forked from OSchip/llvm-project
8da737a18a
The vec_sld interface provides access to the vsldoi instruction. Unlike most of the vec_* interfaces, we do not attempt to change the generated code for vec_sld based on the endian mode. It is too difficult to correctly infer the desired semantics because of different element types, and the corrected instruction sequence is expensive, involving loading a permute control vector and performing a generalized permute. For GCC, this was implemented as "Don't touch the vec_sld" implementation. When it came time for the LLVM implementation, I did the same thing. However, this was hasty and incorrect. In LLVM's version of altivec.h, vec_sld was previously defined in terms of the vec_perm interface. Because vec_perm semantics are adjusted for little endian, this means that leaving vec_sld untouched causes it to generate something different for LE than for BE. Not good. This patch adjusts the form of vec_perm that is used for vec_sld and vec_vsldoi, effectively undoing the modifications so that the same vsldoi instruction will be generated for both BE and LE. There is an accompanying back-end patch to take care of some small ripple effects caused by these changes. llvm-svn: 242297 |
||
|---|---|---|
| clang | ||
| clang-tools-extra | ||
| compiler-rt | ||
| debuginfo-tests | ||
| libclc | ||
| libcxx | ||
| libcxxabi | ||
| libunwind | ||
| lld | ||
| lldb | ||
| llgo | ||
| llvm | ||
| openmp | ||
| polly | ||