diff options
Diffstat (limited to 'compiler/rustc_codegen_llvm/src')
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/allocator.rs | 17 | ||||
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/attributes.rs | 16 | ||||
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/back/lto.rs | 28 | ||||
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/back/write.rs | 11 | ||||
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/builder.rs | 8 | ||||
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/builder/autodiff.rs | 426 | ||||
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/context.rs | 24 | ||||
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/intrinsic.rs | 152 | ||||
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/lib.rs | 6 | ||||
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/llvm/ffi.rs | 19 | ||||
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/llvm/mod.rs | 26 | ||||
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/type_.rs | 2 |
12 files changed, 324 insertions, 411 deletions
diff --git a/compiler/rustc_codegen_llvm/src/allocator.rs b/compiler/rustc_codegen_llvm/src/allocator.rs index 2b5090ed6db..23610aa856c 100644 --- a/compiler/rustc_codegen_llvm/src/allocator.rs +++ b/compiler/rustc_codegen_llvm/src/allocator.rs @@ -8,11 +8,12 @@ use rustc_middle::bug; use rustc_middle::ty::TyCtxt; use rustc_session::config::{DebugInfo, OomStrategy}; use rustc_symbol_mangling::mangle_internal_symbol; +use smallvec::SmallVec; use crate::builder::SBuilder; use crate::declare::declare_simple_fn; use crate::llvm::{self, False, True, Type, Value}; -use crate::{SimpleCx, attributes, debuginfo}; +use crate::{SimpleCx, attributes, debuginfo, llvm_util}; pub(crate) unsafe fn codegen( tcx: TyCtxt<'_>, @@ -147,6 +148,20 @@ fn create_wrapper_function( llvm::Visibility::from_generic(tcx.sess.default_visibility()), ty, ); + + let mut attrs = SmallVec::<[_; 2]>::new(); + + let target_cpu = llvm_util::target_cpu(tcx.sess); + let target_cpu_attr = llvm::CreateAttrStringValue(cx.llcx, "target-cpu", target_cpu); + + let tune_cpu_attr = llvm_util::tune_cpu(tcx.sess) + .map(|tune_cpu| llvm::CreateAttrStringValue(cx.llcx, "tune-cpu", tune_cpu)); + + attrs.push(target_cpu_attr); + attrs.extend(tune_cpu_attr); + + attributes::apply_to_llfn(llfn, llvm::AttributePlace::Function, &attrs); + let no_return = if no_return { // -> ! DIFlagNoReturn let no_return = llvm::AttributeKind::NoReturn.create_attr(cx.llcx); diff --git a/compiler/rustc_codegen_llvm/src/attributes.rs b/compiler/rustc_codegen_llvm/src/attributes.rs index c548f467583..a6daacd95ef 100644 --- a/compiler/rustc_codegen_llvm/src/attributes.rs +++ b/compiler/rustc_codegen_llvm/src/attributes.rs @@ -28,22 +28,6 @@ pub(crate) fn apply_to_callsite(callsite: &Value, idx: AttributePlace, attrs: &[ } } -pub(crate) fn has_attr(llfn: &Value, idx: AttributePlace, attr: AttributeKind) -> bool { - llvm::HasAttributeAtIndex(llfn, idx, attr) -} - -pub(crate) fn has_string_attr(llfn: &Value, name: &str) -> bool { - llvm::HasStringAttribute(llfn, name) -} - -pub(crate) fn remove_from_llfn(llfn: &Value, place: AttributePlace, kind: AttributeKind) { - llvm::RemoveRustEnumAttributeAtIndex(llfn, place, kind); -} - -pub(crate) fn remove_string_attr_from_llfn(llfn: &Value, name: &str) { - llvm::RemoveStringAttrFromFn(llfn, name); -} - /// Get LLVM attribute for the provided inline heuristic. #[inline] fn inline_attr<'ll>(cx: &CodegenCx<'ll, '_>, inline: InlineAttr) -> Option<&'ll Attribute> { diff --git a/compiler/rustc_codegen_llvm/src/back/lto.rs b/compiler/rustc_codegen_llvm/src/back/lto.rs index c269f11e931..853d0295238 100644 --- a/compiler/rustc_codegen_llvm/src/back/lto.rs +++ b/compiler/rustc_codegen_llvm/src/back/lto.rs @@ -24,9 +24,8 @@ use crate::back::write::{ self, CodegenDiagnosticsStage, DiagnosticHandlers, bitcode_section_name, save_temp_bitcode, }; use crate::errors::{LlvmError, LtoBitcodeFromRlib}; -use crate::llvm::AttributePlace::Function; use crate::llvm::{self, build_string}; -use crate::{LlvmCodegenBackend, ModuleLlvm, SimpleCx, attributes}; +use crate::{LlvmCodegenBackend, ModuleLlvm, SimpleCx}; /// We keep track of the computed LTO cache keys from the previous /// session to determine which CGUs we can reuse. @@ -593,31 +592,6 @@ pub(crate) fn run_pass_manager( } if cfg!(llvm_enzyme) && enable_ad && !thin { - let cx = - SimpleCx::new(module.module_llvm.llmod(), &module.module_llvm.llcx, cgcx.pointer_size); - - for function in cx.get_functions() { - let enzyme_marker = "enzyme_marker"; - if attributes::has_string_attr(function, enzyme_marker) { - // Sanity check: Ensure 'noinline' is present before replacing it. - assert!( - attributes::has_attr(function, Function, llvm::AttributeKind::NoInline), - "Expected __enzyme function to have 'noinline' before adding 'alwaysinline'" - ); - - attributes::remove_from_llfn(function, Function, llvm::AttributeKind::NoInline); - attributes::remove_string_attr_from_llfn(function, enzyme_marker); - - assert!