llvm-project/llvm/test/Transforms/SimplifyCFG
Sanjay Patel 5264cc772c [SimplifyCFG] limit recursion depth when speculating instructions (PR26308)
This is a fix for:
https://llvm.org/bugs/show_bug.cgi?id=26308

With the switch to using the TTI cost model in:
http://reviews.llvm.org/rL228826
...it became possible to hit a zero-cost cycle of instructions (gep -> phi -> gep...), 
so we need a cap for the recursion in DominatesMergePoint().

A recursion depth parameter was already added for a different reason in:
http://reviews.llvm.org/rL255660
...so we can just set a limit for it.

I pulled "10" out of the air and made it an independent parameter that we can play with.
It might be higher than it needs to be given the currently low default value of 
PHINodeFoldingThreshold (2). That's the starting cost value that we enter the recursion
with, and most instructions have cost set to TCC_Basic (1), so I don't think we're going
to speculate more than 2 instructions with the current parameters.

As noted in the review and the TODO comment, we can do better than just limiting recursion
depth.

Differential Revision: http://reviews.llvm.org/D16637

llvm-svn: 258971
2016-01-27 19:22:45 +00:00
..
AArch64 [AArch64] add overrides for isCheapToSpeculateCttz() and isCheapToSpeculateCtlz() 2015-11-10 18:11:37 +00:00
AMDGPU AMDGPU: Fix some places missed in rename 2015-06-19 17:39:03 +00:00
ARM [ARM] add overrides for isCheapToSpeculateCttz() and isCheapToSpeculateCtlz() 2015-11-10 19:24:31 +00:00
Mips [MIPS] add overrides for isCheapToSpeculateCttz() and isCheapToSpeculateCtlz() 2015-11-11 17:24:56 +00:00
PowerPC [CodeGenPrepare] Removed duplicate logic. SimplifyCFG already knows how to speculate calls to cttz/ctlz. 2015-02-13 14:15:48 +00:00
SPARC
X86 [SimplifyCFG] limit recursion depth when speculating instructions (PR26308) 2016-01-27 19:22:45 +00:00
2002-05-21-PHIElimination.ll
2002-09-24-PHIAssertion.ll
2003-03-07-DominateProblem.ll
2003-08-05-InvokeCrash.ll Move the personality function from LandingPadInst to Function 2015-06-17 20:52:32 +00:00
2003-08-17-BranchFold.ll
2003-08-17-BranchFoldOrdering.ll
2003-08-17-FoldSwitch-dbg.ll [opaque pointer type] Add textual IR support for explicit type parameter to gep operator 2015-03-13 18:20:45 +00:00
2003-08-17-FoldSwitch.ll
2004-12-10-SimplifyCFGCrash.ll
2005-06-16-PHICrash.ll [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
2005-08-01-PHIUpdateFail.ll [opaque pointer type] Add textual IR support for explicit type parameter to getelementptr instruction 2015-02-27 19:29:02 +00:00
2005-10-02-InvokeSimplify.ll Move the personality function from LandingPadInst to Function 2015-06-17 20:52:32 +00:00
2005-12-03-IncorrectPHIFold.ll [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
2006-02-17-InfiniteUnroll.ll
2006-06-12-InfLoop.ll
2006-08-03-Crash.ll [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
2006-10-19-UncondDiv.ll
2006-12-08-Ptr-ICmp-Branch.ll [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
2007-11-22-InvokeNoUnwind.ll Move the personality function from LandingPadInst to Function 2015-06-17 20:52:32 +00:00
2007-12-21-Crash.ll [opaque pointer type] Add textual IR support for explicit type parameter to the call instruction 2015-04-16 23:24:18 +00:00
2008-01-02-hoist-fp-add.ll [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
2008-05-16-PHIBlockMerge.ll
2008-07-13-InfLoopMiscompile.ll [opaque pointer type] Add textual IR support for explicit type parameter to the call instruction 2015-04-16 23:24:18 +00:00
2008-09-08-MultiplePred.ll [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
2008-09-17-SpeculativeHoist.ll
