Auto merge of #94221 - erikdesjardins:addattr, r=nikic

Add LLVM attributes in batches instead of individually

This should improve performance.

~r? `@ghost` (blocked on #94127)~

compiler/rustc_codegen_llvm/src/abi.rs

@@ -1,6 +1,7 @@
+use crate::attributes;
 use crate::builder::Builder;
 use crate::context::CodegenCx;
-use crate::llvm::{self, AttributePlace};
+use crate::llvm::{self, Attribute, AttributePlace};
 use crate::type_::Type;
 use crate::type_of::LayoutLlvmExt;
 use crate::value::Value;
@@ -20,6 +21,7 @@ use rustc_target::abi::{self, HasDataLayout, Int};
 pub use rustc_target::spec::abi::Abi;
 
 use libc::c_uint;
+use smallvec::SmallVec;
 
 pub trait ArgAttributesExt {
     fn apply_attrs_to_llfn(&self, idx: AttributePlace, cx: &CodegenCx<'_, '_>, llfn: &Value);
@@ -38,57 +40,65 @@ fn should_use_mutable_noalias(cx: &CodegenCx<'_, '_>) -> bool {
     cx.tcx.sess.opts.debugging_opts.mutable_noalias.unwrap_or(true)
 }
 
-const ABI_AFFECTING_ATTRIBUTES: [(ArgAttribute, llvm::Attribute); 1] =
+const ABI_AFFECTING_ATTRIBUTES: [(ArgAttribute, llvm::AttributeKind); 1] =
-    [(ArgAttribute::InReg, llvm::Attribute::InReg)];
+    [(ArgAttribute::InReg, llvm::AttributeKind::InReg)];
 
-const OPTIMIZATION_ATTRIBUTES: [(ArgAttribute, llvm::Attribute); 5] = [
+const OPTIMIZATION_ATTRIBUTES: [(ArgAttribute, llvm::AttributeKind); 5] = [
-    (ArgAttribute::NoAlias, llvm::Attribute::NoAlias),
+    (ArgAttribute::NoAlias, llvm::AttributeKind::NoAlias),
-    (ArgAttribute::NoCapture, llvm::Attribute::NoCapture),
+    (ArgAttribute::NoCapture, llvm::AttributeKind::NoCapture),
-    (ArgAttribute::NonNull, llvm::Attribute::NonNull),
+    (ArgAttribute::NonNull, llvm::AttributeKind::NonNull),
-    (ArgAttribute::ReadOnly, llvm::Attribute::ReadOnly),
+    (ArgAttribute::ReadOnly, llvm::AttributeKind::ReadOnly),
-    (ArgAttribute::NoUndef, llvm::Attribute::NoUndef),
+    (ArgAttribute::NoUndef, llvm::AttributeKind::NoUndef),
 ];
 
+fn get_attrs<'ll>(this: &ArgAttributes, cx: &CodegenCx<'ll, '_>) -> SmallVec<[&'ll Attribute; 8]> {
+    let mut regular = this.regular;
+
+    let mut attrs = SmallVec::new();
+
+    // ABI-affecting attributes must always be applied
+    for (attr, llattr) in ABI_AFFECTING_ATTRIBUTES {
+        if regular.contains(attr) {
+            attrs.push(llattr.create_attr(cx.llcx));
+        }
+    }
+    if let Some(align) = this.pointee_align {
+        attrs.push(llvm::CreateAlignmentAttr(cx.llcx, align.bytes()));
+    }
+    match this.arg_ext {
+        ArgExtension::None => {}
+        ArgExtension::Zext => attrs.push(llvm::AttributeKind::ZExt.create_attr(cx.llcx)),
+        ArgExtension::Sext => attrs.push(llvm::AttributeKind::SExt.create_attr(cx.llcx)),
+    }
+
+    // Only apply remaining attributes when optimizing
+    if cx.sess().opts.optimize != config::OptLevel::No {
+        let deref = this.pointee_size.bytes();
+        if deref != 0 {
+            if regular.contains(ArgAttribute::NonNull) {
+                attrs.push(llvm::CreateDereferenceableAttr(cx.llcx, deref));
+            } else {
+                attrs.push(llvm::CreateDereferenceableOrNullAttr(cx.llcx, deref));
+            }
+            regular -= ArgAttribute::NonNull;
+        }
+        for (attr, llattr) in OPTIMIZATION_ATTRIBUTES {
+            if regular.contains(attr) {
+                attrs.push(llattr.create_attr(cx.llcx));
+            }
+        }
+        if regular.contains(ArgAttribute::NoAliasMutRef) && should_use_mutable_noalias(cx) {
+            attrs.push(llvm::AttributeKind::NoAlias.create_attr(cx.llcx));
+        }
+    }
+
+    attrs
+}
+
 impl ArgAttributesExt for ArgAttributes {
     fn apply_attrs_to_llfn(&self, idx: AttributePlace, cx: &CodegenCx<'_, '_>, llfn: &Value) {
-        let mut regular = self.regular;
+        let attrs = get_attrs(self, cx);
-        unsafe {
+        attributes::apply_to_llfn(llfn, idx, &attrs);
-            // ABI-affecting attributes must always be applied
-            for (attr, llattr) in ABI_AFFECTING_ATTRIBUTES {
-                if regular.contains(attr) {
-                    llattr.apply_llfn(idx, llfn);
-                }
-            }
-            if let Some(align) = self.pointee_align {
-                llvm::LLVMRustAddAlignmentAttr(llfn, idx.as_uint(), align.bytes() as u32);
-            }
-            match self.arg_ext {
-                ArgExtension::None => {}
-                ArgExtension::Zext => llvm::Attribute::ZExt.apply_llfn(idx, llfn),
-                ArgExtension::Sext => llvm::Attribute::SExt.apply_llfn(idx, llfn),
-            }
-            // Only apply remaining attributes when optimizing
-            if cx.sess().opts.optimize == config::OptLevel::No {
-                return;
-            }
-            let deref = self.pointee_size.bytes();
-            if deref != 0 {
-                if regular.contains(ArgAttribute::NonNull) {
-                    llvm::LLVMRustAddDereferenceableAttr(llfn, idx.as_uint(), deref);
-                } else {
-                    llvm::LLVMRustAddDereferenceableOrNullAttr(llfn, idx.as_uint(), deref);
-                }
-                regular -= ArgAttribute::NonNull;
-            }
-            for (attr, llattr) in OPTIMIZATION_ATTRIBUTES {
-                if regular.contains(attr) {
-                    llattr.apply_llfn(idx, llfn);
-                }
-            }
-            if regular.contains(ArgAttribute::NoAliasMutRef) && should_use_mutable_noalias(cx) {
-                llvm::Attribute::NoAlias.apply_llfn(idx, llfn);
-            }
-        }
     }
 
     fn apply_attrs_to_callsite(
@@ -97,52 +107,8 @@ impl ArgAttributesExt for ArgAttributes {
         cx: &CodegenCx<'_, '_>,
         callsite: &Value,
     ) {
-        let mut regular = self.regular;
+        let attrs = get_attrs(self, cx);
-        unsafe {
+        attributes::apply_to_callsite(callsite, idx, &attrs);
-            // ABI-affecting attributes must always be applied
-            for (attr, llattr) in ABI_AFFECTING_ATTRIBUTES {
-                if regular.contains(attr) {
-                    llattr.apply_callsite(idx, callsite);
-                }
-            }
-            if let Some(align) = self.pointee_align {
-                llvm::LLVMRustAddAlignmentCallSiteAttr(
-                    callsite,
-                    idx.as_uint(),
-                    align.bytes() as u32,
-                );
-            }
-            match self.arg_ext {
-                ArgExtension::None => {}
-                ArgExtension::Zext => llvm::Attribute::ZExt.apply_callsite(idx, callsite),
-                ArgExtension::Sext => llvm::Attribute::SExt.apply_callsite(idx, callsite),
-            }
-            // Only apply remaining attributes when optimizing
-            if cx.sess().opts.optimize == config::OptLevel::No {
-                return;
-            }
-            let deref = self.pointee_size.bytes();
-            if deref != 0 {
-                if regular.contains(ArgAttribute::NonNull) {
-                    llvm::LLVMRustAddDereferenceableCallSiteAttr(callsite, idx.as_uint(), deref);
-                } else {
-                    llvm::LLVMRustAddDereferenceableOrNullCallSiteAttr(
-                        callsite,
-                        idx.as_uint(),
-                        deref,
-                    );
-                }
-                regular -= ArgAttribute::NonNull;
-            }
-            for (attr, llattr) in OPTIMIZATION_ATTRIBUTES {
-                if regular.contains(attr) {
-                    llattr.apply_callsite(idx, callsite);
-                }
-            }
-            if regular.contains(ArgAttribute::NoAliasMutRef) && should_use_mutable_noalias(cx) {
-                llvm::Attribute::NoAlias.apply_callsite(idx, callsite);
-            }
-        }
     }
 }
 
