1 use crate::common::Funclet;
2 use crate::context::CodegenCx;
3 use crate::llvm::{self, BasicBlock, False};
4 use crate::llvm::{AtomicOrdering, AtomicRmwBinOp, SynchronizationScope};
6 use crate::type_::Type;
7 use crate::type_of::LayoutLlvmExt;
8 use crate::value::Value;
10 use libc::{c_char, c_uint};
11 use rustc_codegen_ssa::common::{IntPredicate, RealPredicate, TypeKind};
12 use rustc_codegen_ssa::mir::operand::{OperandRef, OperandValue};
13 use rustc_codegen_ssa::mir::place::PlaceRef;
14 use rustc_codegen_ssa::traits::*;
15 use rustc_codegen_ssa::MemFlags;
16 use rustc_data_structures::small_c_str::SmallCStr;
17 use rustc_hir::def_id::DefId;
18 use rustc_middle::ty::layout::{
19 FnAbiError, FnAbiOfHelpers, FnAbiRequest, LayoutError, LayoutOfHelpers, TyAndLayout,
21 use rustc_middle::ty::{self, Ty, TyCtxt};
23 use rustc_target::abi::{self, call::FnAbi, Align, Size, WrappingRange};
24 use rustc_target::spec::{HasTargetSpec, Target};
32 // All Builders must have an llfn associated with them
34 pub struct Builder<'a, 'll, 'tcx> {
35 pub llbuilder: &'ll mut llvm::Builder<'ll>,
36 pub cx: &'a CodegenCx<'ll, 'tcx>,
39 impl Drop for Builder<'_, '_, '_> {
42 llvm::LLVMDisposeBuilder(&mut *(self.llbuilder as *mut _));
47 // FIXME(eddyb) use a checked constructor when they become `const fn`.
48 const EMPTY_C_STR: &CStr = unsafe { CStr::from_bytes_with_nul_unchecked(b"\0") };
50 /// Empty string, to be used where LLVM expects an instruction name, indicating
51 /// that the instruction is to be left unnamed (i.e. numbered, in textual IR).
52 // FIXME(eddyb) pass `&CStr` directly to FFI once it's a thin pointer.
53 const UNNAMED: *const c_char = EMPTY_C_STR.as_ptr();
55 impl<'ll, 'tcx> BackendTypes for Builder<'_, 'll, 'tcx> {
56 type Value = <CodegenCx<'ll, 'tcx> as BackendTypes>::Value;
57 type Function = <CodegenCx<'ll, 'tcx> as BackendTypes>::Function;
58 type BasicBlock = <CodegenCx<'ll, 'tcx> as BackendTypes>::BasicBlock;
59 type Type = <CodegenCx<'ll, 'tcx> as BackendTypes>::Type;
60 type Funclet = <CodegenCx<'ll, 'tcx> as BackendTypes>::Funclet;
62 type DIScope = <CodegenCx<'ll, 'tcx> as BackendTypes>::DIScope;
63 type DILocation = <CodegenCx<'ll, 'tcx> as BackendTypes>::DILocation;
64 type DIVariable = <CodegenCx<'ll, 'tcx> as BackendTypes>::DIVariable;
67 impl abi::HasDataLayout for Builder<'_, '_, '_> {
68 fn data_layout(&self) -> &abi::TargetDataLayout {
73 impl<'tcx> ty::layout::HasTyCtxt<'tcx> for Builder<'_, '_, 'tcx> {
75 fn tcx(&self) -> TyCtxt<'tcx> {
80 impl<'tcx> ty::layout::HasParamEnv<'tcx> for Builder<'_, '_, 'tcx> {
81 fn param_env(&self) -> ty::ParamEnv<'tcx> {
86 impl HasTargetSpec for Builder<'_, '_, '_> {
88 fn target_spec(&self) -> &Target {
93 impl<'tcx> LayoutOfHelpers<'tcx> for Builder<'_, '_, 'tcx> {
94 type LayoutOfResult = TyAndLayout<'tcx>;
97 fn handle_layout_err(&self, err: LayoutError<'tcx>, span: Span, ty: Ty<'tcx>) -> ! {
98 self.cx.handle_layout_err(err, span, ty)
102 impl<'tcx> FnAbiOfHelpers<'tcx> for Builder<'_, '_, 'tcx> {
103 type FnAbiOfResult = &'tcx FnAbi<'tcx, Ty<'tcx>>;
106 fn handle_fn_abi_err(
108 err: FnAbiError<'tcx>,
110 fn_abi_request: FnAbiRequest<'tcx>,
112 self.cx.handle_fn_abi_err(err, span, fn_abi_request)
116 impl<'ll, 'tcx> Deref for Builder<'_, 'll, 'tcx> {
117 type Target = CodegenCx<'ll, 'tcx>;
120 fn deref(&self) -> &Self::Target {
125 impl<'ll, 'tcx> HasCodegen<'tcx> for Builder<'_, 'll, 'tcx> {
126 type CodegenCx = CodegenCx<'ll, 'tcx>;
129 macro_rules! builder_methods_for_value_instructions {
130 ($($name:ident($($arg:ident),*) => $llvm_capi:ident),+ $(,)?) => {
131 $(fn $name(&mut self, $($arg: &'ll Value),*) -> &'ll Value {
133 llvm::$llvm_capi(self.llbuilder, $($arg,)* UNNAMED)
139 impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
140 fn build(cx: &'a CodegenCx<'ll, 'tcx>, llbb: &'ll BasicBlock) -> Self {
141 let bx = Builder::with_cx(cx);
143 llvm::LLVMPositionBuilderAtEnd(bx.llbuilder, llbb);
148 fn cx(&self) -> &CodegenCx<'ll, 'tcx> {
152 fn llbb(&self) -> &'ll BasicBlock {
153 unsafe { llvm::LLVMGetInsertBlock(self.llbuilder) }
156 fn set_span(&mut self, _span: Span) {}
158 fn append_block(cx: &'a CodegenCx<'ll, 'tcx>, llfn: &'ll Value, name: &str) -> &'ll BasicBlock {
160 let name = SmallCStr::new(name);
161 llvm::LLVMAppendBasicBlockInContext(cx.llcx, llfn, name.as_ptr())
165 fn append_sibling_block(&mut self, name: &str) -> &'ll BasicBlock {
166 Self::append_block(self.cx, self.llfn(), name)
169 fn build_sibling_block(&mut self, name: &str) -> Self {
170 let llbb = self.append_sibling_block(name);
171 Self::build(self.cx, llbb)
174 fn ret_void(&mut self) {
176 llvm::LLVMBuildRetVoid(self.llbuilder);
180 fn ret(&mut self, v: &'ll Value) {
