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| author | Ilya Leoshkevich <iii@linux.ibm.com> | 2020-12-08 22:04:00 +0100 |
|---|---|---|
| committer | Ilya Leoshkevich <iii@linux.ibm.com> | 2020-12-09 00:59:01 +0100 |
| commit | d58f112ce03877f73200591cd3c9b38e41e46afe (patch) | |
| tree | bfd8e09a8bc72a4c6de64aead55b8d709549407e /clang/unittests/Frontend/CompilerInvocationTest.cpp | |
| parent | 5171b7b40e9813e3fbfaf1e1e3372895c9ff6081 (diff) | |
| download | llvm-d58f112ce03877f73200591cd3c9b38e41e46afe.zip llvm-d58f112ce03877f73200591cd3c9b38e41e46afe.tar.gz llvm-d58f112ce03877f73200591cd3c9b38e41e46afe.tar.bz2 | |
Prevent FENTRY_CALL reordering
FEntryInserter prepends FENTRY_CALL to the first basic block. In case
there are other instructions, PostRA Machine Instruction Scheduler can
move FENTRY_CALL call around. This actually occurs on SystemZ (see the
testcase). This is bad for the following reasons:
* FENTRY_CALL clobbers registers.
* Linux Kernel depends on whatever FENTRY_CALL expands to to be the very
first instruction in the function.
Fix by adding isCall attribute to FENTRY_CALL, which prevents reordering
by making it a scheduling boundary for PostRA Machine Instruction
Scheduler.
Reviewed By: niravd
Differential Revision: https://reviews.llvm.org/D91218
Diffstat (limited to 'clang/unittests/Frontend/CompilerInvocationTest.cpp')
0 files changed, 0 insertions, 0 deletions