Bug in gcc-20020114: m68k doesn't use tstsf/tstdf patterns

law@redhat.com law@redhat.com
Wed Mar 6 12:50:00 GMT 2002


 In message <200203062031.g26KVHY02626@hyper.wm.sps.mot.com>, Peter Barada 
write
 > >Also notice that the ftst is redundant as we could use condition code
 > >values set by the fadd.s.  That would create a loop which looks like:
 > >
 > >.L8:
 > >        fsglmul.s %d0,%fp0
 > >        fadd.x %fp1,%fp0
 > >        fbnlt .L4
 > >        move.w #1,%a0
 > >.L4:
 > >        subq.l #1,%d1
 > >        jbpl .L8
 > 
 > Hmmm, I'll assume that I should look in notice_update_cc to get the
 > compiler to generate this sequence.
No need.  The right thing will just happen.

 > Thanx for updating the tree.  If you don't mind my asking, why didnt'
 > it go into the 3.1 branch as well?
It doesn't fall under the guidelines for what should go into the GCC 3.1
branch at this time.  In simplest terms, it doesn't fix a correctness
issue of any kind, it merely improves optimization.
jeff



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