( - !attributes::has_string_attr(function, enzyme_marker), - "Expected function to not have 'enzyme_marker'" - ); - - let always_inline = llvm::AttributeKind::AlwaysInline.create_attr(cx.llcx); - attributes::apply_to_llfn(function, Function, &[always_inline]); - } - } - let opt_stage = llvm::OptStage::FatLTO; let stage = write::AutodiffStage::PostAD; if !config.autodiff.contains(&config::AutoDiff::NoPostopt) { diff --git a/compiler/rustc_codegen_llvm/src/back/write.rs b/compiler/rustc_codegen_llvm/src/back/write.rs index 85a06f457eb..62998003ca1 100644 --- a/compiler/rustc_codegen_llvm/src/back/write.rs +++ b/compiler/rustc_codegen_llvm/src/back/write.rs @@ -862,7 +862,7 @@ pub(crate) fn codegen( .generic_activity_with_arg("LLVM_module_codegen_embed_bitcode", &*module.name); let thin_bc = module.thin_lto_buffer.as_deref().expect("cannot find embedded bitcode"); - embed_bitcode(cgcx, llcx, llmod, &config.bc_cmdline, &thin_bc); + embed_bitcode(cgcx, llcx, llmod, &thin_bc); } } @@ -1058,7 +1058,6 @@ fn embed_bitcode( cgcx: &CodegenContext<LlvmCodegenBackend>, llcx: &llvm::Context, llmod: &llvm::Module, - cmdline: &str, bitcode: &[u8], ) { // We're adding custom sections to the output object file, but we definitely @@ -1074,7 +1073,9 @@ fn embed_bitcode( // * Mach-O - this is for macOS. Inspecting the source code for the native // linker here shows that the `.llvmbc` and `.llvmcmd` sections are // automatically skipped by the linker. In that case there's nothing extra - // that we need to do here. + // that we need to do here. We do need to make sure that the + // `__LLVM,__cmdline` section exists even though it is empty as otherwise + // ld64 rejects the object file. // // * Wasm - the native LLD linker is hard-coded to skip `.llvmbc` and // `.llvmcmd` sections, so there's nothing extra we need to do. @@ -1111,7 +1112,7 @@ fn embed_bitcode( llvm::set_linkage(llglobal, llvm::Linkage::PrivateLinkage); llvm::LLVMSetGlobalConstant(llglobal, llvm::True); - let llconst = common::bytes_in_context(llcx, cmdline.as_bytes()); + let llconst = common::bytes_in_context(llcx, &[]); let llglobal = llvm::add_global(llmod, common::val_ty(llconst), c"rustc.embedded.cmdline"); llvm::set_initializer(llglobal, llconst); let section = if cgcx.target_is_like_darwin { @@ -1128,7 +1129,7 @@ fn embed_bitcode( let section_flags = if cgcx.is_pe_coff { "n" } else { "e" }; let asm = create_section_with_flags_asm(".llvmbc", section_flags, bitcode); llvm::append_module_inline_asm(llmod, &asm); - let asm = create_section_with_flags_asm(".llvmcmd", section_flags, cmdline.as_bytes()); + let asm = create_section_with_flags_asm(".llvmcmd", section_flags, &[]); llvm::append_module_inline_asm(llmod, &asm); } } diff --git a/compiler/rustc_codegen_llvm/src/builder.rs b/compiler/rustc_codegen_llvm/src/builder.rs index 917d07e3c61..427c75d40e9 100644 --- a/compiler/rustc_codegen_llvm/src/builder.rs +++ b/compiler/rustc_codegen_llvm/src/builder.rs @@ -1453,7 +1453,7 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> { instance: Option<Instance<'tcx>>, ) { let call = self.call(llty, fn_attrs, Some(fn_abi), llfn, args, funclet, instance); - llvm::LLVMRustSetTailCallKind(call, llvm::TailCallKind::MustTail); + llvm::LLVMSetTailCallKind(call, llvm::TailCallKind::MustTail); match &fn_abi.ret.mode { PassMode::Ignore | PassMode::Indirect { .. } => self.ret_void(), @@ -1696,7 +1696,11 @@ impl<'a, 'll, 'tcx> Builder<'a, 'll, 'tcx> { return; } - self.call_intrinsic(intrinsic, &[self.val_ty(ptr)], &[self.cx.const_u64(size), ptr]); + if crate::llvm_util::get_version() >= (22, 0, 0) { + self.call_intrinsic(intrinsic, &[self.val_ty(ptr)], &[ptr]); + } else { + self.call_intrinsic(intrinsic, &[self.val_ty(ptr)], &[self.cx.const_u64(size), ptr]); + } } } impl<'a, 'll, CX: Borrow<SCx<'ll>>> GenericBuilder<'a, 'll, CX> { diff --git a/compiler/rustc_codegen_llvm/src/builder/autodiff.rs b/compiler/rustc_codegen_llvm/src/builder/autodiff.rs index 829b3c513c2..e2df3265f6f 100644 --- a/compiler/rustc_codegen_llvm/src/builder/autodiff.rs +++ b/compiler/rustc_codegen_llvm/src/builder/autodiff.rs @@ -1,40 +1,92 @@ use std::ptr; -use rustc_ast::expand::autodiff_attrs::{AutoDiffAttrs, AutoDiffItem, DiffActivity, DiffMode}; -use rustc_codegen_ssa::ModuleCodegen; +use rustc_ast::expand::autodiff_attrs::{AutoDiffAttrs, DiffActivity, DiffMode}; use rustc_codegen_ssa::common::TypeKind; -use rustc_codegen_ssa::traits::BaseTypeCodegenMethods; -use rustc_errors::FatalError; -use rustc_middle::bug; -use tracing::{debug, trace}; +use rustc_codegen_ssa::traits::{BaseTypeCodegenMethods, BuilderMethods}; +use rustc_middle::ty::{PseudoCanonicalInput, Ty, TyCtxt, TypingEnv}; +use rustc_middle::{bug, ty}; +use tracing::debug; -use crate::back::write::llvm_err; -use crate::builder::{SBuilder, UNNAMED}; +use crate::builder::{Builder, PlaceRef, UNNAMED}; use crate::context::SimpleCx; use crate::declare::declare_simple_fn; -use crate::errors::{AutoDiffWithoutEnable, LlvmError}; -use crate::llvm::AttributePlace::Function; -use crate::llvm::{Metadata, True}; +use crate::llvm; +use crate::llvm::{Metadata, True, Type}; use crate::value::Value; -use crate::{CodegenContext, LlvmCodegenBackend, ModuleLlvm, attributes, llvm}; -fn get_params(fnc: &Value) -> Vec<&Value> { - let param_num = llvm::LLVMCountParams(fnc) as usize; - let mut fnc_args: Vec<&Value> = vec![]; - fnc_args.reserve(param_num); - unsafe { - llvm::LLVMGetParams(fnc, fnc_args.as_mut_ptr()); - fnc_args.set_len(param_num); +pub(crate) fn adjust_activity_to_abi<'tcx>( + tcx: TyCtxt<'tcx>, + fn_ty: Ty<'tcx>, + da: &mut Vec<DiffActivity>, +) { + if !matches!