[Hexagon] Update kills in hexagon-nvj even more properly than before

Account for the fact that both, the feeder and the compare can be moved
over instructions that kill registers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@306443 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/Hexagon/HexagonNewValueJump.cpp b/lib/Target/Hexagon/HexagonNewValueJump.cpp
index de6b203015d8e38713871fd051771bef79b18ad4..e93f075f4ccd88743a65dd13bf23a83199088bdb 100644 (file)
--- a/lib/Target/Hexagon/HexagonNewValueJump.cpp
+++ b/lib/Target/Hexagon/HexagonNewValueJump.cpp
@@ -69,9 +69,7 @@ namespace {
   public:
     static char ID;
 
-    HexagonNewValueJump() : MachineFunctionPass(ID) {
-      initializeHexagonNewValueJumpPass(*PassRegistry::getPassRegistry());
-    }
+    HexagonNewValueJump() : MachineFunctionPass(ID) {}
 
     void getAnalysisUsage(AnalysisUsage &AU) const override {
       AU.addRequired<MachineBranchProbabilityInfo>();
@@ -445,8 +443,6 @@ bool HexagonNewValueJump::runOnMachineFunction(MachineFunction &MF) {
     unsigned predReg = 0; // predicate reg of the jump.
     unsigned cmpReg1 = 0;
     int cmpOp2 = 0;
-    bool MO1IsKill = false;
-    bool MO2IsKill = false;
     MachineBasicBlock::iterator jmpPos;
     MachineBasicBlock::iterator cmpPos;
     MachineInstr *cmpInstr = nullptr, *jmpInstr = nullptr;
@@ -548,14 +544,10 @@ bool HexagonNewValueJump::runOnMachineFunction(MachineFunction &MF) {
           // We need cmpReg1 and cmpOp2(imm or reg) while building
           // new value jump instruction.
           cmpReg1 = MI.getOperand(1).getReg();
-          if (MI.getOperand(1).isKill())
-            MO1IsKill = true;
 
-          if (isSecondOpReg) {
+          if (isSecondOpReg)
             cmpOp2 = MI.getOperand(2).getReg();
-            if (MI.getOperand(2).isKill())
-              MO2IsKill = true;
-          } else
+          else
             cmpOp2 = MI.getOperand(2).getImm();
           continue;
         }
@@ -605,11 +597,8 @@ bool HexagonNewValueJump::runOnMachineFunction(MachineFunction &MF) {
             if ((COp == Hexagon::C2_cmpeq || COp == Hexagon::C4_cmpneq) &&
                 (feederReg == (unsigned) cmpOp2)) {
               unsigned tmp = cmpReg1;
-              bool tmpIsKill = MO1IsKill;
               cmpReg1 = cmpOp2;
-              MO1IsKill = MO2IsKill;
               cmpOp2 = tmp;
-              MO2IsKill = tmpIsKill;
             }
 
             // Now we have swapped the operands, all we need to check is,
@@ -623,31 +612,33 @@ bool HexagonNewValueJump::runOnMachineFunction(MachineFunction &MF) {
           // make sure we are respecting the kill values of
           // the operands of the feeder.
 
