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| 1 | +# PGO (Profile-Guided Optimization) training script for Node.js (Clang / LLVM) |
| 2 | +# |
| 3 | +# Runs PGO training workloads against an instrumented Node.js binary |
| 4 | +# (Release\node.exe) and merges the resulting .profraw files into |
| 5 | +# node.profdata for use with -fprofile-use. |
| 6 | +# |
| 7 | +# Usage (from a VS Developer Command Prompt): |
| 8 | +# .\pgo.ps1 # Run workloads (15s each) and merge |
| 9 | +# .\pgo.ps1 -Duration 30 # Run workloads (30s each) and merge |
| 10 | +# |
| 11 | +# Prerequisites: |
| 12 | +# - Release\node.exe must be an instrumented build (built with pgo-generate) |
| 13 | +# - llvm-profdata must be available (shipped with VS LLVM toolset) |
| 14 | +# |
| 15 | +# Output: |
| 16 | +# - node.profdata in the repo root (ready for vcbuild.bat pgo-use) |
| 17 | + |
| 18 | +param( |
| 19 | + [int]$Duration = 15 |
| 20 | +) |
| 21 | + |
| 22 | +Set-StrictMode -Version Latest |
| 23 | +$ErrorActionPreference = 'Stop' |
| 24 | + |
| 25 | +# --------------------------------------------------------------------------- |
| 26 | +# Locate llvm-profdata shipped with Visual Studio's LLVM toolset |
| 27 | +# --------------------------------------------------------------------------- |
| 28 | + |
| 29 | +function Find-LlvmProfdata { |
| 30 | + # vcbuild.bat uses %VCINSTALLDIR%\Tools\Llvm\x64\bin for clang.exe - same spot for profdata |
| 31 | + $vcInstallDir = $env:VCINSTALLDIR |
| 32 | + |
| 33 | + if ($vcInstallDir) { |
| 34 | + $candidate = Join-Path $vcInstallDir "Tools\Llvm\x64\bin\llvm-profdata.exe" |
| 35 | + if (Test-Path $candidate) { |
| 36 | + return $candidate |
| 37 | + } |
| 38 | + } |
| 39 | + |
| 40 | + # Fallback: try VS 2022 / 2026 default install locations |
| 41 | + $vsPaths = @( |
| 42 | + "${env:ProgramFiles}\Microsoft Visual Studio\2026\Enterprise\VC\Tools\Llvm\x64\bin", |
| 43 | + "${env:ProgramFiles}\Microsoft Visual Studio\2026\Community\VC\Tools\Llvm\x64\bin", |
| 44 | + "${env:ProgramFiles}\Microsoft Visual Studio\2022\Enterprise\VC\Tools\Llvm\x64\bin", |
| 45 | + "${env:ProgramFiles}\Microsoft Visual Studio\2022\Community\VC\Tools\Llvm\x64\bin" |
| 46 | + ) |
| 47 | + foreach ($dir in $vsPaths) { |
| 48 | + $candidate = Join-Path $dir "llvm-profdata.exe" |
| 49 | + if (Test-Path $candidate) { |
| 50 | + return $candidate |
| 51 | + } |
| 52 | + } |
| 53 | + |
| 54 | + # Last resort: PATH |
| 55 | + $fromPath = Get-Command llvm-profdata -ErrorAction SilentlyContinue |
| 56 | + if ($fromPath) { |
| 57 | + return $fromPath.Source |
| 58 | + } |
| 59 | + |
| 60 | + return $null |
| 61 | +} |
| 62 | + |
| 63 | +# --------------------------------------------------------------------------- |
| 64 | +# Validate prerequisites |
| 65 | +# --------------------------------------------------------------------------- |
| 66 | + |
| 67 | +$instrumentedNode = Join-Path $PSScriptRoot "Release\node.exe" |
| 68 | +if (-not (Test-Path $instrumentedNode)) { |
| 69 | + Write-Error "Instrumented binary not found: $instrumentedNode`nBuild with: vcbuild.bat pgo-generate" |
| 70 | + exit 1 |
| 71 | +} |
| 72 | + |
| 73 | +$pgoRunAll = Join-Path $PSScriptRoot "tools\pgo\pgo-run-all.js" |
| 74 | +if (-not (Test-Path $pgoRunAll)) { |
| 75 | + Write-Error "PGO training script not found: $pgoRunAll" |
| 76 | + exit 1 |
| 77 | +} |
| 78 | + |
| 79 | +$llvmProfdata = Find-LlvmProfdata |
| 80 | +if (-not $llvmProfdata) { |
| 81 | + Write-Error "llvm-profdata not found. Install the LLVM toolset via Visual Studio Installer." |
| 82 | + exit 1 |
| 83 | +} |
| 84 | + |
| 85 | +# --------------------------------------------------------------------------- |
| 86 | +# STEP 1 – Run workloads with the instrumented binary to collect profiles |
| 87 | +# --------------------------------------------------------------------------- |
