Add Polly support. Use can be triggered via -Z polly, when rustc …

…uses an LLVM which includes polly.

Force LLVM rebuild on buildbots.

.gitmodules

@@ -64,4 +64,7 @@
 	path = src/tools/clang
 	url = https://github.com/rust-lang-nursery/clang.git
 	branch = rust-release-80-v1
-
+[submodule "src/polly"]
+	path = src/polly
+	url = https://github.com/llvm-mirror/polly.git
+	branch = master

config.toml.example

@@ -337,6 +337,10 @@
 #optimize-tests = true
 #debuginfo-tests = true
 
+# Flag indicating whether tests are optimized with Polly. If optimize-tests is false,
+# polly-tests will be false regardless of its value here.
+#polly-tests = false
+
 # Flag indicating whether codegen tests will be run or not. If you get an error
 # saying that the FileCheck executable is missing, you may want to disable this.
 # Also see the target's llvm-filecheck option.
@@ -395,6 +399,10 @@
 # Whether to verify generated LLVM IR
 #verify-llvm-ir = false
 
+# Use Polly on the rust compiler itself. If optimize is false, this will be
+# false as well.
+#polly-self = false
+
 # Map all debuginfo paths for libstd and crates to `/rust/$sha/$crate/...`,
 # generally only set for releases
 #remap-debuginfo = false

src/bootstrap/bin/rustc.rs

@@ -91,6 +91,7 @@ fn main() {
         ("RUSTC_REAL", "RUSTC_LIBDIR")
     };
     let stage = env::var("RUSTC_STAGE").expect("RUSTC_STAGE was not set");
+    let stage = usize::from_str(stage.as_str()).expect("RUSTC_STAGE not a usize");
     let sysroot = env::var_os("RUSTC_SYSROOT").expect("RUSTC_SYSROOT was not set");
     let on_fail = env::var_os("RUSTC_ON_FAIL").map(|of| Command::new(of));
 
@@ -159,7 +160,7 @@ fn main() {
         // workaround undefined references to `rust_eh_unwind_resume` generated
         // otherwise, see issue https://github.com/rust-lang/rust/issues/43095.
         if crate_name == "panic_abort" ||
-           crate_name == "compiler_builtins" && stage != "0" {
+           crate_name == "compiler_builtins" && stage != 0 {
             cmd.arg("-C").arg("panic=abort");
         }
 
@@ -287,6 +288,14 @@ fn main() {
         cmd.arg("--cfg").arg("parallel_queries");
     }
 
+    let use_polly = match env::var("RUSTC_USE_POLLY") {
+        Ok(v) => v != "0",
+        Err(_) => false,
+    };
+    if use_polly && stage >= 1 {
+        cmd.arg("-Z").arg("polly");
+    }
+
     if env::var_os("RUSTC_DENY_WARNINGS").is_some() && env::var_os("RUSTC_EXTERNAL_TOOL").is_none()
     {
         cmd.arg("-Dwarnings");

src/bootstrap/builder.rs

@@ -1116,6 +1116,18 @@ impl<'a> Builder<'a> {
             cargo.env("WINAPI_NO_BUNDLED_LIBRARIES", "1");
         }
 
+        let use_polly = match cmd {
+            "test" | "bench" => {
+                self.config.rust_polly_tests
+            },
+            _ => self.config.rust_polly_self
+        };
+        if use_polly && stage > 1 {
+            cargo.env("RUSTC_USE_POLLY", "1");
+        } else {
+            cargo.env("RUSTC_USE_POLLY", "0");
+        }
+
         for _ in 1..self.verbosity {
             cargo.arg("-v");
         }

src/bootstrap/config.rs

@@ -104,12 +104,14 @@ pub struct Config {
     pub rustc_parallel_queries: bool,
     pub rustc_default_linker: Option<String>,
     pub rust_optimize_tests: bool,
+    pub rust_polly_tests: bool,
     pub rust_debuginfo_tests: bool,
     pub rust_dist_src: bool,
     pub rust_codegen_backends: Vec<Interned<String>>,
     pub rust_codegen_backends_dir: String,
     pub rust_verify_llvm_ir: bool,
     pub rust_remap_debuginfo: bool,
+    pub rust_polly_self: bool,
 
     pub build: Interned<String>,
     pub hosts: Vec<Interned<String>>,
@@ -309,6 +311,7 @@ struct Rust {
     rpath: Option<bool>,
     optimize_tests: Option<bool>,
     debuginfo_tests: Option<bool>,
+    polly_tests: Option<bool>,
     codegen_tests: Option<bool>,
     ignore_git: Option<bool>,
     debug: Option<bool>,
@@ -327,6 +330,7 @@ struct Rust {
     backtrace_on_ice: Option<bool>,
     verify_llvm_ir: Option<bool>,
     remap_debuginfo: Option<bool>,
+    polly_self: Option<bool>,
 }
 
