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| author | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2012-05-16 21:22:35 +0000 |
|---|---|---|
| committer | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2012-05-16 21:22:35 +0000 |
| commit | 07a267faec7bd77fdece44f242cb4270120e0ef2 (patch) | |
| tree | 18ee0980df1b39df7fbd2805f38579fc828d7775 /lib/VMCore/Function.cpp | |
| parent | d938935dca297f3f65dddf283f7c55030be6133c (diff) | |
Set sub-register <undef> flags more accurately.
When widening an existing <def,reads-undef> operand to a super-register,
it may be necessary to clear the <undef> flag because the wider register
is now read-modify-write through the instruction.
Conversely, it may be necessary to add an <undef> flag when the
coalescer turns a full-register def into a sub-register def, but the
larger register wasn't live before the instruction.
This happens in test/CodeGen/ARM/coalesce-subregs.ll, but the test
is too small for the <undef> flags to affect the generated code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156951 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/VMCore/Function.cpp')
0 files changed, 0 insertions, 0 deletions