[llvm-branch-commits] [llvm] [BOLT] Map branch source address to the containing basic block in BAT YAML (PR #91273)

[Amir Ayupov via llvm-branch-commits]

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@@ -2378,21 +2378,24 @@ std::error_code DataAggregator::writeBATYAML(BinaryContext &BC,
         return CSI;
       };
 
+      // Lookup containing basic block offset and index
+      auto getBlock = [&BlockMap](uint32_t Offset) {
+        auto BlockIt = BlockMap.upper_bound(Offset);
+        assert(BlockIt != BlockMap.begin());
+        --BlockIt;
+        return std::pair(BlockIt->first, BlockIt->second.getBBIndex());
+      };
+
       for (const auto &[FromOffset, SuccKV] : Branches.IntraIndex) {
-        if (!BlockMap.isInputBlock(FromOffset))
-          continue;
-        const unsigned Index = BlockMap.getBBIndex(FromOffset);
+        const auto &[_, Index] = getBlock(FromOffset);
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aaupov wrote:

> Do we expect getBlock() to always return a good value? 

Yes. It performs an `upper_bound` lookup with an unsigned value against a BlockMap which should contain a zero key (entry basic block). As long as the function has it, we're good. If not, it's worth looking why do we have such a function in BAT.

> There's no chance for malformed input to trigger the assertion above?

No, any offset in the profile is >=0.

https://github.com/llvm/llvm-project/pull/91273