Reproducer files for ISSUE

Dockerfile

FROM --platform=linux/aarch64 ubuntu:22.04
ARG DEBIAN_FRONTEND=noninteractive

### Dependencies:
# for clang-18 installation (pre-compiled), pyenv, and mongodb
RUN apt-get update && \
  apt-get install -y --no-install-recommends \
  make build-essential wget curl llvm \
  lsb-release software-properties-common gnupg git \
  zlib1g-dev libbz2-dev libreadline-dev libsqlite3-dev \
  libncursesw5-dev xz-utils tk-dev libxml2-dev libxmlsec1-dev \
  libffi-dev libcurl4-openssl-dev liblzma-dev libssl-dev openjdk-21-jdk && \
  apt-get clean \
  && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*

WORKDIR /home/bolt

### Install clang-18 (precompiled)
# Ubuntu clang version 18.1.8 (++20240731024944+3b5b5c1ec4a3-1~exp1~20240731145000.144)
RUN bash -c "$(wget -O - https://apt.llvm.org/llvm.sh)"
RUN wget https://apt.llvm.org/llvm.sh && \
  chmod +x llvm.sh && \
  ./llvm.sh 18
RUN which clang-18

### Prepare MongoDB sources:
RUN git clone --branch r7.0.5 https://github.com/mongodb/mongo.git

# Disable debug info for MongoDB
RUN cd mongo && \
  sed -e '/-g2/ s/^#*/#/' -i SConstruct

# Apply patch that I attach in the issue:
RUN wget https://gist.githubusercontent.com/paschalis-mpeis/9eb878f73e18fb9d3f996ae7c59d4792/raw/e9de7728a517e153d4980225ecac92d2e0923498/mongo.patch && \
  cd mongo && \
  git config --global user.email "you@example.com" && \
  git am ../mongo.patch

## Install MongoDB Dependencies and setup environment:
# Install pyenv (https://github.com/pyenv) and use it to set python to 3.10.12
RUN curl -L https://github.com/pyenv/pyenv-installer/raw/master/bin/pyenv-installer | bash

RUN export PYENV_ROOT="$HOME/.pyenv" && \
  export PATH="$PYENV_ROOT/bin:$PATH" && \
  eval "$(pyenv init -)" && \
  pyenv install 3.10.12 && \
  pyenv global 3.10.12 && \
  echo "System Python : $(python3 --version) $(which python3)" && \
  python3 -m venv mongo-db-venv --prompt mongo && \
  . mongo-db-venv/bin/activate && \
  cd mongo && \
  python3 -m ensurepip --upgrade && \
  python3 -m pip install --upgrade setuptools && \
  pip install -r etc/pip/compile-requirements.txt

## Compile MongoDB Stage-0:
# Activates again the python venv and uses it to launch SCons build system.
# In separate directive from above so it's cacheable.
RUN echo "Compiling MongoDB:" && \
  export PYENV_ROOT="$HOME/.pyenv" && \
  export PATH="$PYENV_ROOT/bin:$PATH" && \
  eval "$(pyenv init -)" && \
  pyenv global 3.10.12 && \
  echo "System Python : $(python3 --version) $(which python3)" && \
  . mongo-db-venv/bin/activate && \
  cd mongo && \
  echo "Used Python : $(python3 --version) $(which python3)" && \
  python3 buildscripts/scons.py install-mongod \
    CC=clang-18 CXX=clang++-18 \
    CCFLAGS="-fno-omit-frame-pointer -Wno-deprecated-non-prototype -Wno-enum-constexpr-conversion" \
    LINKFLAGS="-Wl,-q"; exit 0

RUN echo "Binary at: mongo/build/install/bin/mongod " && \
  ls -lh mongo/build/install/bin/mongod && \
  echo "Has Relocations: " && \
  llvm-readelf-18 --sections mongo/build/install/bin/mongod | grep .rela.text

llvm-bolt.txt

BOLT-INFO: shared object or position-independent executable detected
BOLT-INFO: Target architecture: aarch64
BOLT-INFO: BOLT version: d78211912391b724a064ef017dbf239eff10380a
BOLT-INFO: first alloc address is 0x0
BOLT-INFO: creating new program header table at address 0x7e00000, offset 0x7e00000
BOLT-WARNING: debug info will be stripped from the binary. Use -update-debug-sections to keep it.
BOLT-INFO: enabling relocation mode
BOLT-INFO: disabling -align-macro-fusion on non-x86 platform
BOLT-INFO: enabling lite mode
BOLT-INFO: pre-processing profile using branch profile reader
BOLT-WARNING: 48 collisions detected while hashing binary objects. Use -v=1 to see the list.
BOLT-INFO: operating with basic samples profiling data (no LBR).
BOLT-INFO: normalizing samples by instruction count.
BOLT-INFO: number of removed linker-inserted veneers: 0
BOLT-INFO: 1617 out of 153847 functions in the binary (1.1%) have non-empty execution profile
BOLT-INFO: 79 functions with profile could not be optimized
BOLT-INFO: Starting stub-insertion pass
BOLT-INFO: Inserted 9008 stubs in the hot area and 11262 stubs in the cold area. Shared 781 times, iterated 3 times.
BOLT-INFO: patched build-id (flipped last bit)

mongo.patch

From 6feb0b3640160bf0ab553d5e978a321720c8cdb8 Mon Sep 17 00:00:00 2001
From: Paschalis Mpeis <Paschalis.Mpeis@arm.com>
Date: Wed, 10 Jul 2024 09:14:06 +0100
Subject: [PATCH] PATCH

---
 .../abseil-cpp/dist/absl/hash/internal/low_level_hash.cc        | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/third_party/abseil-cpp/dist/absl/hash/internal/low_level_hash.cc b/src/third_party/abseil-cpp/dist/absl/hash/internal/low_level_hash.cc
index 6f9cb9c7bff..d288f3ec94d 100644
--- a/src/third_party/abseil-cpp/dist/absl/hash/internal/low_level_hash.cc
+++ b/src/third_party/abseil-cpp/dist/absl/hash/internal/low_level_hash.cc
@@ -40,7 +40,7 @@ static uint64_t Mix(uint64_t v0, uint64_t v1) {
 }
 
 uint64_t LowLevelHash(const void* data, size_t len, uint64_t seed,
-                      const uint64_t salt[]) {
+                      const uint64_t salt[5]) {
   const uint8_t* ptr = static_cast<const uint8_t*>(data);
   uint64_t starting_length = static_cast<uint64_t>(len);
   uint64_t current_state = seed ^ salt[0];
-- 
2.42.0

mongod.tar.gz

perf.boltdata

perf2bolt.txt