From 72bebb9205c1628601b052d25555aabe6e15e6f4 Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Thu, 31 Jan 2008 03:37:28 +0000
Subject: [PATCH] MRegisterInfo::getLocation() is a really bad idea. Its
 function is to calculate the offset from frame pointer to a stack slot and
 then storing the delta in a MachineLocation object. The name is bad (it
 implies a getter), and MRegisterInfo doesn't need to know about
 MachineLocation. Replace getLocation() with getFrameIndexOffset() which
 returns the delta from frame pointer to stack slot. Dwarf writer can then use
 the information for whatever it wants.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46597 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Target/MRegisterInfo.h | 14 +++++---------
 lib/CodeGen/DwarfWriter.cpp         |  3 ++-
 lib/Target/MRegisterInfo.cpp        | 18 ++++++------------
 3 files changed, 13 insertions(+), 22 deletions(-)

diff --git a/include/llvm/Target/MRegisterInfo.h b/include/llvm/Target/MRegisterInfo.h
index 671ce0a1979..8a90f50c06d 100644
--- a/include/llvm/Target/MRegisterInfo.h
+++ b/include/llvm/Target/MRegisterInfo.h
@@ -27,7 +27,6 @@ namespace llvm {
 class BitVector;
 class MachineFunction;
 class MachineInstr;
-class MachineLocation;
 class MachineMove;
 class RegScavenger;
 class SDNode;
@@ -586,18 +585,15 @@ public:
   /// getFrameRegister - This method should return the register used as a base
   /// for values allocated in the current stack frame.
   virtual unsigned getFrameRegister(MachineFunction &MF) const = 0;
-  
+
+  /// getFrameIndexOffset - Returns the displacement from the frame register to
+  /// the stack frame of the specified index.
+  virtual int getFrameIndexOffset(MachineFunction &MF, unsigned FI) const;
+                           
   /// getRARegister - This method should return the register where the return
   /// address can be found.
   virtual unsigned getRARegister() const = 0;
   
-  /// getLocation - This method should return the actual location of a frame
-  /// variable given the frame index.  The location is returned in ML.
-  /// Subclasses should override this method for special handling of frame
-  /// variables and call MRegisterInfo::getLocation for the default action.
-  virtual void getLocation(MachineFunction &MF, unsigned Index,
-                           MachineLocation &ML) const;
-                           
   /// getInitialFrameState - Returns a list of machine moves that are assumed
   /// on entry to all functions.  Note that LabelID is ignored (assumed to be
   /// the beginning of the function.)
diff --git a/lib/CodeGen/DwarfWriter.cpp b/lib/CodeGen/DwarfWriter.cpp
index 1068f689912..de5709622bf 100644
--- a/lib/CodeGen/DwarfWriter.cpp
+++ b/lib/CodeGen/DwarfWriter.cpp
@@ -1875,7 +1875,8 @@ private:
     
     // Add variable address.
     MachineLocation Location;
-    RI->getLocation(*MF, DV->getFrameIndex(), Location);
+    Location.set(RI->getFrameRegister(*MF),
+                 RI->getFrameIndexOffset(*MF, DV->getFrameIndex()));
     AddAddress(VariableDie, DW_AT_location, Location);
 
     return VariableDie;
diff --git a/lib/Target/MRegisterInfo.cpp b/lib/Target/MRegisterInfo.cpp
index d7e161107ed..0d14aeea55a 100644
--- a/lib/Target/MRegisterInfo.cpp
+++ b/lib/Target/MRegisterInfo.cpp
@@ -16,7 +16,6 @@
 #include "llvm/Target/TargetFrameInfo.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
-#include "llvm/CodeGen/MachineLocation.h"
 #include "llvm/ADT/BitVector.h"
 
 using namespace llvm;
@@ -72,19 +71,14 @@ BitVector MRegisterInfo::getAllocatableSet(MachineFunction &MF,
   return Allocatable;
 }
 
-/// getLocation - This method should return the actual location of a frame
-/// variable given the frame index.  The location is returned in ML.
-/// Subclasses should override this method for special handling of frame
-/// variables and then call MRegisterInfo::getLocation for the default action.
-void MRegisterInfo::getLocation(MachineFunction &MF, unsigned Index,
-                        MachineLocation &ML) const {
+/// getFrameIndexOffset - Returns the displacement from the frame register to
+/// the stack frame of the specified index. This is the default implementation
+/// which is likely incorrect for the target.
+int MRegisterInfo::getFrameIndexOffset(MachineFunction &MF, unsigned FI) const {
   const TargetFrameInfo &TFI = *MF.getTarget().getFrameInfo();
   MachineFrameInfo *MFI = MF.getFrameInfo();
-  ML.set(getFrameRegister(MF),
-         MFI->getObjectOffset(Index) +
-         MFI->getStackSize() -
-         TFI.getOffsetOfLocalArea() +
-         MFI->getOffsetAdjustment());
+  return MFI->getObjectOffset(FI) + MFI->getStackSize() -
+    TFI.getOffsetOfLocalArea() + MFI->getOffsetAdjustment();
 }
 
 /// getInitialFrameState - Returns a list of machine moves that are assumed