Improve Mips back-end's handling of DBG_VALUE.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134224 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 31 insertions, 22 deletions

diff --git a/lib/Target/Mips/MipsRegisterInfo.cpp b/lib/Target/Mips/MipsRegisterInfo.cpp
index 40774c9..202a1d4 100644
--- a/lib/Target/Mips/MipsRegisterInfo.cpp
+++ b/lib/Target/Mips/MipsRegisterInfo.cpp
@@ -35,6 +35,7 @@
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/ADT/BitVector.h"
 #include "llvm/ADT/STLExtras.h"
+#include "llvm/Analysis/DebugInfo.h"
 
 #define GET_REGINFO_MC_DESC
 #define GET_REGINFO_TARGET_DESC
@@ -179,8 +180,29 @@ eliminateFrameIndex(MachineBasicBlock::iterator II, int SPAdj,
                << "spOffset   : " << spOffset << "\n"
                << "stackSize  : " << stackSize << "\n");
 
-  int Offset;
+  const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
+  int MinCSFI = 0;
+  int MaxCSFI = -1;
+
+  if (CSI.size()) {
+    MinCSFI = CSI[0].getFrameIdx();
+    MaxCSFI = CSI[CSI.size() - 1].getFrameIdx();
+  }
+
+  // The following stack frame objects are always referenced relative to $sp:
+  //  1. Outgoing arguments.
+  //  2. Pointer to dynamically allocated stack space.
+  //  3. Locations for callee-saved registers.
+  // Everything else is referenced relative to whatever register 
+  // getFrameRegister() returns.
+  unsigned FrameReg;
 
+  if (MipsFI->isOutArgFI(FrameIndex) || MipsFI->isDynAllocFI(FrameIndex) ||
+      (FrameIndex >= MinCSFI && FrameIndex <= MaxCSFI))
+    FrameReg = Mips::SP;
+  else
+    FrameReg = getFrameRegister(MF); 
+  
   // Calculate final offset.
   // - There is no need to change the offset if the frame object is one of the
   //   following: an outgoing argument, pointer to a dynamically allocated
@@ -188,12 +210,20 @@ eliminateFrameIndex(MachineBasicBlock::iterator II, int SPAdj,
   // - If the frame object is any of the following, its offset must be adjusted
   //   by adding the size of the stack:
   //   incoming argument, callee-saved register location or local variable.  
+  int Offset;
+
   if (MipsFI->isOutArgFI(FrameIndex) || MipsFI->isGPFI(FrameIndex) ||
       MipsFI->isDynAllocFI(FrameIndex))
     Offset = spOffset;
   else
     Offset = spOffset + stackSize;
 
+  if (MI.isDebugValue()) {
+    MI.getOperand(i).ChangeToRegister(FrameReg, false /*isDef*/);
+    MI.getOperand(i+1).ChangeToImmediate(Offset);
+    return;
+  }
+
   Offset    += MI.getOperand(i-1).getImm();
 
   DEBUG(errs() << "Offset     : " << Offset << "\n" << "<--------->\n");
@@ -202,28 +232,7 @@ eliminateFrameIndex(MachineBasicBlock::iterator II, int SPAdj,
   int NewImm = 0;
   MachineBasicBlock &MBB = *MI.getParent();
   bool ATUsed;
-  unsigned FrameReg;
-  const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
-  int MinCSFI = 0;
-  int MaxCSFI = -1;
-
-  if (CSI.size()) {
-    MinCSFI = CSI[0].getFrameIdx();
-    MaxCSFI = CSI[CSI.size() - 1].getFrameIdx();
-  }
 
-  // The following stack frame objects are always referenced relative to $sp:
-  //  1. Outgoing arguments.
-  //  2. Pointer to dynamically allocated stack space.
-  //  3. Locations for callee-saved registers.
-  // Everything else is referenced relative to whatever register 
-  // getFrameRegister() returns.
-  if (MipsFI->isOutArgFI(FrameIndex) || MipsFI->isDynAllocFI(FrameIndex) ||
-      (FrameIndex >= MinCSFI && FrameIndex <= MaxCSFI))
-    FrameReg = Mips::SP;
-  else
-    FrameReg = getFrameRegister(MF); 
-  
   // Offset fits in the 16-bit field
   if (Offset < 0x8000 && Offset >= -0x8000) {
     NewReg = FrameReg;