182 llvm::LLVMBuildRet(self.llbuilder, v);
186 fn br(&mut self, dest: &'ll BasicBlock) {
188 llvm::LLVMBuildBr(self.llbuilder, dest);
195 then_llbb: &'ll BasicBlock,
196 else_llbb: &'ll BasicBlock,
199 llvm::LLVMBuildCondBr(self.llbuilder, cond, then_llbb, else_llbb);
206 else_llbb: &'ll BasicBlock,
207 cases: impl ExactSizeIterator<Item = (u128, &'ll BasicBlock)>,
210 unsafe { llvm::LLVMBuildSwitch(self.llbuilder, v, else_llbb, cases.len() as c_uint) };
211 for (on_val, dest) in cases {
212 let on_val = self.const_uint_big(self.val_ty(v), on_val);
213 unsafe { llvm::LLVMAddCase(switch, on_val, dest) }
222 then: &'ll BasicBlock,
223 catch: &'ll BasicBlock,
224 funclet: Option<&Funclet<'ll>>,
226 debug!("invoke {:?} with args ({:?})", llfn, args);
228 let args = self.check_call("invoke", llty, llfn, args);
229 let bundle = funclet.map(|funclet| funclet.bundle());
230 let bundle = bundle.as_ref().map(|b| &*b.raw);
233 llvm::LLVMRustBuildInvoke(
238 args.len() as c_uint,
247 fn unreachable(&mut self) {
249 llvm::LLVMBuildUnreachable(self.llbuilder);
253 builder_methods_for_value_instructions! {
254 add(a, b) => LLVMBuildAdd,
255 fadd(a, b) => LLVMBuildFAdd,
256 sub(a, b) => LLVMBuildSub,
257 fsub(a, b) => LLVMBuildFSub,
258 mul(a, b) => LLVMBuildMul,
259 fmul(a, b) => LLVMBuildFMul,
260 udiv(a, b) => LLVMBuildUDiv,
261 exactudiv(a, b) => LLVMBuildExactUDiv,
262 sdiv(a, b) => LLVMBuildSDiv,
263 exactsdiv(a, b) => LLVMBuildExactSDiv,
264 fdiv(a, b) => LLVMBuildFDiv,
265 urem(a, b) => LLVMBuildURem,
266 srem(a, b) => LLVMBuildSRem,
267 frem(a, b) => LLVMBuildFRem,
268 shl(a, b) => LLVMBuildShl,
269 lshr(a, b) => LLVMBuildLShr,
270 ashr(a, b) => LLVMBuildAShr,
271 and(a, b) => LLVMBuildAnd,
272 or(a, b) => LLVMBuildOr,
273 xor(a, b) => LLVMBuildXor,
274 neg(x) => LLVMBuildNeg,
275 fneg(x) => LLVMBuildFNeg,
276 not(x) => LLVMBuildNot,
277 unchecked_sadd(x, y) => LLVMBuildNSWAdd,
278 unchecked_uadd(x, y) => LLVMBuildNUWAdd,
279 unchecked_ssub(x, y) => LLVMBuildNSWSub,
280 unchecked_usub(x, y) => LLVMBuildNUWSub,
281 unchecked_smul(x, y) => LLVMBuildNSWMul,
282 unchecked_umul(x, y) => LLVMBuildNUWMul,
285 fn fadd_fast(&mut self, lhs: &'ll Value, rhs: &'ll Value) -> &'ll Value {
287 let instr = llvm::LLVMBuildFAdd(self.llbuilder, lhs, rhs, UNNAMED);
288 llvm::LLVMRustSetFastMath(instr);
293 fn fsub_fast(&mut self, lhs: &'ll Value, rhs: &'ll Value) -> &'ll Value {
295 let instr = llvm::LLVMBuildFSub(self.llbuilder, lhs, rhs, UNNAMED);
296 llvm::LLVMRustSetFastMath(instr);
301 fn fmul_fast(&mut self, lhs: &'ll Value, rhs: &'ll Value) -> &'ll Value {
303 let instr = llvm::LLVMBuildFMul(self.llbuilder, lhs, rhs, UNNAMED);
304 llvm::LLVMRustSetFastMath(instr);
309 fn fdiv_fast(&mut self, lhs: &'ll Value, rhs: &'ll Value) -> &'ll Value {
311 let instr = llvm::LLVMBuildFDiv(self.llbuilder, lhs, rhs, UNNAMED);
312 llvm::LLVMRustSetFastMath(instr);
317 fn frem_fast(&mut self, lhs: &'ll Value, rhs: &'ll Value) -> &'ll Value {
319 let instr = llvm::LLVMBuildFRem(self.llbuilder, lhs, rhs, UNNAMED);
320 llvm::LLVMRustSetFastMath(instr);
331 ) -> (Self::Value, Self::Value) {
332 use rustc_middle::ty::{Int, Uint};
333 use rustc_middle::ty::{IntTy::*, UintTy::*};
335 let new_kind = match ty.kind() {
336 Int(t @ Isize) => Int(t.normalize(self.tcx.sess.target.pointer_width)),
337 Uint(t @ Usize) => Uint(t.normalize(self.tcx.sess.target.pointer_width)),
338 t @ (Uint(_) | Int(_)) => t.clone(),
339 _ => panic!("tried to get overflow intrinsic for op applied to non-int type"),
342 let name = match oop {
343 OverflowOp::Add => match new_kind {
344 Int(I8) => "llvm.sadd.with.overflow.i8",
345 Int(I16) => "llvm.sadd.with.overflow.i16",
346 Int(I32) => "llvm.sadd.with.overflow.i32",
347 Int(I64) => "llvm.sadd.with.overflow.i64",
348 Int(I128) => "llvm.sadd.with.overflow.i128",
350 Uint(U8) => "llvm.uadd.with.overflow.i8",
351 Uint(U16) => "llvm.uadd.with.overflow.i16",
352 Uint(U32) => "llvm.uadd.with.overflow.i32",
353 Uint(U64) => "llvm.uadd.with.overflow.i64",
354 Uint(U128) => "llvm.uadd.with.overflow.i128",
358 OverflowOp::Sub => match new_kind {
359 Int(I8) => "llvm.ssub.with.overflow.i8",
360 Int(I16) => "llvm.ssub.with.overflow.i16",
361 Int(I32) => "llvm.ssub.with.overflow.i32",
362 Int(I64) => "llvm.ssub.with.overflow.i64",
363 Int(I128) => "llvm.ssub.with.overflow.i128",
365 Uint(U8) => "llvm.usub.with.overflow.i8",
366 Uint(U16) => "llvm.usub.with.overflow.i16",
367 Uint(U32) => "llvm.usub.with.overflow.i32",
368 Uint(U64) => "llvm.usub.with.overflow.i64",
369 Uint(U128) => "llvm.usub.with.overflow.i128",
373 OverflowOp::Mul => match new_kind {
374 Int(I8) => "llvm.smul.with.overflow.i8",
375 Int(I16) => "llvm.smul.with.overflow.i16",
