| commit | 047e9d1fa34f28a3db20f841eec1d194abf2a1da | |
| author | Evan Cheng <evan.cheng@apple.com> | |
| Tue, 21 Apr 2009 22:46:52 +0000 (21 22:46 +0000) | ||
| committer | Evan Cheng <evan.cheng@apple.com> | |
| Tue, 21 Apr 2009 22:46:52 +0000 (21 22:46 +0000) | ||
| tree | 4f04dd784d95779528ce075c994f65335631067c | treesnapshot (tar.gz zip) |
| parent | 101a267d8a32e6aef0bbe6fe1b5ff540828a00a4 | commitdiff |
It has finally happened. Spiller is now using live interval info.
This fixes a very subtle bug. vr defined by an implicit_def is allowed overlap with any register since it doesn't actually modify anything. However, if it's used as a two-address use, its live range can be extended and it can be spilled. The spiller must take care not to emit a reload for the vn number that's defined by the implicit_def. This is both a correctness and performance issue.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69743 91177308-0d34-0410-b5e6-96231b3b80d8
This fixes a very subtle bug. vr defined by an implicit_def is allowed overlap with any register since it doesn't actually modify anything. However, if it's used as a two-address use, its live range can be extended and it can be spilled. The spiller must take care not to emit a reload for the vn number that's defined by the implicit_def. This is both a correctness and performance issue.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69743 91177308-0d34-0410-b5e6-96231b3b80d8