[Hexagon] Implement undoing .cur instructions in packetizer

The packetizer needs to convert .cur instruction to its regular form if
the use is not in the same packet as the .cur. The code in the packetizer
handles one type of .cur, which is the vector load case. This patch
updates the packetizer so that it can undo all the .cur instructions.
In the test case, the .cur is the 128B version, but there are also the
post-increment versions.

Patch by Brendon Cahoon.

llvm-svn: 302032

3 files changed, 25 insertions, 2 deletions

diff --git a/llvm/lib/Target/Hexagon/HexagonInstrInfo.cpp b/llvm/lib/Target/Hexagon/HexagonInstrInfo.cpp
index 29f36ba2a50..c2bfd59f135 100644
--- a/llvm/lib/Target/Hexagon/HexagonInstrInfo.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonInstrInfo.cpp
@@ -3368,9 +3368,30 @@ int HexagonInstrInfo::getDotCurOp(const MachineInstr &MI) const {
   return 0;
 }
 
+// Return the regular version of the .cur instruction.
+int HexagonInstrInfo::getNonDotCurOp(const MachineInstr &MI) const {
+  switch (MI.getOpcode()) {
+  default: llvm_unreachable("Unknown .cur type");
+  case Hexagon::V6_vL32b_cur_pi:
+    return Hexagon::V6_vL32b_pi;
+  case Hexagon::V6_vL32b_cur_ai:
+    return Hexagon::V6_vL32b_ai;
+  //128B
+  case Hexagon::V6_vL32b_cur_pi_128B:
+    return Hexagon::V6_vL32b_pi_128B;
+  case Hexagon::V6_vL32b_cur_ai_128B:
+    return Hexagon::V6_vL32b_ai_128B;
+  }
+  return 0;
+}
+
+
 // The diagram below shows the steps involved in the conversion of a predicated
 // store instruction to its .new predicated new-value form.
 //
+// Note: It doesn't include conditional new-value stores as they can't be
+// converted to .new predicate.
+//
 //               p.new NV store [ if(p0.new)memw(R0+#0)=R2.new ]
 //                ^           ^
 //               /             \ (not OK. it will cause new-value store to be
@@ -3491,6 +3512,7 @@ int HexagonInstrInfo::getDotNewOp(const MachineInstr &MI) const {
   return 0;
 }
 
+
 // Returns the opcode to use when converting MI, which is a conditional jump,
 // into a conditional instruction which uses the .new value of the predicate.
 // We also use branch probabilities to add a hint to the jump.
diff --git a/llvm/lib/Target/Hexagon/HexagonInstrInfo.h b/llvm/lib/Target/Hexagon/HexagonInstrInfo.h
index c3cbff3c4f0..21b4f738f6e 100644
--- a/llvm/lib/Target/Hexagon/HexagonInstrInfo.h
+++ b/llvm/lib/Target/Hexagon/HexagonInstrInfo.h
@@ -399,6 +399,7 @@ public:
                              const MachineInstr &GB) const;
   int getCondOpcode(int Opc, bool sense) const;
   int getDotCurOp(const MachineInstr &MI) const;
+  int getNonDotCurOp(const MachineInstr &MI) const;
   int getDotNewOp(const MachineInstr &MI) const;
   int getDotNewPredJumpOp(const MachineInstr &MI,
                           const MachineBranchProbabilityInfo *MBPI) const;
diff --git a/llvm/lib/Target/Hexagon/HexagonVLIWPacketizer.cpp b/llvm/lib/Target/Hexagon/HexagonVLIWPacketizer.cpp
index 5b3a13a60e2..bf1dce67bd0 100644
--- a/llvm/lib/Target/Hexagon/HexagonVLIWPacketizer.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonVLIWPacketizer.cpp
@@ -356,7 +356,7 @@ void HexagonPacketizerList::cleanUpDotCur() {
   MachineInstr *MI = nullptr;
   for (auto BI : CurrentPacketMIs) {
     DEBUG(dbgs() << "Cleanup packet has "; BI->dump(););
-    if (BI->getOpcode() == Hexagon::V6_vL32b_cur_ai) {
+    if (HII->isDotCurInst(*BI)) {
       MI = BI;
       continue;
     }
@@ -369,7 +369,7 @@ void HexagonPacketizerList::cleanUpDotCur() {
   if (!MI)
     return;
   // We did not find a use of the CUR, so de-cur it.
-  MI->setDesc(HII->get(Hexagon::V6_vL32b_ai));
+  MI->setDesc(HII->get(HII->getNonDotCurOp(*MI)));
   DEBUG(dbgs() << "Demoted CUR "; MI->dump(););
 }