Allow overlaps between virtreg and physreg live ranges.
The RegisterCoalescer understands overlapping live ranges where one
register is defined as a copy of the other. With this change, register
allocators using LiveRegMatrix can do the same, at least for copies
between physical and virtual registers.
When a physreg is defined by a copy from a virtreg, allow those live
ranges to overlap:
%CL<def> = COPY %vreg11:sub_8bit; GR32_ABCD:%vreg11
%vreg13<def,tied1> = SAR32rCL %vreg13<tied0>, %CL<imp-use,kill>
We can assign %vreg11 to %ECX, overlapping the live range of %CL.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163336 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveRegMatrix.cpp b/lib/CodeGen/LiveRegMatrix.cpp
index cdb1776..7f22478 100644
--- a/lib/CodeGen/LiveRegMatrix.cpp
+++ b/lib/CodeGen/LiveRegMatrix.cpp
@@ -13,6 +13,7 @@
#define DEBUG_TYPE "regalloc"
#include "LiveRegMatrix.h"
+#include "RegisterCoalescer.h"
#include "VirtRegMap.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
@@ -117,8 +118,9 @@
unsigned PhysReg) {
if (VirtReg.empty())
return false;
+ CoalescerPair CP(VirtReg.reg, PhysReg, *TRI);
for (MCRegUnitIterator Units(PhysReg, TRI); Units.isValid(); ++Units)
- if (VirtReg.overlaps(LIS->getRegUnit(*Units)))
+ if (VirtReg.overlaps(LIS->getRegUnit(*Units), CP, *LIS->getSlotIndexes()))
return true;
return false;
}