diff options
Diffstat (limited to 'compiler/rustc_codegen_llvm/src')
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/back/lto.rs | 25 | ||||
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/back/write.rs | 41 | ||||
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/builder/autodiff.rs | 46 | ||||
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/llvm/ffi.rs | 1 |
4 files changed, 64 insertions, 49 deletions
diff --git a/compiler/rustc_codegen_llvm/src/back/lto.rs b/compiler/rustc_codegen_llvm/src/back/lto.rs index 78c759bbe8c..8bad437eeb7 100644 --- a/compiler/rustc_codegen_llvm/src/back/lto.rs +++ b/compiler/rustc_codegen_llvm/src/back/lto.rs @@ -606,10 +606,31 @@ pub(crate) fn run_pass_manager( // If this rustc version was build with enzyme/autodiff enabled, and if users applied the // `#[autodiff]` macro at least once, then we will later call llvm_optimize a second time. - let first_run = true; debug!("running llvm pm opt pipeline"); unsafe { - write::llvm_optimize(cgcx, dcx, module, config, opt_level, opt_stage, first_run)?; + write::llvm_optimize( + cgcx, + dcx, + module, + config, + opt_level, + opt_stage, + write::AutodiffStage::DuringAD, + )?; + } + // FIXME(ZuseZ4): Make this more granular + if cfg!(llvm_enzyme) && !thin { + unsafe { + write::llvm_optimize( + cgcx, + dcx, + module, + config, + opt_level, + llvm::OptStage::FatLTO, + write::AutodiffStage::PostAD, + )?; + } } debug!("lto done"); Ok(()) diff --git a/compiler/rustc_codegen_llvm/src/back/write.rs b/compiler/rustc_codegen_llvm/src/back/write.rs index 4706744f353..ae4c4d5876e 100644 --- a/compiler/rustc_codegen_llvm/src/back/write.rs +++ b/compiler/rustc_codegen_llvm/src/back/write.rs @@ -530,6 +530,16 @@ fn get_instr_profile_output_path(config: &ModuleConfig) -> Option<CString> { config.instrument_coverage.then(|| c"default_%m_%p.profraw".to_owned()) } +// PreAD will run llvm opts but disable size increasing opts (vectorization, loop unrolling) +// DuringAD is the same as above, but also runs the enzyme opt and autodiff passes. +// PostAD will run all opts, including size increasing opts. +#[derive(Debug, Eq, PartialEq)] +pub(crate) enum AutodiffStage { + PreAD, + DuringAD, + PostAD, +} + pub(crate) unsafe fn llvm_optimize( cgcx: &CodegenContext<LlvmCodegenBackend>, dcx: DiagCtxtHandle<'_>, @@ -537,7 +547,7 @@ pub(crate) unsafe fn llvm_optimize( config: &ModuleConfig, opt_level: config::OptLevel, opt_stage: llvm::OptStage, - skip_size_increasing_opts: bool, + autodiff_stage: AutodiffStage, ) -> Result<(), FatalError> { // Enzyme: // The whole point of compiler based AD is to differentiate optimized IR instead of unoptimized @@ -550,12 +560,16 @@ pub(crate) unsafe fn llvm_optimize( let unroll_loops; let vectorize_slp; let vectorize_loop; + let run_enzyme = cfg!(llvm_enzyme) && autodiff_stage == AutodiffStage::DuringAD; // When we build rustc with enzyme/autodiff support, we want to postpone size-increasing - // optimizations until after differentiation. FIXME(ZuseZ4): Before shipping on nightly, + // optimizations until after differentiation. Our pipeline is thus: (opt + enzyme), (full opt). + // We therefore have two calls to llvm_optimize, if autodiff is used. + // + // FIXME(ZuseZ4): Before shipping on nightly, // we should make this more granular, or at least check that the user has at least one autodiff // call in their code, to justify altering the compilation pipeline. - if skip_size_increasing_opts && cfg!(llvm_enzyme) { + if cfg!(llvm_enzyme) && autodiff_stage != AutodiffStage::PostAD { unroll_loops = false; vectorize_slp = false; vectorize_loop = false; @@ -565,7 +579,7 @@ pub(crate) unsafe fn llvm_optimize( vectorize_slp = config.vectorize_slp; vectorize_loop = config.vectorize_loop; } - trace!(?unroll_loops, ?vectorize_slp, ?vectorize_loop); + trace!(?unroll_loops, ?vectorize_slp, ?vectorize_loop, ?run_enzyme); let using_thin_buffers = opt_stage == llvm::OptStage::PreLinkThinLTO || config.bitcode_needed(); let pgo_gen_path = get_pgo_gen_path(config); let pgo_use_path = get_pgo_use_path(config); @@ -633,6 +647,7 @@ pub(crate) unsafe fn llvm_optimize( vectorize_loop, config.no_builtins, config.emit_lifetime_markers, + run_enzyme, sanitizer_options.as_ref(), pgo_gen_path.as_ref().map_or(std::ptr::null(), |s| s.as_ptr()), pgo_use_path.as_ref().map_or(std::ptr::null(), |s| s.as_ptr()), @@ -684,18 +699,14 @@ pub(crate) unsafe fn optimize( _ => llvm::OptStage::PreLinkNoLTO, }; - // If we know that we will later run AD, then we disable vectorization and loop unrolling - let skip_size_increasing_opts = cfg!(llvm_enzyme); + // If we know that we will later run AD, then we disable vectorization and loop unrolling. + // Otherwise we pretend AD is already done and run the normal opt pipeline (=PostAD). + // FIXME(ZuseZ4): Make this more granular, only set PreAD if we actually have autodiff + // usages, not just if we build rustc with autodiff support. + let autodiff_stage = + if cfg!