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
diff --git a/lib/CodeGen/RegAllocLinearScan.cpp b/lib/CodeGen/RegAllocLinearScan.cpp
index c738315..2e65b3f 100644
--- a/lib/CodeGen/RegAllocLinearScan.cpp
+++ b/lib/CodeGen/RegAllocLinearScan.cpp
@@ -345,7 +345,7 @@
linearScan();
// Rewrite spill code and update the PhysRegsUsed set.
- spiller_->runOnMachineFunction(*mf_, *vrm_);
+ spiller_->runOnMachineFunction(*mf_, *vrm_, li_);
assert(unhandled_.empty() && "Unhandled live intervals remain!");
fixed_.clear();