https://github.com/vitalybuka updated https://github.com/llvm/llvm-project/pull/100794
>From a33fda5a7ffc8a032fc12c44cc23e94ff141cf76 Mon Sep 17 00:00:00 2001 From: Vitaly Buka <vitalyb...@google.com> Date: Fri, 26 Jul 2024 11:18:44 -0700 Subject: [PATCH] [NFC][Load] Find better place for `mustSuppressSpeculation` And extract `suppressSpeculativeLoadForSanitizers`. Pull Request: https://github.com/llvm/llvm-project/pull/100794 --- llvm/include/llvm/Analysis/Loads.h | 7 +++++++ llvm/include/llvm/Analysis/ValueTracking.h | 7 ------- llvm/lib/Analysis/Loads.cpp | 13 +++++++++++++ llvm/lib/Analysis/ValueTracking.cpp | 11 ----------- 4 files changed, 20 insertions(+), 18 deletions(-) diff --git a/llvm/include/llvm/Analysis/Loads.h b/llvm/include/llvm/Analysis/Loads.h index 33e817828b754..38f86f77b4158 100644 --- a/llvm/include/llvm/Analysis/Loads.h +++ b/llvm/include/llvm/Analysis/Loads.h @@ -106,6 +106,13 @@ bool isSafeToLoadUnconditionally(Value *V, Type *Ty, Align Alignment, const DominatorTree *DT = nullptr, const TargetLibraryInfo *TLI = nullptr); +/// Return true if speculation of the given load must be suppressed to avoid +/// ordering or interfering with an active sanitizer. If not suppressed, +/// dereferenceability and alignment must be proven separately. Note: This +/// is only needed for raw reasoning; if you use the interface below +/// (isSafeToSpeculativelyExecute), this is handled internally. +bool mustSuppressSpeculation(const LoadInst &LI); + /// The default number of maximum instructions to scan in the block, used by /// FindAvailableLoadedValue(). extern cl::opt<unsigned> DefMaxInstsToScan; diff --git a/llvm/include/llvm/Analysis/ValueTracking.h b/llvm/include/llvm/Analysis/ValueTracking.h index 5ef6e43483906..96fa16970584d 100644 --- a/llvm/include/llvm/Analysis/ValueTracking.h +++ b/llvm/include/llvm/Analysis/ValueTracking.h @@ -792,13 +792,6 @@ bool onlyUsedByLifetimeMarkers(const Value *V); /// droppable instructions. bool onlyUsedByLifetimeMarkersOrDroppableInsts(const Value *V); -/// Return true if speculation of the given load must be suppressed to avoid -/// ordering or interfering with an active sanitizer. If not suppressed, -/// dereferenceability and alignment must be proven separately. Note: This -/// is only needed for raw reasoning; if you use the interface below -/// (isSafeToSpeculativelyExecute), this is handled internally. -bool mustSuppressSpeculation(const LoadInst &LI); - /// Return true if the instruction does not have any effects besides /// calculating the result and does not have undefined behavior. /// diff --git a/llvm/lib/Analysis/Loads.cpp b/llvm/lib/Analysis/Loads.cpp index 61c6aa5e5a3eb..1704f0db4c599 100644 --- a/llvm/lib/Analysis/Loads.cpp +++ b/llvm/lib/Analysis/Loads.cpp @@ -345,6 +345,19 @@ bool llvm::isDereferenceableAndAlignedInLoop(LoadInst *LI, Loop *L, HeaderFirstNonPHI, AC, &DT); } +static bool suppressSpeculativeLoadForSanitizers(const Instruction &CtxI) { + const Function &F = *CtxI.getFunction(); + // Speculative load may create a race that did not exist in the source. + return F.hasFnAttribute(Attribute::SanitizeThread) || + // Speculative load may load data from dirty regions. + F.hasFnAttribute(Attribute::SanitizeAddress) || + F.hasFnAttribute(Attribute::SanitizeHWAddress); +} + +bool llvm::mustSuppressSpeculation(const LoadInst &LI) { + return !LI.isUnordered() || suppressSpeculativeLoadForSanitizers(LI); +} + /// Check if executing a load of this pointer value cannot trap. /// /// If DT and ScanFrom are specified this method performs context-sensitive diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp index bfd26fadd237b..497f6eafd22d8 100644 --- a/llvm/lib/Analysis/ValueTracking.cpp +++ b/llvm/lib/Analysis/ValueTracking.cpp @@ -6798,17 +6798,6 @@ bool llvm::onlyUsedByLifetimeMarkersOrDroppableInsts(const Value *V) { V, /* AllowLifetime */ true, /* AllowDroppable */ true); } -bool llvm::mustSuppressSpeculation(const LoadInst &LI) { - if (!LI.isUnordered()) - return true; - const Function &F = *LI.getFunction(); - // Speculative load may create a race that did not exist in the source. - return F.hasFnAttribute(Attribute::SanitizeThread) || - // Speculative load may load data from dirty regions. - F.hasFnAttribute(Attribute::SanitizeAddress) || - F.hasFnAttribute(Attribute::SanitizeHWAddress); -} - bool llvm::isSafeToSpeculativelyExecute(const Instruction *Inst, const Instruction *CtxI, AssumptionCache *AC, _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
