[llvm] r260688 - [Hexagon] Handle out-of-range offsets in eliminateFrameIndex

[Krzysztof Parzyszek via llvm-commits]

Author: kparzysz
Date: Fri Feb 12 10:27:23 2016
New Revision: 260688

URL: http://llvm.org/viewvc/llvm-project?rev=260688&view=rev
Log:
[Hexagon] Handle out-of-range offsets in eliminateFrameIndex

Create a virtual register that will hold the actual address and use it
with the offset of 0 in the place of the original FI.


Modified:
    llvm/trunk/lib/Target/Hexagon/HexagonRegisterInfo.cpp

Modified: llvm/trunk/lib/Target/Hexagon/HexagonRegisterInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/Hexagon/HexagonRegisterInfo.cpp?rev=260688&r1=260687&r2=260688&view=diff
==============================================================================
--- llvm/trunk/lib/Target/Hexagon/HexagonRegisterInfo.cpp (original)
+++ llvm/trunk/lib/Target/Hexagon/HexagonRegisterInfo.cpp Fri Feb 12 10:27:23 2016
@@ -135,6 +135,7 @@ void HexagonRegisterInfo::eliminateFrame
   int Offset = HFI.getFrameIndexReference(MF, FI, BP);
   // Add the offset from the instruction.
   int RealOffset = Offset + MI.getOperand(FIOp+1).getImm();
+  bool IsKill = false;
 
   unsigned Opc = MI.getOpcode();
   switch (Opc) {
@@ -149,20 +150,22 @@ void HexagonRegisterInfo::eliminateFrame
       break;
   }
 
-  if (HII.isValidOffset(Opc, RealOffset)) {
-    MI.getOperand(FIOp).ChangeToRegister(BP, false);
-    MI.getOperand(FIOp+1).ChangeToImmediate(RealOffset);
-    return;
+  if (!HII.isValidOffset(Opc, RealOffset)) {
+    // If the offset is not valid, calculate the address in a temporary
+    // register and use it with offset 0.
+    auto &MRI = MF.getRegInfo();
+    unsigned TmpR = MRI.createVirtualRegister(&Hexagon::IntRegsRegClass);
+    DebugLoc DL = MI.getDebugLoc();
+    BuildMI(MB, II, DL, HII.get(Hexagon::A2_addi), TmpR)
+      .addReg(BP)
+      .addImm(RealOffset);
+    BP = TmpR;
+    RealOffset = 0;
+    IsKill = true;
   }
 
-#ifndef NDEBUG
-  const Function *F = MF.getFunction();
-  dbgs() << "In function ";
-  if (F) dbgs() << F->getName();
-  else   dbgs() << "<?>";
-  dbgs() << ", BB#" << MB.getNumber() << "\n" << MI;
-#endif
-  llvm_unreachable("Unhandled instruction");
+  MI.getOperand(FIOp).ChangeToRegister(BP, false, false, IsKill);
+  MI.getOperand(FIOp+1).ChangeToImmediate(RealOffset);
 }