I think it's good practice to avoid having default ctors unless they're really
valid/useful. For OutlinedFunction the default ctor was used to represent a
bail-out value for getOutliningCandidateInfo(), so I changed the API to return
an optional<getOutliningCandidateInfo> instead which seems a tad cleaner.
Differential Revision: https://reviews.llvm.org/D146375
The motivation behind this patch is to unify some of the outliner logic across architectures. This looks nicer in general and makes fixing [issues like this](https://reviews.llvm.org/D124707#3483805) easier.
There are some notable changes here:
1. `isMetaInstruction()` is used directly instead of checking for specific meta-instructions like `IMPLICIT_DEF` or `KILL`. This was already done in the RISC-V implementation, but other architectures still did hardcoded checks.
- As an exception to this, CFI instructions are explicitly delegated to the target because RISC-V has different handling for those.
2. `isTargetIndex()` checks are replaced with an assert; none of the architectures supported actually use `MO_TargetIndex` at this point in time.
3. `isCFIIndex()` and `isFI()` checks are also replaced with asserts, since these operands should not exist in [any context](https://reviews.llvm.org/D122635#3447214) at this stage in the pipeline.
Reviewed by: paquette
Differential Revision: https://reviews.llvm.org/D125072
```
MCRegister getX86SubSuperRegister*(MCRegister Reg, unsigned Size,
bool High = false);
```
A strange behavior of the functions `getX86SubSuperRegister*` was
introduced by llvm-svn:145579: The returned register may not
match the parameters when a 8-bit high register is required.
And llvm-svn: 175762 refined the code and dropped the comments, then we
knew nothing happened there from the code :-(
These two functions are only called with `Size=8` and `High=true` in two places.
One is in `X86FixupBWInsts.cpp` for liveness of registers and the other is in
`X86AsmPrinter.cpp` for inline asm.
For the first one, we provide an alternative in this patch.
For the second one, the strange behaviour caused a bug that an erorr was not reported for mismatched modifier.
```
void f() {
char x;
asm volatile ("mov %%ah, %h0" :"=r"(x)::"%eax", "%ebx", "%ecx", "%edx", "edi", "esi");
}
```
```
$ gcc -S test.c
error: extended registers have no high halves
```
```
$ clang -S test.c
no error
```
so we fix the bug in this patch.
`getX86SubSuperRegister` is just a wrapper of `getX86SubSuperRegisterOrZero` with a `assert`.
I belive we should remove the latter.
Reviewed By: pengfei
Differential Revision: https://reviews.llvm.org/D142834
The register allocator may introduce reloads in the middle of reading
and writing the EFLAGS register, due to the RDFLAGS & WRFLAGS pseudos
being expanded before RA. This may cause an issue where the stack
pointer was adjusted but the stack offset for the reload wasn't
accounted for (see [1]).
To avoid this, expand these pseudos after register allocation.
[1] https://github.com/llvm/llvm-project/issues/59102
Reviewed By: craig.topper, nickdesaulniers, pengfei
Differential Revision: https://reviews.llvm.org/D140045
At the call site of findFirstSet, ZMask | (1 << DstIdx) always have
exactly 3 bits set, and they are all among the 4 least significant
bits, so (ZMask | (1 << DstIdx)) ^ 15 has exactly one bit set. Since
the argument to findFirstSet is nonzero, we can safely switch to
llvm::countr_zero.
Use deduction guides instead of helper functions.
The only non-automatic changes have been:
1. ArrayRef(some_uint8_pointer, 0) needs to be changed into ArrayRef(some_uint8_pointer, (size_t)0) to avoid an ambiguous call with ArrayRef((uint8_t*), (uint8_t*))
2. CVSymbol sym(makeArrayRef(symStorage)); needed to be rewritten as CVSymbol sym{ArrayRef(symStorage)}; otherwise the compiler is confused and thinks we have a (bad) function prototype. There was a few similar situation across the codebase.
3. ADL doesn't seem to work the same for deduction-guides and functions, so at some point the llvm namespace must be explicitly stated.
4. The "reference mode" of makeArrayRef(ArrayRef<T> &) that acts as no-op is not supported (a constructor cannot achieve that).
Per reviewers' comment, some useless makeArrayRef have been removed in the process.
This is a follow-up to https://reviews.llvm.org/D140896 that introduced
the deduction guides.
Differential Revision: https://reviews.llvm.org/D140955
With D134950, targets get notified when a virtual register is created and/or
cloned. Targets can do the needful with the delegate callback. AMDGPU propagates
the virtual register flags maintained in the target file itself. They are useful
to identify a certain type of machine operands while inserting spill stores and
reloads. Since RegAllocFast spills the physical register itself, there is no way
its virtual register can be mapped back to retrieve the flags. It can be solved
by passing the virtual register as an additional argument. This argument has no
use when the spill interfaces are called during the greedy allocator or even the
PrologEpilogInserter and can pass a null register in such cases.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D138656
Machine combiner supports generic reassociation only of associative and
commutative instructions, for example (A + X) + Y => (X + Y) + A. However, we
can extend this generic support to handle patterns like
(X + A) - Y => (X - Y) + A), where `-` is the inverse of `+`.
This patch adds interface functions to process reassociation patterns of
associative/commutative instructions and their inverse variants with minimal
changes in backends.
