Index: uspace/lib/c/arch/sparc64/Makefile.common
===================================================================
--- uspace/lib/c/arch/sparc64/Makefile.common	(revision 0e575cdc8d29c1cb7de15dd37083948ad62165aa)
+++ uspace/lib/c/arch/sparc64/Makefile.common	(revision aa2a04932b630c2c05cc54f5f6a83055b3a8104e)
@@ -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