forked from OSchip/llvm-project
254b4f2500
This fills in the small family of MVE intrinsics that have nothing to do with vectors: they implement bit-shift operations on 32- or 64-bit values held in one or two general-purpose registers. Most of these shift operations saturate if shifting left, and round to nearest if shifting right, although LSLL and ASRL behave like ordinary shifts. When these instructions take a variable shift count in a register, they pay attention to its sign, so that (for example) LSLL or UQRSHLL will shift left if given a positive number but right if given a negative one. That makes even LSLL and ASRL different enough from standard LLVM IR shift semantics that I couldn't see any better alternative than to simply model the whole family as a set of MVE-specific IR intrinsics. (The //immediate// forms of LSLL and ASRL, on the other hand, do behave exactly like a standard IR shift of a 64-bit value. In fact, those forms don't have ACLE intrinsics defined at all, because you can just write an ordinary C shift operation if you want one of those.) The 64-bit shifts have to be instruction-selected in C++, because they deliver two output values. But the 32-bit ones are simple enough that I could write a DAG isel pattern directly into each Instruction record. Reviewers: ostannard, MarkMurrayARM, dmgreen Reviewed By: dmgreen Subscribers: kristof.beyls, hiraditya, cfe-commits, llvm-commits Tags: #clang, #llvm Differential Revision: https://reviews.llvm.org/D70319 |
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| INPUTS | ||
| bindings | ||
| cmake | ||
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| 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/