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make sh-1 support in gcc obsolete?


The SH-1 processor, unlike its sucessors, doesn't have delayed
conditional branches, nor the branch far (braf) instruction.
The lack of delayed conditional branches causes some ugliness
in assembler files.  The lack of braf means that you can't
execute a program on SH-1 that has been compiled with a
gcc from mainline sources after September 2001, because
CRT_CALL_STATIC_FUNCTION uses braf (CRT_CALL_STATIC_FUNCTION
is not used for coff, but then, coff was defunct during that
timespan...).

I presume that we take the lack of interest for this breakage as an
indication of a lack of interest for sh-1 support in new gcc releases
in general.

Now, while sh-coff might be used in the future as a starting
point for a coff-based OS port, I can't see any such redeeming
features for SH-1.  Moreover, by removing sh-1 support, we'll also remove
two multilibs from the standard sh-elf port, thus reducing build times,
test times, and binary toolchain size.
There are also a few more fringe simplification benefits because SH2 and
later procesors all support 32 bit multiply, decrement and test, and
branch to subroutine far (bsrf).

-- 
--------------------------
SuperH
2430 Aztec West / Almondsbury / BRISTOL / BS32 4AQ
T:+44 1454 462330


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