenoku, baziotis
Differential Revision: https://reviews.llvm.org/D74691
Resolution for below fixme:
(ii) Check whether the value is captured in the scope using AANoCapture.
FIXME: This is conservative though, it is better to look at CFG and
check only uses possibly executed before this callsite.
Propagates caller argument's noalias attribute to callee.
Reviewed by: jdoerfert, uenoku
Reviewers: jdoerfert, sstefan1, uenoku
Subscribers: uenoku, sstefan1, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D71617
GCC when configured with --enable-gnu-unique (default on glibc>=2.11)
emits STB_GNU_UNIQUE for certain objects which are otherwise emitted as
STT_OBJECT, such as an inline function's static local variable or its
guard variable, and a static data member of a template.
Clang does not implement -fgnu-unique.
Implementing it as a binding is strange and the feature itself is
considered by some as a misfeature.
Reviewed By: grimar, jhenderson
Differential Revision: https://reviews.llvm.org/D75797
Merge symbol-table-elf.test and common-symbol-elf.test, and add some
more tests (invalid st_type, STT_COMMON, STT_GNU_IFUNC, STT_HIOS, STT_LOPROC, SHN_UNDEF, SHN_ABS, SHN_COMMON, STB_GNU_UNIQUE, invalid binding, etc) to test/llvm-objdump/ELF/symbol-table.test
The naming follows test/llvm-{readobj,objcopy}/ELF .
Some discrepancy from GNU objdump:
* STT_COMMON: can be produced with `ld.bfd -r -z common`, but it almost never exists in practice
* STT_GNU_IFUNC: will be fixed by D75793
* STB_GNU_UNIQUE: will be fixed by D75797
* STT_TLS: GNU objdump does not print 'O'
* unknown binding: GNU objdump does not print 'g'. This probably does not matter.
* A reserved symbol index is displayed as *ABS* in GNU objdump. It is not clear what we should print.
Reviewed By: grimar
Differential Revision: https://reviews.llvm.org/D75796