-          bool updatedIsKill = false;
-          for (unsigned i = 0; i < MI.getNumOperands(); i++) {
-            MachineOperand &MO = MI.getOperand(i);
-            if (MO.isReg() && MO.isUse()) {
-              unsigned feederReg = MO.getReg();
-              for (MachineBasicBlock::iterator localII = feederPos,
-                   end = cmpInstr->getIterator(); localII != end; localII++) {
-                MachineInstr &localMI = *localII;
-                for (unsigned j = 0; j < localMI.getNumOperands(); j++) {
-                  MachineOperand &localMO = localMI.getOperand(j);
-                  if (localMO.isReg() && localMO.isUse() &&
-                      localMO.isKill() && feederReg == localMO.getReg()) {
-                    // We found that there is kill of a use register
-                    // Set up a kill flag on the register
-                    localMO.setIsKill(false);
-                    MO.setIsKill();
-                    updatedIsKill = true;
-                    break;
-                  }
+          auto TransferKills = [jmpPos,cmpPos] (MachineInstr &MI) {
+            for (MachineOperand &MO : MI.operands()) {
+              if (!MO.isReg() || !MO.isUse())
+                continue;
+              unsigned UseR = MO.getReg();
+              for (auto I = std::next(MI.getIterator()); I != jmpPos; ++I) {
+                if (I == cmpPos)
+                  continue;
+                for (MachineOperand &Op : I->operands()) {
+                  if (!Op.isReg() || !Op.isUse() || !Op.isKill())
+                    continue;
+                  if (Op.getReg() != UseR)
+                    continue;
+                  // We found that there is kill of a use register
+                  // Set up a kill flag on the register
+                  Op.setIsKill(false);
+                  MO.setIsKill(true);
+                  return;
                 }
-                if (updatedIsKill) break;
               }
             }
-            if (updatedIsKill) break;
-          }
+          };
+
+          TransferKills(*feederPos);
+          TransferKills(*cmpPos);
+          bool MO1IsKill = cmpPos->killsRegister(cmpReg1, QRI);
+          bool MO2IsKill = isSecondOpReg && cmpPos->killsRegister(cmpOp2, QRI);
 
           MBB->splice(jmpPos, MI.getParent(), MI);
           MBB->splice(jmpPos, MI.getParent(), cmpInstr);

diff --git a/lib/Target/Hexagon/HexagonTargetMachine.cpp b/lib/Target/Hexagon/HexagonTargetMachine.cpp
index 031a1bdefafbf6d4046bdefd125b5d1bb167142f..76d9b31b005ffb7b9fe3302212c6bff4c4b875f9 100644 (file)
--- a/lib/Target/Hexagon/HexagonTargetMachine.cpp
+++ b/lib/Target/Hexagon/HexagonTargetMachine.cpp
@@ -113,6 +113,7 @@ namespace llvm {
   void initializeHexagonLoopIdiomRecognizePass(PassRegistry&);
   void initializeHexagonGenMuxPass(PassRegistry&);
   void initializeHexagonOptAddrModePass(PassRegistry&);
+  void initializeHexagonNewValueJumpPass(PassRegistry&);
   Pass *createHexagonLoopIdiomPass();
 
   FunctionPass *createHexagonBitSimplify();
@@ -158,6 +159,7 @@ extern "C" void LLVMInitializeHexagonTarget() {
   initializeHexagonLoopIdiomRecognizePass(PR);
   initializeHexagonGenMuxPass(PR);
   initializeHexagonOptAddrModePass(PR);
+  initializeHexagonNewValueJumpPass(PR);
 }
 
 HexagonTargetMachine::HexagonTargetMachine(const Target &T, const Triple &TT,

diff --git a/test/CodeGen/Hexagon/newvaluejump-kill2.mir b/test/CodeGen/Hexagon/newvaluejump-kill2.mir
new file mode 100644 (file)
index 0000000..565d07d
--- /dev/null
+++ b/test/CodeGen/Hexagon/newvaluejump-kill2.mir
@@ -0,0 +1,18 @@
+# RUN: llc -march=hexagon -run-pass hexagon-nvj -verify-machineinstrs %s -o - | FileCheck %s
+# CHECK: J4_cmpgtu_t_jumpnv_t killed %r3, killed %r1, %bb.1, implicit-def %pc
+
+---
+name: fred
+tracksRegLiveness: true
+
+body: |
+  bb.0:
+    liveins: %r0
+        %r1 = A2_addi %r0, -1
+        %r2 = A2_tfrsi -1431655765
+        %r3 = A2_tfrsi 2
+        %p0 = C2_cmpgtu killed %r3, %r1
+        %r2 = S4_subaddi killed %r1, 1, killed %r2
+        J2_jumpt killed %p0, %bb.1, implicit-def %pc
+  bb.1:
+...