Mercurial > hg > index.cgi
diff extra/README @ 396:d0c0fede5021
Update to gcc6809lw patch which may help compilation of some sources
Due to persistent random compiler crashes and errors related to "M_REGS",
this patch update (4.6.4-2) essentially removes the varius constraints
allowing the "soft registers" in most operations. It was causing more
problems than it solved and it is not clear that the logic behind those soft
registers even makes sense any more.
This patch also fixes a bogus comparison related to selecting the right size
for a constant. Instead of the excessively clever comparison scheme that was
previously in use, the comparisons have been replaced with straight forward
comparisions for the top and bottom of the relevant 2's complement ranges.
| author | William Astle <lost@l-w.ca> |
|---|---|
| date | Mon, 20 Jul 2015 22:32:41 -0600 |
| parents | b0fb675d1ed4 |
| children | c8ae69cdb5a9 |
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--- a/extra/README Mon Jul 20 17:48:51 2015 -0600 +++ b/extra/README Mon Jul 20 22:32:41 2015 -0600 @@ -16,8 +16,7 @@ Similar to the "as" script above except for lwar. -gcc6809lw-4.6.1-1.patch -gcc6809lw-4.6.4-1.patch +gcc6809lw-*.patch These are patches to the main gcc source distribution for specific releases. The last number after the dash is a patch level for the specific patch. It @@ -93,3 +92,19 @@ for "root" set up correctly if your install prefix requires root privileges. The above is WOMM certified. YMMV. + +NOTES ABOUT SPECIFIC PATCHES +============================ + +gcc6809lw-4.6.4-2.patch + +This patch essentially disables the "soft registers". These were causing +problems leading to compiler crashes. Removing the "t" constraint from +the instruction patterns allowed various issues to go away. It is not clear +if the original reasoning behind these soft registers is even valid any +more. + +Also fixes a clearly incorrect comparision when determining if a constant +fits in 16 bits. For clarity, both the 8 bit and 16 bit comparisons are +replaced with straight forward range comparisons rather than the excessively +clever scheme that was present before.