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CVS commit: src/sys/lib/libkern/arch/sh3

Module Name:    src
Committed By:   uwe
Date:           Thu Aug  4 03:20:10 UTC 2011

Modified Files:
Added Files:
        src/sys/lib/libkern/arch/sh3: sdivsi3_i4i.S udivsi3_i4i.S

Log Message:
For unsignad integer division gcc used to emit a call to __udivsi3
"millicode" function that uses compiler-private ABI.  Newer gcc uses
heavily tuned __udivsi3_i4i that is NOT compatible with __udivsi3
because it's expected to clobber different registers.  We don't want
to link the kernel against libgcc and we don't have resources to write
heavily tuned version ourselves, so clone __udivsi3 but adjust it to
conform to the __udivsi3_i4i clobber spec.

Ditto for signed division.

You can make gcc use old routines with -mdiv=call-div1 to avoid few
extra instructions to save/restore the right registers in the signed
division funcion.

To generate a diff of this commit:
cvs rdiff -u -r1.18 -r1.19 src/sys/lib/libkern/arch/sh3/
cvs rdiff -u -r0 -r1.1 src/sys/lib/libkern/arch/sh3/sdivsi3_i4i.S \

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.

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