diff options
Diffstat (limited to 'docs/WritingAnLLVMBackend.rst')
| -rw-r--r-- | docs/WritingAnLLVMBackend.rst | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/docs/WritingAnLLVMBackend.rst b/docs/WritingAnLLVMBackend.rst index 35a2d164a909..fb7c16fc5458 100644 --- a/docs/WritingAnLLVMBackend.rst +++ b/docs/WritingAnLLVMBackend.rst @@ -51,7 +51,7 @@ These essential documents must be read before reading this document: Formation, SSA-based Optimization, Register Allocation, Prolog/Epilog Code Insertion, Late Machine Code Optimizations, and Code Emission. -* :doc:`TableGenFundamentals` --- a document that describes the TableGen +* :doc:`TableGen/index` --- a document that describes the TableGen (``tblgen``) application that manages domain-specific information to support LLVM code generation. TableGen processes input from a target description file (``.td`` suffix) and generates C++ code that can be used for code @@ -238,6 +238,12 @@ For some targets, you also need to support the following methods: * ``getTargetLowering()`` * ``getJITInfo()`` +Some architectures, such as GPUs, do not support jumping to an arbitrary +program location and implement branching using masked execution and loop using +special instructions around the loop body. In order to avoid CFG modifications +that introduce irreducible control flow not handled by such hardware, a target +must call `setRequiresStructuredCFG(true)` when being initialized. + In addition, the ``XXXTargetMachine`` constructor should specify a ``TargetDescription`` string that determines the data layout for the target machine, including characteristics such as pointer size, alignment, and |