376 Int(I32) => "llvm.smul.with.overflow.i32",
377 Int(I64) => "llvm.smul.with.overflow.i64",
378 Int(I128) => "llvm.smul.with.overflow.i128",
380 Uint(U8) => "llvm.umul.with.overflow.i8",
381 Uint(U16) => "llvm.umul.with.overflow.i16",
382 Uint(U32) => "llvm.umul.with.overflow.i32",
383 Uint(U64) => "llvm.umul.with.overflow.i64",
384 Uint(U128) => "llvm.umul.with.overflow.i128",
390 let res = self.call_intrinsic(name, &[lhs, rhs]);
391 (self.extract_value(res, 0), self.extract_value(res, 1))
394 fn from_immediate(&mut self, val: Self::Value) -> Self::Value {
395 if self.cx().val_ty(val) == self.cx().type_i1() {
396 self.zext(val, self.cx().type_i8())
401 fn to_immediate_scalar(&mut self, val: Self::Value, scalar: abi::Scalar) -> Self::Value {
402 if scalar.is_bool() {
403 return self.trunc(val, self.cx().type_i1());
408 fn alloca(&mut self, ty: &'ll Type, align: Align) -> &'ll Value {
409 let mut bx = Builder::with_cx(self.cx);
410 bx.position_at_start(unsafe { llvm::LLVMGetFirstBasicBlock(self.llfn()) });
411 bx.dynamic_alloca(ty, align)
414 fn dynamic_alloca(&mut self, ty: &'ll Type, align: Align) -> &'ll Value {
416 let alloca = llvm::LLVMBuildAlloca(self.llbuilder, ty, UNNAMED);
417 llvm::LLVMSetAlignment(alloca, align.bytes() as c_uint);
422 fn array_alloca(&mut self, ty: &'ll Type, len: &'ll Value, align: Align) -> &'ll Value {
424 let alloca = llvm::LLVMBuildArrayAlloca(self.llbuilder, ty, len, UNNAMED);
425 llvm::LLVMSetAlignment(alloca, align.bytes() as c_uint);
430 fn load(&mut self, ty: &'ll Type, ptr: &'ll Value, align: Align) -> &'ll Value {
432 let load = llvm::LLVMBuildLoad2(self.llbuilder, ty, ptr, UNNAMED);
433 llvm::LLVMSetAlignment(load, align.bytes() as c_uint);
438 fn volatile_load(&mut self, ty: &'ll Type, ptr: &'ll Value) -> &'ll Value {
440 let load = llvm::LLVMBuildLoad2(self.llbuilder, ty, ptr, UNNAMED);
441 llvm::LLVMSetVolatile(load, llvm::True);
450 order: rustc_codegen_ssa::common::AtomicOrdering,
454 let load = llvm::LLVMRustBuildAtomicLoad(
459 AtomicOrdering::from_generic(order),
461 // LLVM requires the alignment of atomic loads to be at least the size of the type.
462 llvm::LLVMSetAlignment(load, size.bytes() as c_uint);
467 fn load_operand(&mut self, place: PlaceRef<'tcx, &'ll Value>) -> OperandRef<'tcx, &'ll Value> {
468 debug!("PlaceRef::load: {:?}", place);
470 assert_eq!(place.llextra.is_some(), place.layout.is_unsized());
472 if place.layout.is_zst() {
473 return OperandRef::new_zst(self, place.layout);
476 fn scalar_load_metadata<'a, 'll, 'tcx>(
477 bx: &mut Builder<'a, 'll, 'tcx>,
483 if !scalar.is_always_valid(bx) {
484 bx.range_metadata(load, scalar.valid_range);
487 abi::Pointer if !scalar.valid_range.contains(0) => {
488 bx.nonnull_metadata(load);
494 let val = if let Some(llextra) = place.llextra {
495 OperandValue::Ref(place.llval, Some(llextra), place.align)
496 } else if place.layout.is_llvm_immediate() {
497 let mut const_llval = None;
499 if let Some(global) = llvm::LLVMIsAGlobalVariable(place.llval) {
500 if llvm::LLVMIsGlobalConstant(global) == llvm::True {
501 const_llval = llvm::LLVMGetInitializer(global);
505 let llval = const_llval.unwrap_or_else(|| {
506 let load = self.load(place.layout.llvm_type(self), place.llval, place.align);
507 if let abi::Abi::Scalar(scalar) = place.layout.abi {
508 scalar_load_metadata(self, load, scalar);
512 OperandValue::Immediate(self.to_immediate(llval, place.layout))
513 } else if let abi::Abi::ScalarPair(a, b) = place.layout.abi {
514 let b_offset = a.value.size(self).align_to(b.value.align(self).abi);
515 let pair_ty = place.layout.llvm_type(self);
517 let mut load = |i, scalar: abi::Scalar, align| {
518 let llptr = self.struct_gep(pair_ty, place.llval, i as u64);
519 let llty = place.layout.scalar_pair_element_llvm_type(self, i, false);
520 let load = self.load(llty, llptr, align);
521 scalar_load_metadata(self, load, scalar);
522 self.to_immediate_scalar(load, scalar)
526 load(0, a, place.align),
527 load(1, b, place.align.restrict_for_offset(b_offset)),
530 OperandValue::Ref(place.llval, None, place.align)
533 OperandRef { val, layout: place.layout }
536 fn write_operand_repeatedly(
538 cg_elem: OperandRef<'tcx, &'ll Value>,
540 dest: PlaceRef<'tcx, &'ll Value>,
542 let zero = self.const_usize(0);
543 let count = self.const_usize(count);
544 let start = dest.project_index(&mut self, zero).llval;
545 let end = dest.project_index(&mut self, count).llval;
547 let mut header_bx = self.build_sibling_block("repeat_loop_header");
548 let mut body_bx = self.build_sibling_block("repeat_loop_body");
549 let next_bx = self.build_sibling_block("repeat_loop_next");
551 self.br(header_bx.llbb());
