[SystemZ] Use LivePhysRegs instead of isCCLiveOut() in SystemZElimCompare.cpp
Review: Ulrich Weigand
https://reviews.llvm.org/D68267
diff --git a/llvm/lib/Target/SystemZ/SystemZElimCompare.cpp b/llvm/lib/Target/SystemZ/SystemZElimCompare.cpp
index 946eb2b..90f664a 100644
--- a/llvm/lib/Target/SystemZ/SystemZElimCompare.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZElimCompare.cpp
@@ -18,6 +18,7 @@
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/StringRef.h"
+#include "llvm/CodeGen/LivePhysRegs.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
@@ -103,14 +104,6 @@
} // end anonymous namespace
-// Return true if CC is live out of MBB.
-static bool isCCLiveOut(MachineBasicBlock &MBB) {
- for (auto SI = MBB.succ_begin(), SE = MBB.succ_end(); SI != SE; ++SI)
- if ((*SI)->isLiveIn(SystemZ::CC))
- return true;
- return false;
-}
-
// Returns true if MI is an instruction whose output equals the value in Reg.
static bool preservesValueOf(MachineInstr &MI, unsigned Reg) {
switch (MI.getOpcode()) {
@@ -595,7 +588,9 @@
// Walk backwards through the block looking for comparisons, recording
// all CC users as we go. The subroutines can delete Compare and
// instructions before it.
- bool CompleteCCUsers = !isCCLiveOut(MBB);
+ LivePhysRegs LiveRegs(*TRI);
+ LiveRegs.addLiveOuts(MBB);
+ bool CompleteCCUsers = !LiveRegs.contains(SystemZ::CC);
SmallVector<MachineInstr *, 4> CCUsers;
MachineBasicBlock::iterator MBBI = MBB.end();
while (MBBI != MBB.begin()) {