 /// TOML representation of how each build target is configured.
@@ -541,6 +545,10 @@ impl Config {
             ignore_git = rust.ignore_git;
             debug_jemalloc = rust.debug_jemalloc;
             set(&mut config.rust_optimize_tests, rust.optimize_tests);
+            set(&mut config.rust_polly_tests, rust.polly_tests);
+            if !config.rust_optimize_tests {
+                config.rust_polly_tests = false;
+            }
             set(&mut config.rust_debuginfo_tests, rust.debuginfo_tests);
             set(&mut config.codegen_tests, rust.codegen_tests);
             set(&mut config.rust_rpath, rust.rpath);
@@ -580,6 +588,10 @@ impl Config {
                 Some(n) => config.rust_codegen_units = Some(n),
                 None => {}
             }
+
+            config.rust_polly_self = rust
+              .polly_self
+              .unwrap_or(false);
         }
 
         if let Some(ref t) = toml.target {
@@ -644,6 +656,10 @@ impl Config {
         config.rust_debuginfo = debuginfo.unwrap_or(default);
         config.rust_debug_assertions = debug_assertions.unwrap_or(default);
 
+        if !config.rust_optimize {
+          config.rust_polly_self = false;
+        }
+
         let default = config.channel == "dev";
         config.ignore_git = ignore_git.unwrap_or(default);
 

src/bootstrap/native.rs

@@ -148,13 +148,17 @@ impl Step for Llvm {
            .define("LLVM_INCLUDE_DOCS", "OFF")
            .define("LLVM_INCLUDE_BENCHMARKS", "OFF")
            .define("LLVM_ENABLE_ZLIB", "OFF")
-           .define("WITH_POLLY", "OFF")
            .define("LLVM_ENABLE_TERMINFO", "OFF")
            .define("LLVM_ENABLE_LIBEDIT", "OFF")
            .define("LLVM_PARALLEL_COMPILE_JOBS", builder.jobs().to_string())
            .define("LLVM_TARGET_ARCH", target.split('-').next().unwrap())
            .define("LLVM_DEFAULT_TARGET_TRIPLE", target);
 
+        if !self.emscripten {
+            let polly_src = builder.src.join("src/polly");
+            cfg.define("LLVM_EXTERNAL_POLLY_SOURCE_DIR", polly_src);
+        }
+
         if builder.config.llvm_thin_lto && !emscripten {
             cfg.define("LLVM_ENABLE_LTO", "Thin")
                .define("LLVM_ENABLE_LLD", "ON");

src/bootstrap/test.rs

@@ -1045,6 +1045,9 @@ impl Step for Compiletest {
         }
         flags.push("-Zunstable-options".to_string());
         flags.push(builder.config.cmd.rustc_args().join(" "));
+        if builder.config.rust_polly_self {
+            flags.push("-Zpolly".into());
+        }
 
         if let Some(linker) = builder.linker(target) {
             cmd.arg("--linker").arg(linker);

src/ci/docker/dist-i686-linux/Dockerfile

@@ -86,6 +86,10 @@ RUN ./build-headers.sh
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh
 
+# Polly needs `PATH_MAX`
+ENV CFLAGS="-DPATH_MAX=4096 ${CFLAGS}"
+ENV CXXFLAGS="-DPATH_MAX=4096 ${CXXFLAGS}"
+
 ENV HOSTS=i686-unknown-linux-gnu
 
 ENV RUST_CONFIGURE_ARGS \

src/ci/docker/dist-x86_64-linux/Dockerfile

@@ -86,6 +86,10 @@ RUN ./build-headers.sh
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh
 
+# Polly needs `PATH_MAX`
+ENV CFLAGS="-DPATH_MAX=4096 ${CFLAGS}"
+ENV CXXFLAGS="-DPATH_MAX=4096 ${CXXFLAGS}"
+
 ENV HOSTS=x86_64-unknown-linux-gnu
 
