From 5bcd472b8688437b4967bcba077c4089572a17ea Mon Sep 17 00:00:00 2001
From: bjorn3 <17426603+bjorn3@users.noreply.github.com>
Date: Mon, 10 Nov 2025 13:42:32 +0000
Subject: [PATCH] Partially inline get_fn_addr/get_fn in
 codegen_llvm_intrinsic_call

This moves all LLVM intrinsic handling out of the regular call path for
cg_gcc and makes it easier to hook into this code for future cg_llvm
changes.
---
 src/builder.rs       |  2 +-
 src/context.rs       |  7 ++++---
 src/declare.rs       | 14 --------------
 src/intrinsic/mod.rs | 42 +++++++++++++++++++++++++++++++++++++++++-
 4 files changed, 46 insertions(+), 19 deletions(-)

diff --git a/src/builder.rs b/src/builder.rs
index 8b4a8de94bf3..3def9a5c015c 100644
--- a/src/builder.rs
+++ b/src/builder.rs
@@ -314,7 +314,7 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
         self.block.get_function()
     }
 
-    fn function_call(
+    pub fn function_call(
         &mut self,
         func: Function<'gcc>,
         args: &[RValue<'gcc>],
diff --git a/src/context.rs b/src/context.rs
index 67bec261cc2e..d200d5319a93 100644
--- a/src/context.rs
+++ b/src/context.rs
@@ -92,6 +92,8 @@ pub struct CodegenCx<'gcc, 'tcx> {
     pub instances: RefCell<FxHashMap<Instance<'tcx>, LValue<'gcc>>>,
     /// Cache function instances of monomorphic and polymorphic items
     pub function_instances: RefCell<FxHashMap<Instance<'tcx>, Function<'gcc>>>,
+    /// Cache function instances of intrinsics
+    pub intrinsic_instances: RefCell<FxHashMap<Instance<'tcx>, Function<'gcc>>>,
     /// Cache generated vtables
     pub vtables:
         RefCell<FxHashMap<(Ty<'tcx>, Option<ty::ExistentialTraitRef<'tcx>>), RValue<'gcc>>>,
@@ -280,6 +282,7 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
             linkage: Cell::new(FunctionType::Internal),
             instances: Default::default(),
             function_instances: Default::default(),
+            intrinsic_instances: Default::default(),
             on_stack_params: Default::default(),
             on_stack_function_params: Default::default(),
             vtables: Default::default(),
@@ -397,9 +400,7 @@ impl<'gcc, 'tcx> MiscCodegenMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
     fn get_fn_addr(&self, instance: Instance<'tcx>) -> RValue<'gcc> {
         let func_name = self.tcx.symbol_name(instance).name;
 
-        let func = if self.intrinsics.borrow().contains_key(func_name) {
-            self.intrinsics.borrow()[func_name]
-        } else if let Some(variable) = self.get_declared_value(func_name) {
+        let func = if let Some(variable) = self.get_declared_value(func_name) {
             return variable;
         } else {
             get_fn(self, instance)
diff --git a/src/declare.rs b/src/declare.rs
index fec7d9d0a403..e4130b221ee3 100644
--- a/src/declare.rs
+++ b/src/declare.rs
@@ -8,7 +8,6 @@ use rustc_target::callconv::FnAbi;
 
 use crate::abi::{FnAbiGcc, FnAbiGccExt};
 use crate::context::CodegenCx;
-use crate::intrinsic::llvm;
 
 impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
     pub fn get_or_insert_global(
@@ -162,19 +161,6 @@ fn declare_raw_fn<'gcc>(
     param_types: &[Type<'gcc>],
     variadic: bool,
 ) -> Function<'gcc> {
-    if name.starts_with("llvm.") {
-        let intrinsic = match name {
-            "llvm.fma.f16" => {
-                // fma is not a target builtin, but a normal builtin, so we handle it differently
-                // here.
-                cx.context.get_builtin_function("fma")
-            }
-            _ => llvm::intrinsic(name, cx),
-        };
-
-        cx.intrinsics.borrow_mut().insert(name.to_string(), intrinsic);
-        return intrinsic;
-    }
     let func = if cx.functions.borrow().contains_key(name) {
         cx.functions.borrow()[name]
     } else {
diff --git a/src/intrinsic/mod.rs b/src/intrinsic/mod.rs
index 75ea39c23114..77b88a969084 100644
--- a/src/intrinsic/mod.rs
+++ b/src/intrinsic/mod.rs
@@ -615,7 +615,47 @@ impl<'a, 'gcc, 'tcx> IntrinsicCallBuilderMethods<'tcx> for Builder<'a, 'gcc, 'tc
         args: &[OperandRef<'tcx, Self::Value>],
         is_cleanup: bool,
     ) -> Self::Value {
-        let fn_ptr = self.get_fn_addr(instance);
+        let func = if let Some(&func) = self.intrinsic_instances.borrow().get(&instance) {
+            func
+        } else {
+            let sym = self.tcx.symbol_name(instance).name;
+
+            let func = if let Some(func) = self.intrinsics.borrow().get(sym) {
+                *func
+            } else {
+                self.linkage.set(FunctionType::Extern);
+                let fn_abi = self.fn_abi_of_instance(instance, ty::List::empty());
+                let fn_ty = fn_abi.gcc_type(self);
+
+                let func = match sym {
+                    "llvm.fma.f16" => {
+                        // fma is not a target builtin, but a normal builtin, so we handle it differently
+                        // here.
+                        self.context.get_builtin_function("fma")
+                    }
+                    _ => llvm::intrinsic(sym, self),
+                };
+
+                self.intrinsics.borrow_mut().insert(sym.to_string(), func);
+
+                self.on_stack_function_params
+                    .borrow_mut()
+                    .insert(func, fn_ty.on_stack_param_indices);
+                #[cfg(feature = "master")]
+                for fn_attr in fn_ty.fn_attributes {
+                    func.add_attribute(fn_attr);
+                }
+
+                crate::attributes::from_fn_attrs(self, func, instance);
+
+                func
+            };
+
+            self.intrinsic_instances.borrow_mut().insert(instance, func);
+
+            func
+        };
+        let fn_ptr = func.get_address(None);
         let fn_ty = fn_ptr.get_type();
 
         let mut llargs = vec![];