2008-10-03-SpeculativelyExecuteBeforePHI.ll
2008-12-06-SingleEntryPhi.ll
2008-12-16-DCECond.ll [opaque pointer type] Add textual IR support for explicit type parameter to the call instruction 2015-04-16 23:24:18 +00:00
2009-01-18-PHIPropCrash.ll
2009-01-19-UnconditionalTrappingConstantExpr.ll
2009-05-12-externweak.ll [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
2010-03-30-InvokeCrash.ll Move the personality function from LandingPadInst to Function 2015-06-17 20:52:32 +00:00
2011-03-08-UnreachableUse.ll
2011-09-05-TrivialLPad.ll Move the personality function from LandingPadInst to Function 2015-06-17 20:52:32 +00:00
BrUnwind.ll
CoveredLookupTable.ll
DeadSetCC.ll
EmptyBlockMerge.ll [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
EqualPHIEdgeBlockMerge.ll
ForwardSwitchConditionToPHI.ll
HoistCode.ll
MagicPointer.ll [opaque pointer type] Add textual IR support for explicit type parameter to gep operator 2015-03-13 18:20:45 +00:00
PHINode.ll
PR9946.ll
PR16069.ll
PR17073.ll [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
PR25267.ll [SimplifyCFG] Don't use-after-free an SSA value 2015-10-21 18:22:24 +00:00
PhiBlockMerge.ll [SimplifyCFG] Swap to using TargetTransformInfo for cost 2015-02-11 12:15:41 +00:00
PhiBlockMerge2.ll
PhiEliminate.ll
PhiEliminate2.ll
PhiEliminate3.ll
PhiNoEliminate.ll
SpeculativeExec.ll Revert "Revert "Strip metadata when speculatively hoisting instructions (r252604)" 2015-11-18 14:50:18 +00:00
UncondBranchToReturn.ll
UnreachableEliminate.ll Move the personality function from LandingPadInst to Function 2015-06-17 20:52:32 +00:00
assume.ll
attr-noduplicate.ll [opaque pointer type] Add textual IR support for explicit type parameter to getelementptr instruction 2015-02-27 19:29:02 +00:00
basictest.ll DI: Require subprogram definitions to be distinct 2015-08-28 20:26:49 +00:00
branch-cond-merge.ll
branch-cond-prop.ll
branch-fold-dbg.ll DI: Reverse direction of subprogram -> function edge. 2015-11-05 22:03:56 +00:00
branch-fold-test.ll
branch-fold-threshold.ll [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
branch-fold.ll
branch-phi-thread.ll [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
bug-25299.ll [SimplifyCFG] Extend SimplifyResume to handle phi of trivial landing pad. 2016-01-10 05:48:01 +00:00
clamp.ll [SimplifyCFG] Add test for r229099 2015-02-13 11:08:40 +00:00
common-dest-folding.ll [opaque pointer type] Add textual IR support for explicit type parameter to the call instruction 2015-04-16 23:24:18 +00:00
dbginfo.ll [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
dce-cond-after-folding-terminator.ll
duplicate-landingpad.ll Move the personality function from LandingPadInst to Function 2015-06-17 20:52:32 +00:00
duplicate-phis.ll
empty-catchpad.ll [WinEH] Simplify unreachable catchpads 2016-01-05 02:37:41 +00:00
empty-cleanuppad.ll [IR] Remove terminatepad 2015-12-14 18:34:23 +00:00
extract-cost.ll
hoist-common-code.ll [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
hoist-dbgvalue.ll DI: Reverse direction of subprogram -> function edge. 2015-11-05 22:03:56 +00:00
hoist-with-range.ll [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
implied-cond.ll [SimplifyCFG] Constant fold a branch implied by it's incoming edge 2015-10-29 03:11:49 +00:00
indirectbr.ll [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
invoke.ll Move the personality function from LandingPadInst to Function 2015-06-17 20:52:32 +00:00
invoke_unwind.ll [SimplifyCFG] Extend SimplifyResume to handle phi of trivial landing pad. 2016-01-10 05:48:01 +00:00
iterative-simplify.ll [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
