forked from OSchip/llvm-project
d97b3e3e65
Summary: This adds the family of `vshlq_n` and `vshrq_n` ACLE intrinsics, which shift every lane of a vector left or right by a compile-time immediate. They mostly work by expanding to the IR `shl`, `lshr` and `ashr` operations, with their second operand being a vector splat of the immediate. There's a fiddly special case, though. ACLE specifies that the immediate in `vshrq_n` can take values up to //and including// the bit size of the vector lane. But LLVM IR thinks that shifting right by the full size of the lane is UB, and feels free to replace the `lshr` with an `undef` half way through the optimization pipeline. Hence, to keep this legal in source code, I have to detect it at codegen time. Logical (unsigned) right shifts by the element size are handled by simply emitting the zero vector; arithmetic ones are converted into a shift of one bit less, which will always give the same output. In order to do that check, I also had to enhance the tablegen MveEmitter so that it can cope with converting a builtin function's operand into a bare integer to pass to a code-generating subfunction. Previously the only bare integers it knew how to handle were flags generated from within `arm_mve.td`. Reviewers: dmgreen, miyuki, MarkMurrayARM, ostannard Reviewed By: MarkMurrayARM Subscribers: kristof.beyls, hiraditya, cfe-commits, llvm-commits Tags: #clang, #llvm Differential Revision: https://reviews.llvm.org/D71065 |
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| INPUTS | ||
| bindings | ||
| cmake | ||
| docs | ||
| examples | ||
| include | ||
| lib | ||
| runtime | ||
| test | ||
| tools | ||
| unittests | ||
| utils | ||
| www | ||
| .arcconfig | ||
| .clang-format | ||
| .clang-tidy | ||
| .gitignore | ||
| CMakeLists.txt | ||
| CODE_OWNERS.TXT | ||
| INSTALL.txt | ||
| LICENSE.TXT | ||
| ModuleInfo.txt | ||
| NOTES.txt | ||
| README.txt | ||
README.txt
//===----------------------------------------------------------------------===// // C Language Family Front-end //===----------------------------------------------------------------------===// Welcome to Clang. This is a compiler front-end for the C family of languages (C, C++, Objective-C, and Objective-C++) which is built as part of the LLVM compiler infrastructure project. Unlike many other compiler frontends, Clang is useful for a number of things beyond just compiling code: we intend for Clang to be host to a number of different source-level tools. One example of this is the Clang Static Analyzer. If you're interested in more (including how to build Clang) it is best to read the relevant web sites. Here are some pointers: Information on Clang: http://clang.llvm.org/ Building and using Clang: http://clang.llvm.org/get_started.html Clang Static Analyzer: http://clang-analyzer.llvm.org/ Information on the LLVM project: http://llvm.org/ If you have questions or comments about Clang, a great place to discuss them is on the Clang development mailing list: http://lists.llvm.org/mailman/listinfo/cfe-dev If you find a bug in Clang, please file it in the LLVM bug tracker: http://llvm.org/bugs/