Add abbreviations for icmp/fcmp, store and br, which are the most common instructions that don't have abbreviations yet. This requires increasing the abbreviation size to 5 bits. This gives about 3-5% bitcode size reductions for the clang build.
Add `dead_on_return` attribute, which is meant to be taken advantage by the frontend, and states that the memory pointed to by the argument is dead upon function return. As with `byval`, it is supposed to be used for passing aggregates by value. The difference lies in the ABI: `byval` implies that the pointer is explicitly passed as argument to the callee (during codegen the copy is emitted as per byval contract), whereas a `dead_on_return`-marked argument implies that the copy already exists in the IR, is located at a specific stack offset within the caller, and this memory will not be read further by the caller upon callee return – or otherwise poison, if read before being written. RFC: https://discourse.llvm.org/t/rfc-add-dead-on-return-attribute/86871.
Fixes errors about duplicate PHI edges when the input had duplicates with constexprs in them. The constexpr translation makes new basic blocks, causing the verifier to complain about duplicate entries in PHI nodes.
This patch adds support for LLVM IR atomicrmw `fmaximum` and `fminimum`
instructions.
These mirror the `llvm.maximum.*` and `llvm.minimum.*` instructions, but
are atomic and use IEEE754 2019 handling for NaNs, which is different to
`fmax` and `fmin`. See:
https://llvm.org/docs/LangRef.html#llvm-minimum-intrinsic
for more details.
Future changes will allow this LLVM IR to be lowered to specialised
assembler instructions on suitable targets, such as AArch64.
Reverts llvm/llvm-project#136759 due to bad interaction with c792b25e4
This patch adds support for LLVM IR atomicrmw `fmaximum` and `fminimum`
instructions.
These mirror the `llvm.maximum.*` and `llvm.minimum.*` instructions, but
are atomic and use IEEE754 2019 handling for NaNs, which is different to
`fmax` and `fmin`. See:
https://llvm.org/docs/LangRef.html#llvm-minimum-intrinsic
for more details.
Future changes will allow this LLVM IR to be lowered to specialised
assembler instructions on suitable targets, such as AArch64.
This is needed in llvm-reduce to avoid perturbing the uselistorder in
intermediate steps. Really llvm-reduce wants pure serialization with
no dependency on the pass manager. There are other optimizations mixed
in to the serialization here depending on metadata in the module, which
is also bad.
Part of #63621
The "preserve input debug-info format" flag allowed some tooling to opt into not seeing the new debug records yet, and to not autoupgrade. This was good at the time, but un-necessary now that we'll be ditching intrinsics shortly. It also hides errors now: verify-uselistorder was hardcoding this flag to on, and as a result it hasn't seen debug records before. Thus, we missed a uselistorder variation: constant-expressions such as GEPs can be contained within debug records and completely isolated from the value hierachy, see the metadata-use-uselistorder.ll test. These Values didn't get ordered, but were legitimate uses of constants like "i64 0", and we now run into difficulty handling that. The patch to AsmWriter seeks Values to order even through debug-info now. Finally there are a few intrinsics-tests relying on this flag that we can just delete, such as one in llvm-reduce and another few in the LocalTest unit tests. For the fast-isel test, it was added in https://reviews.llvm.org/D67703 explicitly for checking the size of blocks without debug-info and in 1525abb9c94 the codepath it tests moved towards being sunsetted. It'll be totally redundant once RemoveDIs is on permanently. Note that there's now no explicit test for the textual-IR autoupgrade path. I submit that we can rely on the thousands of .ll files where we've only been bothered to update the outputs, not the inputs, to debug records.