Philip Reames b5eb31e440 [LoopDeletion] Break backedge of outermost loops when known not taken ... This is a resubmit of dd6bb367 (which was reverted due to stage2 build failures in 7c63aac), with the additional restriction added to the transform to only consider outer most loops. As shown in the added test case, ensuring LCSSA is up to date when deleting an inner loop is tricky as we may actually need to remove blocks from any outer loops, thus changing the exit block set. For the moment, just avoid transforming this case. I plan to return to this case in a follow up patch and see if we can do better. Original commit message follows... The basic idea is that if SCEV can prove the backedge isn't taken, we can go ahead and get rid of the backedge (and thus the loop) while leaving the rest of the control in place. This nicely handles cases with dispatch between multiple exits and internal side effects. Differential Revision: https://reviews.llvm.org/D93906		2021-01-10 16:02:33 -08:00
..
AMDGPU
ARM	[SCEV] Strenthen nowrap flags after constant folding for mul exprs	2020-10-25 19:43:58 +01:00
NVPTX
X86	Revert "[LoopDeletion] Break backedge of loops when known not taken"	2021-01-04 09:50:47 -08:00
2002-09-09-PointerIndVar.ll
2003-04-16-ExprAnalysis.ll
2003-09-23-NotAtTop.ll
2003-12-10-RemoveInstrCrash.ll
2003-12-15-Crash.ll
2004-03-10-PHIInsertionBug.ll
2004-04-05-InvokeCastCrash.ll
2004-04-07-ScalarEvolutionCrash.ll
2005-02-11-InvokeCrash.ll
2005-02-17-TruncateExprCrash.ll
2005-02-26-ExitValueCompute.ll
2005-06-15-InstMoveCrash.ll
2005-11-18-Crash.ll
2006-03-31-NegativeStride.ll
2006-06-16-Indvar-LCSSA-Crash.ll
2006-09-20-LFTR-Crash.ll
2006-12-10-BitCast.ll
2007-01-06-TripCount.ll
2007-06-06-DeleteDanglesPtr.ll
2007-11-23-BitcastCrash.ll
2008-06-15-SCEVExpanderBug.ll
2008-09-02-IVType.ll
2008-10-03-CouldNotCompute.ll
2008-11-25-APFloatAssert.ll
2009-04-22-IndvarCrash.ll
2009-04-27-Floating.ll
2009-05-24-useafterfree.ll
2011-09-10-widen-nsw.ll
2011-09-19-vectoriv.ll
2011-09-27-hoistsext.ll
2011-10-27-lftrnull.ll
2011-11-01-lftrptr.ll	[NFC][IndVars] Autogenerate check lines in tests being affected by upcoming patch	2020-10-15 23:15:04 +03:00
2011-11-17-selfphi.ll
2012-10-19-congruent-constant.ll
2014-06-21-congruent-constant.ll	[NewPM][LoopUnswitch] Pin loop-unswitch to legacy PM or use simple-loop-unswitch	2020-08-06 10:56:00 -07:00
2020-12-15-trunc-bug-expensive-range-inference.ll	[SCEV] Add missing type check into getRangeForAffineNoSelfWrappingAR	2020-12-15 14:50:32 +07:00
ada-loops.ll
addrec_no_exec_on_every_iteration.ll	Return "[SCEV] Prove implicaitons via AddRec start"	2020-10-08 11:15:35 +07:00
ashr-tripcount.ll
avoid-i0.ll
backedge-on-min-max.ll
bec-cmp.ll
canonicalize-cmp.ll	[Test] Auto-generated checks for some IndVarSimplify tests	2020-09-08 11:15:40 +07:00
casted-argument.ll
checks_against_min_value.ll	[Test] Missing range check removal opportunity	2020-09-18 17:55:23 +07:00
const_phi.ll
constant_result.ll
constant-fold.ll
crash.ll
dangling-use.ll
divide-pointer.ll
dont-recompute.ll	Revert "[SCEV] rewriteLoopExitValues(): even if have hard uses, still rewrite if cheap (PR44668)"	2020-04-03 20:15:04 +03:00
drop-exact.ll
elim-extend.ll	[IndVars] Regenerate test checks (NFC)	2020-06-29 20:33:50 +02:00
eliminate-comparison.ll	[SCEV] Strength nowrap flags after constant folding	2020-10-25 18:00:22 +01:00
eliminate-exit-no-dl.ll
eliminate-exit.ll
eliminate-max.ll
eliminate-overflow-modified.ll	[IndVarSimplify] Fix Modified status for removal of overflow intrinsics	2020-09-29 13:20:59 +02:00
eliminate-rem.ll
eliminate-sat.ll
exit_value_test2.ll	[LoopDeletion] Break backedge of outermost loops when known not taken	2021-01-10 16:02:33 -08:00
exit_value_test3.ll
exit_value_tests.ll	[SimplifyCFG] MergeBlockIntoPredecessor() already knows how to preserve DomTree	2020-12-17 01:03:49 +03:00
floating-point-iv.ll	[SCEV] Drop cached ranges of AddRecs after flag update	2020-11-10 12:37:12 +07:00
full_widening.ll
indirectbr.ll
infer-poison-flags.ll	[Test] Auto-update for some tests	2020-10-14 17:03:33 +07:00