 ENV RUST_CONFIGURE_ARGS \

src/librustc/session/config.rs

@@ -1382,6 +1382,8 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
         "run the self profiler"),
     profile_json: bool = (false, parse_bool, [UNTRACKED],
         "output a json file with profiler results"),
+    polly: bool = (false, parse_bool, [UNTRACKED], "Run the Polly polyhedral \
+           model optimization passes."),
     emit_stack_sizes: bool = (false, parse_bool, [UNTRACKED],
         "emits a section containing stack size metadata"),
     plt: Option<bool> = (None, parse_opt_bool, [TRACKED],

src/librustc_codegen_llvm/back/lto.rs

@@ -569,7 +569,7 @@ fn run_pass_manager(cgcx: &CodegenContext,
     debug!("running the pass manager");
     unsafe {
         let pm = llvm::LLVMCreatePassManager();
-        llvm::LLVMRustAddAnalysisPasses(tm, pm, llmod);
+        llvm::LLVMRustAddAnalysisPasses(tm, pm, llmod, config.polly);
 
         if config.verify_llvm_ir {
             let pass = llvm::LLVMRustFindAndCreatePass("verify\0".as_ptr() as *const _);

src/librustc_codegen_llvm/back/write.rs

@@ -265,6 +265,7 @@ pub struct ModuleConfig {
     no_integrated_as: bool,
     embed_bitcode: bool,
     embed_bitcode_marker: bool,
+    pub polly: bool,
 }
 
 impl ModuleConfig {
@@ -297,7 +298,8 @@ impl ModuleConfig {
             vectorize_loop: false,
             vectorize_slp: false,
             merge_functions: false,
-            inline_threshold: None
+            inline_threshold: None,
+            polly: false,
         }
     }
 
@@ -336,6 +338,8 @@ impl ModuleConfig {
 
         self.merge_functions = sess.opts.optimize == config::OptLevel::Default ||
                                sess.opts.optimize == config::OptLevel::Aggressive;
+        self.polly = sess.opts.debugging_opts.polly && !self.no_prepopulate_passes &&
+                     !sess.target.target.options.is_like_emscripten;
     }
 }
 
@@ -568,8 +572,8 @@ unsafe fn optimize(cgcx: &CodegenContext,
                 || config.obj_is_bitcode || config.emit_bc_compressed || config.embed_bitcode);
             let mut have_name_anon_globals_pass = false;
             if !config.no_prepopulate_passes {
-                llvm::LLVMRustAddAnalysisPasses(tm, fpm, llmod);
-                llvm::LLVMRustAddAnalysisPasses(tm, mpm, llmod);
+                llvm::LLVMRustAddAnalysisPasses(tm, fpm, llmod, config.polly);
+                llvm::LLVMRustAddAnalysisPasses(tm, mpm, llmod, config.polly);
                 let opt_level = config.opt_level.unwrap_or(llvm::CodeGenOptLevel::None);
                 let prepare_for_thin_lto = cgcx.lto == Lto::Thin || cgcx.lto == Lto::ThinLocal ||
                     (cgcx.lto != Lto::Fat && cgcx.opts.debugging_opts.cross_lang_lto.enabled());
@@ -702,11 +706,12 @@ unsafe fn codegen(cgcx: &CodegenContext,
         unsafe fn with_codegen<'ll, F, R>(tm: &'ll llvm::TargetMachine,
                                     llmod: &'ll llvm::Module,
                                     no_builtins: bool,
+                                    polly: bool,
                                     f: F) -> R
             where F: FnOnce(&'ll mut PassManager<'ll>) -> R,
         {
             let cpm = llvm::LLVMCreatePassManager();
-            llvm::LLVMRustAddAnalysisPasses(tm, cpm, llmod);
+            llvm::LLVMRustAddAnalysisPasses(tm, cpm, llmod, polly);
             llvm::LLVMRustAddLibraryInfo(cpm, llmod, no_builtins);
             f(cpm)
         }
@@ -801,7 +806,8 @@ unsafe fn codegen(cgcx: &CodegenContext,
                     cursor.position() as size_t
                 }
 
-                with_codegen(tm, llmod, config.no_builtins, |cpm| {
+                with_codegen(tm, llmod, config.no_builtins, config.polly,
+                             |cpm| {
                     llvm::LLVMRustPrintModule(cpm, llmod, out.as_ptr(), demangle_callback);
                     llvm::LLVMDisposePassManager(cpm);
                 });
@@ -819,15 +825,17 @@ unsafe fn codegen(cgcx: &CodegenContext,
                 } else {
                     llmod
                 };
-                with_codegen(tm, llmod, config.no_builtins, |cpm| {
+                with_codegen(tm, llmod, config.no_builtins, config.polly,
+                             |cpm| {
                     write_output_file(diag_handler, tm, cpm, llmod, &path,
                                     llvm::FileType::AssemblyFile)
                 })?;
                 timeline.record("asm");
             }
 
             if write_obj {
-                with_codegen(tm, llmod, config.no_builtins, |cpm| {
+                with_codegen(tm, llmod, config.no_builtins, config.polly,
+                             |cpm| {
                     write_output_file(diag_handler, tm, cpm, llmod, &obj_out,
                                     llvm::FileType::ObjectFile)
                 })?;
@@ -2221,7 +2229,8 @@ pub unsafe fn with_llvm_pmb(llmod: &llvm::Module,
         llvm::LLVMPassManagerBuilderSetDisableUnrollLoops(builder, 1);
     }
 
