Stabilize -Zprofile-sample-use

compiler/rustc_codegen_llvm/src/attributes.rs

@@ -435,7 +435,7 @@ pub(crate) fn llfn_attrs_from_instance<'ll, 'tcx>(
         to_add.push(uwtable_attr(cx.llcx, sess.opts.unstable_opts.use_sync_unwind));
     }
 
-    if sess.opts.unstable_opts.profile_sample_use.is_some() {
+    if sess.opts.cg.profile_sample_use.is_some() {
         to_add.push(llvm::CreateAttrString(cx.llcx, "use-sample-profile"));
     }
 

compiler/rustc_codegen_ssa/src/back/linker.rs

@@ -422,7 +422,7 @@ impl<'a> GccLinker<'a> {
             config::OptLevel::Aggressive => "O3",
         };
 
-        if let Some(path) = &self.sess.opts.unstable_opts.profile_sample_use {
+        if let Some(path) = &self.sess.opts.cg.profile_sample_use {
             self.link_arg(&format!("-plugin-opt=sample-profile={}", path.display()));
         };
         let prefix = if self.codegen_backend == "gcc" {

compiler/rustc_codegen_ssa/src/back/write.rs

@@ -179,7 +179,7 @@ impl ModuleConfig {
                 SwitchWithOptPath::Disabled
             ),
             pgo_use: if_regular!(sess.opts.cg.profile_use.clone(), None),
-            pgo_sample_use: if_regular!(sess.opts.unstable_opts.profile_sample_use.clone(), None),
+            pgo_sample_use: if_regular!(sess.opts.cg.profile_sample_use.clone(), None),
             debug_info_for_profiling: sess.opts.unstable_opts.debuginfo_for_profiling,
             instrument_coverage: if_regular!(sess.instrument_coverage(), false),
 

compiler/rustc_interface/src/passes.rs

@@ -651,7 +651,7 @@ fn write_out_deps(tcx: TyCtxt<'_>, outputs: &OutputFilenames, out_filenames: &[P
                 checksum_hash_algo,
             ));
         }
-        if let Some(ref profile_sample) = sess.opts.unstable_opts.profile_sample_use {
+        if let Some(ref profile_sample) = sess.opts.cg.profile_sample_use {
             files.extend(hash_iter_files(
                 iter::once(normalize_path(profile_sample.as_path().to_path_buf())),
                 checksum_hash_algo,

compiler/rustc_interface/src/tests.rs

@@ -631,6 +631,7 @@ fn test_codegen_options_tracking_hash() {
     tracked!(passes, vec![String::from("1"), String::from("2")]);
     tracked!(prefer_dynamic, true);
     tracked!(profile_generate, SwitchWithOptPath::Enabled(None));
+    tracked!(profile_sample_use, Some(PathBuf::from("abc")));
     tracked!(profile_use, Some(PathBuf::from("abc")));
     tracked!(relocation_model, Some(RelocModel::Pic));
     tracked!(relro_level, Some(RelroLevel::Full));
@@ -845,7 +846,6 @@ fn test_unstable_options_tracking_hash() {
     tracked!(plt, Some(true));
     tracked!(polonius, Polonius::Legacy);
     tracked!(precise_enum_drop_elaboration, false);
-    tracked!(profile_sample_use, Some(PathBuf::from("abc")));
     tracked!(profiler_runtime, "abc".to_string());
     tracked!(reg_struct_return, true);
     tracked!(regparm, Some(3));

compiler/rustc_session/src/config.rs

@@ -2489,11 +2489,11 @@ pub fn build_session_options(early_dcx: &mut EarlyDiagCtxt, matches: &getopts::M
         early_dcx.early_fatal("options `-C profile-generate` and `-C profile-use` are exclusive");
     }
 
-    if unstable_opts.profile_sample_use.is_some()
+    if cg.profile_sample_use.is_some()
         && (cg.profile_generate.enabled() || cg.profile_use.is_some())
     {
         early_dcx.early_fatal(
-            "option `-Z profile-sample-use` cannot be used with `-C profile-generate` or `-C profile-use`",
+            "option `-C profile-sample-use` cannot be used with `-C profile-generate` or `-C profile-use`",
         );
     }
 

compiler/rustc_session/src/options.rs

@@ -2139,6 +2139,8 @@ options! {
     profile_generate: SwitchWithOptPath = (SwitchWithOptPath::Disabled,
         parse_switch_with_opt_path, [TRACKED],
         "compile the program with profiling instrumentation"),
+    profile_sample_use: Option<PathBuf> = (None, parse_opt_pathbuf, [TRACKED],
+        "use the given `.prof` file for sample-based profile-guided optimization"),
     profile_use: Option<PathBuf> = (None, parse_opt_pathbuf, [TRACKED],
         "use the given `.profdata` file for profile-guided optimization"),
     #[rustc_lint_opt_deny_field_access("use `Session::relocation_model` instead of this field")]
@@ -2257,7 +2259,7 @@ options! {
     debuginfo_compression: DebugInfoCompression = (DebugInfoCompression::None, parse_debuginfo_compression, [TRACKED],
         "compress debug info sections (none, zlib, zstd, default: none)"),
     debuginfo_for_profiling: bool = (false, parse_bool, [TRACKED],
-        "emit discriminators and other data necessary for AutoFDO"),
+        "emit extra debug info to make sample profile more accurate"),
     deduplicate_diagnostics: bool = (true, parse_bool, [UNTRACKED],
         "deduplicate identical diagnostics (default: yes)"),
     default_visibility: Option<SymbolVisibility> = (None, parse_opt_symbol_visibility, [TRACKED],
@@ -2562,8 +2564,6 @@ options! {
         "how to run proc-macro code (default: same-thread)"),
     profile_closures: bool = (false, parse_no_value, [UNTRACKED],
         "profile size of closures"),
-    profile_sample_use: Option<PathBuf> = (None, parse_opt_pathbuf, [TRACKED],
-        "use the given `.prof` file for sampled profile-guided optimization (also known as AutoFDO)"),
     profiler_runtime: String = (String::from("profiler_builtins"), parse_string, [TRACKED],
         "name of the profiler runtime crate to automatically inject (default: `profiler_builtins`)"),
     query_dep_graph: bool = (false, parse_bool, [UNTRACKED],

compiler/rustc_session/src/session.rs

@@ -1168,7 +1168,7 @@ fn validate_commandline_args_with_session_available(sess: &Session) {
     }
 
     // Do the same for sample profile data.
-    if let Some(ref path) = sess.opts.unstable_opts.profile_sample_use {
+    if let Some(ref path) = sess.opts.cg.profile_sample_use {
         if !path.exists() {
             sess.dcx().emit_err(errors::ProfileSampleUseFileDoesNotExist { path });
         }

src/doc/rustc/src/codegen-options/index.md

@@ -525,6 +525,15 @@ an optional argument which is the path to a directory into which the
 instrumented binary will emit the collected data. See the chapter on
 [profile-guided optimization] for more information.
 
+## profile-sample-use
+
+This flag specifies the profiling data file to be used for sample-based
+profile-guided optimization (SPGO). The flag takes a mandatory argument which
+is the path to a valid `.prof` file. See the chapter on
+[profile-guided optimization] for more information.
+The `-Zdebuginfo-for-profiling` can be used to improve the quality of the
+profiling data.
+
 ## profile-use
 
 This flag specifies the profiling data file to be used for profile-guided