552 let current = header_bx.phi(self.val_ty(start), &[start], &[self.llbb()]);
554 let keep_going = header_bx.icmp(IntPredicate::IntNE, current, end);
555 header_bx.cond_br(keep_going, body_bx.llbb(), next_bx.llbb());
557 let align = dest.align.restrict_for_offset(dest.layout.field(self.cx(), 0).size);
560 .store(&mut body_bx, PlaceRef::new_sized_aligned(current, cg_elem.layout, align));
562 let next = body_bx.inbounds_gep(
563 self.backend_type(cg_elem.layout),
565 &[self.const_usize(1)],
567 body_bx.br(header_bx.llbb());
568 header_bx.add_incoming_to_phi(current, next, body_bx.llbb());
573 fn range_metadata(&mut self, load: &'ll Value, range: WrappingRange) {
574 if self.sess().target.arch == "amdgpu" {
575 // amdgpu/LLVM does something weird and thinks an i64 value is
576 // split into a v2i32, halving the bitwidth LLVM expects,
577 // tripping an assertion. So, for now, just disable this
583 let llty = self.cx.val_ty(load);
585 self.cx.const_uint_big(llty, range.start),
586 self.cx.const_uint_big(llty, range.end.wrapping_add(1)),
589 llvm::LLVMSetMetadata(
591 llvm::MD_range as c_uint,
592 llvm::LLVMMDNodeInContext(self.cx.llcx, v.as_ptr(), v.len() as c_uint),
597 fn nonnull_metadata(&mut self, load: &'ll Value) {
599 llvm::LLVMSetMetadata(
601 llvm::MD_nonnull as c_uint,
602 llvm::LLVMMDNodeInContext(self.cx.llcx, ptr::null(), 0),
607 fn type_metadata(&mut self, function: &'ll Value, typeid: String) {
608 let typeid_metadata = self.typeid_metadata(typeid);
609 let v = [self.const_usize(0), typeid_metadata];
611 llvm::LLVMGlobalSetMetadata(
613 llvm::MD_type as c_uint,
614 llvm::LLVMValueAsMetadata(llvm::LLVMMDNodeInContext(
623 fn typeid_metadata(&mut self, typeid: String) -> Self::Value {
625 llvm::LLVMMDStringInContext(
627 typeid.as_ptr() as *const c_char,
628 typeid.as_bytes().len() as c_uint,
633 fn store(&mut self, val: &'ll Value, ptr: &'ll Value, align: Align) -> &'ll Value {
634 self.store_with_flags(val, ptr, align, MemFlags::empty())
644 debug!("Store {:?} -> {:?} ({:?})", val, ptr, flags);
645 let ptr = self.check_store(val, ptr);
647 let store = llvm::LLVMBuildStore(self.llbuilder, val, ptr);
649 if flags.contains(MemFlags::UNALIGNED) { 1 } else { align.bytes() as c_uint };
650 llvm::LLVMSetAlignment(store, align);
651 if flags.contains(MemFlags::VOLATILE) {
652 llvm::LLVMSetVolatile(store, llvm::True);
654 if flags.contains(MemFlags::NONTEMPORAL) {
655 // According to LLVM [1] building a nontemporal store must
656 // *always* point to a metadata value of the integer 1.
658 // [1]: https://llvm.org/docs/LangRef.html#store-instruction
659 let one = self.cx.const_i32(1);
660 let node = llvm::LLVMMDNodeInContext(self.cx.llcx, &one, 1);
661 llvm::LLVMSetMetadata(store, llvm::MD_nontemporal as c_uint, node);
671 order: rustc_codegen_ssa::common::AtomicOrdering,
674 debug!("Store {:?} -> {:?}", val, ptr);
675 let ptr = self.check_store(val, ptr);
677 let store = llvm::LLVMRustBuildAtomicStore(
681 AtomicOrdering::from_generic(order),
683 // LLVM requires the alignment of atomic stores to be at least the size of the type.
684 llvm::LLVMSetAlignment(store, size.bytes() as c_uint);
688 fn gep(&mut self, ty: &'ll Type, ptr: &'ll Value, indices: &[&'ll Value]) -> &'ll Value {
695 indices.len() as c_uint,
705 indices: &[&'ll Value],
708 llvm::LLVMBuildInBoundsGEP2(
713 indices.len() as c_uint,
719 fn struct_gep(&mut self, ty: &'ll Type, ptr: &'ll Value, idx: u64) -> &'ll Value {
720 assert_eq!(idx as c_uint as u64, idx);
721 unsafe { llvm::LLVMBuildStructGEP2(self.llbuilder, ty, ptr, idx as c_uint, UNNAMED) }
725 fn trunc(&mut self, val: &'ll Value, dest_ty: &'ll Type) -> &'ll Value {
726 unsafe { llvm::LLVMBuildTrunc(self.llbuilder, val, dest_ty, UNNAMED) }
729 fn sext(&mut self, val: &'ll Value, dest_ty: &'ll Type) -> &'ll Value {
730 unsafe { llvm::LLVMBuildSExt(self.llbuilder, val, dest_ty, UNNAMED) }
733 fn fptoui_sat(&mut self, val: &'ll Value, dest_ty: &'ll Type) -> Option<&'ll Value> {
734 self.fptoint_sat(false, val, dest_ty)
737 fn fptosi_sat(&mut self, val: &'ll Value, dest_ty: &'ll Type) -> Option<&'ll Value> {
738 self.fptoint_sat(true, val, dest_ty)
741 fn fptoui(&mut self, val: &'ll Value, dest_ty: &'ll Type) -> &'ll Value {
742 // On WebAssembly the `fptoui` and `fptosi` instructions currently have
743 // poor codegen. The reason for this is that the corresponding wasm
744 // instructions, `i32.trunc_f32_s` for example, will trap when the float
745 // is out-of-bounds, infinity, or nan. This means that LLVM
746 // automatically inserts control flow around `fptoui` and `fptosi`
747 // because the LLVM instruction `fptoui` is defined as producing a
748 // poison value, not having UB on out-of-bounds values.
