[llvm-branch-commits] [clang] [lldb] [libcxx] [mlir] [openmp] [clang-tools-extra] [flang] [libc] [llvm] [BOLT] Deduplicate equal offsets in BAT (PR #76905)

[Amir Ayupov via llvm-branch-commits]

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@@ -207,15 +280,23 @@ void BoltAddressTranslation::parseMaps(std::vector<uint64_t> &HotFuncs,
       const uint64_t OutputAddress = PrevAddress + OutputDelta;
       const uint64_t OutputOffset = OutputAddress - Address;
       PrevAddress = OutputAddress;
-      const int64_t InputDelta = DE.getSLEB128(&Offset, &Err);
-      InputOffset += InputDelta;
+      int64_t InputDelta = 0;
+      if (J < EqualElems) {
+        InputOffset = (OutputOffset << 1) | (*BEBitMask)[J];
+      } else {
+        InputDelta = DE.getSLEB128(&Offset, &Err);
+        InputOffset += InputDelta;
+      }
       Map.insert(std::pair<uint32_t, uint32_t>(OutputOffset, InputOffset));
       LLVM_DEBUG(
           dbgs() << formatv("{0:x} -> {1:x} ({2}/{3}b -> {4}/{5}b), {6:x}\n",
                             OutputOffset, InputOffset, OutputDelta,
-                            encodeULEB128(OutputDelta, nulls()), InputDelta,
-                            encodeSLEB128(InputDelta, nulls()), OutputAddress));
+                            getULEB128Size(OutputDelta), InputDelta,
+                            (J < EqualElems) ? 0 : getSLEB128Size(InputDelta),
+                            OutputAddress));
     }
+    if (BEBitMask)
+      delete BEBitMask;
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aaupov wrote:

Good point. I can keep APInt uninitialized if it's not used.

https://github.com/llvm/llvm-project/pull/76905