(fn_ty.kind(), ty::FnDef(..)) { + bug!("expected fn def for autodiff, got {:?}", fn_ty); } - fnc_args -} -fn has_sret(fnc: &Value) -> bool { - let num_args = llvm::LLVMCountParams(fnc) as usize; - if num_args == 0 { - false - } else { - unsafe { llvm::LLVMRustHasAttributeAtIndex(fnc, 0, llvm::AttributeKind::StructRet) } + // We don't actually pass the types back into the type system. + // All we do is decide how to handle the arguments. + let sig = fn_ty.fn_sig(tcx).skip_binder(); + + let mut new_activities = vec![]; + let mut new_positions = vec![]; + for (i, ty) in sig.inputs().iter().enumerate() { + if let Some(inner_ty) = ty.builtin_deref(true) { + if inner_ty.is_slice() { + // Now we need to figure out the size of each slice element in memory to allow + // safety checks and usability improvements in the backend. + let sty = match inner_ty.builtin_index() { + Some(sty) => sty, + None => { + panic!("slice element type unknown"); + } + }; + let pci = PseudoCanonicalInput { + typing_env: TypingEnv::fully_monomorphized(), + value: sty, + }; + + let layout = tcx.layout_of(pci); + let elem_size = match layout { + Ok(layout) => layout.size, + Err(_) => { + bug!("autodiff failed to compute slice element size"); + } + }; + let elem_size: u32 = elem_size.bytes() as u32; + + // We know that the length will be passed as extra arg. + if !da.is_empty() { + // We are looking at a slice. The length of that slice will become an + // extra integer on llvm level. Integers are always const. + // However, if the slice get's duplicated, we want to know to later check the + // size. So we mark the new size argument as FakeActivitySize. + // There is one FakeActivitySize per slice, so for convenience we store the + // slice element size in bytes in it. We will use the size in the backend. + let activity = match da[i] { + DiffActivity::DualOnly + | DiffActivity::Dual + | DiffActivity::Dualv + | DiffActivity::DuplicatedOnly + | DiffActivity::Duplicated => { + DiffActivity::FakeActivitySize(Some(elem_size)) + } + DiffActivity::Const => DiffActivity::Const, + _ => bug!("unexpected activity for ptr/ref"), + }; + new_activities.push(activity); + new_positions.push(i + 1); + } + + continue; + } + } + } + // now add the extra activities coming from slices + // Reverse order to not invalidate the indices + for _ in 0..new_activities.len() { + let pos = new_positions.pop().unwrap(); + let activity = new_activities.pop().unwrap(); + da.insert(pos, activity); } } @@ -48,14 +100,13 @@ fn has_sret(fnc: &Value) -> bool { // need to match those. // FIXME(ZuseZ4): This logic is a bit more complicated than it should be, can we simplify it // using iterators and peek()? -fn match_args_from_caller_to_enzyme<'ll>( +fn match_args_from_caller_to_enzyme<'ll, 'tcx>( cx: &SimpleCx<'ll>, - builder: &SBuilder<'ll, 'll>, + builder: &mut Builder<'_, 'll, 'tcx>, width: u32, args: &mut Vec<&'ll llvm::Value>, inputs: &[DiffActivity], outer_args: &[&'ll llvm::Value], - has_sret: bool, ) { debug!("matching autodiff arguments"); // We now handle the issue that Rust level arguments not always match the llvm-ir level @@ -67,14 +118,6 @@ fn match_args_from_caller_to_enzyme<'ll>( let mut outer_pos: usize = 0; let mut activity_pos = 0; - if has_sret { - // Then the first outer arg is the sret pointer. Enzyme doesn't know about sret, so the - // inner function will still return something. We increase our outer_pos by one, - // and once we're done with all other args we will take the return of the inner call and - // update the sret pointer with it - outer_pos = 1; - } - let enzyme_const = cx.create_metadata(b"enzyme_const"); let enzyme_out = cx.create_metadata(b"enzyme_out"); let enzyme_dup = cx.create_metadata(b"enzyme_dup"); @@ -193,92 +236,6 @@ fn match_args_from_caller_to_enzyme<'ll>( } } -// On LLVM-IR, we can luckily declare __enzyme_ functions without specifying the input -// arguments. We do however need to declare them with their correct return type. -// We already figured the correct return type out in our frontend, when generating the outer_fn, -// so we can now just go ahead and use that. This is not always trivial, e.g. because sret. -// Beyond sret, this article describes our challenges nicely: -// <https://yorickpeterse.com/articles/the-mess-that-is-handling-structure-arguments-and-returns-in-llvm/> -// I.e. (i32, f32) will get merged into