750 // This method, however, is only used with non-saturating casts that
751 // have UB on out-of-bounds values. This means that it's ok if we use
752 // the raw wasm instruction since out-of-bounds values can do whatever
753 // we like. To ensure that LLVM picks the right instruction we choose
754 // the raw wasm intrinsic functions which avoid LLVM inserting all the
755 // other control flow automatically.
756 if self.sess().target.is_like_wasm {
757 let src_ty = self.cx.val_ty(val);
758 if self.cx.type_kind(src_ty) != TypeKind::Vector {
759 let float_width = self.cx.float_width(src_ty);
760 let int_width = self.cx.int_width(dest_ty);
761 let name = match (int_width, float_width) {
762 (32, 32) => Some("llvm.wasm.trunc.unsigned.i32.f32"),
763 (32, 64) => Some("llvm.wasm.trunc.unsigned.i32.f64"),
764 (64, 32) => Some("llvm.wasm.trunc.unsigned.i64.f32"),
765 (64, 64) => Some("llvm.wasm.trunc.unsigned.i64.f64"),
768 if let Some(name) = name {
769 return self.call_intrinsic(name, &[val]);
773 unsafe { llvm::LLVMBuildFPToUI(self.llbuilder, val, dest_ty, UNNAMED) }
776 fn fptosi(&mut self, val: &'ll Value, dest_ty: &'ll Type) -> &'ll Value {
777 // see `fptoui` above for why wasm is different here
778 if self.sess().target.is_like_wasm {
779 let src_ty = self.cx.val_ty(val);
780 if self.cx.type_kind(src_ty) != TypeKind::Vector {
781 let float_width = self.cx.float_width(src_ty);
782 let int_width = self.cx.int_width(dest_ty);
783 let name = match (int_width, float_width) {
784 (32, 32) => Some("llvm.wasm.trunc.signed.i32.f32"),
785 (32, 64) => Some("llvm.wasm.trunc.signed.i32.f64"),
786 (64, 32) => Some("llvm.wasm.trunc.signed.i64.f32"),
787 (64, 64) => Some("llvm.wasm.trunc.signed.i64.f64"),
790 if let Some(name) = name {
791 return self.call_intrinsic(name, &[val]);
795 unsafe { llvm::LLVMBuildFPToSI(self.llbuilder, val, dest_ty, UNNAMED) }
798 fn uitofp(&mut self, val: &'ll Value, dest_ty: &'ll Type) -> &'ll Value {
799 unsafe { llvm::LLVMBuildUIToFP(self.llbuilder, val, dest_ty, UNNAMED) }
802 fn sitofp(&mut self, val: &'ll Value, dest_ty: &'ll Type) -> &'ll Value {
803 unsafe { llvm::LLVMBuildSIToFP(self.llbuilder, val, dest_ty, UNNAMED) }
806 fn fptrunc(&mut self, val: &'ll Value, dest_ty: &'ll Type) -> &'ll Value {
807 unsafe { llvm::LLVMBuildFPTrunc(self.llbuilder, val, dest_ty, UNNAMED) }
810 fn fpext(&mut self, val: &'ll Value, dest_ty: &'ll Type) -> &'ll Value {
811 unsafe { llvm::LLVMBuildFPExt(self.llbuilder, val, dest_ty, UNNAMED) }
814 fn ptrtoint(&mut self, val: &'ll Value, dest_ty: &'ll Type) -> &'ll Value {
815 unsafe { llvm::LLVMBuildPtrToInt(self.llbuilder, val, dest_ty, UNNAMED) }
818 fn inttoptr(&mut self, val: &'ll Value, dest_ty: &'ll Type) -> &'ll Value {
819 unsafe { llvm::LLVMBuildIntToPtr(self.llbuilder, val, dest_ty, UNNAMED) }
822 fn bitcast(&mut self, val: &'ll Value, dest_ty: &'ll Type) -> &'ll Value {
823 unsafe { llvm::LLVMBuildBitCast(self.llbuilder, val, dest_ty, UNNAMED) }
826 fn intcast(&mut self, val: &'ll Value, dest_ty: &'ll Type, is_signed: bool) -> &'ll Value {
827 unsafe { llvm::LLVMRustBuildIntCast(self.llbuilder, val, dest_ty, is_signed) }
830 fn pointercast(&mut self, val: &'ll Value, dest_ty: &'ll Type) -> &'ll Value {
831 unsafe { llvm::LLVMBuildPointerCast(self.llbuilder, val, dest_ty, UNNAMED) }
835 fn icmp(&mut self, op: IntPredicate, lhs: &'ll Value, rhs: &'ll Value) -> &'ll Value {
836 let op = llvm::IntPredicate::from_generic(op);
837 unsafe { llvm::LLVMBuildICmp(self.llbuilder, op as c_uint, lhs, rhs, UNNAMED) }
840 fn fcmp(&mut self, op: RealPredicate, lhs: &'ll Value, rhs: &'ll Value) -> &'ll Value {
841 let op = llvm::RealPredicate::from_generic(op);
842 unsafe { llvm::LLVMBuildFCmp(self.llbuilder, op as c_uint, lhs, rhs, UNNAMED) }
845 /* Miscellaneous instructions */
855 assert!(!flags.contains(MemFlags::NONTEMPORAL), "non-temporal memcpy not supported");
856 let size = self.intcast(size, self.type_isize(), false);
857 let is_volatile = flags.contains(MemFlags::VOLATILE);
858 let dst = self.pointercast(dst, self.type_i8p());
859 let src = self.pointercast(src, self.type_i8p());
861 llvm::LLVMRustBuildMemCpy(
864 dst_align.bytes() as c_uint,
866 src_align.bytes() as c_uint,
882 assert!(!flags.contains(MemFlags::NONTEMPORAL), "non-temporal memmove not supported");
883 let size = self.intcast(size, self.type_isize(), false);
884 let is_volatile = flags.contains(MemFlags::VOLATILE);