lifetime.ll
merge-cond-stores-2.ll [SimplifyCFG] Don't create unnecessary PHIs 2015-12-16 14:12:44 +00:00
merge-cond-stores.ll Revert "Don't create unnecessary PHIs" 2015-12-14 22:36:57 +00:00
multiple-phis.ll [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
no_speculative_loads_with_asan.ll [asan] Disabling speculative loads under asan. Patch by Mike Aizatsky 2015-10-14 00:21:05 +00:00
no_speculative_loads_with_tsan.ll [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
noreturn-call.ll
phi-undef-loadstore.ll [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
preserve-branchweights-partial.ll IR: Make metadata typeless in assembly 2014-12-15 19:07:53 +00:00
preserve-branchweights-switch-create.ll IR: Make metadata typeless in assembly 2014-12-15 19:07:53 +00:00
preserve-branchweights.ll [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
preserve-load-metadata-2.ll Preserve load alignment and dereferenceable metadata during some transformations 2015-11-02 17:53:51 +00:00
preserve-load-metadata-3.ll Preserve load alignment and dereferenceable metadata during some transformations 2015-11-02 17:53:51 +00:00
preserve-load-metadata.ll Preserve load alignment and dereferenceable metadata during some transformations 2015-11-02 17:53:51 +00:00
preserve-make-implicit-on-switch-to-br.ll [ConstantFoldTerminator] Preserve make.implicit metadata when converting SwitchInst to BranchInst 2015-08-07 19:30:12 +00:00
return-merge.ll
seh-nounwind.ll Move the personality function from LandingPadInst to Function 2015-06-17 20:52:32 +00:00
select-gep.ll [opaque pointer type] Add textual IR support for explicit type parameter to getelementptr instruction 2015-02-27 19:29:02 +00:00
sink-common-code.ll [SimplifyCFG] Revise common code sinking 2014-12-23 08:26:55 +00:00
speculate-math.ll Revert "Revert "[SimplifyCFG] allow speculation of exactly one expensive instruction (PR24818)"" 2016-01-27 02:59:41 +00:00
speculate-store.ll [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
speculate-vector-ops.ll
speculate-with-offset.ll [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
statepoint-invoke-unwind.ll [gc.statepoint] Change gc.statepoint intrinsic's return type to token type instead of i32 type 2015-12-26 07:54:32 +00:00
switch-dead-default.ll [SimplifyCFG] Use known bits to eliminate dead switch defaults 2015-09-10 17:44:47 +00:00
switch-masked-bits.ll
switch-on-const-select.ll
switch-range-to-icmp.ll SimplifyCFG: don't remove unreachable default switch destinations 2015-01-26 19:52:32 +00:00
switch-simplify-crash.ll
switch-to-br.ll Add some tests for SimplifyCFG's ConstantFoldTerminator(). NFC. 2014-12-04 22:19:25 +00:00
switch-to-icmp.ll
switch-to-select-multiple-edge-per-block-phi.ll [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
switch-to-select-two-case.ll SimplifyCFG: don't remove unreachable default switch destinations 2015-01-26 19:52:32 +00:00
switch_create.ll [SimplifyCFG] Don't mistake icmp of and for a tree of comparisons 2016-01-27 02:43:28 +00:00
switch_switch_fold.ll
switch_thread.ll
trap-debugloc.ll DI: Reverse direction of subprogram -> function edge. 2015-11-05 22:03:56 +00:00
trapping-load-unreachable.ll [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
two-entry-phi-return.ll
unreachable-blocks.ll [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
volatile-phioper.ll [opaque pointer type] Add textual IR support for explicit type parameter to the call instruction 2015-04-16 23:24:18 +00:00
wineh-unreachable.ll [SimplifyCFG] Further improve our ability to remove redundant catchpads 2016-01-05 07:42:17 +00:00