[PATCH 30/32] sparc64/niagara: Add per-section compilation and linking support

[Joel Sherrill]

updates #2577.

For the niagara BSP variant without this option sample executables
sizes were as follows:

   text	   data	    bss	    	  dec	    	  hex	filename
 143616	   2704	2113472	2259792	 227b50	ticker.exe
  71872	   1720	2105312	2178904	 213f58	minimum.exe
 983600	   3128	2126160	3112888	 2f7fb8	cxx_iostream.exe
 648448	   8864	2129200	2786512	 2a84d0	fileio.exe
 548976	  21520	2147872	2718368	 297aa0	pppd.exe
 253344	   3872	2117440	2374656	 243c00	capture.exe
 161520	   2840	2113616	2277976	 22c258	nsecs.exe
 215568	   3344	2114112	2333024	 239960	paranoia.exe
 261744	   2728	2115328	2379800	 245018	cdtest.exe
 139648	   2704	2113440	2255792	 226bb0	base_sp.exe
 142416	   2712	2117216	2262344	 228548	unlimited.exe
 150464	   2648	2113424	2266536	 2295a8	hello.exe
 343504	  10704	2126400	2480608	 25d9e0	loopback.exe

For the niagara BSP variant with this option sample executables
sizes were as follows:

   text	   data	    bss	    	  dec	    	  hex	filename
 133408	   2624	2113184	2249216	 225200	ticker.exe
  57152	    320	2100928	2158400	 20ef40	minimum.exe
 590160	   3024	2120400	2713584	 2967f0	cxx_iostream.exe
 623568	   8784	2128640	2760992	 2a2120	fileio.exe
 503616	  21256	2146816	2671688	 28c448	pppd.exe
 239152	   3752	2117152	2360056	 2402f8	capture.exe
 152128	   2760	2113312	2268200	 229c28	nsecs.exe
 203808	   3256	2113808	2320872	 2369e8	paranoia.exe
 244128	   2656	2115040	2361824	 2409e0	cdtest.exe
 128672	   2616	2113152	2244440	 223f58	base_sp.exe
 129408	   2608	2112816	2244832	 2240e0	unlimited.exe
 137040	   2528	2109040	2248608	 224fa0	hello.exe
 314256	  10520	2126016	2450792	 256568	loopback.exe
---
 c/src/lib/libbsp/sparc64/niagara/make/custom/niagara.cfg | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/c/src/lib/libbsp/sparc64/niagara/make/custom/niagara.cfg b/c/src/lib/libbsp/sparc64/niagara/make/custom/niagara.cfg
index 187e1fa..1178993 100644
--- a/c/src/lib/libbsp/sparc64/niagara/make/custom/niagara.cfg
+++ b/c/src/lib/libbsp/sparc64/niagara/make/custom/niagara.cfg
@@ -15,3 +15,6 @@ CPU_CFLAGS = -mcpu=niagara -DSUN4V
 
 # optimize flag: typically -g -O2
 CFLAGS_OPTIMIZE_V = -g -O2
+CFLAGS_OPTIMIZE_V += -ffunction-sections -fdata-sections
+
+LDFLAGS = -Wl,--gc-sections
-- 
1.8.3.1