@@ -444,15 +410,14 @@ impl<'ll, 'tcx> FnAbiLlvmExt<'ll, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
     }
 
     fn apply_attrs_llfn(&self, cx: &CodegenCx<'ll, 'tcx>, llfn: &'ll Value) {
-        // FIXME(eddyb) can this also be applied to callsites?
+        let mut func_attrs = SmallVec::<[_; 2]>::new();
         if self.ret.layout.abi.is_uninhabited() {
-            llvm::Attribute::NoReturn.apply_llfn(llvm::AttributePlace::Function, llfn);
+            func_attrs.push(llvm::AttributeKind::NoReturn.create_attr(cx.llcx));
         }
-
-        // FIXME(eddyb, wesleywiser): apply this to callsites as well?
         if !self.can_unwind {
-            llvm::Attribute::NoUnwind.apply_llfn(llvm::AttributePlace::Function, llfn);
+            func_attrs.push(llvm::AttributeKind::NoUnwind.create_attr(cx.llcx));
         }
+        attributes::apply_to_llfn(llfn, llvm::AttributePlace::Function, &{ func_attrs });
 
         let mut i = 0;
         let mut apply = |attrs: &ArgAttributes| {
@@ -467,13 +432,8 @@ impl<'ll, 'tcx> FnAbiLlvmExt<'ll, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
             PassMode::Indirect { ref attrs, extra_attrs: _, on_stack } => {
                 assert!(!on_stack);
                 let i = apply(attrs);
-                unsafe {
+                let sret = llvm::CreateStructRetAttr(cx.llcx, self.ret.layout.llvm_type(cx));
-                    llvm::LLVMRustAddStructRetAttr(
+                attributes::apply_to_llfn(llfn, llvm::AttributePlace::Argument(i), &[sret]);
-                        llfn,
-                        llvm::AttributePlace::Argument(i).as_uint(),
-                        self.ret.layout.llvm_type(cx),
-                    );
-                }
             }
             PassMode::Cast(cast) => {
                 cast.attrs.apply_attrs_to_llfn(llvm::AttributePlace::ReturnValue, cx, llfn);
@@ -488,13 +448,8 @@ impl<'ll, 'tcx> FnAbiLlvmExt<'ll, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
                 PassMode::Ignore => {}
                 PassMode::Indirect { ref attrs, extra_attrs: None, on_stack: true } => {
                     let i = apply(attrs);
-                    unsafe {
+                    let byval = llvm::CreateByValAttr(cx.llcx, arg.layout.llvm_type(cx));
-                        llvm::LLVMRustAddByValAttr(
+                    attributes::apply_to_llfn(llfn, llvm::AttributePlace::Argument(i), &[byval]);
-                            llfn,
-                            llvm::AttributePlace::Argument(i).as_uint(),
-                            arg.layout.llvm_type(cx),
-                        );
-                    }
                 }
                 PassMode::Direct(ref attrs)
                 | PassMode::Indirect { ref attrs, extra_attrs: None, on_stack: false } => {
@@ -517,12 +472,14 @@ impl<'ll, 'tcx> FnAbiLlvmExt<'ll, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
     }
 
     fn apply_attrs_callsite(&self, bx: &mut Builder<'_, 'll, 'tcx>, callsite: &'ll Value) {
+        let mut func_attrs = SmallVec::<[_; 2]>::new();
         if self.ret.layout.abi.is_uninhabited() {
-            llvm::Attribute::NoReturn.apply_callsite(llvm::AttributePlace::Function, callsite);
+            func_attrs.push(llvm::AttributeKind::NoReturn.create_attr(bx.cx.llcx));
         }
         if !self.can_unwind {
-            llvm::Attribute::NoUnwind.apply_callsite(llvm::AttributePlace::Function, callsite);
+            func_attrs.push(llvm::AttributeKind::NoUnwind.create_attr(bx.cx.llcx));
         }
+        attributes::apply_to_callsite(callsite, llvm::AttributePlace::Function, &{ func_attrs });
 
         let mut i = 0;
         let mut apply = |cx: &CodegenCx<'_, '_>, attrs: &ArgAttributes| {
@@ -537,13 +494,8 @@ impl<'ll, 'tcx> FnAbiLlvmExt<'ll, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
             PassMode::Indirect { ref attrs, extra_attrs: _, on_stack } => {
                 assert!(!on_stack);
                 let i = apply(bx.cx, attrs);
-                unsafe {
+                let sret = llvm::CreateStructRetAttr(bx.cx.llcx, self.ret.layout.llvm_type(bx));
-                    llvm::LLVMRustAddStructRetCallSiteAttr(
+                attributes::apply_to_callsite(callsite, llvm::AttributePlace::Argument(i), &[sret]);
-                        callsite,
-                        llvm::AttributePlace::Argument(i).as_uint(),
-                        self.ret.layout.llvm_type(bx),
-                    );
-                }
             }
             PassMode::Cast(cast) => {
                 cast.attrs.apply_attrs_to_callsite(
@@ -572,13 +524,12 @@ impl<'ll, 'tcx> FnAbiLlvmExt<'ll, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
                 PassMode::Ignore => {}
                 PassMode::Indirect { ref attrs, extra_attrs: None, on_stack: true } => {
                     let i = apply(bx.cx, attrs);
-                    unsafe {
+                    let byval = llvm::CreateByValAttr(bx.cx.llcx, arg.layout.llvm_type(bx));
-                        llvm::LLVMRustAddByValCallSiteAttr(
+                    attributes::apply_to_callsite(
-                            callsite,
+                        callsite,
-                            llvm::AttributePlace::Argument(i).as_uint(),
+                        llvm::AttributePlace::Argument(i),
-                            arg.layout.llvm_type(bx),
+                        &[byval],
-                        );
+                    );
-                    }
                 }
                 PassMode::Direct(ref attrs)
                 | PassMode::Indirect { ref attrs, extra_attrs: None, on_stack: false } => {
@@ -610,10 +561,12 @@ impl<'ll, 'tcx> FnAbiLlvmExt<'ll, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
         if self.conv == Conv::CCmseNonSecureCall {
             // This will probably get ignored on all targets but those supporting the TrustZone-M
             // extension (thumbv8m targets).
-            llvm::AddCallSiteAttrString(
+            let cmse_nonsecure_call =
+                llvm::CreateAttrString(bx.cx.llcx, cstr::cstr!("cmse_nonsecure_call"));
+            attributes::apply_to_callsite(
                 callsite,
                 llvm::AttributePlace::Function,
-                cstr::cstr!("cmse_nonsecure_call"),
+                &[cmse_nonsecure_call],
             );
         }
     }

compiler/rustc_codegen_llvm/src/allocator.rs

@@ -64,7 +64,8 @@ pub(crate) unsafe fn codegen(
             llvm::LLVMRustSetVisibility(llfn, llvm::Visibility::Hidden);
         }
         if tcx.sess.must_emit_unwind_tables() {
-            attributes::emit_uwtable(llfn);
+            let uwtable = attributes::uwtable_attr(llcx);
+            attributes::apply_to_llfn(llfn, llvm::AttributePlace::Function, &[uwtable]);
         }
 
         let callee = kind.fn_name(method.name);
@@ -105,20 +106,22 @@ pub(crate) unsafe fn codegen(
     let name = "__rust_alloc_error_handler";
     let llfn = llvm::LLVMRustGetOrInsertFunction(llmod, name.as_ptr().cast(), name.len(), ty);
     // -> ! DIFlagNoReturn
-    llvm::Attribute::NoReturn.apply_llfn(llvm::AttributePlace::Function, llfn);
+    let no_return = llvm::AttributeKind::NoReturn.create_attr(llcx);
+    attributes::apply_to_llfn(llfn, llvm::AttributePlace::Function, &[no_return]);
 
     if tcx.sess.target.default_hidden_visibility {
         llvm::LLVMRustSetVisibility(llfn, llvm::Visibility::Hidden);
     }
     if tcx.sess.must_emit_unwind_tables() {
-        attributes::emit_uwtable(llfn);
+        let uwtable = attributes::uwtable_attr(llcx);
+        attributes::apply_to_llfn(llfn, llvm::AttributePlace::Function, &[uwtable]);
     }
 
     let kind = if has_alloc_error_handler { AllocatorKind::Global } else { AllocatorKind::Default };
     let callee = kind.fn_name(sym::oom);
     let callee = llvm::LLVMRustGetOrInsertFunction(llmod, callee.as_ptr().cast(), callee.len(), ty);
     // -> ! DIFlagNoReturn
-    llvm::Attribute::NoReturn.apply_llfn(llvm::AttributePlace::Function, callee);
+    attributes::apply_to_llfn(callee, llvm::AttributePlace::Function, &[no_return]);
     llvm::LLVMRustSetVisibility(callee, llvm::Visibility::Hidden);
 
     let llbb = llvm::LLVMAppendBasicBlockInContext(llcx, llfn, "entry\0".as_ptr().cast());

compiler/rustc_codegen_llvm/src/asm.rs

@@ -1,3 +1,4 @@
+use crate::attributes;
 use crate::builder::Builder;
 use crate::common::Funclet;
 use crate::context::CodegenCx;
@@ -18,6 +19,7 @@ use rustc_target::abi::*;
 use rustc_target::asm::*;
 
 use libc::{c_char, c_uint};
+use smallvec::SmallVec;
 use tracing::debug;
 
 impl<'ll, 'tcx> AsmBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> {
@@ -273,19 +275,20 @@ impl<'ll, 'tcx> AsmBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> {
         )
         .unwrap_or_else(|| span_bug!(line_spans[0], "LLVM asm constraint validation failed"));
 