885 let dst = self.pointercast(dst, self.type_i8p());
886 let src = self.pointercast(src, self.type_i8p());
888 llvm::LLVMRustBuildMemMove(
891 dst_align.bytes() as c_uint,
893 src_align.bytes() as c_uint,
903 fill_byte: &'ll Value,
908 let is_volatile = flags.contains(MemFlags::VOLATILE);
909 let ptr = self.pointercast(ptr, self.type_i8p());
911 llvm::LLVMRustBuildMemSet(
914 align.bytes() as c_uint,
925 then_val: &'ll Value,
926 else_val: &'ll Value,
928 unsafe { llvm::LLVMBuildSelect(self.llbuilder, cond, then_val, else_val, UNNAMED) }
931 fn va_arg(&mut self, list: &'ll Value, ty: &'ll Type) -> &'ll Value {
932 unsafe { llvm::LLVMBuildVAArg(self.llbuilder, list, ty, UNNAMED) }
935 fn extract_element(&mut self, vec: &'ll Value, idx: &'ll Value) -> &'ll Value {
936 unsafe { llvm::LLVMBuildExtractElement(self.llbuilder, vec, idx, UNNAMED) }
939 fn vector_splat(&mut self, num_elts: usize, elt: &'ll Value) -> &'ll Value {
941 let elt_ty = self.cx.val_ty(elt);
942 let undef = llvm::LLVMGetUndef(self.type_vector(elt_ty, num_elts as u64));
943 let vec = self.insert_element(undef, elt, self.cx.const_i32(0));
944 let vec_i32_ty = self.type_vector(self.type_i32(), num_elts as u64);
945 self.shuffle_vector(vec, undef, self.const_null(vec_i32_ty))
949 fn extract_value(&mut self, agg_val: &'ll Value, idx: u64) -> &'ll Value {
950 assert_eq!(idx as c_uint as u64, idx);
951 unsafe { llvm::LLVMBuildExtractValue(self.llbuilder, agg_val, idx as c_uint, UNNAMED) }
954 fn insert_value(&mut self, agg_val: &'ll Value, elt: &'ll Value, idx: u64) -> &'ll Value {
955 assert_eq!(idx as c_uint as u64, idx);
956 unsafe { llvm::LLVMBuildInsertValue(self.llbuilder, agg_val, elt, idx as c_uint, UNNAMED) }
965 // Use LLVMSetPersonalityFn to set the personality. It supports arbitrary Consts while,
966 // LLVMBuildLandingPad requires the argument to be a Function (as of LLVM 12). The
967 // personality lives on the parent function anyway.
968 self.set_personality_fn(pers_fn);
970 llvm::LLVMBuildLandingPad(self.llbuilder, ty, None, num_clauses as c_uint, UNNAMED)
974 fn set_cleanup(&mut self, landing_pad: &'ll Value) {
976 llvm::LLVMSetCleanup(landing_pad, llvm::True);
980 fn resume(&mut self, exn: &'ll Value) -> &'ll Value {
981 unsafe { llvm::LLVMBuildResume(self.llbuilder, exn) }
984 fn cleanup_pad(&mut self, parent: Option<&'ll Value>, args: &[&'ll Value]) -> Funclet<'ll> {
985 let name = cstr!("cleanuppad");
987 llvm::LLVMRustBuildCleanupPad(
990 args.len() as c_uint,
995 Funclet::new(ret.expect("LLVM does not have support for cleanuppad"))
1000 funclet: &Funclet<'ll>,
1001 unwind: Option<&'ll BasicBlock>,
1004 unsafe { llvm::LLVMRustBuildCleanupRet(self.llbuilder, funclet.cleanuppad(), unwind) };
1005 ret.expect("LLVM does not have support for cleanupret")
1008 fn catch_pad(&mut self, parent: &'ll Value, args: &[&'ll Value]) -> Funclet<'ll> {
1009 let name = cstr!("catchpad");
1011 llvm::LLVMRustBuildCatchPad(
1014 args.len() as c_uint,
1019 Funclet::new(ret.expect("LLVM does not have support for catchpad"))
1024 parent: Option<&'ll Value>,
1025 unwind: Option<&'ll BasicBlock>,
1026 num_handlers: usize,
1028 let name = cstr!("catchswitch");
1030 llvm::LLVMRustBuildCatchSwitch(
1034 num_handlers as c_uint,
1038 ret.expect("LLVM does not have support for catchswitch")
1041 fn add_handler(&mut self, catch_switch: &'ll Value, handler: &'ll BasicBlock) {
1043 llvm::LLVMRustAddHandler(catch_switch, handler);
1047 fn set_personality_fn(&mut self, personality: &'ll Value) {
1049 llvm::LLVMSetPersonalityFn(self.llfn(), personality);
1053 // Atomic Operations
1059 order: rustc_codegen_ssa::common::AtomicOrdering,
1060 failure_order: rustc_codegen_ssa::common::AtomicOrdering,
1063 let weak = if weak { llvm::True } else { llvm::False };
1065 llvm::LLVMRustBuildAtomicCmpXchg(
1070 AtomicOrdering::from_generic(order),
1071 AtomicOrdering::from_generic(failure_order),
1078 op: rustc_codegen_ssa::common::AtomicRmwBinOp,
1081 order: rustc_codegen_ssa::common::AtomicOrdering,
1084 llvm::LLVMBuildAtomicRMW(
1086 AtomicRmwBinOp::from_generic(op),
1089 AtomicOrdering::from_generic(order),
1097 order: rustc_codegen_ssa::common::AtomicOrdering,
1098 scope: rustc_codegen_ssa::common::SynchronizationScope,
1101 llvm::LLVMRustBuildAtomicFence(
1103 AtomicOrdering::from_generic(order),
1104 SynchronizationScope::from_generic(scope),
