u-boot.git/arch/arc/lib/libgcc2.c, branch v2016.01 Unnamed repository; edit this file 'description' to name the repository. arc: build libgcc in U-Boot 2015-02-09T13:41:20+00:00 Alexey Brodkin abrodkin@synopsys.com 2015-02-03T10:58:20+00:00 a67ef280f46803e319639f5380ff8da6c6b7fbe7 This way we may have very limited set of functions implemented so we save some space. Also it allows us to build U-Boot for any ARC core with the same one toolchain because we don't rely on pre-built libgcc. For example: * we may use little-endian toolchain but build U-Boot for ether endianess * we may use non-multilibbed uClibc toolchain but build U-Boot for whatever ARC CPU flavour that current GCC supports Private libgcc built from generic C implementation contributes only 144 bytes to .text section so we don't see significant degradation of size: --->8--- $ arc-linux-size u-boot.libgcc-prebuilt text data bss dec hex filename 222217 24912 214820 461949 70c7d u-boot.libgcc-prebuilt $ arc-linux-size u-boot.libgcc-private text data bss dec hex filename 222361 24912 214820 462093 70d0d u-boot.libgcc-private --->8--- Also I don't notice visible performance degradation compared to pre-built libgcc (where at least "*div*" functions are had-written in assembly) on typical operations of downloading 10Mb uImage over TFTP and bootm. Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> 
This way we may have very limited set of functions implemented so we
save some space.

Also it allows us to build U-Boot for any ARC core with the same one
toolchain because we don't rely on pre-built libgcc.

For example:
 * we may use little-endian toolchain but build U-Boot for ether
endianess
 * we may use non-multilibbed uClibc toolchain but build U-Boot for
whatever ARC CPU flavour that current GCC supports

Private libgcc built from generic C implementation contributes only 144
bytes to .text section so we don't see significant degradation of size:
--->8---
$ arc-linux-size u-boot.libgcc-prebuilt
   text	   data	    bss	    dec	    hex	filename
 222217	  24912	 214820	 461949	  70c7d	u-boot.libgcc-prebuilt

$ arc-linux-size u-boot.libgcc-private
   text	   data	    bss	    dec	    hex	filename
 222361	  24912	 214820	 462093	  70d0d	u-boot.libgcc-private
--->8---

Also I don't notice visible performance degradation compared to
pre-built libgcc (where at least "*div*" functions are had-written in
assembly) on typical operations of downloading 10Mb uImage over TFTP and
bootm.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>