+        let mut attrs = SmallVec::<[_; 2]>::new();
         if options.contains(InlineAsmOptions::PURE) {
             if options.contains(InlineAsmOptions::NOMEM) {
-                llvm::Attribute::ReadNone.apply_callsite(llvm::AttributePlace::Function, result);
+                attrs.push(llvm::AttributeKind::ReadNone.create_attr(self.cx.llcx));
             } else if options.contains(InlineAsmOptions::READONLY) {
-                llvm::Attribute::ReadOnly.apply_callsite(llvm::AttributePlace::Function, result);
+                attrs.push(llvm::AttributeKind::ReadOnly.create_attr(self.cx.llcx));
             }
-            llvm::Attribute::WillReturn.apply_callsite(llvm::AttributePlace::Function, result);
+            attrs.push(llvm::AttributeKind::WillReturn.create_attr(self.cx.llcx));
         } else if options.contains(InlineAsmOptions::NOMEM) {
-            llvm::Attribute::InaccessibleMemOnly
+            attrs.push(llvm::AttributeKind::InaccessibleMemOnly.create_attr(self.cx.llcx));
-                .apply_callsite(llvm::AttributePlace::Function, result);
         } else {
             // LLVM doesn't have an attribute to represent ReadOnly + SideEffect
         }
+        attributes::apply_to_callsite(result, llvm::AttributePlace::Function, &{ attrs });
 
         // Write results to outputs
         for (idx, op) in operands.iter().enumerate() {

compiler/rustc_codegen_llvm/src/attributes.rs

@@ -7,53 +7,75 @@ use rustc_codegen_ssa::traits::*;
 use rustc_data_structures::small_c_str::SmallCStr;
 use rustc_hir::def_id::DefId;
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;
-use rustc_middle::ty::layout::HasTyCtxt;
 use rustc_middle::ty::{self, TyCtxt};
 use rustc_session::config::OptLevel;
-use rustc_session::Session;
 use rustc_target::spec::abi::Abi;
 use rustc_target::spec::{FramePointer, SanitizerSet, StackProbeType, StackProtector};
+use smallvec::SmallVec;
 
 use crate::attributes;
 use crate::llvm::AttributePlace::Function;
-use crate::llvm::{self, Attribute};
+use crate::llvm::{self, Attribute, AttributeKind, AttributePlace};
 use crate::llvm_util;
 pub use rustc_attr::{InlineAttr, InstructionSetAttr, OptimizeAttr};
 
 use crate::context::CodegenCx;
 use crate::value::Value;
 
-/// Mark LLVM function to use provided inline heuristic.
+pub fn apply_to_llfn(llfn: &Value, idx: AttributePlace, attrs: &[&Attribute]) {
-#[inline]
+    if !attrs.is_empty() {
-fn inline<'ll>(cx: &CodegenCx<'ll, '_>, val: &'ll Value, inline: InlineAttr) {
+        llvm::AddFunctionAttributes(llfn, idx, attrs);
-    use self::InlineAttr::*;
+    }
-    match inline {
-        Hint => Attribute::InlineHint.apply_llfn(Function, val),
-        Always => Attribute::AlwaysInline.apply_llfn(Function, val),
-        Never => {
-            if cx.tcx().sess.target.arch != "amdgpu" {
-                Attribute::NoInline.apply_llfn(Function, val);
-            }
-        }
-        None => {}
-    };
 }
 
-/// Apply LLVM sanitize attributes.
+pub fn remove_from_llfn(llfn: &Value, idx: AttributePlace, attrs: &[AttributeKind]) {
+    if !attrs.is_empty() {
+        llvm::RemoveFunctionAttributes(llfn, idx, attrs);
+    }
+}
+
+pub fn apply_to_callsite(callsite: &Value, idx: AttributePlace, attrs: &[&Attribute]) {
+    if !attrs.is_empty() {
+        llvm::AddCallSiteAttributes(callsite, idx, attrs);
+    }
+}
+
+/// Get LLVM attribute for the provided inline heuristic.
 #[inline]
-pub fn sanitize<'ll>(cx: &CodegenCx<'ll, '_>, no_sanitize: SanitizerSet, llfn: &'ll Value) {
+fn inline_attr<'ll>(cx: &CodegenCx<'ll, '_>, inline: InlineAttr) -> Option<&'ll Attribute> {
+    match inline {
+        InlineAttr::Hint => Some(AttributeKind::InlineHint.create_attr(cx.llcx)),
+        InlineAttr::Always => Some(AttributeKind::AlwaysInline.create_attr(cx.llcx)),
+        InlineAttr::Never => {
+            if cx.sess().target.arch != "amdgpu" {
+                Some(AttributeKind::NoInline.create_attr(cx.llcx))
+            } else {
+                None
+            }
+        }
+        InlineAttr::None => None,
+    }
+}
+
+/// Get LLVM sanitize attributes.
+#[inline]
+pub fn sanitize_attrs<'ll>(
+    cx: &CodegenCx<'ll, '_>,
+    no_sanitize: SanitizerSet,
+) -> SmallVec<[&'ll Attribute; 4]> {
+    let mut attrs = SmallVec::new();
     let enabled = cx.tcx.sess.opts.debugging_opts.sanitizer - no_sanitize;
     if enabled.contains(SanitizerSet::ADDRESS) {
-        llvm::Attribute::SanitizeAddress.apply_llfn(Function, llfn);
+        attrs.push(llvm::AttributeKind::SanitizeAddress.create_attr(cx.llcx));
     }
     if enabled.contains(SanitizerSet::MEMORY) {
-        llvm::Attribute::SanitizeMemory.apply_llfn(Function, llfn);
+        attrs.push(llvm::AttributeKind::SanitizeMemory.create_attr(cx.llcx));
     }
     if enabled.contains(SanitizerSet::THREAD) {
-        llvm::Attribute::SanitizeThread.apply_llfn(Function, llfn);
+        attrs.push(llvm::AttributeKind::SanitizeThread.create_attr(cx.llcx));
     }
     if enabled.contains(SanitizerSet::HWADDRESS) {
-        llvm::Attribute::SanitizeHWAddress.apply_llfn(Function, llfn);
+        attrs.push(llvm::AttributeKind::SanitizeHWAddress.create_attr(cx.llcx));
     }
     if enabled.contains(SanitizerSet::MEMTAG) {
         // Check to make sure the mte target feature is actually enabled.
@@ -66,26 +88,21 @@ pub fn sanitize<'ll>(cx: &CodegenCx<'ll, '_>, no_sanitize: SanitizerSet, llfn: &
             sess.err("`-Zsanitizer=memtag` requires `-Ctarget-feature=+mte`");
         }
 
-        llvm::Attribute::SanitizeMemTag.apply_llfn(Function, llfn);
+        attrs.push(llvm::AttributeKind::SanitizeMemTag.create_attr(cx.llcx));
     }
+    attrs
 }
 
 /// Tell LLVM to emit or not emit the information necessary to unwind the stack for the function.
 #[inline]
-pub fn emit_uwtable(val: &Value) {
+pub fn uwtable_attr(llcx: &llvm::Context) -> &Attribute {
     // NOTE: We should determine if we even need async unwind tables, as they
     // take have more overhead and if we can use sync unwind tables we
     // probably should.
-    llvm::EmitUWTableAttr(val, true);
+    llvm::CreateUWTableAttr(llcx, true)
 }
 
-/// Tell LLVM if this function should be 'naked', i.e., skip the epilogue and prologue.
+pub fn frame_pointer_type_attr<'ll>(cx: &CodegenCx<'ll, '_>) -> Option<&'ll Attribute> {
-#[inline]
-fn naked(val: &Value, is_naked: bool) {
-    Attribute::Naked.toggle_llfn(Function, val, is_naked);
-}
-
-pub fn set_frame_pointer_type<'ll>(cx: &CodegenCx<'ll, '_>, llfn: &'ll Value) {
     let mut fp = cx.sess().target.frame_pointer;
     // "mcount" function relies on stack pointer.
     // See <https://sourceware.org/binutils/docs/gprof/Implementation.html>.
@@ -96,19 +113,14 @@ pub fn set_frame_pointer_type<'ll>(cx: &CodegenCx<'ll, '_>, llfn: &'ll Value) {
     let attr_value = match fp {
         FramePointer::Always => cstr!("all"),
         FramePointer::NonLeaf => cstr!("non-leaf"),
-        FramePointer::MayOmit => return,
+        FramePointer::MayOmit => return None,
     };
-    llvm::AddFunctionAttrStringValue(
+    Some(llvm::CreateAttrStringValue(cx.llcx, cstr!("frame-pointer"), attr_value))
-        llfn,
-        llvm::AttributePlace::Function,
-        cstr!("frame-pointer"),
-        attr_value,
-    );
 }
 
