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llvm-project/llvm/test/Transforms/SimplifyCFG
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Sanjay Patel 38a022623a [SimplifyCFG] allow speculation of exactly one expensive instruction (PR24818) 
This is the last general step to allow more IR-level speculation with a safety harness in place in CodeGenPrepare.

The intent is to restore the behavior enabled by:
http://reviews.llvm.org/rL228826

but prevent bad performance such as:
https://llvm.org/bugs/show_bug.cgi?id=24818

Earlier patches in this sequence:
D12882 (disable SimplifyCFG speculation for expensive instructions)
D13297 (have CGP despeculate expensive ops)
D14630 (have CGP despeculate special versions of cttz/ctlz)

As shown in the test cases, we only have two instructions currently affected: ctz for some x86 and fdiv generally. 
Allowing exactly one expensive instruction is a bit of a hack, but it lines up with what is currently implemented
in CGP. If we make the despeculation more general in CGP, we can make the speculation here more liberal.

A follow-up patch will adjust the cost for sqrt and possibly other typically expensive math intrinsics (currently
everything is cheap by default). GPU targets would likely want to override those expensive default costs (just as
they probably should already override the cost of div/rem) because just about any math is cheaper than control-flow
on those targets.

Differential Revision: http://reviews.llvm.org/D15213

llvm-svn: 255660
 		2015-12-15 17:38:29 +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
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X86 [SimplifyCFG] allow speculation of exactly one expensive instruction (PR24818) 2015-12-15 17:38:29 +00:00
2002-05-21-PHIElimination.ll
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2002-09-24-PHIAssertion.ll
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2003-03-07-DominateProblem.ll
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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
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2003-08-17-BranchFoldOrdering.ll
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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
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2004-12-10-SimplifyCFGCrash.ll
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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
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2006-06-12-InfLoop.ll
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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
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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
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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
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2008-10-03-SpeculativelyExecuteBeforePHI.ll
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2008-12-06-SingleEntryPhi.ll
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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
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2009-01-19-UnconditionalTrappingConstantExpr.ll
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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
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2011-09-05-TrivialLPad.ll Move the personality function from LandingPadInst to Function 2015-06-17 20:52:32 +00:00
BrUnwind.ll
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CoveredLookupTable.ll
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DeadSetCC.ll
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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
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ForwardSwitchConditionToPHI.ll
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HoistCode.ll
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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
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PR9946.ll
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PR16069.ll
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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
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PhiEliminate.ll
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PhiEliminate2.ll
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PhiEliminate3.ll
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PhiNoEliminate.ll
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SpeculativeExec.ll Revert "Revert "Strip metadata when speculatively hoisting instructions (r252604)" 2015-11-18 14:50:18 +00:00
UncondBranchToReturn.ll
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UnreachableEliminate.ll Move the personality function from LandingPadInst to Function 2015-06-17 20:52:32 +00:00
assume.ll
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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
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branch-cond-prop.ll
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branch-fold-dbg.ll DI: Reverse direction of subprogram -> function edge. 2015-11-05 22:03:56 +00:00
branch-fold-test.ll
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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
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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
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
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duplicate-landingpad.ll Move the personality function from LandingPadInst to Function 2015-06-17 20:52:32 +00:00
duplicate-phis.ll
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empty-cleanuppad.ll [IR] Remove terminatepad 2015-12-14 18:34:23 +00:00
extract-cost.ll
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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 [OperandBundles] Fix a transform in simplifycfg 2015-12-08 22:26:08 +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
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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
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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
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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 [SimplifyCFG] allow speculation of exactly one expensive instruction (PR24818) 2015-12-15 17:38:29 +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
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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 Move the personality function from LandingPadInst to Function 2015-06-17 20:52:32 +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
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switch-on-const-select.ll
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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
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switch-to-br.ll Add some tests for SimplifyCFG's ConstantFoldTerminator(). NFC. 2014-12-04 22:19:25 +00:00
switch-to-icmp.ll
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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 [opaque pointer type] Add textual IR support for explicit type parameter to load instruction 2015-02-27 21:17:42 +00:00
switch_switch_fold.ll
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switch_thread.ll
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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
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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 [IR] Remove terminatepad 2015-12-14 18:34:23 +00:00