i64, but we don't handle that yet. -fn compute_enzyme_fn_ty<'ll>( - cx: &SimpleCx<'ll>, - attrs: &AutoDiffAttrs, - fn_to_diff: &'ll Value, - outer_fn: &'ll Value, -) -> &'ll llvm::Type { - let fn_ty = cx.get_type_of_global(outer_fn); - let mut ret_ty = cx.get_return_type(fn_ty); - - let has_sret = has_sret(outer_fn); - - if has_sret { - // Now we don't just forward the return type, so we have to figure it out based on the - // primal return type, in combination with the autodiff settings. - let fn_ty = cx.get_type_of_global(fn_to_diff); - let inner_ret_ty = cx.get_return_type(fn_ty); - - let void_ty = unsafe { llvm::LLVMVoidTypeInContext(cx.llcx) }; - if inner_ret_ty == void_ty { - // This indicates that even the inner function has an sret. - // Right now I only look for an sret in the outer function. - // This *probably* needs some extra handling, but I never ran - // into such a case. So I'll wait for user reports to have a test case. - bug!("sret in inner function"); - } - - if attrs.width == 1 { - // Enzyme returns a struct of style: - // `{ original_ret(if requested), float, float, ... }` - let mut struct_elements = vec![]; - if attrs.has_primal_ret() { - struct_elements.push(inner_ret_ty); - } - // Next, we push the list of active floats, since they will be lowered to `enzyme_out`, - // and therefore part of the return struct. - let param_tys = cx.func_params_types(fn_ty); - for (act, param_ty) in attrs.input_activity.iter().zip(param_tys) { - if matches!(act, DiffActivity::Active) { - // Now find the float type at position i based on the fn_ty, - // to know what (f16/f32/f64/...) to add to the struct. - struct_elements.push(param_ty); - } - } - ret_ty = cx.type_struct(&struct_elements, false); - } else { - // First we check if we also have to deal with the primal return. - match attrs.mode { - DiffMode::Forward => match attrs.ret_activity { - DiffActivity::Dual => { - let arr_ty = - unsafe { llvm::LLVMArrayType2(inner_ret_ty, attrs.width as u64 + 1) }; - ret_ty = arr_ty; - } - DiffActivity::DualOnly => { - let arr_ty = - unsafe { llvm::LLVMArrayType2(inner_ret_ty, attrs.width as u64) }; - ret_ty = arr_ty; - } - DiffActivity::Const => { - todo!("Not sure, do we need to do something here?"); - } - _ => { - bug!("unreachable"); - } - }, - DiffMode::Reverse => { - todo!("Handle sret for reverse mode"); - } - _ => { - bug!("unreachable"); - } - } - } - } - - // LLVM can figure out the input types on it's own, so we take a shortcut here. - unsafe { llvm::LLVMFunctionType(ret_ty, ptr::null(), 0, True) } -} - /// When differentiating `fn_to_diff`, take a `outer_fn` and generate another /// function with expected naming and calling conventions[^1] which will be /// discovered by the enzyme LLVM pass and its body populated with the differentiated @@ -288,11 +245,15 @@ fn compute_enzyme_fn_ty<'ll>( /// [^1]: <https://enzyme.mit.edu/getting_started/CallingConvention/> // FIXME(ZuseZ4): `outer_fn` should include upstream safety checks to // cover some assumptions of enzyme/autodiff, which could lead to UB otherwise. -fn generate_enzyme_call<'ll>( +pub(crate) fn generate_enzyme_call<'ll, 'tcx>( + builder: &mut Builder<'_, 'll, 'tcx>, cx: &SimpleCx<'ll>, fn_to_diff: &'ll Value, - outer_fn: &'ll Value, + outer_name: &str, + ret_ty: &'ll Type, + fn_args: &[&'ll Value], attrs: AutoDiffAttrs, + dest: PlaceRef<'tcx, &'ll Value>, ) { // We have to pick the name depending on whether we want forward or reverse mode autodiff. let mut ad_name: String = match attrs.mode { @@ -302,11 +263,9 @@ fn generate_enzyme_call<'ll>( } .to_string(); - // add outer_fn name to ad_name to make it unique, in case users apply autodiff to multiple + // add outer_name to ad_name to make it unique, in case users apply autodiff to multiple // functions. Unwrap will only panic, if LLVM gave us an invalid string. - let name = llvm::get_value_name(outer_fn); - let outer_fn_name = std::str::from_utf8(&name).unwrap(); - ad_name.push_str(outer_fn_name); + ad_name.push_str(outer_name); // Let us assume the user wrote the following function square: // @@ -316,14 +275,8 @@ fn generate_enzyme_call<'ll>( // %0 = fmul double %x, %x // ret double %0 // } - // ``` - // - // The user now applies autodiff to the function square, in which case fn_to_diff will be `square`. - // Our macro generates the following placeholder code (slightly simplified): // - // ```llvm // define double @dsquare(double %x) { - // ; placeholder code // return 0.0; // } // ``` @@ -340,175 +293,44 @@ fn generate_enzyme_call<'ll>( // ret double %0 // } // ``` - unsafe { - let enzyme_ty = compute_enzyme_fn_ty(cx, &attrs, fn_to_diff, outer_fn); - - // FIXME(ZuseZ4): the CC/Addr/Vis values are best effort guesses, we should look at tests and - // think a bit more about what should go here. - let cc = llvm::LLVMGetFunctionCallConv(outer_fn); - let ad_fn = declare_simple_fn( - cx, - &ad_name, - llvm::CallConv::try_from(cc).expect("invalid callconv"), - llvm::UnnamedAddr::No, - llvm::Visibility::Default, - enzyme_ty, - ); - - // Otherwise