 /// Tell LLVM what instrument function to insert.
 #[inline]
-fn set_instrument_function<'ll>(cx: &CodegenCx<'ll, '_>, llfn: &'ll Value) {
+fn instrument_function_attr<'ll>(cx: &CodegenCx<'ll, '_>) -> Option<&'ll Attribute> {
     if cx.sess().instrument_mcount() {
         // Similar to `clang -pg` behavior. Handled by the
         // `post-inline-ee-instrument` LLVM pass.
@@ -117,16 +129,17 @@ fn set_instrument_function<'ll>(cx: &CodegenCx<'ll, '_>, llfn: &'ll Value) {
         // See test/CodeGen/mcount.c in clang.
         let mcount_name = CString::new(cx.sess().target.mcount.as_str().as_bytes()).unwrap();
 
-        llvm::AddFunctionAttrStringValue(
+        Some(llvm::CreateAttrStringValue(
-            llfn,
+            cx.llcx,
-            llvm::AttributePlace::Function,
             cstr!("instrument-function-entry-inlined"),
             &mcount_name,
-        );
+        ))
+    } else {
+        None
     }
 }
 
-fn set_probestack<'ll>(cx: &CodegenCx<'ll, '_>, llfn: &'ll Value) {
+fn probestack_attr<'ll>(cx: &CodegenCx<'ll, '_>) -> Option<&'ll Attribute> {
     // Currently stack probes seem somewhat incompatible with the address
     // sanitizer and thread sanitizer. With asan we're already protected from
     // stack overflow anyway so we don't really need stack probes regardless.
@@ -137,107 +150,105 @@ fn set_probestack<'ll>(cx: &CodegenCx<'ll, '_>, llfn: &'ll Value) {
         .sanitizer
         .intersects(SanitizerSet::ADDRESS | SanitizerSet::THREAD)
     {
-        return;
+        return None;
     }
 
     // probestack doesn't play nice either with `-C profile-generate`.
     if cx.sess().opts.cg.profile_generate.enabled() {
-        return;
+        return None;
     }
 
     // probestack doesn't play nice either with gcov profiling.
     if cx.sess().opts.debugging_opts.profile {
-        return;
+        return None;
     }
 
     let attr_value = match cx.sess().target.stack_probes {
-        StackProbeType::None => None,
+        StackProbeType::None => return None,
         // Request LLVM to generate the probes inline. If the given LLVM version does not support
         // this, no probe is generated at all (even if the attribute is specified).
-        StackProbeType::Inline => Some(cstr!("inline-asm")),
+        StackProbeType::Inline => cstr!("inline-asm"),
         // Flag our internal `__rust_probestack` function as the stack probe symbol.
         // This is defined in the `compiler-builtins` crate for each architecture.
-        StackProbeType::Call => Some(cstr!("__rust_probestack")),
+        StackProbeType::Call => cstr!("__rust_probestack"),
         // Pick from the two above based on the LLVM version.
         StackProbeType::InlineOrCall { min_llvm_version_for_inline } => {
             if llvm_util::get_version() < min_llvm_version_for_inline {
-                Some(cstr!("__rust_probestack"))
+                cstr!("__rust_probestack")
             } else {
-                Some(cstr!("inline-asm"))
+                cstr!("inline-asm")
             }
         }
     };
-    if let Some(attr_value) = attr_value {
+    Some(llvm::CreateAttrStringValue(cx.llcx, cstr!("probe-stack"), attr_value))
-        llvm::AddFunctionAttrStringValue(
-            llfn,
-            llvm::AttributePlace::Function,
-            cstr!("probe-stack"),
-            attr_value,
-        );
-    }
 }
 
-fn set_stackprotector<'ll>(cx: &CodegenCx<'ll, '_>, llfn: &'ll Value) {
+fn stackprotector_attr<'ll>(cx: &CodegenCx<'ll, '_>) -> Option<&'ll Attribute> {
     let sspattr = match cx.sess().stack_protector() {
-        StackProtector::None => return,
+        StackProtector::None => return None,
-        StackProtector::All => Attribute::StackProtectReq,
+        StackProtector::All => AttributeKind::StackProtectReq,
-        StackProtector::Strong => Attribute::StackProtectStrong,
+        StackProtector::Strong => AttributeKind::StackProtectStrong,
-        StackProtector::Basic => Attribute::StackProtect,
+        StackProtector::Basic => AttributeKind::StackProtect,
     };
 
-    sspattr.apply_llfn(Function, llfn)
+    Some(sspattr.create_attr(cx.llcx))
 }
 
-pub fn apply_target_cpu_attr<'ll>(cx: &CodegenCx<'ll, '_>, llfn: &'ll Value) {
+pub fn target_cpu_attr<'ll>(cx: &CodegenCx<'ll, '_>) -> &'ll Attribute {
     let target_cpu = SmallCStr::new(llvm_util::target_cpu(cx.tcx.sess));
-    llvm::AddFunctionAttrStringValue(
+    llvm::CreateAttrStringValue(cx.llcx, cstr!("target-cpu"), target_cpu.as_c_str())
-        llfn,
-        llvm::AttributePlace::Function,
-        cstr!("target-cpu"),
-        target_cpu.as_c_str(),
-    );
 }
 
-pub fn apply_tune_cpu_attr<'ll>(cx: &CodegenCx<'ll, '_>, llfn: &'ll Value) {
+pub fn tune_cpu_attr<'ll>(cx: &CodegenCx<'ll, '_>) -> Option<&'ll Attribute> {
-    if let Some(tune) = llvm_util::tune_cpu(cx.tcx.sess) {
+    llvm_util::tune_cpu(cx.tcx.sess).map(|tune| {
         let tune_cpu = SmallCStr::new(tune);
-        llvm::AddFunctionAttrStringValue(
+        llvm::CreateAttrStringValue(cx.llcx, cstr!("tune-cpu"), tune_cpu.as_c_str())
-            llfn,
+    })
-            llvm::AttributePlace::Function,
-            cstr!("tune-cpu"),
-            tune_cpu.as_c_str(),
-        );
-    }
 }
 
-/// Sets the `NonLazyBind` LLVM attribute on a given function,
+/// Get the `NonLazyBind` LLVM attribute,
-/// assuming the codegen options allow skipping the PLT.
+/// if the codegen options allow skipping the PLT.
-pub fn non_lazy_bind<'ll>(sess: &Session, llfn: &'ll Value) {
+pub fn non_lazy_bind_attr<'ll>(cx: &CodegenCx<'ll, '_>) -> Option<&'ll Attribute> {
     // Don't generate calls through PLT if it's not necessary
-    if !sess.needs_plt() {
+    if !cx.sess().needs_plt() {
-        Attribute::NonLazyBind.apply_llfn(Function, llfn);
+        Some(AttributeKind::NonLazyBind.create_attr(cx.llcx))
+    } else {
+        None
     }
 }
 
-pub(crate) fn default_optimisation_attrs<'ll>(sess: &Session, llfn: &'ll Value) {
+/// Returns attributes to remove and to add, respectively,
-    match sess.opts.optimize {
+/// to set the default optimizations attrs on a function.
+#[inline]
+pub(crate) fn default_optimisation_attrs<'ll>(
+    cx: &CodegenCx<'ll, '_>,
+) -> (
+    // Attributes to remove
+    SmallVec<[AttributeKind; 3]>,
+    // Attributes to add
+    SmallVec<[&'ll Attribute; 2]>,
+) {
+    let mut to_remove = SmallVec::new();
+    let mut to_add = SmallVec::new();
+    match cx.sess().opts.optimize {
         OptLevel::Size => {
-            llvm::Attribute::MinSize.unapply_llfn(Function, llfn);
+            to_remove.push(llvm::AttributeKind::MinSize);
-            llvm::Attribute::OptimizeForSize.apply_llfn(Function, llfn);
+            to_add.push(llvm::AttributeKind::OptimizeForSize.create_attr(cx.llcx));
-            llvm::Attribute::OptimizeNone.unapply_llfn(Function, llfn);
+            to_remove.push(llvm::AttributeKind::OptimizeNone);
         }
         OptLevel::SizeMin => {
-            llvm::Attribute::MinSize.apply_llfn(Function, llfn);
+            to_add.push(llvm::AttributeKind::MinSize.create_attr(cx.llcx));
-            llvm::Attribute::OptimizeForSize.apply_llfn(Function, llfn);
+            to_add.push(llvm::AttributeKind::OptimizeForSize.create_attr(cx.llcx));
-            llvm::Attribute::OptimizeNone.unapply_llfn(Function, llfn);
+            to_remove.push(llvm::AttributeKind::OptimizeNone);
         }
         OptLevel::No => {
-            llvm::Attribute::MinSize.unapply_llfn(Function, llfn);
+            to_remove.push(llvm::AttributeKind::MinSize);
-            llvm::Attribute::OptimizeForSize.unapply_llfn(Function, llfn);
+            to_remove.push(llvm::AttributeKind::OptimizeForSize);
-            llvm::Attribute::OptimizeNone.unapply_llfn(Function, llfn);
+            to_remove.push(llvm::AttributeKind::OptimizeNone);
         }
         _ => {}
     }
+    (to_remove, to_add)
 }
 
