Rollup merge of #142640 - Sa4dUs:ad-intrinsic, r=ZuseZ4

Implement autodiff using intrinsics
This PR aims to move autodiff logic to `autodiff` intrinsic. Allowing us to delete a great part of our frontend code and overall, simplify the compilation pipeline of autodiff functions.

Author: Zalathar

Cargo.lock

@@ -4309,7 +4309,6 @@ name = "rustc_monomorphize"
 version = "0.0.0"
 dependencies = [
 "rustc_abi",
-"rustc_ast",
 "rustc_data_structures",
 "rustc_errors",
 "rustc_fluent_macro",
@@ -4318,7 +4317,6 @@ dependencies = [
 "rustc_middle",
 "rustc_session",
 "rustc_span",
-"rustc_symbol_mangling",
 "rustc_target",
 "serde",
 "serde_json",

compiler/rustc_builtin_macros/src/autodiff.rs

@@ -93,7 +93,6 @@ use gccjit::{CType, Context, OptimizationLevel};
 #[cfg(feature = "master")]
 use gccjit::{TargetInfo,Version};
 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,TargetMachineFactoryFn,
@@ -363,12 +362,7 @@ impl WriteBackendMethods for GccCodegenBackend {
 _exported_symbols_for_lto:&[String],
 each_linked_rlib_for_lto:&[PathBuf],
 modules:Vec<FatLtoInput<Self>>,
-diff_functions:Vec<AutoDiffItem>,
 ) -> Result<ModuleCodegen<Self::Module>,FatalError>{
-if !diff_functions.is_empty(){
-unimplemented!();
-}
-
  back::lto::run_fat(cgcx, each_linked_rlib_for_lto, modules)
 }
 

compiler/rustc_codegen_gcc/src/lib.rs

@@ -28,22 +28,6 @@ pub(crate) fn apply_to_callsite(callsite: &Value, idx: AttributePlace, attrs: &[
 }
 }
 
-pub(crate)fnhas_attr(llfn:&Value,idx:AttributePlace,attr:AttributeKind) -> bool{
- llvm::HasAttributeAtIndex(llfn, idx, attr)
-}
-
-pub(crate)fnhas_string_attr(llfn:&Value,name:&str) -> bool{
- llvm::HasStringAttribute(llfn, name)
-}
-
-pub(crate)fnremove_from_llfn(llfn:&Value,place:AttributePlace,kind:AttributeKind){
- llvm::RemoveRustEnumAttributeAtIndex(llfn, place, kind);
-}
-
-pub(crate)fnremove_string_attr_from_llfn(llfn:&Value,name:&str){
- llvm::RemoveStringAttrFromFn(llfn, name);
-}
-
 /// Get LLVM attribute for the provided inline heuristic.
 #[inline]
 fninline_attr<'ll>(cx:&CodegenCx<'ll,'_>,inline:InlineAttr) -> Option<&'llAttribute>{

compiler/rustc_codegen_llvm/src/attributes.rs

@@ -24,9 +24,8 @@ use crate::back::write::{
 self,CodegenDiagnosticsStage,DiagnosticHandlers, bitcode_section_name, save_temp_bitcode,
 };
 usecrate::errors::{LlvmError,LtoBitcodeFromRlib};
-usecrate::llvm::AttributePlace::Function;
 usecrate::llvm::{self, build_string};
-usecrate::{LlvmCodegenBackend,ModuleLlvm,SimpleCx, attributes};
+usecrate::{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(
 }
 
 ifcfg!(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){