Index: uspace/lib/c/arch/sparc64/Makefile.common
===================================================================
--- uspace/lib/c/arch/sparc64/Makefile.common	(revision 730ff630d02f514f0321609e309c9d85fa438fd7)
+++ uspace/lib/c/arch/sparc64/Makefile.common	(revision b3cf94696741d529bde1e5bbdf993a27d72136cc)
@@ -27,5 +27,12 @@
 #
 
-GCC_CFLAGS += -mcpu=ultrasparc -m64 -mcmodel=medlow
+ifeq ($(PROCESSOR),sun4v)
+GCC_CFLAGS += -mcpu=niagara -mno-vis
+else
+GCC_CFLAGS += -mcpu=ultrasparc
+endif
+
+GCC_CFLAGS += -m64 -mcmodel=medlow
+
 LFLAGS = -no-check-sections