Differential Revision: https://reviews.llvm.org/D136754
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated. The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.
This is part of an effort to migrate from llvm::Optional to
std::optional:
https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
Before this patch, the code enumerated `getCondFromBranch`, `getCondFromSETCC` and `getCondFromFromCMov` to get the condition code of a `MachineInstr`, and assigned the result to variable `OldCC` when `MI || IsSwapped || ImmDelta != 0` was satisfiled.
After this patch, the `if-else` structure is eliminated by using `getCondFromMI`. Since `OldCC` is only used when `MI || IsSwapped || ImmDelta != 0` is true, it is initialized with `getCondFromMI` directly outside the scope of `if` now.
Reviewed By: pengfei
Differential Revision: https://reviews.llvm.org/D138349
Following on from D129634, this patch fixes more X86 CodeGen test
failures with D129213 applied, which adds verification of LiveIntervals
after the TwoAddressInstruction pass runs. These failures only showed up
with LLVM_ENABLE_EXPENSIVE_CHECKS=ON which adds the equivalent of an
implicit -verify-machineinstrs on all tests.
Differential Revision: https://reviews.llvm.org/D136596
Clang may optimize conditional tailcall blocks with the following layout:
cmp <condition>
je tailcall_target
ret
When retpoline is in place, indirect calls are converted into direct calls to a retpoline thunk. When these indirect calls are tail calls, they may be subject to the above described optimization (there is no indirect JCC, but since now the jump is direct it can be made conditional). The above layout is non-ideal for the Linux kernel scenario because the branches into thunks may be patched back into indirect branches during runtime depending on the underlying CPU features, what would not be feasible if the binary is emitted with the optimized layout above.
Thus, prevent clang from emitting this it if CodeModel is Kernel.
Feature request from the respective kernel mailing list: https://lore.kernel.org/llvm/Yv3uI%2FMoJVctmBCh@worktop.programming.kicks-ass.net/
Reviewed By: nickdesaulniers, pengfei
Differential Revision: https://reviews.llvm.org/D134915
The linker may convert such an ADD into a LEA, so we must not
use the EFLAGS output.
This causes miscompiles with -fsanitize=null after
bacdf80f42b46044262e97e98398d1bd0b75900d added
llvm.threadlocal.address -- previously, global variables were known to
be non-null, but the intrinsic is not currently known to return
nonnull. (That should be corrected, but it shouldn't've caused
miscompiles!)
Differential Revision: https://reviews.llvm.org/D131716
This specific optimisation is handled in OptimizeBlock in BranchFolding
so is redundant. As discussed on the review thread, I've verified that
we have test coverage for that optimisation within test/CodeGen/X86 by
disabling the BranchFolding version of this transform after applying
this patch and rerunning the test suite.
Differential Revision: https://reviews.llvm.org/D129204
Fix all instances of:
*** Bad machine code: Kill missing from LiveVariables ***
in the X86 CodeGen tests with D129213 applied, which adds verification
of LiveIntervals after the TwoAddressInstruction pass runs.
Differential Revision: https://reviews.llvm.org/D129634
This was stored in LiveIntervals, but not actually used for anything
related to LiveIntervals. It was only used in one check for if a load
instruction is rematerializable. I also don't think this was entirely
correct, since it was implicitly assuming constant loads are also
dereferenceable.
Remove this and rely only on the invariant+dereferenceable flags in
the memory operand. Set the flag based on the AA query upfront. This
should have the same net benefit, but has the possible disadvantage of
making this AA query nonlazy.
Preserve the behavior of assuming pointsToConstantMemory implying
dereferenceable for now, but maybe this should be changed.
This resolves problems reported in commit 1a20252978c76cf2518aa45b175a9e5d6d36c4f0.
1. Promote to float lowering for nodes XINT_TO_FP
2. Bail out f16 from shuffle combine due to vector type is not legal in the version
GCC and Clang/LLVM will support `_Float16` on X86 in C/C++, following
the latest X86 psABI. (https://gitlab.com/x86-psABIs)
_Float16 arithmetic will be performed using native half-precision. If
native arithmetic instructions are not available, it will be performed
at a higher precision (currently always float) and then truncated down
to _Float16 immediately after each single arithmetic operation.
Reviewed By: LuoYuanke
Differential Revision: https://reviews.llvm.org/D107082
1. When checking if a candidate contains a CFI instruction, actually
iterate over all of the instructions, instead of stopping halfway
through.
2. Make sure copied CFI directives refer to the correct instruction.
Fixes https://github.com/llvm/llvm-project/issues/55842
Differential Revision: https://reviews.llvm.org/D126930
There is intrinsic `@llvm.x86.ldtilecfg` which is lowered to LDTILECFG.
This intrinsic is open for user to configure tile registers by
themselves. There is a chance that `@llvm.x86.ldtilecfg` would be mixed
with the new AMX intrinsics which depend on compiler to configure tile
registers. Separate pusedo instruction PLDTILECFGV would avoid
unexpected behavious when `@llvm.x86.ldtilecfg` is mixed with new AMX
intrinsics. Though user should not mix the two programming model,
compiler should avoid crash or UB when they are mixed.
Differential Revision: https://reviews.llvm.org/D126519
