HomePhabricator

[Intrinsic] Add llvm.minimum and llvm.maximum instrinsic functions

Description

[Intrinsic] Add llvm.minimum and llvm.maximum instrinsic functions

Summary:
These new intrinsics have the semantics of the minimum and maximum
operations specified by the latest draft of IEEE 754-2018. Unlike
llvm.minnum and llvm.maxnum, these new intrinsics propagate NaNs and
always treat -0.0 as less than 0.0. minimum and maximum lower
directly to the existing fminnan and fmaxnan ISel DAG nodes. It is
safe to reuse these DAG nodes because before this patch were only
emitted in situations where there were known to be no NaN arguments or
where NaN propagation was correct and there were known to be no zero
arguments. I know of only four backends that lower fminnan and
fmaxnan: WebAssembly, ARM, AArch64, and SystemZ, and each of these
lowers fminnan and fmaxnan to instructions that are compatible with
the IEEE 754-2018 semantics.

Reviewers: aheejin, dschuff, sunfish, javed.absar

Subscribers: kristof.beyls, dexonsmith, kristina, llvm-commits

Differential Revision: https://reviews.llvm.org/D52764

Details

Committed
tlivelyOct 13 2018, 12:21 AM
Differential Revision
D52764: [Intrinsic] Add llvm.minimum and llvm.maximum instrinsic functions
Parents
rL344436: [WebAssembly][NFC] Unify ARGUMENT classes
Branches
Unknown
Tags
Unknown