forked from OSchip/llvm-project
dac7b23cc3
This batch of intrinsics fills in all the shift instructions that take a variable shift distance in a register, instead of an immediate. Some of these instructions take a single shift distance in a scalar register and apply it to all lanes; others take a vector of per-lane distances. These instructions are all basically one family, varying in whether they saturate out-of-range values, and whether they round when bits are shifted off the bottom. I've implemented them at the IR level by a much smaller family of IR intrinsics, which take flag parameters to indicate saturating and/or rounding (along with the usual one to specify signed/unsigned integers). An oddity is that all of them are //left// shift instructions – but if you pass a negative shift count, they'll shift right. So the vector shift distances are always vectors of //signed// integers, regardless of whether you're considering the other input vector to be of signed or unsigned. Also, even the simplest `vshlq` instruction in this family (neither saturating nor rounding) has to be implemented as an IR intrinsic, because the ordinary LLVM IR `shl` operation would consider an out-of-range shift count to be undefined behavior. Reviewers: dmgreen, MarkMurrayARM, miyuki, ostannard Reviewed By: dmgreen Subscribers: kristof.beyls, hiraditya, cfe-commits, llvm-commits Tags: #clang, #llvm Differential Revision: https://reviews.llvm.org/D72329 |
||
|---|---|---|
| .. | ||
| clang | ||
| clang-c | ||
| CMakeLists.txt | ||