diff options
Diffstat (limited to 'compiler/rustc_codegen_llvm')
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/back/write.rs | 5 | ||||
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/builder/autodiff.rs | 2 |
2 files changed, 6 insertions, 1 deletions
diff --git a/compiler/rustc_codegen_llvm/src/back/write.rs b/compiler/rustc_codegen_llvm/src/back/write.rs index 5e46fb1a1f5..3cfd739b70c 100644 --- a/compiler/rustc_codegen_llvm/src/back/write.rs +++ b/compiler/rustc_codegen_llvm/src/back/write.rs @@ -576,6 +576,11 @@ pub(crate) unsafe fn llvm_optimize( // When we build rustc with enzyme/autodiff support, we want to postpone size-increasing // optimizations until after differentiation. Our pipeline is thus: (opt + enzyme), (full opt). // We therefore have two calls to llvm_optimize, if autodiff is used. + // + // We also must disable merge_functions, since autodiff placeholder/dummy bodies tend to be + // identical. We run opts before AD, so there is a chance that LLVM will merge our dummies. + // In that case, we lack some dummy bodies and can't replace them with the real AD code anymore. + // We then would need to abort compilation. This was especially common in test cases. if consider_ad && autodiff_stage != AutodiffStage::PostAD { merge_functions = false; unroll_loops = false; diff --git a/compiler/rustc_codegen_llvm/src/builder/autodiff.rs b/compiler/rustc_codegen_llvm/src/builder/autodiff.rs index 5e7ef27143b..f5023e0ca5a 100644 --- a/compiler/rustc_codegen_llvm/src/builder/autodiff.rs +++ b/compiler/rustc_codegen_llvm/src/builder/autodiff.rs @@ -445,7 +445,7 @@ pub(crate) fn differentiate<'ll>( return Err(diag_handler.handle().emit_almost_fatal(AutoDiffWithoutEnable)); } - // Before dumping the module, we want all the TypeTrees to become part of the module. + // 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); |