| 88 | + |
| 89 | +Write-Host "`n=== STEP 1: Collect PGO profiles ===" -ForegroundColor Cyan |
| 90 | + |
| 91 | +# Directory that will receive .profraw files from the instrumented binary. |
| 92 | +# %p (PID) and %m (module hash) keep concurrent/fork'd processes from colliding. |
| 93 | +$profileDir = Join-Path $PSScriptRoot "pgo-profiles" |
| 94 | + |
| 95 | +if (Test-Path $profileDir) { |
| 96 | + Remove-Item -Recurse -Force $profileDir |
| 97 | +} |
| 98 | +New-Item -ItemType Directory -Path $profileDir | Out-Null |
| 99 | + |
| 100 | +$env:LLVM_PROFILE_FILE = Join-Path $profileDir "node-%p-%m.profraw" |
| 101 | + |
| 102 | +Write-Host "Instrumented node : $instrumentedNode" |
| 103 | +Write-Host "Profile output : $($env:LLVM_PROFILE_FILE)" |
| 104 | +Write-Host "Duration per script: ${Duration}s" |
| 105 | +Write-Host "" |
| 106 | + |
| 107 | +$sw = [System.Diagnostics.Stopwatch]::StartNew() |
| 108 | +$proc = Start-Process ` |
| 109 | + -FilePath $instrumentedNode ` |
| 110 | + -ArgumentList "`"$pgoRunAll`" --verbose --duration=$Duration" ` |
| 111 | + -Wait -PassThru -NoNewWindow |
| 112 | +$sw.Stop() |
| 113 | +Write-Host ("PGO training completed in {0}m {1}s (exit code: {2})" -f ` |
| 114 | + $sw.Elapsed.Minutes, $sw.Elapsed.Seconds, $proc.ExitCode) |
| 115 | +if ($proc.ExitCode -ne 0) { |
| 116 | + Write-Warning "PGO training exited with code $($proc.ExitCode) - continuing with merge" |
| 117 | +} |
| 118 | + |
| 119 | +# Remove the env var so subsequent builds are not affected |
| 120 | +Remove-Item Env:\LLVM_PROFILE_FILE -ErrorAction SilentlyContinue |
| 121 | + |
| 122 | +# --------------------------------------------------------------------------- |
| 123 | +# STEP 2 – Merge .profraw files -> node.profdata |
| 124 | +# --------------------------------------------------------------------------- |
| 125 | + |
| 126 | +Write-Host "`n=== STEP 2: Merge profile data ===" -ForegroundColor Cyan |
| 127 | + |
| 128 | +Write-Host "Using llvm-profdata: $llvmProfdata" |
| 129 | + |
| 130 | +$profrawFiles = Get-ChildItem -Path $profileDir -Filter "*.profraw" -ErrorAction SilentlyContinue |
| 131 | +if ($profrawFiles.Count -eq 0) { |
| 132 | + Write-Error "No .profraw files found in '$profileDir'. The instrumented binary may not have generated profile data." |
| 133 | + exit 1 |
| 134 | +} |
| 135 | + |
| 136 | +$totalSize = ($profrawFiles | Measure-Object -Property Length -Sum).Sum |
| 137 | +$totalSizeMB = [math]::Round($totalSize / 1MB, 1) |
| 138 | +Write-Host "Found $($profrawFiles.Count) .profraw file(s), ${totalSizeMB} MB total" |
| 139 | + |
| 140 | +$profdata = Join-Path $PSScriptRoot "node.profdata" |
| 141 | +$mergeArgs = @("merge", "--output=$profdata") + ($profrawFiles | Select-Object -ExpandProperty FullName) |
| 142 | + |
| 143 | +$mergeStopwatch = [System.Diagnostics.Stopwatch]::StartNew() |
| 144 | +& $llvmProfdata @mergeArgs |
| 145 | +$mergeExitCode = $LASTEXITCODE |
| 146 | +$mergeStopwatch.Stop() |
| 147 | + |
| 148 | +if ($mergeExitCode -ne 0) { |
| 149 | + Write-Error "llvm-profdata merge failed (exit code $mergeExitCode)" |
| 150 | + exit $mergeExitCode |
| 151 | +} |
| 152 | + |
| 153 | +$profdataSize = [math]::Round((Get-Item $profdata).Length / 1MB, 1) |
| 154 | +Write-Host "Merge completed in $([math]::Round($mergeStopwatch.Elapsed.TotalSeconds, 1))s" |
| 155 | + |
| 156 | +# Clean up .profraw files now that they've been merged |
| 157 | +Remove-Item -Recurse -Force $profileDir |
| 158 | +Write-Host "Removed $($profrawFiles.Count) .profraw file(s) (${totalSizeMB} MB reclaimed)" |
| 159 | + |
| 160 | +Write-Host "`n=== PGO training complete ===" -ForegroundColor Green |
| 161 | +Write-Host " Profile data: $profdata (${profdataSize} MB)" |
| 162 | +Write-Host " Next step: vcbuild.bat pgo-use" |
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