 /// Composite function which sets LLVM attributes for function depending on its AST (`#[attribute]`)
@@ -249,30 +260,35 @@ pub fn from_fn_attrs<'ll, 'tcx>(
 ) {
     let codegen_fn_attrs = cx.tcx.codegen_fn_attrs(instance.def_id());
 
+    let mut to_remove = SmallVec::<[_; 4]>::new();
+    let mut to_add = SmallVec::<[_; 16]>::new();
+
     match codegen_fn_attrs.optimize {
         OptimizeAttr::None => {
-            default_optimisation_attrs(cx.tcx.sess, llfn);
+            let (to_remove_opt, to_add_opt) = default_optimisation_attrs(cx);
+            to_remove.extend(to_remove_opt);
+            to_add.extend(to_add_opt);
         }
         OptimizeAttr::Speed => {
-            llvm::Attribute::MinSize.unapply_llfn(Function, llfn);
+            to_remove.push(llvm::AttributeKind::MinSize);
-            llvm::Attribute::OptimizeForSize.unapply_llfn(Function, llfn);
+            to_remove.push(llvm::AttributeKind::OptimizeForSize);
-            llvm::Attribute::OptimizeNone.unapply_llfn(Function, llfn);
+            to_remove.push(llvm::AttributeKind::OptimizeNone);
         }
         OptimizeAttr::Size => {
-            llvm::Attribute::MinSize.apply_llfn(Function, llfn);
+            to_add.push(llvm::AttributeKind::MinSize.create_attr(cx.llcx));
-            llvm::Attribute::OptimizeForSize.apply_llfn(Function, llfn);
+            to_add.push(llvm::AttributeKind::OptimizeForSize.create_attr(cx.llcx));
-            llvm::Attribute::OptimizeNone.unapply_llfn(Function, llfn);
+            to_remove.push(llvm::AttributeKind::OptimizeNone);
         }
     }
 
-    let inline_attr = if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::NAKED) {
+    let inline = if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::NAKED) {
         InlineAttr::Never
     } else if codegen_fn_attrs.inline == InlineAttr::None && instance.def.requires_inline(cx.tcx) {
         InlineAttr::Hint
     } else {
         codegen_fn_attrs.inline
     };
-    inline(cx, llfn, inline_attr);
+    to_add.extend(inline_attr(cx, inline));
 
     // The `uwtable` attribute according to LLVM is:
     //
@@ -291,52 +307,54 @@ pub fn from_fn_attrs<'ll, 'tcx>(
     // You can also find more info on why Windows always requires uwtables here:
     //      https://bugzilla.mozilla.org/show_bug.cgi?id=1302078
     if cx.sess().must_emit_unwind_tables() {
-        attributes::emit_uwtable(llfn);
+        to_add.push(uwtable_attr(cx.llcx));
     }
 
     if cx.sess().opts.debugging_opts.profile_sample_use.is_some() {
-        llvm::AddFunctionAttrString(llfn, Function, cstr!("use-sample-profile"));
+        to_add.push(llvm::CreateAttrString(cx.llcx, cstr!("use-sample-profile")));
     }
 
     // FIXME: none of these three functions interact with source level attributes.
-    set_frame_pointer_type(cx, llfn);
+    to_add.extend(frame_pointer_type_attr(cx));
-    set_instrument_function(cx, llfn);
+    to_add.extend(instrument_function_attr(cx));
-    set_probestack(cx, llfn);
+    to_add.extend(probestack_attr(cx));
-    set_stackprotector(cx, llfn);
+    to_add.extend(stackprotector_attr(cx));
 
     if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::COLD) {
-        Attribute::Cold.apply_llfn(Function, llfn);
+        to_add.push(AttributeKind::Cold.create_attr(cx.llcx));
     }
     if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::FFI_RETURNS_TWICE) {
-        Attribute::ReturnsTwice.apply_llfn(Function, llfn);
+        to_add.push(AttributeKind::ReturnsTwice.create_attr(cx.llcx));
     }
     if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::FFI_PURE) {
-        Attribute::ReadOnly.apply_llfn(Function, llfn);
+        to_add.push(AttributeKind::ReadOnly.create_attr(cx.llcx));
     }
     if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::FFI_CONST) {
-        Attribute::ReadNone.apply_llfn(Function, llfn);
+        to_add.push(AttributeKind::ReadNone.create_attr(cx.llcx));
     }
     if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::NAKED) {
-        naked(llfn, true);
+        to_add.push(AttributeKind::Naked.create_attr(cx.llcx));
     }
     if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::ALLOCATOR) {
-        Attribute::NoAlias.apply_llfn(llvm::AttributePlace::ReturnValue, llfn);
+        // apply to return place instead of function (unlike all other attributes applied in this function)
+        let no_alias = AttributeKind::NoAlias.create_attr(cx.llcx);
+        attributes::apply_to_llfn(llfn, AttributePlace::ReturnValue, &[no_alias]);
     }
     if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::CMSE_NONSECURE_ENTRY) {
-        llvm::AddFunctionAttrString(llfn, Function, cstr!("cmse_nonsecure_entry"));
+        to_add.push(llvm::CreateAttrString(cx.llcx, cstr!("cmse_nonsecure_entry")));
     }
     if let Some(align) = codegen_fn_attrs.alignment {
         llvm::set_alignment(llfn, align as usize);
     }
-    sanitize(cx, codegen_fn_attrs.no_sanitize, llfn);
+    to_add.extend(sanitize_attrs(cx, codegen_fn_attrs.no_sanitize));
 
     // Always annotate functions with the target-cpu they are compiled for.
     // Without this, ThinLTO won't inline Rust functions into Clang generated
     // functions (because Clang annotates functions this way too).
-    apply_target_cpu_attr(cx, llfn);
+    to_add.push(target_cpu_attr(cx));
     // tune-cpu is only conveyed through the attribute for our purpose.
     // The target doesn't care; the subtarget reads our attribute.
-    apply_tune_cpu_attr(cx, llfn);
+    to_add.extend(tune_cpu_attr(cx));
 
     let function_features =
         codegen_fn_attrs.target_features.iter().map(|f| f.as_str()).collect::<Vec<&str>>();
@@ -379,22 +397,12 @@ pub fn from_fn_attrs<'ll, 'tcx>(
         // If this function is an import from the environment but the wasm
         // import has a specific module/name, apply them here.
         if let Some(module) = wasm_import_module(cx.tcx, instance.def_id()) {
-            llvm::AddFunctionAttrStringValue(
+            to_add.push(llvm::CreateAttrStringValue(cx.llcx, cstr!("wasm-import-module"), &module));
-                llfn,
-                llvm::AttributePlace::Function,
-                cstr!("wasm-import-module"),
-                &module,
-            );
 
             let name =
                 codegen_fn_attrs.link_name.unwrap_or_else(|| cx.tcx.item_name(instance.def_id()));
             let name = CString::new(name.as_str()).unwrap();
-            llvm::AddFunctionAttrStringValue(
+            to_add.push(llvm::CreateAttrStringValue(cx.llcx, cstr!("wasm-import-name"), &name));
-                llfn,
-                llvm::AttributePlace::Function,
-                cstr!("wasm-import-name"),
-                &name,
-            );
         }
 
         // The `"wasm"` abi on wasm targets automatically enables the
@@ -414,13 +422,11 @@ pub fn from_fn_attrs<'ll, 'tcx>(
         global_features.extend(function_features.into_iter());
         let features = global_features.join(",");
         let val = CString::new(features).unwrap();
-        llvm::AddFunctionAttrStringValue(
+        to_add.push(llvm::CreateAttrStringValue(cx.llcx, cstr!("target-features"), &val));
-            llfn,
-            llvm::AttributePlace::Function,
-            cstr!("target-features"),
-            &val,
-        );
     }
+
+    attributes::remove_from_llfn(llfn, Function, &to_remove);
+    attributes::apply_to_llfn(llfn, Function, &to_add);
 }
 
 fn wasm_import_module(tcx: TyCtxt<'_>, id: DefId) -> Option<CString> {

compiler/rustc_codegen_llvm/src/base.rs

@@ -95,7 +95,8 @@ pub fn compile_codegen_unit(tcx: TyCtxt<'_>, cgu_name: Symbol) -> (ModuleCodegen
             // If this codegen unit contains the main function, also create the
             // wrapper here
             if let Some(entry) = maybe_create_entry_wrapper::<Builder<'_, '_, '_>>(&cx) {
-                attributes::sanitize(&cx, SanitizerSet::empty(), entry);
+                let attrs = attributes::sanitize_attrs(&cx, SanitizerSet::empty());
+                attributes::apply_to_llfn(entry, llvm::AttributePlace::Function, &attrs);
             }
 
