RFR(S): 8220374: C2: LoopStripMining doesn't strip as expected
rkennke at redhat.com
Wed Mar 13 09:56:25 UTC 2019
> Fix for 8193597 accidentally broke loop strip mining: that change caused
> the inner and outer loop to have the same exit condition. So loop strip
> mining has been effectively disabled for more than a year (a month after
> it was pushed !?).
> The fix above correctly sets the inner and outer loop exit
> condition. Initially, when the loop is strip mined, the inner loop exit
> condition is left as is and the outer loop exit condition is set to
> always exit. After optimizations, the outer loop exit condition must be
> set to be the same as the inner loop exit condition and then, the inner
> loop exit condition must be adjusted so the inner loop runs for no more
> than LoopStripMiningIter iterations.
> Thanks to Martin Doerr for the test case and the bug report.
Looks good to me! Thanks!
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