[PATCH] MIPS gas: use $zero as alias for $0

[Thiemo Seufer]

Hi All,

this adds '$zero' as an alias name for the hardware special register $0.
It also allows the use of $kt0, $kt1 aliases, this is compatible to native
mips tools.


Thiemo


2002-06-01  Thiemo Seufer <seufer@csv.ica.uni-stuttgart.de>

	/gas/ChangeLog
	* config/tc-mips.c: Add define for $zero register.
	(md_begin): Add $zero as alias name for $0.
	(mips_ip): Likewise.
	(mips16_ip): Likewise.
	(tc_get_register): Likewise. Add support for $kt0, kt1 register
	names.
	(insn_uses_reg): Use ZERO define.


diff -BurpNX /bigdisk/src/binutils-exclude source-orig/gas/config/tc-mips.c source/gas/config/tc-mips.c
--- source-orig/gas/config/tc-mips.c	Fri May 31 04:31:10 2002
+++ source/gas/config/tc-mips.c	Fri May 31 20:56:30 2002
@@ -82,6 +82,7 @@ static int mips_output_flavor () { retur
 static char *mips_regmask_frag;
 #endif
 
+#define ZERO 0
 #define AT  1
 #define TREG 24
 #define PIC_CALL_REG 25
@@ -1351,6 +1351,8 @@ md_begin ()
 				   &zero_address_frag));
   symbol_table_insert (symbol_new ("$kt1", reg_section, KT1,
 				   &zero_address_frag));
+  symbol_table_insert (symbol_new ("$zero", reg_section, ZERO,
+				   &zero_address_frag));
   symbol_table_insert (symbol_new ("$pc", reg_section, -1,
 				   &zero_address_frag));
 
@@ -1534,8 +1536,8 @@ insn_uses_reg (ip, reg, class)
       class = MIPS_GR_REG;
     }
 
-  /* Don't report on general register 0, since it never changes.  */
-  if (class == MIPS_GR_REG && reg == 0)
+  /* Don't report on general register ZERO, since it never changes.  */
+  if (class == MIPS_GR_REG && reg == ZERO)
     return 0;
 
   if (class == MIPS_FP_REG)
@@ -8231,6 +8219,11 @@ mips_ip (str, ip)
 			  s += 4;
 			  regno = KT1;
 			}
+		      else if (s[1] == 'z' && s[2] == 'e' && s[3] == 'r' && s[4] == '0')
+			{
+			  s += 5;
+			  regno = ZERO;
+			}
 		      else if (itbl_have_entries)
 			{
 			  char *p, *n;
@@ -9189,6 +9115,11 @@ mips16_ip (str, ip)
 		      s += 4;
 		      regno = KT1;
 		    }
+		  else if (s[1] == 'z' && s[2] == 'e' && s[3] == 'r' && s[4] == 'o')
+		    {
+		      s += 5;
+		      regno = ZERO;
+		    }
 		  else
 		    break;
 		}
@@ -12230,6 +12203,12 @@ tc_get_register (frame)
 	reg = GP;
       else if (strncmp (input_line_pointer, "at", 2) == 0)
 	reg = AT;
+      else if (strncmp (input_line_pointer, "kt0", 3) == 0)
+	reg = KT0;
+      else if (strncmp (input_line_pointer, "kt1", 3) == 0)
+	reg = KT1;
+      else if (strncmp (input_line_pointer, "zero", 4) == 0)
+	reg = ZERO;
       else
 	{
 	  as_warn (_("Unrecognized register name"));