re PR target/12817 ([SYSV] Altivec code generation error with many registers used)

	PR target/12817
	* config/rs6000/rs6000.c (rs6000_emit_prologue): Use r0 for vrsave.

From-SVN: r91553

gcc/ChangeLog

+2004-12-01  Alan Modra  <amodra@bigpond.net.au>
+
+	PR target/12817
+	* config/rs6000/rs6000.c (rs6000_emit_prologue): Use r0 for vrsave.
+
 2004-12-01  Joseph S. Myers  <joseph@codesourcery.com>
 
 	* doc/standards.texi: Update for C99 TC2.

gcc/config/rs6000/rs6000.c

@@ -14030,8 +14030,10 @@ rs6000_emit_prologue (void)
       rtx reg, mem, vrsave;
       int offset;
 
-      /* Get VRSAVE onto a GPR.  */
-      reg = gen_rtx_REG (SImode, 12);
+      /* Get VRSAVE onto a GPR.  Note that ABI_V4 might be using r12
+	 as frame_reg_rtx and r11 as the static chain pointer for
+	 nested functions.  */
+      reg = gen_rtx_REG (SImode, 0);
       vrsave = gen_rtx_REG (SImode, VRSAVE_REGNO);
       if (TARGET_MACHO)
 	emit_insn (gen_get_vrsave_internal (reg));