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
An instruction is a meta-instruction if it doesn't produce any output
in the form of executable instructions. So in the concept, a
meta-instruction does not have to be target independent.
Before this patch, `isMetaInstruction` is implemented by checking the
opcode of the instruction, add we have no way to add target dependent
opcode to the list, which does not make sense.
After this patch, a bit `isMeta` is added for class `Instruction` in
tablegen, which is used to indicate whether it's a meta instruction.
Reviewed By: pengfei
Differential Revision: https://reviews.llvm.org/D121600
This moves the registry higher in the LLVM library dependency stack.
Every client of the target registry needs to link against MC anyway to
actually use the target, so we might as well move this out of Support.
This allows us to ensure that Support doesn't have includes from MC/*.
Differential Revision: https://reviews.llvm.org/D111454
Way back in D24994, the combination of LexicalScopes::dominates and
LiveDebugValues was identified as having worst-case quadratic complexity,
but it wasn't triggered by any code path at the time. I've since run into a
scenario where this occurs, in a very large basic block where large numbers
of inlined DBG_VALUEs are present.
The quadratic-ness comes from LiveDebugValues::join calling "dominates" on
every variable location, and LexicalScopes::dominates potentially touching
every instruction in a block to test for the presence of a scope. We have,
however, already computed the presence of scopes in blocks, in the
"InstrRanges" of each scope. This patch switches the dominates method to
examine whether a block is present in a scope's InsnRanges, avoiding
walking through the whole block.
At the same time, fix getMachineBasicBlocks to account for the fact that
InsnRanges can cover multiple blocks, and add some unit tests, as Lexical
Scopes didn't have any.
Differential revision: https://reviews.llvm.org/D73725