When the result of an EXTRACT_SUBREG, INSERT_SUBREG, or SUBREG_TO_REG
operator is used by a CopyToReg to export the value to a different
block, don't reuse the CopyToReg's register for the subreg operation
result if the register isn't precisely the right class for the
subreg operation.
Also, rename the h-registers.ll test, now that there are more
than one.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69087 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodesEmit.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodesEmit.cpp
index 94333d3..42fe1f5 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodesEmit.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodesEmit.cpp
@@ -402,19 +402,16 @@
const TargetRegisterClass *TRC = MRI.getRegClass(VReg);
const TargetRegisterClass *SRC = getSubRegisterRegClass(TRC, SubIdx);
- if (VRBase) {
- // Grab the destination register
-#ifndef NDEBUG
- const TargetRegisterClass *DRC = MRI.getRegClass(VRBase);
- assert(SRC && DRC && (SRC == DRC || DRC->hasSubClass(SRC)) &&
- "Source subregister and destination must have the same class");
-#endif
- } else {
+ // Figure out the register class to create for the destreg.
+ // Note that if we're going to directly use an existing register,
+ // it must be precisely the required class, and not a subclass
+ // thereof.
+ if (VRBase == 0 || SRC != MRI.getRegClass(VRBase)) {
// Create the reg
assert(SRC && "Couldn't find source register class");
VRBase = MRI.createVirtualRegister(SRC);
}
-
+
// Add def, source, and subreg index
MI->addOperand(MachineOperand::CreateReg(VRBase, true));
AddOperand(MI, Node->getOperand(0), 0, 0, VRBaseMap);
@@ -427,19 +424,21 @@
SDValue N2 = Node->getOperand(2);
unsigned SubReg = getVR(N1, VRBaseMap);
unsigned SubIdx = cast<ConstantSDNode>(N2)->getZExtValue();
-
-
+ const TargetRegisterClass *TRC = MRI.getRegClass(SubReg);
+ const TargetRegisterClass *SRC =
+ getSuperRegisterRegClass(TRC, SubIdx,
+ Node->getValueType(0));
+
// Figure out the register class to create for the destreg.
- const TargetRegisterClass *TRC = 0;
- if (VRBase) {
- TRC = MRI.getRegClass(VRBase);
- } else {
- TRC = getSuperRegisterRegClass(MRI.getRegClass(SubReg), SubIdx,
- Node->getValueType(0));
- assert(TRC && "Couldn't determine register class for insert_subreg");
- VRBase = MRI.createVirtualRegister(TRC); // Create the reg
+ // Note that if we're going to directly use an existing register,
+ // it must be precisely the required class, and not a subclass
+ // thereof.
+ if (VRBase == 0 || SRC != MRI.getRegClass(VRBase)) {
+ // Create the reg
+ assert(SRC && "Couldn't find source register class");
+ VRBase = MRI.createVirtualRegister(SRC);
}
-
+
// Create the insert_subreg or subreg_to_reg machine instruction.
MachineInstr *MI = BuildMI(MF, Node->getDebugLoc(), TII->get(Opc));
MI->addOperand(MachineOperand::CreateReg(VRBase, true));