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author | Evan Cheng <evan.cheng@apple.com> | 2010-10-27 23:17:17 +0000 |
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committer | Evan Cheng <evan.cheng@apple.com> | 2010-10-27 23:17:17 +0000 |
commit | de5fa932b9bc0eebe803c9549586bf512eeb12f9 (patch) | |
tree | bed7c6c922ce10b21bcd886e34a61aadf780584e /lib/CodeGen/ScheduleDAGInstrs.cpp | |
parent | 7e3383c007f53b3a00675af225e428cb66ddf404 (diff) | |
download | llvm-de5fa932b9bc0eebe803c9549586bf512eeb12f9.tar.gz llvm-de5fa932b9bc0eebe803c9549586bf512eeb12f9.tar.bz2 llvm-de5fa932b9bc0eebe803c9549586bf512eeb12f9.tar.xz |
Putting r117193 back except for the compile time cost. Rather than assuming fallthroughs uses all registers, just gather the union of all successor liveins.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117506 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/ScheduleDAGInstrs.cpp')
-rw-r--r-- | lib/CodeGen/ScheduleDAGInstrs.cpp | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/lib/CodeGen/ScheduleDAGInstrs.cpp b/lib/CodeGen/ScheduleDAGInstrs.cpp index 9b5d13b120..abd68caf12 100644 --- a/lib/CodeGen/ScheduleDAGInstrs.cpp +++ b/lib/CodeGen/ScheduleDAGInstrs.cpp @@ -168,9 +168,16 @@ void ScheduleDAGInstrs::AddSchedBarrierDeps() { } } else { // For others, e.g. fallthrough, conditional branch, assume the exit - // uses all the registers. - // FIXME: This causes too much compile time regression. We need to compute - // liveout instead. + // uses all the registers that are livein to the successor blocks. + SmallSet<unsigned, 8> Seen; + for (MachineBasicBlock::succ_iterator SI = BB->succ_begin(), + SE = BB->succ_end(); SI != SE; ++SI) + for (MachineBasicBlock::livein_iterator I = (*SI)->livein_begin(), + E = (*SI)->livein_end(); I != E; ++I) { + unsigned Reg = *I; + if (Seen.insert(Reg)) + Uses[Reg].push_back(&ExitSU); + } } } |