On 26.09.2016 15:19, Pitchumani Sivanupandi wrote:
Attached patch for PR71676 and PR71678.
PR71676 is for AVR target that generates wrong code when switch case index is
more than 16 bits.
Switch case index of larger than SImode are checked for out of range before
'casesi' expand. RTL expand of casesi gets index as SImode, but index is
compared in HImode and ignores upper 16bits.
Attached patch changes the expansion for casesi to make the index comparison
in SImode and code generation accordingly.
PR71678 is ICE because below pattern in 'casesi' is not recognized.
(set (reg:HI 47)
(minus:HI (subreg:HI (subreg:SI (reg:DI 44) 0) 0)
(reg:HI 45)))
Fix of PR71676 avoids the above pattern as it changes the comparison
to SImode.
But this means that all comparisons are now performed in SImode which is a
great performance loss for most programs which will switch on 16-bit values.
IMO we need a less intrusive (w.r.t. performance) approach.
Johann
Regtested using avrtest. No regression found.
If OK, could someone commit please?
Is this OK for gcc-5-branch?
Regards,
Pitchumani
gcc/ChangeLog
2016-09-26 Pitchumani Sivanupandi <pitchuman...@atmel.com>
PR target/71676
PR target/71678
* config/avr/avr.md (casesi): Change index compare to SI mode.
gcc/testsuite/ChangeLog
2016-09-26 Pitchumani Sivanupandi <pitchuman...@atmel.com>
PR target/71676
PR target/71678
* gcc.target/avr/pr71676-1.c: New test.
* gcc.target/avr/pr71676.c: New test.
* gcc.target/avr/pr71678.c: New test.