1109 fn set_invariant_load(&mut self, load: &'ll Value) {
1111 llvm::LLVMSetMetadata(
1113 llvm::MD_invariant_load as c_uint,
1114 llvm::LLVMMDNodeInContext(self.cx.llcx, ptr::null(), 0),
1119 fn lifetime_start(&mut self, ptr: &'ll Value, size: Size) {
1120 self.call_lifetime_intrinsic("llvm.lifetime.start.p0i8", ptr, size);
1123 fn lifetime_end(&mut self, ptr: &'ll Value, size: Size) {
1124 self.call_lifetime_intrinsic("llvm.lifetime.end.p0i8", ptr, size);
1127 fn instrprof_increment(
1129 fn_name: &'ll Value,
1131 num_counters: &'ll Value,
1135 "instrprof_increment() with args ({:?}, {:?}, {:?}, {:?})",
1136 fn_name, hash, num_counters, index
1139 let llfn = unsafe { llvm::LLVMRustGetInstrProfIncrementIntrinsic(self.cx().llmod) };
1140 let llty = self.cx.type_func(
1141 &[self.cx.type_i8p(), self.cx.type_i64(), self.cx.type_i32(), self.cx.type_i32()],
1142 self.cx.type_void(),
1144 let args = &[fn_name, hash, num_counters, index];
1145 let args = self.check_call("call", llty, llfn, args);
1148 let _ = llvm::LLVMRustBuildCall(
1152 args.as_ptr() as *const &llvm::Value,
1153 args.len() as c_uint,
1163 args: &[&'ll Value],
1164 funclet: Option<&Funclet<'ll>>,
1166 debug!("call {:?} with args ({:?})", llfn, args);
1168 let args = self.check_call("call", llty, llfn, args);
1169 let bundle = funclet.map(|funclet| funclet.bundle());
1170 let bundle = bundle.as_ref().map(|b| &*b.raw);
1173 llvm::LLVMRustBuildCall(
1177 args.as_ptr() as *const &llvm::Value,
1178 args.len() as c_uint,
1184 fn zext(&mut self, val: &'ll Value, dest_ty: &'ll Type) -> &'ll Value {
1185 unsafe { llvm::LLVMBuildZExt(self.llbuilder, val, dest_ty, UNNAMED) }
1188 fn apply_attrs_to_cleanup_callsite(&mut self, llret: &'ll Value) {
1189 // Cleanup is always the cold path.
1190 llvm::Attribute::Cold.apply_callsite(llvm::AttributePlace::Function, llret);
1192 // In LLVM versions with deferred inlining (currently, system LLVM < 14),
1193 // inlining drop glue can lead to exponential size blowup, see #41696 and #92110.
1194 if !llvm_util::is_rust_llvm() && llvm_util::get_version() < (14, 0, 0) {
1195 llvm::Attribute::NoInline.apply_callsite(llvm::AttributePlace::Function, llret);
1200 impl<'ll> StaticBuilderMethods for Builder<'_, 'll, '_> {
1201 fn get_static(&mut self, def_id: DefId) -> &'ll Value {
1202 // Forward to the `get_static` method of `CodegenCx`
1203 self.cx().get_static(def_id)
1207 impl<'a, 'll, 'tcx> Builder<'a, 'll, 'tcx> {
1208 fn with_cx(cx: &'a CodegenCx<'ll, 'tcx>) -> Self {
1209 // Create a fresh builder from the crate context.
1210 let llbuilder = unsafe { llvm::LLVMCreateBuilderInContext(cx.llcx) };
1211 Builder { llbuilder, cx }
1214 pub fn llfn(&self) -> &'ll Value {
1215 unsafe { llvm::LLVMGetBasicBlockParent(self.llbb()) }
1218 fn position_at_start(&mut self, llbb: &'ll BasicBlock) {
1220 llvm::LLVMRustPositionBuilderAtStart(self.llbuilder, llbb);
1224 pub fn minnum(&mut self, lhs: &'ll Value, rhs: &'ll Value) -> &'ll Value {
1225 unsafe { llvm::LLVMRustBuildMinNum(self.llbuilder, lhs, rhs) }
1228 pub fn maxnum(&mut self, lhs: &'ll Value, rhs: &'ll Value) -> &'ll Value {
1229 unsafe { llvm::LLVMRustBuildMaxNum(self.llbuilder, lhs, rhs) }
1232 pub fn insert_element(
1238 unsafe { llvm::LLVMBuildInsertElement(self.llbuilder, vec, elt, idx, UNNAMED) }
1241 pub fn shuffle_vector(
1247 unsafe { llvm::LLVMBuildShuffleVector(self.llbuilder, v1, v2, mask, UNNAMED) }
1250 pub fn vector_reduce_fadd(&mut self, acc: &'ll Value, src: &'ll Value) -> &'ll Value {
1251 unsafe { llvm::LLVMRustBuildVectorReduceFAdd(self.llbuilder, acc, src) }
1253 pub fn vector_reduce_fmul(&mut self, acc: &'ll Value, src: &'ll Value) -> &'ll Value {
1254 unsafe { llvm::LLVMRustBuildVectorReduceFMul(self.llbuilder, acc, src) }
1256 pub fn vector_reduce_fadd_fast(&mut self, acc: &'ll Value, src: &'ll Value) -> &'ll Value {
1258 let instr = llvm::LLVMRustBuildVectorReduceFAdd(self.llbuilder, acc, src);
1259 llvm::LLVMRustSetFastMath(instr);
1263 pub fn vector_reduce_fmul_fast(&mut self, acc: &'ll Value, src: &'ll Value) -> &'ll Value {
1265 let instr = llvm::LLVMRustBuildVectorReduceFMul(self.llbuilder, acc, src);
1266 llvm::LLVMRustSetFastMath(instr);
1270 pub fn vector_reduce_add(&mut self, src: &'ll Value) -> &'ll Value {
1271 unsafe { llvm::LLVMRustBuildVectorReduceAdd(self.llbuilder, src) }
1273 pub fn vector_reduce_mul(&mut self, src: &'ll Value) -> &'ll Value {
