forked from OSchip/llvm-project
28ecff5cf1
Summary: When we're building with XRay instrumentation, we use a trick that preserves references from the function to a function sled index. This index table lives in a separate section, and without this trick the linker is free to garbage-collect this section and all the segments it refers to. Until we're able to tell the linkers to preserve these sections, we use this reference trick to keep around both the index and the entries in the instrumentation map. Before this change we emitted both a synthetic reference to the label in the instrumentation map, and to the entry in the function map index. This change removes the first synthetic reference and only emits one synthetic reference to the index -- the index entry has the references to the labels in the instrumentation map, so the linker will still preserve those if the function itself is preserved. This reduces the amount of synthetic references we emit from 16 bytes to just 8 bytes in x86_64, and similarly to other platforms. Reviewers: dblaikie Subscribers: javed.absar, kpw, pelikan, llvm-commits Differential Revision: https://reviews.llvm.org/D34340 llvm-svn: 305880 |
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| clang | ||
| clang-tools-extra | ||
| compiler-rt | ||
| debuginfo-tests | ||
| libclc | ||
| libcxx | ||
| libcxxabi | ||
| libunwind | ||
| lld | ||
| lldb | ||
| llgo | ||
| llvm | ||
| openmp | ||
| parallel-libs | ||
| polly | ||