From 795f53ba640129d9d50e908aeabff90e751dbbed Mon Sep 17 00:00:00 2001 From: Diego Novillo Date: Wed, 22 Oct 2014 13:00:05 +0000 Subject: Support using sample profiles with partial debug info (driver) Summary: When using a profile, we used to require the use -gmlt so that we could get access to the line locations. This is used to match line numbers in the input profile to the line numbers in the function's IR. But this is actually not necessary. The driver can provide source location tracking without the emission of debug information. In these cases, the annotation 'llvm.dbg.cu' is missing from the IR, but the actual line location annotations are still present. This patch tells the driver to only emit source location tracking when -fprofile-sample-use is present in the command line. Reviewers: echristo, dblaikie Subscribers: llvm-commits Differential Revision: http://reviews.llvm.org/D5888 llvm-svn: 220383 --- clang/lib/Frontend/CompilerInvocation.cpp | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'clang/lib/Frontend/CompilerInvocation.cpp') diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp index 2c4118c..9bf14c7 100644 --- a/clang/lib/Frontend/CompilerInvocation.cpp +++ b/clang/lib/Frontend/CompilerInvocation.cpp @@ -575,8 +575,14 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK, NeedLocTracking = true; } - // If the user requested one of the flags in the -Rpass family, make sure - // that the backend tracks source location information. + // If the user requested to use a sample profile for PGO, then the + // backend will need to track source location information so the profile + // can be incorporated into the IR. + if (!Opts.SampleProfileFile.empty()) + NeedLocTracking = true; + + // If the user requested a flag that requires source locations available in + // the backend, make sure that the backend tracks source location information. if (NeedLocTracking && Opts.getDebugInfo() == CodeGenOptions::NoDebugInfo) Opts.setDebugInfo(CodeGenOptions::LocTrackingOnly); -- cgit v1.1