             // Run replace-all-uses-with for statics that need it

compiler/rustc_codegen_llvm/src/builder.rs

@@ -1,3 +1,4 @@
+use crate::attributes;
 use crate::common::Funclet;
 use crate::context::CodegenCx;
 use crate::llvm::{self, BasicBlock, False};
@@ -22,6 +23,7 @@ use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_span::Span;
 use rustc_target::abi::{self, call::FnAbi, Align, Size, WrappingRange};
 use rustc_target::spec::{HasTargetSpec, Target};
+use smallvec::SmallVec;
 use std::borrow::Cow;
 use std::ffi::CStr;
 use std::iter;
@@ -1174,14 +1176,18 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
     }
 
     fn apply_attrs_to_cleanup_callsite(&mut self, llret: &'ll Value) {
+        let mut attrs = SmallVec::<[_; 2]>::new();
+
         // Cleanup is always the cold path.
-        llvm::Attribute::Cold.apply_callsite(llvm::AttributePlace::Function, llret);
+        attrs.push(llvm::AttributeKind::Cold.create_attr(self.llcx));
 
         // In LLVM versions with deferred inlining (currently, system LLVM < 14),
         // inlining drop glue can lead to exponential size blowup, see #41696 and #92110.
         if !llvm_util::is_rust_llvm() && llvm_util::get_version() < (14, 0, 0) {
-            llvm::Attribute::NoInline.apply_callsite(llvm::AttributePlace::Function, llret);
+            attrs.push(llvm::AttributeKind::NoInline.create_attr(self.llcx));
         }
+
+        attributes::apply_to_callsite(llret, llvm::AttributePlace::Function, &attrs);
     }
 }
 

compiler/rustc_codegen_llvm/src/context.rs

@@ -520,7 +520,8 @@ impl<'ll, 'tcx> MiscMethods<'tcx> for CodegenCx<'ll, 'tcx> {
                 } else {
                     let fty = self.type_variadic_func(&[], self.type_i32());
                     let llfn = self.declare_cfn(name, llvm::UnnamedAddr::Global, fty);
-                    attributes::apply_target_cpu_attr(self, llfn);
+                    let target_cpu = attributes::target_cpu_attr(self);
+                    attributes::apply_to_llfn(llfn, llvm::AttributePlace::Function, &[target_cpu]);
                     llfn
                 }
             }
@@ -550,12 +551,16 @@ impl<'ll, 'tcx> MiscMethods<'tcx> for CodegenCx<'ll, 'tcx> {
     }
 
     fn set_frame_pointer_type(&self, llfn: &'ll Value) {
-        attributes::set_frame_pointer_type(self, llfn)
+        if let Some(attr) = attributes::frame_pointer_type_attr(self) {
+            attributes::apply_to_llfn(llfn, llvm::AttributePlace::Function, &[attr]);
+        }
     }
 
     fn apply_target_cpu_attr(&self, llfn: &'ll Value) {
-        attributes::apply_target_cpu_attr(self, llfn);
+        let mut attrs = SmallVec::<[_; 2]>::new();
-        attributes::apply_tune_cpu_attr(self, llfn);
+        attrs.push(attributes::target_cpu_attr(self));
+        attrs.extend(attributes::tune_cpu_attr(self));
+        attributes::apply_to_llfn(llfn, llvm::AttributePlace::Function, &attrs);
     }
 
     fn create_used_variable(&self) {

compiler/rustc_codegen_llvm/src/declare.rs

@@ -18,8 +18,8 @@ use crate::llvm;
 use crate::llvm::AttributePlace::Function;
 use crate::type_::Type;
 use crate::value::Value;
-use rustc_codegen_ssa::traits::*;
 use rustc_middle::ty::Ty;
+use smallvec::SmallVec;
 use tracing::debug;
 
 /// Declare a function.
@@ -41,12 +41,21 @@ fn declare_raw_fn<'ll>(
     llvm::SetFunctionCallConv(llfn, callconv);
     llvm::SetUnnamedAddress(llfn, unnamed);
 
+    let mut attrs_to_remove = SmallVec::<[_; 4]>::new();
+    let mut attrs_to_add = SmallVec::<[_; 4]>::new();
+
     if cx.tcx.sess.opts.cg.no_redzone.unwrap_or(cx.tcx.sess.target.disable_redzone) {
-        llvm::Attribute::NoRedZone.apply_llfn(Function, llfn);
+        attrs_to_add.push(llvm::AttributeKind::NoRedZone.create_attr(cx.llcx));
     }
 
-    attributes::default_optimisation_attrs(cx.tcx.sess, llfn);
+    let (to_remove, to_add) = attributes::default_optimisation_attrs(cx);
-    attributes::non_lazy_bind(cx.sess(), llfn);
+    attrs_to_remove.extend(to_remove);
+    attrs_to_add.extend(to_add);
+
+    attrs_to_add.extend(attributes::non_lazy_bind_attr(cx));
+
+    attributes::remove_from_llfn(llfn, Function, &attrs_to_remove);
+    attributes::apply_to_llfn(llfn, Function, &attrs_to_add);
 
     llfn
 }

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -155,7 +155,7 @@ pub enum DLLStorageClass {
 /// though it is not ABI compatible (since it's a C++ enum)
 #[repr(C)]
 #[derive(Copy, Clone, Debug)]
-pub enum Attribute {
+pub enum AttributeKind {
     AlwaysInline = 0,
     ByVal = 1,
     Cold = 2,
@@ -643,6 +643,9 @@ extern "C" {
 extern "C" {
     pub type ConstantInt;
 }
+extern "C" {
+    pub type Attribute;
+}
 extern "C" {
     pub type Metadata;
 }
@@ -1169,6 +1172,21 @@ extern "C" {
     ) -> Option<&Value>;
     pub fn LLVMSetTailCall(CallInst: &Value, IsTailCall: Bool);
 
+    // Operations on attributes
+    pub fn LLVMRustCreateAttrNoValue(C: &Context, attr: AttributeKind) -> &Attribute;
+    pub fn LLVMRustCreateAttrString(C: &Context, Name: *const c_char) -> &Attribute;
+    pub fn LLVMRustCreateAttrStringValue(
+        C: &Context,
+        Name: *const c_char,
+        Value: *const c_char,
+    ) -> &Attribute;
+    pub fn LLVMRustCreateAlignmentAttr(C: &Context, bytes: u64) -> &Attribute;
+    pub fn LLVMRustCreateDereferenceableAttr(C: &Context, bytes: u64) -> &Attribute;
+    pub fn LLVMRustCreateDereferenceableOrNullAttr(C: &Context, bytes: u64) -> &Attribute;
+    pub fn LLVMRustCreateByValAttr<'a>(C: &'a Context, ty: &'a Type) -> &'a Attribute;
+    pub fn LLVMRustCreateStructRetAttr<'a>(C: &'a Context, ty: &'a Type) -> &'a Attribute;
+    pub fn LLVMRustCreateUWTableAttr(C: &Context, async_: bool) -> &Attribute;
+
     // Operations on functions
     pub fn LLVMRustGetOrInsertFunction<'a>(
         M: &'a Module,
@@ -1177,20 +1195,18 @@ extern "C" {
         FunctionTy: &'a Type,
     ) -> &'a Value;
     pub fn LLVMSetFunctionCallConv(Fn: &Value, CC: c_uint);
-    pub fn LLVMRustAddAlignmentAttr(Fn: &Value, index: c_uint, bytes: u32);
+    pub fn LLVMRustAddFunctionAttributes<'a>(
-    pub fn LLVMRustAddDereferenceableAttr(Fn: &Value, index: c_uint, bytes: u64);
+        Fn: &'a Value,
-    pub fn LLVMRustAddDereferenceableOrNullAttr(Fn: &Value, index: c_uint, bytes: u64);
+        index: c_uint,
-    pub fn LLVMRustAddByValAttr(Fn: &Value, index: c_uint, ty: &Type);
+        Attrs: *const &'a Attribute,
-    pub fn LLVMRustAddStructRetAttr(Fn: &Value, index: c_uint, ty: &Type);
+        AttrsLen: size_t,
-    pub fn LLVMRustAddFunctionAttribute(Fn: &Value, index: c_uint, attr: Attribute);
+    );
-    pub fn LLVMRustEmitUWTableAttr(Fn: &Value, async_: bool);
+    pub fn LLVMRustRemoveFunctionAttributes(
-    pub fn LLVMRustAddFunctionAttrStringValue(
         Fn: &Value,
         index: c_uint,
-        Name: *const c_char,
+        Attrs: *const AttributeKind,
-        Value: *const c_char,
+        AttrsLen: size_t,
     );
-    pub fn LLVMRustRemoveFunctionAttributes(Fn: &Value, index: c_uint, attr: Attribute);
 
     // Operations on parameters
     pub fn LLVMIsAArgument(Val: &Value) -> Option<&Value>;
@@ -1211,13 +1227,12 @@ extern "C" {
 