LLVM might inline our temporary code before the enzyme pass has a chance to - // do it's work. - let attr = llvm::AttributeKind::NoInline.create_attr(cx.llcx); - attributes::apply_to_llfn(ad_fn, Function, &[attr]); - - // We add a made-up attribute just such that we can recognize it after AD to update - // (no)-inline attributes. We'll then also remove this attribute. - let enzyme_marker_attr = llvm::CreateAttrString(cx.llcx, "enzyme_marker"); - attributes::apply_to_llfn(outer_fn, Function, &[enzyme_marker_attr]); - - // first, remove all calls from fnc - let entry = llvm::LLVMGetFirstBasicBlock(outer_fn); - let br = llvm::LLVMRustGetTerminator(entry); - llvm::LLVMRustEraseInstFromParent(br); - - let last_inst = llvm::LLVMRustGetLastInstruction(entry).unwrap(); - let mut builder = SBuilder::build(cx, entry); - - let num_args = llvm::LLVMCountParams(&fn_to_diff); - let mut args = Vec::with_capacity(num_args as usize + 1); - args.push(fn_to_diff); - - let enzyme_primal_ret = cx.create_metadata(b"enzyme_primal_return"); - if matches!(attrs.ret_activity, DiffActivity::Dual | DiffActivity::Active) { - args.push(cx.get_metadata_value(enzyme_primal_ret)); - } - if attrs.width > 1 { - let enzyme_width = cx.create_metadata(b"enzyme_width"); - args.push(cx.get_metadata_value(enzyme_width)); - args.push(cx.get_const_int(cx.type_i64(), attrs.width as u64)); - } - - let has_sret = has_sret(outer_fn); - let outer_args: Vec<&llvm::Value> = get_params(outer_fn); - match_args_from_caller_to_enzyme( - &cx, - &builder, - attrs.width, - &mut args, - &attrs.input_activity, - &outer_args, - has_sret, - ); - - let call = builder.call(enzyme_ty, ad_fn, &args, None); - - // This part is a bit iffy. LLVM requires that a call to an inlineable function has some - // metadata attached to it, but we just created this code oota. Given that the - // differentiated function already has partly confusing metadata, and given that this - // affects nothing but the auttodiff IR, we take a shortcut and just steal metadata from the - // dummy code which we inserted at a higher level. - // FIXME(ZuseZ4): Work with Enzyme core devs to clarify what debug metadata issues we have, - // and how to best improve it for enzyme core and rust-enzyme. - let md_ty = cx.get_md_kind_id("dbg"); - if llvm::LLVMRustHasMetadata(last_inst, md_ty) { - let md = llvm::LLVMRustDIGetInstMetadata(last_inst) - .expect("failed to get instruction metadata"); - let md_todiff = cx.get_metadata_value(md); - llvm::LLVMSetMetadata(call, md_ty, md_todiff); - } else { - // We don't panic, since depending on whether we are in debug or release mode, we might - // have no debug info to copy, which would then be ok. - trace!("no dbg info"); - } - - // Now that we copied the metadata, get rid of dummy code. - llvm::LLVMRustEraseInstUntilInclusive(entry, last_inst); - - if cx.val_ty(call) == cx.type_void() || has_sret { - if has_sret { - // This is what we already have in our outer_fn (shortened): - // define void @_foo(ptr <..> sret([32 x i8]) initializes((0, 32)) %0, <...>) { - // %7 = call [4 x double] (...) @__enzyme_fwddiff_foo(ptr @square, metadata !"enzyme_width", i64 4, <...>) - // <Here we are, we want to add the following two lines> - // store [4 x double] %7, ptr %0, align 8 - // ret void - // } - - // now store the result of the enzyme call into the sret pointer. - let sret_ptr = outer_args[0]; - let call_ty = cx.val_ty(call); - if attrs.width == 1 { - assert_eq!(cx.type_kind(call_ty), TypeKind::Struct); - } else { - assert_eq!(cx.type_kind(call_ty), TypeKind::Array); - } - llvm::LLVMBuildStore(&builder.llbuilder, call, sret_ptr); - } - builder.ret_void(); - } else { - builder.ret(call); - } - - // Let's crash in case that we messed something up above and generated invalid IR. - llvm::LLVMRustVerifyFunction( - outer_fn, - llvm::LLVMRustVerifierFailureAction::LLVMAbortProcessAction, - ); - } -} - -pub(crate) fn differentiate<'ll>( - module: &'ll ModuleCodegen<ModuleLlvm>, - cgcx: &CodegenContext<LlvmCodegenBackend>, - diff_items: Vec<AutoDiffItem>, -) -> Result<(), FatalError> { - for item in &diff_items { - trace!("{}", item); + let enzyme_ty = unsafe { llvm::LLVMFunctionType(ret_ty, ptr::null(), 0, True) }; + + // FIXME(ZuseZ4): the CC/Addr/Vis values are best effort guesses, we should look at tests and + // think a bit more about what should go here. + let cc = unsafe { llvm::LLVMGetFunctionCallConv(fn_to_diff) }; + let ad_fn = declare_simple_fn( + cx, + &ad_name, + llvm::CallConv::try_from(cc).expect("invalid callconv"), + llvm::UnnamedAddr::No, + llvm::Visibility::Default, + enzyme_ty, + ); + + let num_args = llvm::LLVMCountParams(&fn_to_diff); + let mut args = Vec::with_capacity(num_args as usize + 1); + args.push(fn_to_diff); + + let enzyme_primal_ret = cx.create_metadata(b"enzyme_primal_return"); + if matches!