forked from OSchip/llvm-project
c7ff5b38f2
Now compiler defines 5 sets of constants to represent rounding mode. These are: 1. `llvm::APFloatBase::roundingMode`. It specifies all 5 rounding modes defined by IEEE-754 and is used in `APFloat` implementation. 2. `clang::LangOptions::FPRoundingModeKind`. It specifies 4 of 5 IEEE-754 rounding modes and a special value for dynamic rounding mode. It is used in clang frontend. 3. `llvm::fp::RoundingMode`. Defines the same values as `clang::LangOptions::FPRoundingModeKind` but in different order. It is used to specify rounding mode in in IR and functions that operate IR. 4. Rounding mode representation used by `FLT_ROUNDS` (C11, 5.2.4.2.2p7). Besides constants for rounding mode it also uses a special value to indicate error. It is convenient to use in intrinsic functions, as it represents platform-independent representation for rounding mode. In this role it is used in some pending patches. 5. Values like `FE_DOWNWARD` and other, which specify rounding mode in library calls `fesetround` and `fegetround`. Often they represent bits of some control register, so they are target-dependent. The same names (not values) and a special name `FE_DYNAMIC` are used in `#pragma STDC FENV_ROUND`. The first 4 sets of constants are target independent and could have the same numerical representation. It would simplify conversion between the representations. Also now `clang::LangOptions::FPRoundingModeKind` and `llvm::fp::RoundingMode` do not contain the value for IEEE-754 rounding direction `roundTiesToAway`, although it is supported natively on some targets. This change defines all the rounding mode type via one `llvm::RoundingMode`, which also contains rounding mode for IEEE rounding direction `roundTiesToAway`. Differential Revision: https://reviews.llvm.org/D77379 |
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| include | ||
| lib | ||
| runtime | ||
| test | ||
| tools | ||
| unittests | ||
| utils | ||
| www | ||
| .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/