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| author | Stephen Hines <srhines@google.com> | 2014-04-23 16:57:46 -0700 |
|---|---|---|
| committer | Stephen Hines <srhines@google.com> | 2014-04-24 15:53:16 -0700 |
| commit | 36b56886974eae4f9c5ebc96befd3e7bfe5de338 (patch) | |
| tree | e6cfb69fbbd937f450eeb83bfb83b9da3b01275a /docs/WritingAnLLVMBackend.rst | |
| parent | 69a8640022b04415ae9fac62f8ab090601d8f889 (diff) | |
| download | external_llvm-36b56886974eae4f9c5ebc96befd3e7bfe5de338.zip external_llvm-36b56886974eae4f9c5ebc96befd3e7bfe5de338.tar.gz external_llvm-36b56886974eae4f9c5ebc96befd3e7bfe5de338.tar.bz2 | |
Update to LLVM 3.5a.
Change-Id: Ifadecab779f128e62e430c2b4f6ddd84953ed617
Diffstat (limited to 'docs/WritingAnLLVMBackend.rst')
| -rw-r--r-- | docs/WritingAnLLVMBackend.rst | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/docs/WritingAnLLVMBackend.rst b/docs/WritingAnLLVMBackend.rst index 35a2d16..429f52a 100644 --- a/docs/WritingAnLLVMBackend.rst +++ b/docs/WritingAnLLVMBackend.rst @@ -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 |