     // Operations on call sites
     pub fn LLVMSetInstructionCallConv(Instr: &Value, CC: c_uint);
-    pub fn LLVMRustAddCallSiteAttribute(Instr: &Value, index: c_uint, attr: Attribute);
+    pub fn LLVMRustAddCallSiteAttributes<'a>(
-    pub fn LLVMRustAddCallSiteAttrString(Instr: &Value, index: c_uint, Name: *const c_char);
+        Instr: &'a Value,
-    pub fn LLVMRustAddAlignmentCallSiteAttr(Instr: &Value, index: c_uint, bytes: u32);
+        index: c_uint,
-    pub fn LLVMRustAddDereferenceableCallSiteAttr(Instr: &Value, index: c_uint, bytes: u64);
+        Attrs: *const &'a Attribute,
-    pub fn LLVMRustAddDereferenceableOrNullCallSiteAttr(Instr: &Value, index: c_uint, bytes: u64);
+        AttrsLen: size_t,
-    pub fn LLVMRustAddByValCallSiteAttr(Instr: &Value, index: c_uint, ty: &Type);
+    );
-    pub fn LLVMRustAddStructRetCallSiteAttr(Instr: &Value, index: c_uint, ty: &Type);
 
     // Operations on load/store instructions (only)
     pub fn LLVMSetVolatile(MemoryAccessInst: &Value, volatile: Bool);

compiler/rustc_codegen_llvm/src/llvm/mod.rs

@@ -31,24 +31,58 @@ impl LLVMRustResult {
     }
 }
 
-pub fn EmitUWTableAttr(llfn: &Value, async_: bool) {
+pub fn AddFunctionAttributes<'ll>(llfn: &'ll Value, idx: AttributePlace, attrs: &[&'ll Attribute]) {
-    unsafe { LLVMRustEmitUWTableAttr(llfn, async_) }
-}
-
-pub fn AddFunctionAttrStringValue(llfn: &Value, idx: AttributePlace, attr: &CStr, value: &CStr) {
     unsafe {
-        LLVMRustAddFunctionAttrStringValue(llfn, idx.as_uint(), attr.as_ptr(), value.as_ptr())
+        LLVMRustAddFunctionAttributes(llfn, idx.as_uint(), attrs.as_ptr(), attrs.len());
     }
 }
 
-pub fn AddFunctionAttrString(llfn: &Value, idx: AttributePlace, attr: &CStr) {
+pub fn RemoveFunctionAttributes(llfn: &Value, idx: AttributePlace, attrs: &[AttributeKind]) {
     unsafe {
-        LLVMRustAddFunctionAttrStringValue(llfn, idx.as_uint(), attr.as_ptr(), std::ptr::null())
+        LLVMRustRemoveFunctionAttributes(llfn, idx.as_uint(), attrs.as_ptr(), attrs.len());
     }
 }
 
-pub fn AddCallSiteAttrString(callsite: &Value, idx: AttributePlace, attr: &CStr) {
+pub fn AddCallSiteAttributes<'ll>(
-    unsafe { LLVMRustAddCallSiteAttrString(callsite, idx.as_uint(), attr.as_ptr()) }
+    callsite: &'ll Value,
+    idx: AttributePlace,
+    attrs: &[&'ll Attribute],
+) {
+    unsafe {
+        LLVMRustAddCallSiteAttributes(callsite, idx.as_uint(), attrs.as_ptr(), attrs.len());
+    }
+}
+
+pub fn CreateAttrStringValue<'ll>(llcx: &'ll Context, attr: &CStr, value: &CStr) -> &'ll Attribute {
+    unsafe { LLVMRustCreateAttrStringValue(llcx, attr.as_ptr(), value.as_ptr()) }
+}
+
+pub fn CreateAttrString<'ll>(llcx: &'ll Context, attr: &CStr) -> &'ll Attribute {
+    unsafe { LLVMRustCreateAttrStringValue(llcx, attr.as_ptr(), std::ptr::null()) }
+}
+
+pub fn CreateAlignmentAttr(llcx: &Context, bytes: u64) -> &Attribute {
+    unsafe { LLVMRustCreateAlignmentAttr(llcx, bytes) }
+}
+
+pub fn CreateDereferenceableAttr(llcx: &Context, bytes: u64) -> &Attribute {
+    unsafe { LLVMRustCreateDereferenceableAttr(llcx, bytes) }
+}
+
+pub fn CreateDereferenceableOrNullAttr(llcx: &Context, bytes: u64) -> &Attribute {
+    unsafe { LLVMRustCreateDereferenceableOrNullAttr(llcx, bytes) }
+}
+
+pub fn CreateByValAttr<'ll>(llcx: &'ll Context, ty: &'ll Type) -> &'ll Attribute {
+    unsafe { LLVMRustCreateByValAttr(llcx, ty) }
+}
+
+pub fn CreateStructRetAttr<'ll>(llcx: &'ll Context, ty: &'ll Type) -> &'ll Attribute {
+    unsafe { LLVMRustCreateStructRetAttr(llcx, ty) }
+}
+
+pub fn CreateUWTableAttr(llcx: &Context, async_: bool) -> &Attribute {
+    unsafe { LLVMRustCreateUWTableAttr(llcx, async_) }
 }
 
 #[derive(Copy, Clone)]
@@ -132,25 +166,10 @@ pub fn set_thread_local_mode(global: &Value, mode: ThreadLocalMode) {
     }
 }
 
-impl Attribute {
+impl AttributeKind {
-    pub fn apply_llfn(&self, idx: AttributePlace, llfn: &Value) {
+    /// Create an LLVM Attribute with no associated value.
-        unsafe { LLVMRustAddFunctionAttribute(llfn, idx.as_uint(), *self) }
+    pub fn create_attr(self, llcx: &Context) -> &Attribute {
-    }
+        unsafe { LLVMRustCreateAttrNoValue(llcx, self) }
-
-    pub fn apply_callsite(&self, idx: AttributePlace, callsite: &Value) {
-        unsafe { LLVMRustAddCallSiteAttribute(callsite, idx.as_uint(), *self) }
-    }
-
-    pub fn unapply_llfn(&self, idx: AttributePlace, llfn: &Value) {
-        unsafe { LLVMRustRemoveFunctionAttributes(llfn, idx.as_uint(), *self) }
-    }
-
-    pub fn toggle_llfn(&self, idx: AttributePlace, llfn: &Value, set: bool) {
-        if set {
-            self.apply_llfn(idx, llfn);
-        } else {
-            self.unapply_llfn(idx, llfn);
-        }
     }
 }
 

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -232,142 +232,103 @@ static Attribute::AttrKind fromRust(LLVMRustAttribute Kind) {
   report_fatal_error("bad AttributeKind");
 }
 
