Added more comments
llvm-svn: 1498
diff --git a/llvm/lib/Target/Sparc/SparcRegClassInfo.h b/llvm/lib/Target/Sparc/SparcRegClassInfo.h
index fd76815..0a5f516 100644
--- a/llvm/lib/Target/Sparc/SparcRegClassInfo.h
+++ b/llvm/lib/Target/Sparc/SparcRegClassInfo.h
@@ -15,7 +15,6 @@
// Integer Register Class
//-----------------------------------------------------------------------------
-
// Int register names in same order as enum in class SparcIntRegOrder
static string const IntRegNames[] =
@@ -38,7 +37,7 @@
// --- following colors are volatile across function calls
// %g0 can't be used for coloring - always 0
- //%g1-%g5 (g6-7 are reserved for system)
+
o0, o1, o2, o3, o4, o5, o7, // %o0-%o5,
// %o6 is sp,
@@ -59,9 +58,12 @@
i6, i7, g0, g1, g2, g3, g4, g5, g6, g7, o6
- //*** NOTE: If we decide to use globals, some of them are volatile
- //**** see sparc64ABI (change isRegVloatile method below)
-
+ //*** NOTE: If we decide to use some %g regs, they are volatile
+ // (see sparc64ABI)
+ // Move the %g regs from the end of the enumeration to just above the
+ // enumeration of %o0 (change StartOfAllRegs below)
+ // change isRegVloatile method below
+ // Also change IntRegNames above.
};
@@ -110,6 +112,9 @@
};
+
+
+
//-----------------------------------------------------------------------------
// Float Register Class
//-----------------------------------------------------------------------------
@@ -158,7 +163,6 @@
}
-
};
@@ -219,10 +223,6 @@
return IntCCRegNames[reg];
}
- // according to Sparc 64 ABI, %ccr is volatile
- inline bool isRegVolatile(const int Reg) const { return true; }
-
-
};
@@ -238,13 +238,15 @@
Node->setColor(0); // only one int cc reg is available
}
-
+ // according to Sparc 64 ABI, %ccr is volatile
+ //
inline bool isRegVolatile(const int Reg) const { return true; }
};
+
//-----------------------------------------------------------------------------
// Float CC Register Class
// Only 4 Float CC registers are available
@@ -271,10 +273,6 @@
return FloatCCRegNames[reg];
}
- // according to Sparc 64 ABI, all %fp regs are volatile
- inline bool isRegVolatile(const int Reg) const { return true; }
-
-
};
@@ -293,7 +291,9 @@
Node->setColor(c);
}
- // *** TODO: Check this
+
+ // according to Sparc 64 ABI, all %fp CC regs are volatile
+ //
inline bool isRegVolatile(const int Reg) const { return true; }
diff --git a/llvm/lib/Target/Sparc/SparcRegInfo.cpp b/llvm/lib/Target/Sparc/SparcRegInfo.cpp
index 6a0460d..6543397 100644
--- a/llvm/lib/Target/Sparc/SparcRegInfo.cpp
+++ b/llvm/lib/Target/Sparc/SparcRegInfo.cpp
@@ -1161,31 +1161,28 @@
//----------------------------------------------------------------------------
// This method inserts caller saving/restoring instructons before/after
-// a call machine instruction.
+// a call machine instruction. The caller saving/restoring instructions are
+// inserted like:
+//
+// ** caller saving instructions
+// other instructions inserted for the call by ColorCallArg
+// CALL instruction
+// other instructions inserted for the call ColorCallArg
+// ** caller restoring instructions
+//
//----------------------------------------------------------------------------
void UltraSparcRegInfo::insertCallerSavingCode(const MachineInstr *MInst,
const BasicBlock *BB,
PhyRegAlloc &PRA) const {
- // assert( (getInstrInfo()).isCall( MInst->getOpCode() ) );
- // Clear the temp area of the stack
- //PRA.mcInfo.popAllTempValues(target);
- // TODO*** Don't do this since we can have a situation like
- /*
-
- stx %o1 %i6 1999 <--- inserted by this code
- stx %o5 %i6 2007
-
- *****
- stx %o1 %i6 2007 ???? <-- inserted by statck2stack call arg
-
- */
-
-
+ // has set to record which registers were saved/restored
+ //
hash_set<unsigned> PushedRegSet;
+
+
// Now find the LR of the return value of the call
// The last *implicit operand* is the return value of a call
// Insert it to to he PushedRegSet since we must not save that register
@@ -1350,11 +1347,6 @@
} // for each value in the LV set after instruction
- // Clear the temp area of the stack
- // PRA.mcInfo.popAllTempValues(target);
- // TODO *** see above call - optimize later
-
-
}
//---------------------------------------------------------------------------