(attrs.ret_activity, DiffActivity::Dual | DiffActivity::Active) { + args.push(cx.get_metadata_value(enzyme_primal_ret)); } - - let diag_handler = cgcx.create_dcx(); - - let cx = SimpleCx::new(module.module_llvm.llmod(), module.module_llvm.llcx, cgcx.pointer_size); - - // First of all, did the user try to use autodiff without using the -Zautodiff=Enable flag? - if !diff_items.is_empty() - && !cgcx.opts.unstable_opts.autodiff.contains(&rustc_session::config::AutoDiff::Enable) - { - return Err(diag_handler.handle().emit_almost_fatal(AutoDiffWithoutEnable)); - } - - // Here we replace the placeholder code with the actual autodiff code, which calls Enzyme. - for item in diff_items.iter() { - let name = item.source.clone(); - let fn_def: Option<&llvm::Value> = cx.get_function(&name); - let Some(fn_def) = fn_def else { - return Err(llvm_err( - diag_handler.handle(), - LlvmError::PrepareAutoDiff { - src: item.source.clone(), - target: item.target.clone(), - error: "could not find source function".to_owned(), - }, - )); - }; - debug!(?item.target); - let fn_target: Option<&llvm::Value> = cx.get_function(&item.target); - let Some(fn_target) = fn_target else { - return Err(llvm_err( - diag_handler.handle(), - LlvmError::PrepareAutoDiff { - src: item.source.clone(), - target: item.target.clone(), - error: "could not find target function".to_owned(), - }, - )); - }; - - generate_enzyme_call(&cx, fn_def, fn_target, item.attrs.clone()); + if attrs.width > 1 { + let enzyme_width = cx.create_metadata(b"enzyme_width"); + args.push(cx.get_metadata_value(enzyme_width)); + args.push(cx.get_const_int(cx.type_i64(), attrs.width as u64)); } - // FIXME(ZuseZ4): support SanitizeHWAddress and prevent illegal/unsupported opts + match_args_from_caller_to_enzyme( + &cx, + builder, + attrs.width, + &mut args, + &attrs.input_activity, + fn_args, + ); - trace!("done with differentiate()"); + let call = builder.call(enzyme_ty, None, None, ad_fn, &args, None, None); - Ok(()) + builder.store_to_place(call, dest.val); } diff --git a/compiler/rustc_codegen_llvm/src/context.rs b/compiler/rustc_codegen_llvm/src/context.rs index 27ae729a531..2d91ae64e2d 100644 --- a/compiler/rustc_codegen_llvm/src/context.rs +++ b/compiler/rustc_codegen_llvm/src/context.rs @@ -8,7 +8,6 @@ use std::str; use rustc_abi::{HasDataLayout, Size, TargetDataLayout, VariantIdx}; use rustc_codegen_ssa::back::versioned_llvm_target; use rustc_codegen_ssa::base::{wants_msvc_seh, wants_wasm_eh}; -use rustc_codegen_ssa::common::TypeKind; use rustc_codegen_ssa::errors as ssa_errors; use rustc_codegen_ssa::traits::*; use rustc_data_structures::base_n::{ALPHANUMERIC_ONLY, ToBaseN}; @@ -378,6 +377,15 @@ pub(crate) unsafe fn create_module<'ll>( } } + if let Some(regparm_count) = sess.opts.unstable_opts.regparm { + llvm::add_module_flag_u32( + llmod, + llvm::ModuleFlagMergeBehavior::Error, + "NumRegisterParameters", + regparm_count, + ); + } + if let Some(BranchProtection { bti, pac_ret }) = sess.opts.unstable_opts.branch_protection { if sess.target.arch == "aarch64" { llvm::add_module_flag_u32( @@ -660,10 +668,6 @@ impl<'ll, 'tcx> CodegenCx<'ll, 'tcx> { } } impl<'ll> SimpleCx<'ll> { - pub(crate) fn get_return_type(&self, ty: &'ll Type) -> &'ll Type { - assert_eq!(self.type_kind(ty), TypeKind::Function); - unsafe { llvm::LLVMGetReturnType(ty) } - } pub(crate) fn get_type_of_global(&self, val: &'ll Value) -> &'ll Type { unsafe { llvm::LLVMGlobalGetValueType(val) } } @@ -727,16 +731,6 @@ impl<'ll, CX: Borrow<SCx<'ll>>> GenericCx<'ll, CX> { llvm::LLVMMDStringInContext2(self.llcx(), name.as_ptr() as *const c_char, name.len()) } } - - pub(crate) fn get_functions(&self) -> Vec<&'ll Value> { - let mut functions = vec![]; - let mut func = unsafe { llvm::LLVMGetFirstFunction(self.llmod()) }; - while let Some(f) = func { - functions.push(f); - func = unsafe { llvm::LLVMGetNextFunction(f) } - } - functions - } } impl<'ll, 'tcx> MiscCodegenMethods<'tcx> for CodegenCx<'ll, 'tcx> { diff --git a/compiler/rustc_codegen_llvm/src/intrinsic.rs b/compiler/rustc_codegen_llvm/src/intrinsic.rs index 7b27e496986..4935f8d7dff 100644 --- a/compiler/rustc_codegen_llvm/src/intrinsic.rs +++ b/compiler/rustc_codegen_llvm/src/intrinsic.rs @@ -3,24 +3,29 @@ use std::cmp::Ordering; use rustc_abi::{Align, BackendRepr, ExternAbi, Float, HasDataLayout, Primitive, Size}; use rustc_codegen_ssa::base::{compare_simd_types, wants_msvc_seh, wants_wasm_eh}; +use rustc_codegen_ssa::codegen_attrs::autodiff_attrs; use rustc_codegen_ssa::common::{IntPredicate, TypeKind}; use rustc_codegen_ssa::errors::{ExpectedPointerMutability, InvalidMonomorphization}; use rustc_codegen_ssa::mir::operand::{OperandRef, OperandValue}; use rustc_codegen_ssa::mir::place::{PlaceRef, PlaceValue}; use rustc_codegen_ssa::traits::*; -use rustc_hir as hir; +use rustc_hir::def_id::LOCAL_CRATE; +use rustc_hir::{self as hir}; use rustc_middle::mir::BinOp; use rustc_middle::ty::layout::{FnAbiOf, HasTyCtxt, HasTypingEnv, LayoutOf}; -use rustc_middle::ty::{self, GenericArgsRef, Ty}; +use rustc_middle::ty::{self, GenericArgsRef, Instance, Ty, TyCtxt, TypingEnv}; use rustc_middle::{bug, span_bug}; use