interesting-invoke-use.ll	OpaquePtr: Update more tests to use typed sret	2020-11-20 20:08:43 -05:00
iterationCount_zext_or_trunc.ll
iv-fold.ll
iv-sext.ll
iv-widen-elim-ext.ll
iv-zext.ll
lcssa-preservation.ll
lftr_disabled.ll
lftr-address-space-pointers.ll
lftr-dead-ivs.ll	[Test] Auto-update for some tests	2020-10-14 17:03:33 +07:00
lftr-multi-exit.ll	[Test] Auto-generated checks for some IndVarSimplify tests	2020-09-08 11:15:40 +07:00
lftr-pr20680.ll
lftr-pr31181.ll	[Test] Auto-update for some tests	2020-10-14 17:03:33 +07:00
lftr-pr41998.ll
lftr-promote.ll
lftr-reuse.ll
lftr.ll	[Test] Auto-update for some tests	2020-10-14 17:03:33 +07:00
loop_evaluate7.ll
loop_evaluate8.ll
loop_evaluate9.ll	OpaquePtr: Bulk update tests to use typed byval	2020-11-20 14:00:46 -05:00
loop_evaluate11.ll
loop_evaluate_1.ll	[SimplifyCFG] Teach FoldTwoEntryPHINode() to preserve DomTree	2020-12-20 00:18:33 +03:00
loop_evaluate_2.ll	[SimplifyCFG] Teach FoldTwoEntryPHINode() to preserve DomTree	2020-12-20 00:18:33 +03:00
loop_evaluate_3.ll
loop_evaluate_4.ll
loop_evaluate_5.ll
loop_evaluate_6.ll
loop-predication.ll
lrev-existing-umin.ll	Revert "[SCEV] rewriteLoopExitValues(): even if have hard uses, still rewrite if cheap (PR44668)"	2020-04-03 20:15:04 +03:00
masked-iv.ll
monotonic_checks.ll	Return "[IndVars] Remove monotonic checks with unknown exit count"	2020-10-28 18:51:40 +07:00
no-iv-rewrite.ll	[NFC] Run update script on test	2020-08-17 12:53:14 +01:00
phi-uses-value-multiple-times.ll
post-inc-range.ll
pr18223.ll	[Test] Auto-generated checks for some IndVarSimplify tests	2020-09-08 11:15:40 +07:00
pr22222.ll
pr24783.ll
pr24952.ll
pr25060.ll
pr25578.ll
pr26974.ll
pr28705.ll	Revert "[SCEV] rewriteLoopExitValues(): even if have hard uses, still rewrite if cheap (PR44668)"	2020-04-03 20:15:04 +03:00
pr32045.ll
pr38674.ll
pr38855.ll	[FunctionAttrs] Rename functionattrs -> function-attrs	2020-07-28 09:09:13 -07:00
pr39673.ll	Revert "[SCEV] rewriteLoopExitValues(): even if have hard uses, still rewrite if cheap (PR44668)"	2020-04-03 20:15:04 +03:00
pr40454.ll
pr45835.ll	[IndVarSimplify][LoopUtils] Avoid TOCTOU/ordering issues (PR45835)	2020-05-21 13:05:55 +03:00
predicated_ranges.ll	[IndVars] Use isLoopBackedgeGuardedByCond for last iteration check	2020-11-26 12:37:21 +07:00
preserve-memoryssa.ll
preserve-signed-wrap.ll
promote-iv-to-eliminate-casts.ll	Revert D89381 "[SCEV] Recommit "Use nw flag and symbolic iteration count to sharpen ranges of AddRecs", attempt 2"	2020-10-20 21:03:58 -07:00
replace-loop-exit-folds.ll	[SCEV] Strenthen nowrap flags after constant folding for mul exprs	2020-10-25 19:43:58 +01:00
replace-sdiv-by-udiv.ll
replace-srem-by-urem.ll
rewrite-loop-exit-value.ll
rewrite-loop-exit-values-phi.ll	[IndVarSimplify] Fix Modified status when handling dead PHI nodes	2020-11-26 14:28:21 +01:00
rlev-add-me.ll
scev-expander-preserve-lcssa.ll	[test] Fix scev-expander-preserve-lcssa.ll under NPM	2020-12-10 09:46:08 -08:00
scevexpander-phi-base-case.ll
sentinel.ll	[Test] Add one more test on IndVars that was failing on one of older builds	2020-08-07 14:23:55 +07:00
shared-exit-between-nested-loop.ll	[IndVarSimplify] Notify top most loop to drop cached exit counts	2020-11-19 15:37:54 +08:00
sharpen-range.ll
shrunk-constant.ll	[test] Fix shrunk-constant.ll under NPM	2020-10-21 21:21:24 -07:00
signed-trip-count.ll
single-element-range.ll
sink-alloca.ll
sink-from-preheader.ll
sink-trapping.ll
strengthen-overflow.ll
tripcount_compute.ll
tripcount_infinite.ll	[NFCI][SimplifyCFG] Mark all the SimplifyCFG tests that already don't invalidate DomTree as such	2020-12-17 01:03:49 +03:00
trivial-checks.ll	[Test] Add tests showing that IndVars cannot prove (X + 1 > X)	2020-09-17 22:37:43 +07:00
udiv-invariant-but-traps.ll
udiv.ll
ult-sub-to-eq.ll
use-range-metadata.ll
variable-stride-ivs-0.ll
widen-i32-i8ptr.ll	[NFC][IndVars] Autogenerate check lines in tests being affected by upcoming patch	2020-10-15 23:15:04 +03:00
widen-loop-comp.ll	[IndVars] A test for adding trunc instructions to unwind blocks	2020-12-18 17:08:26 +07:00
zext-nuw.ll	[IndVars] Regenerate test checks (NFC)	2020-11-02 22:31:11 +01:00