[all-commits] [llvm/llvm-project] ff020d: [BOLT] Fix heatmaps on large BOLTE'd binaries.

[Paschalis Mpeis via All-commits]

  Branch: refs/heads/users/paschalis-mpeis/bolt-heatmap-fix
  Home:   https://github.com/llvm/llvm-project
  Commit: ff020d9ae49deae831e07922cad0f738d9ee4cef
      https://github.com/llvm/llvm-project/commit/ff020d9ae49deae831e07922cad0f738d9ee4cef
  Author: Paschalis Mpeis (aws-mem-aarch64) <paschalis.mpeis at arm.com>
  Date:   2024-06-25 (Tue, 25 Jun 2024)

  Changed paths:
    M bolt/lib/Profile/DataAggregator.cpp

  Log Message:
  -----------
  [BOLT] Fix heatmaps on large BOLTE'd binaries.

Large binaries get two text segments mapped when loaded in memory, ie:
```
2f7200000-2fabca000 r--p 00000000        bolted-binary <- 1st text segment
2fabd9000-2fe47c000 r-xp 039c9000        bolted-binary
2fe48b000-2fe61d000 r--p 0727b000        bolted-binary
2fe62c000-2fe660000 rw-p 0740c000        bolted-binary
2fe660000-2fea4c000 rw-p 00000000
2fec00000-303dad000 r-xp 07a00000        bolted-binary <- 2nd. only on bolted binary
```

BOLT processes only the first, which is not having a correct BaseAddress,
causing a wrong computation of a BinaryMMapInfo's size.

Consequently, BOLT wrongly thinks that many of the samples fall outside
the binary and ignores them. As a result, the computed heatmap is
incomplete, and the section hotness statistics are wrong.

This bug is present in both the AArch64 and x86 backends.



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