-template<typename T> static inline void AddAttribute(T *t, unsigned Index, Attribute Attr) {
+template<typename T> static inline void AddAttributes(T *t, unsigned Index,
-#if LLVM_VERSION_LT(14, 0)
+                                                      LLVMAttributeRef *Attrs, size_t AttrsLen) {
-  t->addAttribute(Index, Attr);
+  AttributeList PAL = t->getAttributes();
-#else
-  t->addAttributeAtIndex(Index, Attr);
-#endif
-}
-
-extern "C" void LLVMRustAddCallSiteAttribute(LLVMValueRef Instr, unsigned Index,
-                                             LLVMRustAttribute RustAttr) {
-  CallBase *Call = unwrap<CallBase>(Instr);
-  Attribute Attr = Attribute::get(Call->getContext(), fromRust(RustAttr));
-  AddAttribute(Call, Index, Attr);
-}
-
-extern "C" void LLVMRustAddCallSiteAttrString(LLVMValueRef Instr, unsigned Index,
-                                              const char *Name) {
-  CallBase *Call = unwrap<CallBase>(Instr);
-  Attribute Attr = Attribute::get(Call->getContext(), Name);
-  AddAttribute(Call, Index, Attr);
-}
-
-extern "C" void LLVMRustAddAlignmentCallSiteAttr(LLVMValueRef Instr,
-                                                 unsigned Index,
-                                                 uint32_t Bytes) {
-  CallBase *Call = unwrap<CallBase>(Instr);
-  Attribute Attr = Attribute::getWithAlignment(Call->getContext(), Align(Bytes));
-  AddAttribute(Call, Index, Attr);
-}
-
-extern "C" void LLVMRustAddDereferenceableCallSiteAttr(LLVMValueRef Instr,
-                                                       unsigned Index,
-                                                       uint64_t Bytes) {
-  CallBase *Call = unwrap<CallBase>(Instr);
-  Attribute Attr = Attribute::getWithDereferenceableBytes(Call->getContext(), Bytes);
-  AddAttribute(Call, Index, Attr);
-}
-
-extern "C" void LLVMRustAddDereferenceableOrNullCallSiteAttr(LLVMValueRef Instr,
-                                                             unsigned Index,
-                                                             uint64_t Bytes) {
-  CallBase *Call = unwrap<CallBase>(Instr);
-  Attribute Attr = Attribute::getWithDereferenceableOrNullBytes(Call->getContext(), Bytes);
-  AddAttribute(Call, Index, Attr);
-}
-
-extern "C" void LLVMRustAddByValCallSiteAttr(LLVMValueRef Instr, unsigned Index,
-                                             LLVMTypeRef Ty) {
-  CallBase *Call = unwrap<CallBase>(Instr);
-  Attribute Attr = Attribute::getWithByValType(Call->getContext(), unwrap(Ty));
-  AddAttribute(Call, Index, Attr);
-}
-
-extern "C" void LLVMRustAddStructRetCallSiteAttr(LLVMValueRef Instr, unsigned Index,
-                                                 LLVMTypeRef Ty) {
-  CallBase *Call = unwrap<CallBase>(Instr);
-  Attribute Attr = Attribute::getWithStructRetType(Call->getContext(), unwrap(Ty));
-  AddAttribute(Call, Index, Attr);
-}
-
-extern "C" void LLVMRustAddFunctionAttribute(LLVMValueRef Fn, unsigned Index,
-                                             LLVMRustAttribute RustAttr) {
-  Function *A = unwrap<Function>(Fn);
-  Attribute Attr = Attribute::get(A->getContext(), fromRust(RustAttr));
-  AddAttribute(A, Index, Attr);
-}
-
-extern "C" void LLVMRustAddAlignmentAttr(LLVMValueRef Fn,
-                                         unsigned Index,
-                                         uint32_t Bytes) {
-  Function *A = unwrap<Function>(Fn);
-  AddAttribute(A, Index, Attribute::getWithAlignment(
-      A->getContext(), llvm::Align(Bytes)));
-}
-
-extern "C" void LLVMRustAddDereferenceableAttr(LLVMValueRef Fn, unsigned Index,
-                                               uint64_t Bytes) {
-  Function *A = unwrap<Function>(Fn);
-  AddAttribute(A, Index, Attribute::getWithDereferenceableBytes(A->getContext(),
-                                                                Bytes));
-}
-
-extern "C" void LLVMRustAddDereferenceableOrNullAttr(LLVMValueRef Fn,
-                                                     unsigned Index,
-                                                     uint64_t Bytes) {
-  Function *A = unwrap<Function>(Fn);
-  AddAttribute(A, Index, Attribute::getWithDereferenceableOrNullBytes(
-      A->getContext(), Bytes));
-}
-
-extern "C" void LLVMRustAddByValAttr(LLVMValueRef Fn, unsigned Index,
-                                     LLVMTypeRef Ty) {
-  Function *F = unwrap<Function>(Fn);
-  Attribute Attr = Attribute::getWithByValType(F->getContext(), unwrap(Ty));
-  AddAttribute(F, Index, Attr);
-}
-
-extern "C" void LLVMRustAddStructRetAttr(LLVMValueRef Fn, unsigned Index,
-                                         LLVMTypeRef Ty) {
-  Function *F = unwrap<Function>(Fn);
-  Attribute Attr = Attribute::getWithStructRetType(F->getContext(), unwrap(Ty));
-  AddAttribute(F, Index, Attr);
-}
-
-extern "C" void LLVMRustEmitUWTableAttr(LLVMValueRef Fn, bool Async) {
-  Function *F = unwrap<Function>(Fn);
-#if LLVM_VERSION_LT(15, 0)
-  Attribute Attr = Attribute::get(F->getContext(), Attribute::UWTable);
-#else
-  Attribute Attr = Attribute::getWithUWTableKind(
-      F->getContext(), Async ? UWTableKind::Async : UWTableKind::Sync);
-#endif
-  AddAttribute(F, AttributeList::AttrIndex::FunctionIndex, Attr);
-}
-
-extern "C" void LLVMRustAddFunctionAttrStringValue(LLVMValueRef Fn,
-                                                   unsigned Index,
-                                                   const char *Name,
-                                                   const char *Value) {
-  Function *F = unwrap<Function>(Fn);
-  AddAttribute(F, Index, Attribute::get(
-      F->getContext(), StringRef(Name), StringRef(Value)));
-}
-
-extern "C" void LLVMRustRemoveFunctionAttributes(LLVMValueRef Fn,
-                                                 unsigned Index,
-                                                 LLVMRustAttribute RustAttr) {
-  Function *F = unwrap<Function>(Fn);
-  AttributeList PAL = F->getAttributes();
   AttributeList PALNew;
 #if LLVM_VERSION_LT(14, 0)
-  PALNew = PAL.removeAttribute(F->getContext(), Index, fromRust(RustAttr));
+  AttrBuilder B;
+  for (LLVMAttributeRef Attr : makeArrayRef(Attrs, AttrsLen))
+    B.addAttribute(unwrap(Attr));
+  PALNew = PAL.addAttributes(t->getContext(), Index, B);
 #else
-  PALNew = PAL.removeAttributeAtIndex(F->getContext(), Index, fromRust(RustAttr));
+  AttrBuilder B(t->getContext());
+  for (LLVMAttributeRef Attr : makeArrayRef(Attrs, AttrsLen))
+    B.addAttribute(unwrap(Attr));
+  PALNew = PAL.addAttributesAtIndex(t->getContext(), Index, B);
+#endif
+  t->setAttributes(PALNew);
+}
+
+template<typename T> static inline void RemoveAttributes(T *t, unsigned Index,
+                                                         LLVMRustAttribute *RustAttrs,
+                                                         size_t RustAttrsLen) {
+  AttributeList PAL = t->getAttributes();
+  AttributeList PALNew;
+#if LLVM_VERSION_LT(14, 0)
+  AttrBuilder B;
+  for (LLVMRustAttribute RustAttr : makeArrayRef(RustAttrs, RustAttrsLen))
+    B.addAttribute(fromRust(RustAttr));
+  PALNew = PAL.removeAttributes(t->getContext(), Index, B);
+#else
+  AttributeMask Mask;
+  for (LLVMRustAttribute RustAttr : makeArrayRef(RustAttrs, RustAttrsLen))
+    Mask.addAttribute(fromRust(RustAttr));
+  PALNew = PAL.removeAttributesAtIndex(t->getContext(), Index, Mask);
+#endif
+  t->setAttributes(PALNew);
+}
+
+extern "C" void LLVMRustAddFunctionAttributes(LLVMValueRef Fn, unsigned Index,
+                                              LLVMAttributeRef *Attrs, size_t AttrsLen) {
+  Function *F = unwrap<Function>(Fn);
+  AddAttributes(F, Index, Attrs, AttrsLen);
+}
+
+extern "C" void LLVMRustRemoveFunctionAttributes(LLVMValueRef Fn, unsigned Index,
+                                                 LLVMRustAttribute *RustAttrs,
+                                                 size_t RustAttrsLen) {
+  Function *F = unwrap<Function>(Fn);
+  RemoveAttributes(F, Index, RustAttrs, RustAttrsLen);
+}
+
+extern "C" void LLVMRustAddCallSiteAttributes(LLVMValueRef Instr, unsigned Index,
+                                              LLVMAttributeRef *Attrs, size_t AttrsLen) {
+  CallBase *Call = unwrap<CallBase>(Instr);
+  AddAttributes(Call, Index, Attrs, AttrsLen);
+}
+
+extern "C" LLVMAttributeRef LLVMRustCreateAttrNoValue(LLVMContextRef C,
+                                                      LLVMRustAttribute RustAttr) {
+  return wrap(Attribute::get(*unwrap(C), fromRust(RustAttr)));
+}
+
+extern "C" LLVMAttributeRef LLVMRustCreateAttrStringValue(LLVMContextRef C,
+                                                          const char *Name,
+                                                          const char *Value) {
+  return wrap(Attribute::get(*unwrap(C), StringRef(Name), StringRef(Value)));
+}
+
+extern "C" LLVMAttributeRef LLVMRustCreateAlignmentAttr(LLVMContextRef C,
+                                                        uint64_t Bytes) {
+  return wrap(Attribute::getWithAlignment(*unwrap(C), llvm::Align(Bytes)));
+}
+
+extern "C" LLVMAttributeRef LLVMRustCreateDereferenceableAttr(LLVMContextRef C,
+                                                              uint64_t Bytes) {
+  return wrap(Attribute::getWithDereferenceableBytes(*unwrap(C), Bytes));
+}
+
+extern "C" LLVMAttributeRef LLVMRustCreateDereferenceableOrNullAttr(LLVMContextRef C,
+                                                                    uint64_t Bytes) {
+  return wrap(Attribute::getWithDereferenceableOrNullBytes(*unwrap(C), Bytes));
+}
+
+extern "C" LLVMAttributeRef LLVMRustCreateByValAttr(LLVMContextRef C, LLVMTypeRef Ty) {
+  return wrap(Attribute::getWithByValType(*unwrap(C), unwrap(Ty)));
+}
+
+extern "C" LLVMAttributeRef LLVMRustCreateStructRetAttr(LLVMContextRef C, LLVMTypeRef Ty) {
+  return wrap(Attribute::getWithStructRetType(*unwrap(C), unwrap(Ty)));
+}
+
+extern "C" LLVMAttributeRef LLVMRustCreateUWTableAttr(LLVMContextRef C, bool Async) {
+#if LLVM_VERSION_LT(15, 0)
+  return wrap(Attribute::get(*unwrap(C), Attribute::UWTable));
+#else
+  return wrap(Attribute::getWithUWTableKind(
+      *unwrap(C), Async ? UWTableKind::Async : UWTableKind::Sync));
 #endif
-  F->setAttributes(PALNew);
 }
 
 // Enable a fast-math flag