Backport fix to set mips_dbx_regno entries to IGNORED_DWARF_REGNUM by default

  2012-12-12  Steve Ellcey  <sellcey@mips.com>
	* config/mips/mips.c (mips_option_override): Set
	mips_dbx_regno entries to IGNORED_DWARF_REGNUM by default.

  2012-12-10  Steve Ellcey  <sellcey@mips.com>
	PR target/54061
	rtl.h (IGNORED_DWARF_REGNUM): New.
	* dwarf2out.c (reg_loc_descriptor): Check for IGNORED_DWARF_REGNUM.
	(mem_loc_descriptor): Ditto.
	* config/mips/mips.h (ALL_COP_REG_FIRST): New.
	(ALL_COP_REG_LAST): New.
	(ALL_COP_REG_NUM): Redefine using above macros.
	* config/mips/mips.c (mips_option_override): Set mips_dbx_regno
	coprocessor entries to IGNORED_DWARF_REGNUM.

Error reads:
  target C++: libicui18n <= external/icu4c/i18n/olsontz.cpp
  external/icu4c/i18n/decimfmt.cpp: In member function 'virtual icu_50::UnicodeString&
    icu_50::DecimalFormat::format(const icu_50::StringPiece&, icu_50::UnicodeString&,
    icu_50::FieldPositionIterator*, UErrorCode&) const':
  external/icu4c/i18n/decimfmt.cpp:1322:1: internal compiler error: in dbx_reg_number,
  at dwarf2out.c:10185

See http://gcc.gnu.org/ml/gcc-patches/2012-12/msg00830.html

Change-Id: I84110b5b54d8d9262043811eddb0edc1c42303f8

4 files changed, 28 insertions, 8 deletions

diff --git a/gcc-4.7/gcc/config/mips/mips.c b/gcc-4.7/gcc/config/mips/mips.c
index 02e757b5b..ae222b891 100644
--- a/gcc-4.7/gcc/config/mips/mips.c
+++ b/gcc-4.7/gcc/config/mips/mips.c
@@ -16082,7 +16082,7 @@ mips_option_override (void)
 
   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
     {
-      mips_dbx_regno[i] = INVALID_REGNUM;
+      mips_dbx_regno[i] = IGNORED_DWARF_REGNUM;
       if (GP_REG_P (i) || FP_REG_P (i) || ALL_COP_REG_P (i))
 	mips_dwarf_regno[i] = i;
       else
diff --git a/gcc-4.7/gcc/config/mips/mips.h b/gcc-4.7/gcc/config/mips/mips.h
index 71c55d24f..ddd4c47d5 100644
--- a/gcc-4.7/gcc/config/mips/mips.h
+++ b/gcc-4.7/gcc/config/mips/mips.h
@@ -1638,8 +1638,11 @@ struct mips_cpu_info {
 #define COP3_REG_FIRST 144
 #define COP3_REG_LAST 175
 #define COP3_REG_NUM (COP3_REG_LAST - COP3_REG_FIRST + 1)
-/* ALL_COP_REG_NUM assumes that COP0,2,and 3 are numbered consecutively.  */
-#define ALL_COP_REG_NUM (COP3_REG_LAST - COP0_REG_FIRST + 1)
+
+/* These definitions assume that COP0, 2 and 3 are numbered consecutively.  */
+#define ALL_COP_REG_FIRST COP0_REG_FIRST
+#define ALL_COP_REG_LAST COP3_REG_LAST
+#define ALL_COP_REG_NUM (ALL_COP_REG_LAST - ALL_COP_REG_FIRST + 1)
 
 #define DSP_ACC_REG_FIRST 176
 #define DSP_ACC_REG_LAST 181
diff --git a/gcc-4.7/gcc/dwarf2out.c b/gcc-4.7/gcc/dwarf2out.c
index 36a63ca45..c6bd91cc3 100644
--- a/gcc-4.7/gcc/dwarf2out.c
+++ b/gcc-4.7/gcc/dwarf2out.c
@@ -10243,7 +10243,12 @@ reg_loc_descriptor (rtx rtl, enum var_init_status initialized)
   if (hard_regno_nregs[REGNO (rtl)][GET_MODE (rtl)] > 1 || regs)
     return multiple_reg_loc_descriptor (rtl, regs, initialized);
   else
-    return one_reg_loc_descriptor (dbx_reg_number (rtl), initialized);
+    {
+      unsigned int dbx_regnum = dbx_reg_number (rtl);
+      if (dbx_regnum == IGNORED_DWARF_REGNUM)
+	return 0;
+      return one_reg_loc_descriptor (dbx_regnum, initialized);
+    }
 }
 
 /* Return a location descriptor that designates a machine register for
@@ -11679,6 +11684,7 @@ mem_loc_descriptor (rtx rtl, enum machine_mode mode,
 	      ))
 	{
 	  dw_die_ref type_die;
+	  unsigned int dbx_regnum;
 
 	  if (dwarf_strict)
 	    break;
@@ -11688,8 +11694,12 @@ mem_loc_descriptor (rtx rtl, enum machine_mode mode,
 					 GET_MODE_CLASS (mode) == MODE_INT);
 	  if (type_die == NULL)
 	    break;
+
+	  dbx_regnum = dbx_reg_number (rtl);
+	  if (dbx_regnum == IGNORED_DWARF_REGNUM)
+	    break;
 	  mem_loc_result = new_loc_descr (DW_OP_GNU_regval_type,
-					  dbx_reg_number (rtl), 0);
+					  dbx_regnum, 0);
 	  mem_loc_result->dw_loc_oprnd2.val_class = dw_val_class_die_ref;
 	  mem_loc_result->dw_loc_oprnd2.v.val_die_ref.die = type_die;
 	  mem_loc_result->dw_loc_oprnd2.v.val_die_ref.external = 0;
@@ -11900,9 +11910,13 @@ mem_loc_descriptor (rtx rtl, enum machine_mode mode,
 	    op0 = mem_loc_descriptor (ENTRY_VALUE_EXP (rtl), mode,
 				      VOIDmode, VAR_INIT_STATUS_INITIALIZED);
 	  else
-	    op0
-	      = one_reg_loc_descriptor (dbx_reg_number (ENTRY_VALUE_EXP (rtl)),
-					VAR_INIT_STATUS_INITIALIZED);
+	    {
+              unsigned int dbx_regnum = dbx_reg_number (ENTRY_VALUE_EXP (rtl));
+	      if (dbx_regnum == IGNORED_DWARF_REGNUM)
+		return NULL;
+	      op0 = one_reg_loc_descriptor (dbx_regnum,
+					    VAR_INIT_STATUS_INITIALIZED);
+	    }
 	}
       else if (MEM_P (ENTRY_VALUE_EXP (rtl))
 	       && REG_P (XEXP (ENTRY_VALUE_EXP (rtl), 0)))
diff --git a/gcc-4.7/gcc/rtl.h b/gcc-4.7/gcc/rtl.h
index 5b43e05d4..40f685a33 100644
--- a/gcc-4.7/gcc/rtl.h
+++ b/gcc-4.7/gcc/rtl.h
@@ -2335,6 +2335,9 @@ extern rtx gen_rtx_MEM (enum machine_mode, rtx);
 /* REGNUM never really appearing in the INSN stream.  */
 #define INVALID_REGNUM			(~(unsigned int) 0)
 
+/* REGNUM for which no debug information can be generated.  */
+#define IGNORED_DWARF_REGNUM            (INVALID_REGNUM - 1)
+
 extern rtx output_constant_def (tree, int);
 extern rtx lookup_constant_def (tree);