[AssumptionCache] Add affected values for separate_storage

[nikic]

Add the underlying object of both separate_storage arguments as affected values. This allows us to use assumptionsFor() in BasicAA, which will be more efficient if there are many assumes in the function.

[llvmbot]

@llvm/pr-subscribers-llvm-analysis

Author: Nikita Popov (nikic)

Changes

Add the underlying object of both separate_storage arguments as affected values. This allows us to use assumptionsFor() in BasicAA, which will be more efficient if there are many assumes in the function.

---

Full diff: https://github.com/llvm/llvm-project/pull/76806.diff

2 Files Affected:

• (modified) llvm/lib/Analysis/AssumptionCache.cpp (+10-3)
• (modified) llvm/lib/Analysis/BasicAliasAnalysis.cpp (+1-1)

diff --git a/llvm/lib/Analysis/AssumptionCache.cpp b/llvm/lib/Analysis/AssumptionCache.cpp
index fb3a6f8de2d6ac..1b7277df0e0cd0 100644
--- a/llvm/lib/Analysis/AssumptionCache.cpp
+++ b/llvm/lib/Analysis/AssumptionCache.cpp
@@ -17,6 +17,7 @@
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Analysis/AssumeBundleQueries.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/Analysis/ValueTracking.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/InstrTypes.h"
@@ -77,9 +78,15 @@ findAffectedValues(CallBase *CI, TargetTransformInfo *TTI,
   };
 
   for (unsigned Idx = 0; Idx != CI->getNumOperandBundles(); Idx++) {
-    if (CI->getOperandBundleAt(Idx).Inputs.size() > ABA_WasOn &&
-        CI->getOperandBundleAt(Idx).getTagName() != IgnoreBundleTag)
-      AddAffected(CI->getOperandBundleAt(Idx).Inputs[ABA_WasOn], Idx);
+    OperandBundleUse Bundle = CI->getOperandBundleAt(Idx);
+    if (Bundle.getTagName() == "separate_storage") {
+      assert(Bundle.Inputs.size() == 2 &&
+             "separate_storage must have two args");
+      AddAffected(getUnderlyingObject(Bundle.Inputs[0]), Idx);
+      AddAffected(getUnderlyingObject(Bundle.Inputs[1]), Idx);
+    } else if (Bundle.Inputs.size() > ABA_WasOn &&
+               Bundle.getTagName() != IgnoreBundleTag)
+      AddAffected(Bundle.Inputs[ABA_WasOn], Idx);
   }
 
   Value *Cond = CI->getArgOperand(0), *A, *B;
diff --git a/llvm/lib/Analysis/BasicAliasAnalysis.cpp b/llvm/lib/Analysis/BasicAliasAnalysis.cpp
index 3de147368f2346..418c2d8019c8aa 100644
--- a/llvm/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/llvm/lib/Analysis/BasicAliasAnalysis.cpp
@@ -1544,7 +1544,7 @@ AliasResult BasicAAResult::aliasCheck(const Value *V1, LocationSize V1Size,
     return AliasResult::NoAlias;
 
   if (CtxI && EnableSeparateStorageAnalysis) {
-    for (auto &AssumeVH : AC.assumptions()) {
+    for (auto &AssumeVH : AC.assumptionsFor(O1)) {
       if (!AssumeVH)
         continue;
 

[davidtgoldblatt]

LGTM, good idea.