rustc_span::{Span, Symbol, sym}; -use rustc_symbol_mangling::mangle_internal_symbol; +use rustc_symbol_mangling::{mangle_internal_symbol, symbol_name_for_instance_in_crate}; +use rustc_target::callconv::PassMode; use rustc_target::spec::PanicStrategy; use tracing::debug; use crate::abi::FnAbiLlvmExt; use crate::builder::Builder; +use crate::builder::autodiff::{adjust_activity_to_abi, generate_enzyme_call}; use crate::context::CodegenCx; +use crate::errors::AutoDiffWithoutEnable; use crate::llvm::{self, Metadata}; use crate::type_::Type; use crate::type_of::LayoutLlvmExt; @@ -189,6 +194,10 @@ impl<'ll, 'tcx> IntrinsicCallBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> { &[ptr, args[1].immediate()], ) } + sym::autodiff => { + codegen_autodiff(self, tcx, instance, args, result); + return Ok(()); + } sym::is_val_statically_known => { if let OperandValue::Immediate(imm) = args[0].val { self.call_intrinsic( @@ -1113,6 +1122,143 @@ fn get_rust_try_fn<'a, 'll, 'tcx>( rust_try } +fn codegen_autodiff<'ll, 'tcx>( + bx: &mut Builder<'_, 'll, 'tcx>, + tcx: TyCtxt<'tcx>, + instance: ty::Instance<'tcx>, + args: &[OperandRef<'tcx, &'ll Value>], + result: PlaceRef<'tcx, &'ll Value>, +) { + if !tcx.sess.opts.unstable_opts.autodiff.contains(&rustc_session::config::AutoDiff::Enable) { + let _ = tcx.dcx().emit_almost_fatal(AutoDiffWithoutEnable); + } + + let fn_args = instance.args; + let callee_ty = instance.ty(tcx, bx.typing_env()); + + let sig = callee_ty.fn_sig(tcx).skip_binder(); + + let ret_ty = sig.output(); + let llret_ty = bx.layout_of(ret_ty).llvm_type(bx); + + // Get source, diff, and attrs + let (source_id, source_args) = match fn_args.into_type_list(tcx)[0].kind() { + ty::FnDef(def_id, source_params) => (def_id, source_params), + _ => bug!("invalid autodiff intrinsic args"), + }; + + let fn_source = match Instance::try_resolve(tcx, bx.cx.typing_env(), *source_id, source_args) { + Ok(Some(instance)) => instance, + Ok(None) => bug!( + "could not resolve ({:?}, {:?}) to a specific autodiff instance", + source_id, + source_args + ), + Err(_) => { + // An error has already been emitted + return; + } + }; + + let source_symbol = symbol_name_for_instance_in_crate(tcx, fn_source.clone(), LOCAL_CRATE); + let Some(fn_to_diff) = bx.cx.get_function(&source_symbol) else { + bug!("could not find source function") + }; + + let (diff_id, diff_args) = match fn_args.into_type_list(tcx)[1].kind() { + ty::FnDef(def_id, diff_args) => (def_id, diff_args), + _ => bug!("invalid args"), + }; + + let fn_diff = match Instance::try_resolve(tcx, bx.cx.typing_env(), *diff_id, diff_args) { + Ok(Some(instance)) => instance, + Ok(None) => bug!( + "could not resolve ({:?}, {:?}) to a specific autodiff instance", + diff_id, + diff_args + ), + Err(_) => { + // An error has already been emitted + return; + } + }; + + let val_arr = get_args_from_tuple(bx, args[2], fn_diff); + let diff_symbol = symbol_name_for_instance_in_crate(tcx, fn_diff.clone(), LOCAL_CRATE); + + let Some(mut diff_attrs) = autodiff_attrs(tcx, fn_diff.def_id()) else { + bug!("could not find autodiff attrs") + }; + + adjust_activity_to_abi( + tcx, + fn_source.ty(tcx, TypingEnv::fully_monomorphized()), + &mut diff_attrs.input_activity, + ); + + // Build body + generate_enzyme_call( + bx, + bx.cx, + fn_to_diff, + &diff_symbol, + llret_ty, + &val_arr, + diff_attrs.clone(), + result, + ); +} + +fn get_args_from_tuple<'ll, 'tcx>( + bx: &mut Builder<'_, 'll, 'tcx>, + tuple_op: OperandRef<'tcx, &'ll Value>, + fn_instance: Instance<'tcx>, +) -> Vec<&'ll Value> { + let cx = bx.cx; + let fn_abi = cx.fn_abi_of_instance(fn_instance, ty::List::empty()); + + match tuple_op.val { + OperandValue::Immediate(val) => vec![val], + OperandValue::Pair(v1, v2) => vec![v1, v2], + OperandValue::Ref(ptr) => { + let tuple_place = PlaceRef { val: ptr, layout: tuple_op.layout }; + + let mut result = Vec::with_capacity(fn_abi.args.len()); + let mut tuple_index = 0; + + for arg in &fn_abi.args { + match arg.mode { + PassMode::Ignore => {} + PassMode::Direct(_) | PassMode::Cast { .. } => { + let field = tuple_place.project_field(bx, tuple_index); + let llvm_ty = field.layout.llvm_type(bx.cx); + let val = bx.load(llvm_ty, field.val.llval, field.val.align); + result.push(val); + tuple_index += 1; + } + PassMode::Pair(_, _) => { + let field = tuple_place.project_field(bx, tuple_index); + let llvm_ty = field.layout.llvm_type(bx.cx); + let pair_val = bx.load(llvm_ty, field.val.llval, field.val.align); + result.push(bx.extract_value(pair_val, 0)); + result.push(bx.extract_value(pair_val, 1)); + tuple_index += 1; + } + PassMode::Indirect { .. } => { + let field = tuple_place.project_field(bx, tuple_index); + result.push(field.val.llval); + tuple_index += 1; + } + } + } + + result + } + + OperandValue::ZeroSized => vec![], + } +} + fn generic_simd_intrinsic<'ll, 'tcx>( bx: &mut Builder<'_, 'll, 'tcx>, name: Symbol, diff --git a/compiler/rustc_codegen_llvm/src/lib.rs b/compiler/rustc_codegen_llvm/src/lib.rs index