tryLatency compares two sched candidates. For the top zone it prefers
the one with lesser depth, but only if that depth is greater than the
total latency of the instructions we've already scheduled -- otherwise
its latency would be hidden and there would be no stall.
Unfortunately it only tests the depth of one of the candidates. This can
lead to situations where the TopDepthReduce heuristic does not kick in,
but a lower priority heuristic chooses the other candidate, whose depth
*is* greater than the already scheduled latency, which causes a stall.
The fix is to apply the heuristic if the depth of *either* candidate is
greater than the already scheduled latency.
All this also applies to the BotHeightReduce heuristic in the bottom
zone.
Differential Revision: https://reviews.llvm.org/D72392
Summary:
If we didn't set the value for hasSideEffects bit in our td file, `llvm-tblgen`
will set it as true for those instructions which has no match pattern.
The instructions `MTLR` and `MFLR` don't set the hasSideEffects flag and don't
have match pattern, so their hasSideEffects flag will be set true by
`llvm-tblgen`.
But in fact, we can use `[LR]` to model the two instructions, so they should not
have SideEffects.
This patch is to modify the hasSideEffects of MTLR and MFLR from 1 to 0.
Reviewed By: jsji
Differential Revision: https://reviews.llvm.org/D71390
Summary:
This is brought up in
https://reviews.llvm.org/D64662?id=209923#inline-599490
CFI information are non-relevant to quite some testcases,
we should get rid of checking them when its unecessary.
This patch avoid generating cfi info in testcases that are not
testing prolog/epilog or exception handling.
Reviewers: kbarton, hfinkel, nemanjai, #powerpc
Reviewed By: hfinkel
Subscribers: MaskRay, shchenz, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67016
llvm-svn: 370505
Jay Foad