It's (currently) not safe to keep certain physical registers live across basic blocks, e.g. x86 fp stack registers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64374 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/VirtRegMap.cpp b/lib/CodeGen/VirtRegMap.cpp
index 95cb0cf..84c48c6 100644
--- a/lib/CodeGen/VirtRegMap.cpp
+++ b/lib/CodeGen/VirtRegMap.cpp
@@ -496,6 +496,12 @@
I = PhysRegsAvailable.begin(), E = PhysRegsAvailable.end();
I != E; ++I) {
unsigned Reg = (*I).first;
+ const TargetRegisterClass* RC = TRI->getPhysicalRegisterRegClass(Reg);
+ // FIXME: A temporary workaround. We can't reuse available value if it's
+ // not safe to move the def of the virtual register's class. e.g.
+ // X86::RFP* register classes. Do not add it as a live-in.
+ if (!TII->isSafeToMoveRegClassDefs(RC))
+ continue;
if (!MBB.isLiveIn(Reg))
MBB.addLiveIn(Reg);
}
@@ -1361,7 +1367,12 @@
bool DoReMat = VRM.isReMaterialized(VirtReg);
int SSorRMId = DoReMat
? VRM.getReMatId(VirtReg) : VRM.getStackSlot(VirtReg);
- unsigned InReg = Spills.getSpillSlotOrReMatPhysReg(SSorRMId);
+ const TargetRegisterClass* RC = RegInfo->getRegClass(VirtReg);
+ // FIXME: A temporary workaround. Don't reuse available value if it's
+ // not safe to move the def of the virtual register's class. e.g.
+ // X86::RFP* register classes.
+ unsigned InReg = TII->isSafeToMoveRegClassDefs(RC) ?
+ Spills.getSpillSlotOrReMatPhysReg(SSorRMId) : 0;
if (InReg == Phys) {
// If the value is already available in the expected register, save
// a reload / remat.
@@ -1387,7 +1398,6 @@
// If the reloaded / remat value is available in another register,
// copy it to the desired register.
- const TargetRegisterClass* RC = RegInfo->getRegClass(VirtReg);
TII->copyRegToReg(MBB, &MI, Phys, InReg, RC, RC);
// This invalidates Phys.