re PR rtl-optimization/49154 (build fails on cris-elf in libgcc: ICE in…

re PR rtl-optimization/49154 (build fails on cris-elf in libgcc: ICE in setup_pressure_classes, at ira.c:902)

2011-05-26  Vladimir Makarov  <vmakarov@redhat.com>

	PR rtl-optimization/49154
	* ira.c (setup_pressure_classes): Process class without sublcasses
	as a candidate for pressure classes.

From-SVN: r174309

gcc/ChangeLog

+2011-05-26  Vladimir Makarov  <vmakarov@redhat.com>
+
+	PR rtl-optimization/49154
+	* ira.c (setup_pressure_classes): Process class without sublcasses
+	as a candidate for pressure classes.
+
 2011-05-26  Richard Sandiford  <rdsandiford@googlemail.com>
 
 	PR rtl-optimization/48575

gcc/ira.c

@@ -799,7 +799,12 @@ setup_pressure_classes (void)
     {
       if (ira_available_class_regs[cl] == 0)
 	continue;
-      if (ira_available_class_regs[cl] != 1)
+      if (ira_available_class_regs[cl] != 1
+	  /* A register class without subclasses may contain a few
+	     hard registers and movement between them is costly
+	     (e.g. SPARC FPCC registers).  We still should consider it
+	     as a candidate for a pressure class.  */
+	  && alloc_reg_class_subclasses[cl][0] != LIM_REG_CLASSES)
 	{
 	  /* Check that the moves between any hard registers of the
 	     current class are not more expensive for a legal mode