[llvm] r364422 - [InlineCost] cleanup calculations of Cost and Threshold
Jordan Rupprecht via llvm-commits
llvm-commits at lists.llvm.org
Tue Jul 2 17:05:01 PDT 2019
Hi Fedor,
We're seeing some very unexpectedly large stack frame sizes as a result of
this patch, e.g. from ~300 bytes to ~25kb. We're trying to reduce a test
case to share. Is this kind of change expected with this patch?
On Wed, Jun 26, 2019 at 6:24 AM Fedor Sergeev via llvm-commits <
llvm-commits at lists.llvm.org> wrote:
> Author: fedor.sergeev
> Date: Wed Jun 26 06:24:24 2019
> New Revision: 364422
>
> URL: http://llvm.org/viewvc/llvm-project?rev=364422&view=rev
> Log:
> [InlineCost] cleanup calculations of Cost and Threshold
>
> Summary:
> Doing better separation of Cost and Threshold.
> Cost counts the abstract complexity of live instructions, while Threshold
> is an upper bound of complexity that inlining is comfortable to pay.
> There are two parts:
> - huge 15K last-call-to-static bonus is no longer subtracted from Cost
> but rather is now added to Threshold.
>
> That makes much more sense, as the cost of inlining (Cost) is not
> changed by the fact
> that internal function is called once. It only changes the
> likelyhood of this inlining
> being profitable (Threshold).
>
> - bonus for calls proved-to-be-inlinable into callee is no longer
> subtracted from Cost
> but added to Threshold instead.
>
> While calculations are somewhat different, overall InlineResult should
> stay the same since Cost >= Threshold compares the same.
>
> Reviewers: eraman, greened, chandlerc, yrouban, apilipenko
> Reviewed By: apilipenko
> Tags: #llvm
> Differential Revision: https://reviews.llvm.org/D60740
>
> Modified:
> llvm/trunk/lib/Analysis/InlineCost.cpp
>
> llvm/trunk/test/LTO/Resolution/X86/diagnostic-handler-remarks-with-hotness.ll
> llvm/trunk/test/LTO/Resolution/X86/diagnostic-handler-remarks.ll
> llvm/trunk/test/LTO/X86/diagnostic-handler-remarks-with-hotness.ll
> llvm/trunk/test/LTO/X86/diagnostic-handler-remarks.ll
> llvm/trunk/test/Transforms/Inline/ARM/inline-fp.ll
>
> Modified: llvm/trunk/lib/Analysis/InlineCost.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/InlineCost.cpp?rev=364422&r1=364421&r2=364422&view=diff
>
> ==============================================================================
> --- llvm/trunk/lib/Analysis/InlineCost.cpp (original)
> +++ llvm/trunk/lib/Analysis/InlineCost.cpp Wed Jun 26 06:24:24 2019
> @@ -897,7 +897,15 @@ void CallAnalyzer::updateThreshold(CallB
> // and the callsite.
> int SingleBBBonusPercent = 50;
> int VectorBonusPercent = 150;
> - int LastCallToStaticBonus = InlineConstants::LastCallToStaticBonus;
> +
> + int LastCallToStaticBonus = 0;
> + bool OnlyOneCallAndLocalLinkage =
> + F.hasLocalLinkage() && F.hasOneUse() && &F ==
> Call.getCalledFunction();
> + // If there is only one call of the function, and it has internal
> linkage,
> + // we can allow to inline pretty anything as it will lead to size
> reduction
> + // anyway.
> + if (OnlyOneCallAndLocalLinkage)
> + LastCallToStaticBonus = InlineConstants::LastCallToStaticBonus;
>
> // Lambda to set all the above bonus and bonus percentages to 0.
> auto DisallowAllBonuses = [&]() {
> @@ -970,20 +978,13 @@ void CallAnalyzer::updateThreshold(CallB
> }
> }
>
> - // Finally, take the target-specific inlining threshold multiplier into
> - // account.
> + // Take the target-specific inlining threshold multiplier into account.
> Threshold *= TTI.getInliningThresholdMultiplier();
>
> SingleBBBonus = Threshold * SingleBBBonusPercent / 100;
> VectorBonus = Threshold * VectorBonusPercent / 100;
>
> - bool OnlyOneCallAndLocalLinkage =
> - F.hasLocalLinkage() && F.hasOneUse() && &F ==
> Call.getCalledFunction();
> - // If there is only one call of the function, and it has internal
> linkage,
> - // the cost of inlining it drops dramatically. It may seem odd to update
> - // Cost in updateThreshold, but the bonus depends on the logic in this
> method.
