[RFA] MIPS: Provide DWARF 2 mappings for HI, LO, and HILO

[Kevin Buettner]

The patch below adds mappings from the internal gcc register numbers
HI_REGNUM, LO_REGNUM, and HILO_REGNUM to unused values above those
presently used in debugging information.  Previously, these registers
were mapped to -1 which would then erroneously appear in DWARF 2
location expressions.

For further background, see the thread starting with:

    http://gcc.gnu.org/ml/gcc-patches/2003-03/msg00558.html

Okay?

	* config/mips/mips.c (override_optioins): Provide mappings for
	HI_REGNUM, LO_REGNUM, and HILO_REGNUM.
	* config/mips/mips.h (MD_DBX_FIRST): Define.

Index: config/mips/mips.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/mips/mips.c,v
retrieving revision 1.252
diff -u -p -r1.252 mips.c
--- config/mips/mips.c	19 Feb 2003 18:03:09 -0000	1.252
+++ config/mips/mips.c	28 Mar 2003 05:08:55 -0000
@@ -5767,6 +5767,10 @@ override_options ()
   for (i = FP_REG_FIRST; i <= FP_REG_LAST; i++)
     mips_dbx_regno[i] = i + start;
 
+  start = MD_DBX_FIRST - MD_REG_FIRST;
+  for (i = MD_REG_FIRST; i <= MD_REG_LAST; i++)
+    mips_dbx_regno[i] = i + start;
+
   /* Set up array giving whether a given register can hold a given mode.
      At present, restrict ints from being in FP registers, because reload
      is a little enthusiastic about storing extra values in FP registers,
Index: config/mips/mips.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/mips/mips.h,v
retrieving revision 1.241
diff -u -p -r1.241 mips.h
--- config/mips/mips.h	14 Mar 2003 15:53:48 -0000	1.241
+++ config/mips/mips.h	28 Mar 2003 05:08:57 -0000
@@ -1851,6 +1851,7 @@ do {							\
 #define MD_REG_FIRST 64
 #define MD_REG_LAST  66
 #define MD_REG_NUM   (MD_REG_LAST - MD_REG_FIRST + 1)
+#define MD_DBX_FIRST (FP_DBX_FIRST + FP_REG_NUM)
 
 #define ST_REG_FIRST 67
 #define ST_REG_LAST  74