[llvm] c4ad24d - [Attributor][NCFI] Explicitly state what interfering accesses to look for

[Johannes Doerfert via llvm-commits]

Author: Johannes Doerfert
Date: 2023-02-02T13:59:57-08:00
New Revision: c4ad24deeed8165f1c636473459982b8d9570e74

URL: https://github.com/llvm/llvm-project/commit/c4ad24deeed8165f1c636473459982b8d9570e74
DIFF: https://github.com/llvm/llvm-project/commit/c4ad24deeed8165f1c636473459982b8d9570e74.diff

LOG: [Attributor][NCFI] Explicitly state what interfering accesses to look for

We used to check the query instructions for effects but that does not
work well with complex accesses we will probably support in the future.
Now we simply let the user decide what accesses to look for.

Added: 
    

Modified: 
    llvm/include/llvm/Transforms/IPO/Attributor.h
    llvm/lib/Transforms/IPO/Attributor.cpp
    llvm/lib/Transforms/IPO/AttributorAttributes.cpp

Removed: 
    


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diff  --git a/llvm/include/llvm/Transforms/IPO/Attributor.h b/llvm/include/llvm/Transforms/IPO/Attributor.h
index da171f8940749..9cd351f8d580b 100644
--- a/llvm/include/llvm/Transforms/IPO/Attributor.h
+++ b/llvm/include/llvm/Transforms/IPO/Attributor.h
@@ -5483,6 +5483,7 @@ struct AAPointerInfo : public AbstractAttribute {
   /// read the intial value of the underlying memory.
   virtual bool forallInterferingAccesses(
       Attributor &A, const AbstractAttribute &QueryingAA, Instruction &I,
+      bool FindInterferingWrites, bool FindInterferingReads,
       function_ref<bool(const Access &, bool)> CB, bool &HasBeenWrittenTo,
       AA::RangeTy &Range) const = 0;
 

diff  --git a/llvm/lib/Transforms/IPO/Attributor.cpp b/llvm/lib/Transforms/IPO/Attributor.cpp
index b9134ce26e800..67d21adb6bdb7 100644
--- a/llvm/lib/Transforms/IPO/Attributor.cpp
+++ b/llvm/lib/Transforms/IPO/Attributor.cpp
@@ -451,8 +451,10 @@ static bool getPotentialCopiesOfMemoryValue(
     AA::RangeTy Range;
     auto &PI = A.getAAFor<AAPointerInfo>(QueryingAA, IRPosition::value(Obj),
                                          DepClassTy::NONE);
-    if (!PI.forallInterferingAccesses(A, QueryingAA, I, CheckAccess,
-                                      HasBeenWrittenTo, Range)) {
+    if (!PI.forallInterferingAccesses(A, QueryingAA, I,
+                                      /* FindInterferingWrites */ IsLoad,
+                                      /* FindInterferingReads */ !IsLoad,
+                                      CheckAccess, HasBeenWrittenTo, Range)) {
       LLVM_DEBUG(
           dbgs()
           << "Failed to verify all interfering accesses for underlying object: "

diff  --git a/llvm/lib/Transforms/IPO/AttributorAttributes.cpp b/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
index 2730adf1086a6..569a4a9424581 100644
--- a/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
+++ b/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
@@ -1032,6 +1032,7 @@ struct AAPointerInfoImpl
 
   bool forallInterferingAccesses(
       Attributor &A, const AbstractAttribute &QueryingAA, Instruction &I,
+      bool FindInterferingWrites, bool FindInterferingReads,
       function_ref<bool(const Access &, bool)> UserCB, bool &HasBeenWrittenTo,
       AA::RangeTy &Range) const override {
     HasBeenWrittenTo = false;
@@ -1099,8 +1100,6 @@ struct AAPointerInfoImpl
     const auto &NoRecurseAA = A.getAAFor<AANoRecurse>(
         QueryingAA, IRPosition::function(Scope), DepClassTy::OPTIONAL);
 
-    const bool FindInterferingWrites = I.mayReadFromMemory();
-    const bool FindInterferingReads = I.mayWriteToMemory();
     const bool UseDominanceReasoning =
         FindInterferingWrites && NoRecurseAA.isKnownNoRecurse();
     const DominatorTree *DT =