> - if (OnlyOneCallAndLocalLinkage)
> - Cost -= LastCallToStaticBonus;
> + Threshold += LastCallToStaticBonus;
> }
>
> bool CallAnalyzer::visitCmpInst(CmpInst &I) {
> @@ -1330,9 +1331,10 @@ bool CallAnalyzer::visitCallBase(CallBas
> CallAnalyzer CA(TTI, GetAssumptionCache, GetBFI, PSI, ORE, *F, Call,
> IndirectCallParams);
> if (CA.analyzeCall(Call)) {
> - // We were able to inline the indirect call! Subtract the cost from
> the
> - // threshold to get the bonus we want to apply, but don't go below
> zero.
> - Cost -= std::max(0, CA.getThreshold() - CA.getCost());
> + // We were able to inline the indirect call! Increase the threshold
> + // with the bonus we want to apply (less the cost of inlinee).
> + // Make sure the bonus doesn't go below zero.
> + Threshold += std::max(0, CA.getThreshold() - CA.getCost());
> }
>
> if (!F->onlyReadsMemory())
>
> Modified:
> llvm/trunk/test/LTO/Resolution/X86/diagnostic-handler-remarks-with-hotness.ll
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/LTO/Resolution/X86/diagnostic-handler-remarks-with-hotness.ll?rev=364422&r1=364421&r2=364422&view=diff
>
> ==============================================================================
> ---
> llvm/trunk/test/LTO/Resolution/X86/diagnostic-handler-remarks-with-hotness.ll
> (original)
> +++
> llvm/trunk/test/LTO/Resolution/X86/diagnostic-handler-remarks-with-hotness.ll
> Wed Jun 26 06:24:24 2019
> @@ -27,13 +27,13 @@
> ; YAML-NEXT: - Caller: main
> ; YAML-NEXT: - String: ' with '
> ; YAML-NEXT: - String: '(cost='
> -; YAML-NEXT: - Cost: '-15000'
> +; YAML-NEXT: - Cost: '0'
> ; YAML-NEXT: - String: ', threshold='
> -; YAML-NEXT: - Threshold: '337'
> +; YAML-NEXT: - Threshold: '15337'
> ; YAML-NEXT: - String: ')'
> ; YAML-NEXT: ...
>
> -; CHECK: tinkywinky inlined into main with (cost=-15000, threshold=337)
> (hotness: 300)
> +; CHECK: tinkywinky inlined into main with (cost=0, threshold=15337)
> (hotness: 300)
>
> target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
> target triple = "x86_64-scei-ps4"
>
> Modified: llvm/trunk/test/LTO/Resolution/X86/diagnostic-handler-remarks.ll
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/LTO/Resolution/X86/diagnostic-handler-remarks.ll?rev=364422&r1=364421&r2=364422&view=diff
>
> ==============================================================================
> --- llvm/trunk/test/LTO/Resolution/X86/diagnostic-handler-remarks.ll
> (original)
> +++ llvm/trunk/test/LTO/Resolution/X86/diagnostic-handler-remarks.ll Wed
> Jun 26 06:24:24 2019
> @@ -30,9 +30,9 @@
> ; YAML-NEXT: - Caller: main
> ; YAML-NEXT: - String: ' with '
> ; YAML-NEXT: - String: '(cost='
> -; YAML-NEXT: - Cost: '-15000'
> +; YAML-NEXT: - Cost: '0'
> ; YAML-NEXT: - String: ', threshold='
> -; YAML-NEXT: - Threshold: '337'
> +; YAML-NEXT: - Threshold: '15337'
> ; YAML-NEXT: - String: ')'
> ; YAML-NEXT: ...
>
>
> Modified:
> llvm/trunk/test/LTO/X86/diagnostic-handler-remarks-with-hotness.ll
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/LTO/X86/diagnostic-handler-remarks-with-hotness.ll?rev=364422&r1=364421&r2=364422&view=diff
>
> ==============================================================================
> --- llvm/trunk/test/LTO/X86/diagnostic-handler-remarks-with-hotness.ll
> (original)
> +++ llvm/trunk/test/LTO/X86/diagnostic-handler-remarks-with-hotness.ll Wed
> Jun 26 06:24:24 2019
> @@ -19,9 +19,9 @@
> ; YAML-NEXT: - Caller: main
> ; YAML-NEXT: - String: ' with '
> ; YAML-NEXT: - String: '(cost='
> -; YAML-NEXT: - Cost: '-15000'
> +; YAML-NEXT: - Cost: '0'
> ; YAML-NEXT: - String: ', threshold='
> -; YAML-NEXT: - Threshold: '337'
> +; YAML-NEXT: - Threshold: '15337'
> ; YAML-NEXT: - String: ')'
> ; YAML-NEXT: ...
