[TwoAddressInstruction] Update LiveIntervals after INSERT_SUBREG with undef read #66211
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… undef read Update LiveIntervals after rewriting: %reg = INSERT_SUBREG undef %reg, %subreg, subidx to: undef %reg:subidx = COPY %subreg D113044 implemented this for the non-undef case.
jayfoad
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jayfoad
commented
Sep 13, 2023
| S.MergeValueNumberInto(DefSeg->valno, UseSeg->valno); | ||
| LiveRange::iterator DefSeg = S.FindSegmentContaining(Idx); | ||
| if (mi->getOperand(0).isUndef()) { | ||
| S.removeValNo(DefSeg->valno); |
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TBH I am pretty nervous about all this low level fiddling around with live ranges. I would be much happier if there was some higher level API I could use to do this kind of update.
|
I see #65916 has just been merged which fixes exactly the same kind of problem. |
ZijunZhaoCCK
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Sep 19, 2023
… undef read (llvm#66211) Update LiveIntervals after rewriting: %reg = INSERT_SUBREG undef %reg, %subreg, subidx to: undef %reg:subidx = COPY %subreg D113044 implemented this for the non-undef case.
lukel97
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Sep 21, 2023
…65997) Similar to #65598, if we're using a vslideup to insert a fixed length vector into another vector, then we can work out the minimum number of registers it will need to slide up across given the minimum VLEN, and shrink the type operated on to reduce LMUL accordingly. This is somewhat dependent on #66211 , since it introduces a subregister copy that triggers a crash with -early-live-intervals in one of the tests. Stacked upon #66211
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Oct 24, 2023
… undef read (llvm#66211) Update LiveIntervals after rewriting: %reg = INSERT_SUBREG undef %reg, %subreg, subidx to: undef %reg:subidx = COPY %subreg D113044 implemented this for the non-undef case.
zahiraam
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Oct 24, 2023
… undef read (llvm#66211) Update LiveIntervals after rewriting: %reg = INSERT_SUBREG undef %reg, %subreg, subidx to: undef %reg:subidx = COPY %subreg D113044 implemented this for the non-undef case.
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Update LiveIntervals after rewriting:
%reg = INSERT_SUBREG undef %reg, %subreg, subidx
to:
undef %reg:subidx = COPY %subreg
D113044 implemented this for the non-undef case.