-    llvm::LLVMRustAddBuilderLibraryInfo(builder, llmod, config.no_builtins);
+    llvm::LLVMRustAddBuilderLibraryInfo(builder, llmod, config.no_builtins,
+                                        config.polly);
 
     // Here we match what clang does (kinda). For O0 we only inline
     // always-inline functions (but don't add lifetime intrinsics), at O1 we

src/librustc_codegen_llvm/llvm/ffi.rs

@@ -1470,10 +1470,12 @@ extern "C" {
                                        EmitStackSizeSection: bool)
                                        -> Option<&'static mut TargetMachine>;
     pub fn LLVMRustDisposeTargetMachine(T: &'static mut TargetMachine);
-    pub fn LLVMRustAddAnalysisPasses(T: &'a TargetMachine, PM: &PassManager<'a>, M: &'a Module);
+    pub fn LLVMRustAddAnalysisPasses(T: &'a TargetMachine, PM: &PassManager<'a>, M: &'a Module,
+                                     Polly: bool);
     pub fn LLVMRustAddBuilderLibraryInfo(PMB: &'a PassManagerBuilder,
                                          M: &'a Module,
-                                         DisableSimplifyLibCalls: bool);
+                                         DisableSimplifyLibCalls: bool,
+                                         Polly: bool);
     pub fn LLVMRustConfigurePassManagerBuilder(PMB: &PassManagerBuilder,
                                                OptLevel: CodeGenOptLevel,
                                                MergeFunctions: bool,

src/librustc_llvm/build.rs

@@ -161,11 +161,54 @@ fn main() {
         cfg.define("LLVM_RUSTLLVM", None);
     }
 
+    let (enable_polly, polly_link_kind, polly_link_isl) = {
+        let mut cmd = Command::new(&llvm_config);
+        cmd.arg("--libdir");
+        let libdir = output(&mut cmd);
+        let libdir = libdir.lines().next().unwrap();
+        let libdir = Path::new(&libdir);
+        assert!(libdir.exists());
+
+        // We can't specify the full libname to rust, so the linker will always expect (on unix)
+        // LLVMPolly to be libLLVMPolly, which won't be present. I didn't realize this fact until
+        // after I wrote the following, but maybe this issue will be resolved in the future.
+        let allow_shared = false;
+        let mut found_static = false;
+        let mut found_shared = false;
+        for entry in libdir.read_dir().unwrap() {
+            if let Ok(entry) = entry {
+                if let Some(name) = entry.path().file_name() {
+                    let name = name.to_str().unwrap();
+                    if name.contains("Polly") {
+                        if !found_static {
+                            found_static = !name.contains("LLVM");
+                        }
+                        if !found_shared {
+                            found_shared = name.contains("LLVM");
+                        }
+                    }
+                }
+            }
+        }
+
+        let found_static = found_static;
+        let found_shared = allow_shared && found_shared;
+        let enabled = !cfg!(feature = "emscripten") &&
+            (found_static || found_shared);
+        let (kind, isl) = match (found_static, found_shared) {
+            (false, false) => ("", false),
+            (true, _) => ("static", true),
+            (false, true) => ("dylib", false),
+        };
+        (enabled, kind, isl)
+    };
+
     build_helper::rerun_if_changed_anything_in_dir(Path::new("../rustllvm"));
     cfg.file("../rustllvm/PassWrapper.cpp")
        .file("../rustllvm/RustWrapper.cpp")
        .file("../rustllvm/ArchiveWrapper.cpp")
        .file("../rustllvm/Linker.cpp")
+       .define("ENABLE_POLLY", if enable_polly { "1" } else { "0" })
        .cpp(true)
        .cpp_link_stdlib(None) // we handle this below
        .compile("rustllvm");
@@ -218,6 +261,20 @@ fn main() {
         println!("cargo:rustc-link-lib={}={}", kind, name);
     }
 
+    if enable_polly {
+        match polly_link_kind {
+            "dylib" => {
+                panic!("dynamically linking polly is not possible :(");
+                //println!("cargo:rustc-flags=-l:LLVMPolly")
+            },
+            _ => println!("cargo:rustc-link-lib={}=Polly", polly_link_kind),
+        }
+
+        if polly_link_isl {
+            println!("cargo:rustc-link-lib={}=PollyISL", polly_link_kind);
+        }
+    }
+
     // LLVM ldflags
     //
     // If we're a cross-compile of LLVM then unfortunately we can't trust these