(llvm_enzyme) { AutodiffStage::PreAD } else { AutodiffStage::PostAD }; return unsafe { - llvm_optimize( - cgcx, - dcx, - module, - config, - opt_level, - opt_stage, - skip_size_increasing_opts, - ) + llvm_optimize(cgcx, dcx, module, config, opt_level, opt_stage, autodiff_stage) }; } Ok(()) diff --git a/compiler/rustc_codegen_llvm/src/builder/autodiff.rs b/compiler/rustc_codegen_llvm/src/builder/autodiff.rs index dd5e726160d..b2c1088e3fc 100644 --- a/compiler/rustc_codegen_llvm/src/builder/autodiff.rs +++ b/compiler/rustc_codegen_llvm/src/builder/autodiff.rs @@ -4,10 +4,9 @@ use rustc_ast::expand::autodiff_attrs::{AutoDiffAttrs, AutoDiffItem, DiffActivit use rustc_codegen_ssa::ModuleCodegen; use rustc_codegen_ssa::back::write::ModuleConfig; use rustc_errors::FatalError; -use rustc_session::config::Lto; use tracing::{debug, trace}; -use crate::back::write::{llvm_err, llvm_optimize}; +use crate::back::write::llvm_err; use crate::builder::SBuilder; use crate::context::SimpleCx; use crate::declare::declare_simple_fn; @@ -53,8 +52,6 @@ fn generate_enzyme_call<'ll>( let mut ad_name: String = match attrs.mode { DiffMode::Forward => "__enzyme_fwddiff", DiffMode::Reverse => "__enzyme_autodiff", - DiffMode::ForwardFirst => "__enzyme_fwddiff", - DiffMode::ReverseFirst => "__enzyme_autodiff", _ => panic!("logic bug in autodiff, unrecognized mode"), } .to_string(); @@ -153,7 +150,7 @@ fn generate_enzyme_call<'ll>( _ => {} } - trace!("matching autodiff arguments"); + debug!("matching autodiff arguments"); // We now handle the issue that Rust level arguments not always match the llvm-ir level // arguments. A slice, `&[f32]`, for example, is represented as a pointer and a length on // llvm-ir level. The number of activities matches the number of Rust level arguments, so we @@ -164,10 +161,10 @@ fn generate_enzyme_call<'ll>( let mut activity_pos = 0; let outer_args: Vec<&llvm::Value> = get_params(outer_fn); while activity_pos < inputs.len() { - let activity = inputs[activity_pos as usize]; + let diff_activity = inputs[activity_pos as usize]; // Duplicated arguments received a shadow argument, into which enzyme will write the // gradient. - let (activity, duplicated): (&Metadata, bool) = match activity { + let (activity, duplicated): (&Metadata, bool) = match diff_activity { DiffActivity::None => panic!("not a valid input activity"), DiffActivity::Const => (enzyme_const, false), DiffActivity::Active => (enzyme_out, false), @@ -222,7 +219,15 @@ fn generate_enzyme_call<'ll>( // A duplicated pointer will have the following two outer_fn arguments: // (..., ptr, ptr, ...). We add the following llvm-ir to our __enzyme call: // (..., metadata! enzyme_dup, ptr, ptr, ...). - assert!(llvm::LLVMRustGetTypeKind(next_outer_ty) == llvm::TypeKind::Pointer); + if matches!( + diff_activity, + DiffActivity::Duplicated | DiffActivity::DuplicatedOnly + ) { + assert!( + llvm::LLVMRustGetTypeKind(next_outer_ty) == llvm::TypeKind::Pointer + ); + } + // In the case of Dual we don't have assumptions, e.g. f32 would be valid. args.push(next_outer_arg); outer_pos += 2; activity_pos += 1; @@ -277,7 +282,7 @@ pub(crate) fn differentiate<'ll>( module: &'ll ModuleCodegen<ModuleLlvm>, cgcx: &CodegenContext<LlvmCodegenBackend>, diff_items: Vec<AutoDiffItem>, - config: &ModuleConfig, + _config: &ModuleConfig, ) -> Result<(), FatalError> { for item in &diff_items { trace!("{}", item); @@ -318,29 +323,6 @@ pub(crate) fn differentiate<'ll>( // FIXME(ZuseZ4): support SanitizeHWAddress and prevent illegal/unsupported opts - if let Some(opt_level) = config.opt_level { - let opt_stage = match cgcx.lto { - Lto::Fat => llvm::OptStage::PreLinkFatLTO, - Lto::Thin | Lto::ThinLocal => llvm::OptStage::PreLinkThinLTO, - _ if cgcx.opts.cg.linker_plugin_lto.enabled() => llvm::OptStage::PreLinkThinLTO, - _ => llvm::OptStage::PreLinkNoLTO, - }; - // This is our second opt call, so now we run all opts, - // to make sure we get the best performance. - let skip_size_increasing_opts = false; - trace!("running Module Optimization after differentiation"); - unsafe { - llvm_optimize( - cgcx, - diag_handler.handle(), - module, - config, - opt_level, - opt_stage, - skip_size_increasing_opts, - )? - }; - } trace!("done with differentiate()"); Ok(()) diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs index 50a40c9c309..4d6a76b23ea 100644 --- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs +++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs @@ -2382,6 +2382,7 @@ unsafe extern "C" { LoopVectorize: bool, DisableSimplifyLibCalls: bool, EmitLifetimeMarkers: bool, + RunEnzyme: bool, SanitizerOptions: Option<&SanitizerOptions>, PGOGenPath: *const c_char, PGOUsePath: *const c_char, |