3 files changed, 32 insertions, 28 deletions
diff --git a/compiler/rustc_codegen_llvm/src/intrinsic.rs b/compiler/rustc_codegen_llvm/src/intrinsic.rs
index c38c5d4c644..cabcfc9b42b 100644
--- a/compiler/rustc_codegen_llvm/src/intrinsic.rs
+++ b/compiler/rustc_codegen_llvm/src/intrinsic.rs
@@ -340,6 +340,37 @@ impl<'ll, 'tcx> IntrinsicCallBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> {
                     self.const_i32(cache_type),
                 ])
             }
+            sym::carrying_mul_add => {
+                let (size, signed) = fn_args.type_at(0).int_size_and_signed(self.tcx);
+
+                let wide_llty = self.type_ix(size.bits() * 2);
+                let args = args.as_array().unwrap();
+                let [a, b, c, d] = args.map(|a| self.intcast(a.immediate(), wide_llty, signed));
+
+                let wide = if signed {
+                    let prod = self.unchecked_smul(a, b);
+                    let acc = self.unchecked_sadd(prod, c);
+                    self.unchecked_sadd(acc, d)
+                } else {
+                    let prod = self.unchecked_umul(a, b);
+                    let acc = self.unchecked_uadd(prod, c);
+                    self.unchecked_uadd(acc, d)
+                };
+
+                let narrow_llty = self.type_ix(size.bits());
+                let low = self.trunc(wide, narrow_llty);
+                let bits_const = self.const_uint(wide_llty, size.bits());
+                // No need for ashr when signed; LLVM changes it to lshr anyway.
+                let high = self.lshr(wide, bits_const);
+                // FIXME: could be `trunc nuw`, even for signed.
+                let high = self.trunc(high, narrow_llty);
+
+                let pair_llty = self.type_struct(&[narrow_llty, narrow_llty], false);
+                let pair = self.const_poison(pair_llty);
+                let pair = self.insert_value(pair, low, 0);
+                let pair = self.insert_value(pair, high, 1);
+                pair
+            }
             sym::ctlz
             | sym::ctlz_nonzero
             | sym::cttz
diff --git a/compiler/rustc_codegen_llvm/src/lib.rs b/compiler/rustc_codegen_llvm/src/lib.rs
index 0de0c6a7a89..dca7738daf7 100644
--- a/compiler/rustc_codegen_llvm/src/lib.rs
+++ b/compiler/rustc_codegen_llvm/src/lib.rs
@@ -17,6 +17,7 @@
 #![feature(iter_intersperse)]
 #![feature(let_chains)]
 #![feature(rustdoc_internals)]
+#![feature(slice_as_array)]
 #![feature(try_blocks)]
 #![warn(unreachable_pub)]
 // tidy-alphabetical-end
diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
index d62632d1431..9a2bfd95562 100644
--- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
@@ -56,25 +56,6 @@ pub enum LLVMRustResult {
     Failure,
 }
 
-// Rust version of the C struct with the same name in rustc_llvm/llvm-wrapper/RustWrapper.cpp.
-#[repr(C)]
-pub struct LLVMRustCOFFShortExport {
-    pub name: *const c_char,
-    pub ordinal_present: bool,
-    /// value of `ordinal` only important when `ordinal_present` is true
-    pub ordinal: u16,
-}
-
-impl LLVMRustCOFFShortExport {
-    pub fn new(name: *const c_char, ordinal: Option<u16>) -> LLVMRustCOFFShortExport {
-        LLVMRustCOFFShortExport {
-            name,
-            ordinal_present: ordinal.is_some(),
-            ordinal: ordinal.unwrap_or(0),
-        }
-    }
-}
-
 /// Translation of LLVM's MachineTypes enum, defined in llvm\include\llvm\BinaryFormat\COFF.h.
 ///
 /// We include only architectures supported on Windows.
@@ -2347,15 +2328,6 @@ unsafe extern "C" {
     ) -> &'a mut RustArchiveMember<'a>;
     pub fn LLVMRustArchiveMemberFree<'a>(Member: &'a mut RustArchiveMember<'a>);
 
-    pub fn LLVMRustWriteImportLibrary(
-        ImportName: *const c_char,
-        Path: *const c_char,
-        Exports: *const LLVMRustCOFFShortExport,
-        NumExports: usize,
-        Machine: u16,
-        MinGW: bool,
-    ) -> LLVMRustResult;
-
     pub fn LLVMRustSetDataLayoutFromTargetMachine<'a>(M: &'a Module, TM: &'a TargetMachine);
 
     pub fn LLVMRustPositionBuilderAtStart<'a>(B: &Builder<'a>, BB: &'a BasicBlock);