ca84b6de8b1..79e80db6f55 100644 --- a/compiler/rustc_codegen_llvm/src/lib.rs +++ b/compiler/rustc_codegen_llvm/src/lib.rs @@ -30,7 +30,6 @@ use context::SimpleCx; use errors::ParseTargetMachineConfig; use llvm_util::target_config; use rustc_ast::expand::allocator::AllocatorKind; -use rustc_ast::expand::autodiff_attrs::AutoDiffItem; use rustc_codegen_ssa::back::lto::{SerializedModule, ThinModule}; use rustc_codegen_ssa::back::write::{ CodegenContext, FatLtoInput, ModuleConfig, TargetMachineFactoryConfig, TargetMachineFactoryFn, @@ -173,15 +172,10 @@ impl WriteBackendMethods for LlvmCodegenBackend { exported_symbols_for_lto: &[String], each_linked_rlib_for_lto: &[PathBuf], modules: Vec<FatLtoInput<Self>>, - diff_fncs: Vec<AutoDiffItem>, ) -> Result<ModuleCodegen<Self::Module>, FatalError> { let mut module = back::lto::run_fat(cgcx, exported_symbols_for_lto, each_linked_rlib_for_lto, modules)?; - if !diff_fncs.is_empty() { - builder::autodiff::differentiate(&module, cgcx, diff_fncs)?; - } - let dcx = cgcx.create_dcx(); let dcx = dcx.handle(); back::lto::run_pass_manager(cgcx, dcx, &mut module, false)?; diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs index ad3c3d5932e..8265b0114ce 100644 --- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs +++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs @@ -97,6 +97,7 @@ pub(crate) enum ModuleFlagMergeBehavior { // Consts for the LLVM CallConv type, pre-cast to usize. +/// Must match the layout of `LLVMTailCallKind`. #[derive(Copy, Clone, PartialEq, Debug)] #[repr(C)] #[allow(dead_code)] @@ -332,10 +333,15 @@ impl RealPredicate { } } -/// LLVMTypeKind -#[derive(Copy, Clone, PartialEq, Debug)] +/// Must match the layout of `LLVMTypeKind`. +/// +/// Use [`RawEnum<TypeKind>`] for values of `LLVMTypeKind` returned from LLVM, +/// to avoid risk of UB if LLVM adds new enum values. +/// +/// All of LLVM's variants should be declared here, even if no Rust-side code refers +/// to them, because unknown variants will cause [`RawEnum::to_rust`] to panic. +#[derive(Copy, Clone, PartialEq, Debug, TryFromU32)] #[repr(C)] -#[expect(dead_code, reason = "Some variants are unused, but are kept to match LLVM-C")] pub(crate) enum TypeKind { Void = 0, Half = 1, @@ -1046,6 +1052,8 @@ unsafe extern "C" { CanThrow: llvm::Bool, ) -> &'ll Value; + pub(crate) safe fn LLVMGetTypeKind(Ty: &Type) -> RawEnum<TypeKind>; + // Operations on integer types pub(crate) fn LLVMInt1TypeInContext(C: &Context) -> &Type; pub(crate) fn LLVMInt8TypeInContext(C: &Context) -> &Type; @@ -1197,7 +1205,7 @@ unsafe extern "C" { pub(crate) safe fn LLVMIsGlobalConstant(GlobalVar: &Value) -> Bool; pub(crate) safe fn LLVMSetGlobalConstant(GlobalVar: &Value, IsConstant: Bool); pub(crate) safe fn LLVMSetTailCall(CallInst: &Value, IsTailCall: Bool); - pub(crate) safe fn LLVMRustSetTailCallKind(CallInst: &Value, Kind: TailCallKind); + pub(crate) safe fn LLVMSetTailCallKind(CallInst: &Value, kind: TailCallKind); // Operations on attributes pub(crate) fn LLVMCreateStringAttribute( @@ -1841,9 +1849,6 @@ unsafe extern "C" { // Create and destroy contexts. pub(crate) fn LLVMRustContextCreate(shouldDiscardNames: bool) -> &'static mut Context; - /// See llvm::LLVMTypeKind::getTypeID. - pub(crate) fn LLVMRustGetTypeKind(Ty: &Type) -> TypeKind; - // Operations on all values pub(crate) fn LLVMRustGlobalAddMetadata<'a>( Val: &'a Value, diff --git a/compiler/rustc_codegen_llvm/src/llvm/mod.rs b/compiler/rustc_codegen_llvm/src/llvm/mod.rs index 154ba4fd690..0ea0af0c9af 100644 --- a/compiler/rustc_codegen_llvm/src/llvm/mod.rs +++ b/compiler/rustc_codegen_llvm/src/llvm/mod.rs @@ -42,32 +42,6 @@ pub(crate) fn AddFunctionAttributes<'ll>( } } -pub(crate) fn HasAttributeAtIndex<'ll>( - llfn: &'ll Value, - idx: AttributePlace, - kind: AttributeKind, -) -> bool { - unsafe { LLVMRustHasAttributeAtIndex(llfn, idx.as_uint(), kind) } -} - -pub(crate) fn HasStringAttribute<'ll>(llfn: &'ll Value, name: &str) -> bool { - unsafe { LLVMRustHasFnAttribute(llfn, name.as_c_char_ptr(), name.len()) } -} - -pub(crate) fn RemoveStringAttrFromFn<'ll>(llfn: &'ll Value, name: &str) { - unsafe { LLVMRustRemoveFnAttribute(llfn, name.as_c_char_ptr(), name.len()) } -} - -pub(crate) fn RemoveRustEnumAttributeAtIndex( - llfn: &Value, - place: AttributePlace, - kind: AttributeKind, -) { - unsafe { - LLVMRustRemoveEnumAttributeAtIndex(llfn, place.as_uint(), kind); - } -} - pub(crate) fn AddCallSiteAttributes<'ll>( callsite: &'ll Value, idx: AttributePlace, diff --git a/compiler/rustc_codegen_llvm/src/type_.rs b/compiler/rustc_codegen_llvm/src/type_.rs index 89365503138..f02d16baf94 100644 --- a/compiler/rustc_codegen_llvm/src/type_.rs +++ b/compiler/rustc_codegen_llvm/src/type_.rs @@ -204,7 +204,7 @@ impl<'ll, CX: Borrow<SCx<'ll>>> BaseTypeCodegenMethods for GenericCx<'ll, CX> { } fn type_kind(&self, ty: &'ll Type) -> TypeKind { - unsafe { llvm::LLVMRustGetTypeKind(ty).to_generic() } + llvm::LLVMGetTypeKind(ty).to_rust().to_generic() } fn type_ptr(&self) -> &'ll Type { |