[Hexagon] Update store offset when not packetizing it with allocframe

When the packetizer wants to put a store to a stack slot in the same
packet with an allocframe, it updates the store offset to reflect the
value of SP before it is updated by allocframe. If the store cannot
be packetized with the allocframe after all, the offset needs to be
updated back to the previous value.

llvm-svn: 276749

2 files changed, 51 insertions, 15 deletions

diff --git a/llvm/lib/Target/Hexagon/HexagonVLIWPacketizer.cpp b/llvm/lib/Target/Hexagon/HexagonVLIWPacketizer.cpp
index d326b947131..ba98b27561c 100644
--- a/llvm/lib/Target/Hexagon/HexagonVLIWPacketizer.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonVLIWPacketizer.cpp
@@ -101,7 +101,6 @@ INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
 INITIALIZE_PASS_END(HexagonPacketizer, "packets", "Hexagon Packetizer",
                     false, false)
 
-
 HexagonPacketizerList::HexagonPacketizerList(MachineFunction &MF,
       MachineLoopInfo &MLI, AliasAnalysis *AA,
       const MachineBranchProbabilityInfo *MBPI)
@@ -436,6 +435,43 @@ bool HexagonPacketizerList::demoteToDotOld(MachineInstr* MI) {
   return true;
 }
 
+bool HexagonPacketizerList::useCallersSP(MachineInstr *MI) {
+  unsigned Opc = MI->getOpcode();
+  switch (Opc) {
+    case Hexagon::S2_storerd_io:
+    case Hexagon::S2_storeri_io:
+    case Hexagon::S2_storerh_io:
+    case Hexagon::S2_storerb_io:
+      break;
+    default:
+      llvm_unreachable("Unexpected instruction");
+  }
+  unsigned FrameSize = MF.getFrameInfo()->getStackSize();
+  MachineOperand &Off = MI->getOperand(1);
+  int64_t NewOff = Off.getImm() - (FrameSize + HEXAGON_LRFP_SIZE);
+  if (HII->isValidOffset(Opc, NewOff)) {
+    Off.setImm(NewOff);
+    return true;
+  }
+  return false;
+}
+
+void HexagonPacketizerList::useCalleesSP(MachineInstr *MI) {
+  unsigned Opc = MI->getOpcode();
+  switch (Opc) {
+    case Hexagon::S2_storerd_io:
+    case Hexagon::S2_storeri_io:
+    case Hexagon::S2_storerh_io:
+    case Hexagon::S2_storerb_io:
+      break;
+    default:
+      llvm_unreachable("Unexpected instruction");
+  }
+  unsigned FrameSize = MF.getFrameInfo()->getStackSize();
+  MachineOperand &Off = MI->getOperand(1);
+  Off.setImm(Off.getImm() + FrameSize + HEXAGON_LRFP_SIZE);
+}
+
 enum PredicateKind {
   PK_False,
   PK_True,
@@ -1144,7 +1180,6 @@ bool HexagonPacketizerList::isLegalToPacketizeTogether(SUnit *SUI, SUnit *SUJ) {
     IgnoreDepMIs.clear();
 
   MachineBasicBlock::iterator II = I;
-  const unsigned FrameSize = MF.getFrameInfo()->getStackSize();
 
   // Solo instructions cannot go in the packet.
   assert(!isSoloInstruction(*I) && "Unexpected solo instr!");
@@ -1391,17 +1426,13 @@ bool HexagonPacketizerList::isLegalToPacketizeTogether(SUnit *SUI, SUnit *SUJ) {
         case Hexagon::S2_storerh_io:
         case Hexagon::S2_storerb_io:
           if (I->getOperand(0).getReg() == HRI->getStackRegister()) {
-            int64_t Imm = I->getOperand(1).getImm();
-            int64_t NewOff = Imm - (FrameSize + HEXAGON_LRFP_SIZE);
-            if (HII->isValidOffset(Opc, NewOff)) {
-              GlueAllocframeStore = true;
-              // Since this store is to be glued with allocframe in the same
-              // packet, it will use SP of the previous stack frame, i.e.
-              // caller's SP. Therefore, we need to recalculate offset
-              // according to this change.
-              I->getOperand(1).setImm(NewOff);
+            // Since this store is to be glued with allocframe in the same
+            // packet, it will use SP of the previous stack frame, i.e.
+            // caller's SP. Therefore, we need to recalculate offset
+            // according to this change.
+            GlueAllocframeStore = useCallersSP(I);
+            if (GlueAllocframeStore)
               continue;
-            }
           }
         default:
           break;
@@ -1467,9 +1498,8 @@ bool HexagonPacketizerList::isLegalToPruneDependencies(SUnit *SUI, SUnit *SUJ) {
   // instruction. If so, restore its offset to its original value, i.e. use
   // current SP instead of caller's SP.
   if (GlueAllocframeStore) {
-    unsigned FrameSize = MF.getFrameInfo()->getStackSize();
-    MachineOperand &MOff = I->getOperand(1);
-    MOff.setImm(MOff.getImm() + FrameSize + HEXAGON_LRFP_SIZE);
+    useCalleesSP(I);
+    GlueAllocframeStore = false;
   }
   return false;
 }
@@ -1536,6 +1566,10 @@ HexagonPacketizerList::addToPacket(MachineInstr &MI) {
     endPacket(MBB, MI);
     if (PromotedToDotNew)
       demoteToDotOld(&MI);
+    if (GlueAllocframeStore) {
+      useCalleesSP(&MI);
+      GlueAllocframeStore = false;
+    }
     ResourceTracker->reserveResources(MI);
     reserveResourcesForConstExt();
   }
diff --git a/llvm/lib/Target/Hexagon/HexagonVLIWPacketizer.h b/llvm/lib/Target/Hexagon/HexagonVLIWPacketizer.h
index 3f8ed5af354..bd5546d9bdb 100644
--- a/llvm/lib/Target/Hexagon/HexagonVLIWPacketizer.h
+++ b/llvm/lib/Target/Hexagon/HexagonVLIWPacketizer.h
@@ -94,6 +94,8 @@ protected:
   bool canPromoteToNewValueStore(const MachineInstr* MI,
                                  const MachineInstr* PacketMI, unsigned DepReg);
   bool demoteToDotOld(MachineInstr* MI);
+  bool useCallersSP(MachineInstr *MI);
+  void useCalleesSP(MachineInstr *MI);
   bool arePredicatesComplements(MachineInstr &MI1, MachineInstr &MI2);
   bool restrictingDepExistInPacket(MachineInstr*, unsigned);
   bool isNewifiable(const MachineInstr *MI);