>
>
> Modified: llvm/trunk/test/LTO/X86/diagnostic-handler-remarks.ll
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/LTO/X86/diagnostic-handler-remarks.ll?rev=364422&r1=364421&r2=364422&view=diff
>
> ==============================================================================
> --- llvm/trunk/test/LTO/X86/diagnostic-handler-remarks.ll (original)
> +++ llvm/trunk/test/LTO/X86/diagnostic-handler-remarks.ll Wed Jun 26
> 06:24:24 2019
> @@ -55,9 +55,9 @@
> ; YAML-NEXT: - Caller: main
> ; YAML-NEXT: - String: ' with '
> ; YAML-NEXT: - String: '(cost='
> -; YAML-NEXT: - Cost: '-15000'
> +; YAML-NEXT: - Cost: '0'
> ; YAML-NEXT: - String: ', threshold='
> -; YAML-NEXT: - Threshold: '337'
> +; YAML-NEXT: - Threshold: '15337'
> ; YAML-NEXT: - String: ')'
> ; YAML-NEXT: ...
>
>
> Modified: llvm/trunk/test/Transforms/Inline/ARM/inline-fp.ll
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Inline/ARM/inline-fp.ll?rev=364422&r1=364421&r2=364422&view=diff
>
> ==============================================================================
> --- llvm/trunk/test/Transforms/Inline/ARM/inline-fp.ll (original)
> +++ llvm/trunk/test/Transforms/Inline/ARM/inline-fp.ll Wed Jun 26 06:24:24
> 2019
> @@ -7,7 +7,7 @@
> ; NOFP-DAG: single not inlined into test_single because too costly to
> inline (cost=125, threshold=75)
> ; NOFP-DAG: single not inlined into test_single because too costly to
> inline (cost=125, threshold=75)
> ; NOFP-DAG: single_cheap inlined into test_single_cheap with (cost=-15,
> threshold=75)
> -; NOFP-DAG: single_cheap inlined into test_single_cheap with
> (cost=-15015, threshold=75)
> +; NOFP-DAG: single_cheap inlined into test_single_cheap with (cost=-15,
> threshold=15075)
> ; NOFP-DAG: double not inlined into test_double because too costly to
> inline (cost=125, threshold=75)
> ; NOFP-DAG: double not inlined into test_double because too costly to
> inline (cost=125, threshold=75)
> ; NOFP-DAG: single_force_soft not inlined into test_single_force_soft
> because too costly to inline (cost=125, threshold=75)
> @@ -16,20 +16,20 @@
> ; NOFP-DAG: single_force_soft_fneg not inlined into
> test_single_force_soft_fneg because too costly to inline (cost=100,
> threshold=75)
>
> ; FULLFP-DAG: single inlined into test_single with (cost=0, threshold=75)
> -; FULLFP-DAG: single inlined into test_single with (cost=-15000,
> threshold=75)
> +; FULLFP-DAG: single inlined into test_single with (cost=0,
> threshold=15075)
> ; FULLFP-DAG: single_cheap inlined into test_single_cheap with (cost=-15,
> threshold=75)
> -; FULLFP-DAG: single_cheap inlined into test_single_cheap with
> (cost=-15015, threshold=75)
> +; FULLFP-DAG: single_cheap inlined into test_single_cheap with (cost=-15,
> threshold=15075)
> ; FULLFP-DAG: double inlined into test_double with (cost=0, threshold=75)
> -; FULLFP-DAG: double inlined into test_double with (cost=-15000,
> threshold=75)
> +; FULLFP-DAG: double inlined into test_double with (cost=0,
> threshold=15075)
> ; FULLFP-DAG: single_force_soft not inlined into test_single_force_soft
> because too costly to inline (cost=125, threshold=75)
> ; FULLFP-DAG: single_force_soft not inlined into test_single_force_soft
> because too costly to inline (cost=125, threshold=75)
> ; FULLFP-DAG: single_force_soft_fneg not inlined into
> test_single_force_soft_fneg because too costly to inline (cost=100,
> threshold=75)
> ; FULLFP-DAG: single_force_soft_fneg not inlined into
> test_single_force_soft_fneg because too costly to inline (cost=100,
> threshold=75)
>
> ; SINGLEFP-DAG: single inlined into test_single with (cost=0,
> threshold=75)
> -; SINGLEFP-DAG: single inlined into test_single with (cost=-15000,
> threshold=75)
> +; SINGLEFP-DAG: single inlined into test_single with (cost=0,
> threshold=15075)
> ; SINGLEFP-DAG: single_cheap inlined into test_single_cheap with
> (cost=-15, threshold=75)
> -; SINGLEFP-DAG: single_cheap inlined into test_single_cheap with
> (cost=-15015, threshold=75)
> +; SINGLEFP-DAG: single_cheap inlined into test_single_cheap with
> (cost=-15, threshold=15075)
> ; SINGLEFP-DAG: double not inlined into test_double because too costly to
> inline (cost=125, threshold=75)
> ; SINGLEFP-DAG: double not inlined into test_double because too costly to
> inline (cost=125, threshold=75)
> ; SINGLEFP-DAG: single_force_soft not inlined into test_single_force_soft
> because too costly to inline (cost=125, threshold=75)
>
>
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> llvm-commits at lists.llvm.org
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