[llvm] [Assignment Tracking] Trim assignments for untagged out of bounds stores (PR #66095)

[Stephen Tozer via llvm-commits]

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@@ -1979,20 +1979,22 @@ static AssignmentTrackingLowering::OverlapMap buildOverlapMapAndRecordDeclares(
                      I, Fn.getParent()->getDataLayout())) {
         // Find markers linked to this alloca.
         for (DbgAssignIntrinsic *DAI : at::getAssignmentMarkers(Info->Base)) {
-          // Discard the fragment if it covers the entire variable.
-          std::optional<DIExpression::FragmentInfo> FragInfo =
-              [&Info, DAI]() -> std::optional<DIExpression::FragmentInfo> {
-            DIExpression::FragmentInfo F;
-            F.OffsetInBits = Info->OffsetInBits;
-            F.SizeInBits = Info->SizeInBits;
-            if (auto ExistingFrag = DAI->getExpression()->getFragmentInfo())
-              F.OffsetInBits += ExistingFrag->OffsetInBits;
-            if (auto Sz = DAI->getVariable()->getSizeInBits()) {
-              if (F.OffsetInBits == 0 && F.SizeInBits == *Sz)
-                return std::nullopt;
-            }
-            return F;
-          }();
+          std::optional<DIExpression::FragmentInfo> FragInfo;
+
+          // Skip this assignment if the affected bits are outside of the
+          // variable fragment.
+          if (!at::calculateFragmentIntersect(
+                  I.getModule()->getDataLayout(), Info->Base,
+                  Info->OffsetInBits, Info->SizeInBits, DAI, FragInfo) ||
+              (FragInfo && FragInfo->SizeInBits == 0))
+            continue;
+
+          // FragInfo from calculateFragmentIntersect is is nullopt if the
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SLTozer wrote:

Double "is"

https://github.com/llvm/llvm-project/pull/66095