Add pseudo instructions to the XCore for (load|store|load address) of a

frame index. eliminateFrameIndex will replace these instructions with
(LDWSP|STWSP|LDAWSP) or (LDW|STW|LDAWF) if a frame pointer is in use.

This fixes PR 3324. Previously we used LDWSP, STWSP, LDAWSP before frame
pointer elimination. However since they were marked as implicitly using
SP they could not be rematerialised.

llvm-svn: 62238

1 files changed, 30 insertions, 31 deletions

diff --git a/llvm/lib/Target/XCore/XCoreRegisterInfo.cpp b/llvm/lib/Target/XCore/XCoreRegisterInfo.cpp
index 5293c82f134..d40404e2fe9 100644
--- a/llvm/lib/Target/XCore/XCoreRegisterInfo.cpp
+++ b/llvm/lib/Target/XCore/XCoreRegisterInfo.cpp
@@ -211,19 +211,18 @@ void XCoreRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
   
   bool FP = hasFP(MF);
   
+  unsigned Reg = MI.getOperand(0).getReg();
+  bool isKill = MI.getOpcode() == XCore::STWFI && MI.getOperand(0).isKill();
+
+  assert(XCore::GRRegsRegisterClass->contains(Reg) &&
+         "Unexpected register operand");
+  
+  MachineBasicBlock &MBB = *MI.getParent();
+  
   if (FP) {
     bool isUs = isImmUs(Offset);
-    MachineBasicBlock &MBB = *MI.getParent();
     unsigned FramePtr = XCore::R10;
-    unsigned Reg = MI.getOperand(0).getReg();
-    bool isKill = MI.getOperand(0).isKill();
     
-    if (Reg == XCore::LR) {
-      // The LR should have been save in the prologue.
-      cerr << "saving LR to FP unimplemented\n";
-      abort();
-    }
-
     MachineInstr *New = 0;
     if (!isUs) {
       if (!RS) {
@@ -234,18 +233,18 @@ void XCoreRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
                                                  SPAdj);
       loadConstant(MBB, II, ScratchReg, Offset);
       switch (MI.getOpcode()) {
-      case XCore::LDWSP_lru6:
+      case XCore::LDWFI:
         New = BuildMI(MBB, II, TII.get(XCore::LDW_3r), Reg)
               .addReg(FramePtr)
               .addReg(ScratchReg, false, false, true);
         break;
-      case XCore::STWSP_lru6:
+      case XCore::STWFI:
         New = BuildMI(MBB, II, TII.get(XCore::STW_3r))
               .addReg(Reg, false, false, isKill)
               .addReg(FramePtr)
               .addReg(ScratchReg, false, false, true);
         break;
-      case XCore::LDAWSP_lru6:
+      case XCore::LDAWFI:
         New = BuildMI(MBB, II, TII.get(XCore::LDAWF_l3r), Reg)
               .addReg(FramePtr)
               .addReg(ScratchReg, false, false, true);
@@ -255,18 +254,18 @@ void XCoreRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
       }
     } else {
       switch (MI.getOpcode()) {
-      case XCore::LDWSP_lru6:
+      case XCore::LDWFI:
         New = BuildMI(MBB, II, TII.get(XCore::LDW_2rus), Reg)
               .addReg(FramePtr)
               .addImm(Offset);
         break;
-      case XCore::STWSP_lru6:
+      case XCore::STWFI:
         New = BuildMI(MBB, II, TII.get(XCore::STW_2rus))
               .addReg(Reg, false, false, isKill)
               .addReg(FramePtr)
               .addImm(Offset);
         break;
-      case XCore::LDAWSP_lru6:
+      case XCore::LDAWFI:
         New = BuildMI(MBB, II, TII.get(XCore::LDAWF_l2rus), Reg)
               .addReg(FramePtr)
               .addImm(Offset);
@@ -275,9 +274,6 @@ void XCoreRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
         assert(0 && "Unexpected Opcode\n");
       }
     }
-    
-    // Erase old instruction.
-    MBB.erase(II);
   } else {
     bool isU6 = isImmU6(Offset);
     if (!isU6 && !isImmU16(Offset)) {
@@ -286,25 +282,30 @@ void XCoreRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
       abort();
     }
 
-    int NewOpcode = MI.getOpcode();
-
-    switch (NewOpcode) {
-    case XCore::LDWSP_lru6:
+    switch (MI.getOpcode()) {
+    int NewOpcode;
+    case XCore::LDWFI:
       NewOpcode = (isU6) ? XCore::LDWSP_ru6 : XCore::LDWSP_lru6;
+      BuildMI(MBB, II, TII.get(NewOpcode), Reg)
+            .addImm(Offset);
       break;
-    case XCore::STWSP_lru6:
+    case XCore::STWFI:
       NewOpcode = (isU6) ? XCore::STWSP_ru6 : XCore::STWSP_lru6;
+      BuildMI(MBB, II, TII.get(NewOpcode))
+            .addReg(Reg, false, false, isKill)
+            .addImm(Offset);
       break;
-    case XCore::LDAWSP_lru6:
+    case XCore::LDAWFI:
       NewOpcode = (isU6) ? XCore::LDAWSP_ru6 : XCore::LDAWSP_lru6;
+      BuildMI(MBB, II, TII.get(NewOpcode), Reg)
+            .addImm(Offset);
       break;
     default:
       assert(0 && "Unexpected Opcode\n");
     }
-
-    MI.setDesc(TII.get(NewOpcode));
-    FrameOp.ChangeToImmediate(Offset);
   }
+  // Erase old instruction.
+  MBB.erase(II);
 }
 
 void
@@ -372,8 +373,7 @@ storeToStack(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
   int Opcode = isU6 ? XCore::STWSP_ru6 : XCore::STWSP_lru6;
   BuildMI(MBB, I, TII.get(Opcode))
     .addReg(SrcReg)
-    .addImm(Offset)
-    .addImm(0);
+    .addImm(Offset);
 }
 
 void XCoreRegisterInfo::
@@ -388,8 +388,7 @@ loadFromStack(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
   }
   int Opcode = isU6 ? XCore::LDWSP_ru6 : XCore::LDWSP_lru6;
   BuildMI(MBB, I, TII.get(Opcode), DstReg)
-    .addImm(Offset)
-    .addImm(0);
+    .addImm(Offset);
 }
 
 void XCoreRegisterInfo::emitPrologue(MachineFunction &MF) const {