1274 unsafe { llvm::LLVMRustBuildVectorReduceMul(self.llbuilder, src) }
1276 pub fn vector_reduce_and(&mut self, src: &'ll Value) -> &'ll Value {
1277 unsafe { llvm::LLVMRustBuildVectorReduceAnd(self.llbuilder, src) }
1279 pub fn vector_reduce_or(&mut self, src: &'ll Value) -> &'ll Value {
1280 unsafe { llvm::LLVMRustBuildVectorReduceOr(self.llbuilder, src) }
1282 pub fn vector_reduce_xor(&mut self, src: &'ll Value) -> &'ll Value {
1283 unsafe { llvm::LLVMRustBuildVectorReduceXor(self.llbuilder, src) }
1285 pub fn vector_reduce_fmin(&mut self, src: &'ll Value) -> &'ll Value {
1287 llvm::LLVMRustBuildVectorReduceFMin(self.llbuilder, src, /*NoNaNs:*/ false)
1290 pub fn vector_reduce_fmax(&mut self, src: &'ll Value) -> &'ll Value {
1292 llvm::LLVMRustBuildVectorReduceFMax(self.llbuilder, src, /*NoNaNs:*/ false)
1295 pub fn vector_reduce_fmin_fast(&mut self, src: &'ll Value) -> &'ll Value {
1298 llvm::LLVMRustBuildVectorReduceFMin(self.llbuilder, src, /*NoNaNs:*/ true);
1299 llvm::LLVMRustSetFastMath(instr);
1303 pub fn vector_reduce_fmax_fast(&mut self, src: &'ll Value) -> &'ll Value {
1306 llvm::LLVMRustBuildVectorReduceFMax(self.llbuilder, src, /*NoNaNs:*/ true);
1307 llvm::LLVMRustSetFastMath(instr);
1311 pub fn vector_reduce_min(&mut self, src: &'ll Value, is_signed: bool) -> &'ll Value {
1312 unsafe { llvm::LLVMRustBuildVectorReduceMin(self.llbuilder, src, is_signed) }
1314 pub fn vector_reduce_max(&mut self, src: &'ll Value, is_signed: bool) -> &'ll Value {
1315 unsafe { llvm::LLVMRustBuildVectorReduceMax(self.llbuilder, src, is_signed) }
1318 pub fn add_clause(&mut self, landing_pad: &'ll Value, clause: &'ll Value) {
1320 llvm::LLVMAddClause(landing_pad, clause);
1324 pub fn catch_ret(&mut self, funclet: &Funclet<'ll>, unwind: &'ll BasicBlock) -> &'ll Value {
1326 unsafe { llvm::LLVMRustBuildCatchRet(self.llbuilder, funclet.cleanuppad(), unwind) };
1327 ret.expect("LLVM does not have support for catchret")
1330 fn check_store(&mut self, val: &'ll Value, ptr: &'ll Value) -> &'ll Value {
1331 let dest_ptr_ty = self.cx.val_ty(ptr);
1332 let stored_ty = self.cx.val_ty(val);
1333 let stored_ptr_ty = self.cx.type_ptr_to(stored_ty);
1335 assert_eq!(self.cx.type_kind(dest_ptr_ty), TypeKind::Pointer);
1337 if dest_ptr_ty == stored_ptr_ty {
1341 "type mismatch in store. \
1342 Expected {:?}, got {:?}; inserting bitcast",
1343 dest_ptr_ty, stored_ptr_ty
1345 self.bitcast(ptr, stored_ptr_ty)
1354 args: &'b [&'ll Value],
1355 ) -> Cow<'b, [&'ll Value]> {
1357 self.cx.type_kind(fn_ty) == TypeKind::Function,
1358 "builder::{} not passed a function, but {:?}",
1363 let param_tys = self.cx.func_params_types(fn_ty);
1365 let all_args_match = iter::zip(¶m_tys, args.iter().map(|&v| self.val_ty(v)))
1366 .all(|(expected_ty, actual_ty)| *expected_ty == actual_ty);
1369 return Cow::Borrowed(args);
1372 let casted_args: Vec<_> = iter::zip(param_tys, args)
1374 .map(|(i, (expected_ty, &actual_val))| {
1375 let actual_ty = self.val_ty(actual_val);
1376 if expected_ty != actual_ty {
1378 "type mismatch in function call of {:?}. \
1379 Expected {:?} for param {}, got {:?}; injecting bitcast",
1380 llfn, expected_ty, i, actual_ty
1382 self.bitcast(actual_val, expected_ty)
1389 Cow::Owned(casted_args)
1392 pub fn va_arg(&mut self, list: &'ll Value, ty: &'ll Type) -> &'ll Value {
1393 unsafe { llvm::LLVMBuildVAArg(self.llbuilder, list, ty, UNNAMED) }
1396 crate fn call_intrinsic(&mut self, intrinsic: &str, args: &[&'ll Value]) -> &'ll Value {
1397 let (ty, f) = self.cx.get_intrinsic(intrinsic);
1398 self.call(ty, f, args, None)
1401 fn call_lifetime_intrinsic(&mut self, intrinsic: &str, ptr: &'ll Value, size: Size) {
1402 let size = size.bytes();
1407 if !self.cx().sess().emit_lifetime_markers() {
1411 let ptr = self.pointercast(ptr, self.cx.type_i8p());
1412 self.call_intrinsic(intrinsic, &[self.cx.const_u64(size), ptr]);
1418 vals: &[&'ll Value],
1419 bbs: &[&'ll BasicBlock],
1421 assert_eq!(vals.len(), bbs.len());
1422 let phi = unsafe { llvm::LLVMBuildPhi(self.llbuilder, ty, UNNAMED) };
1424 llvm::LLVMAddIncoming(phi, vals.as_ptr(), bbs.as_ptr(), vals.len() as c_uint);
1429 fn add_incoming_to_phi(&mut self, phi: &'ll Value, val: &'ll Value, bb: &'ll BasicBlock) {
1431 llvm::LLVMAddIncoming(phi, &val, &bb, 1 as c_uint);
1435 fn fptoint_sat_broken_in_llvm(&self) -> bool {
1436 match self.tcx.sess.target.arch.as_str() {
1437 // FIXME - https://bugs.llvm.org/show_bug.cgi?id=50083
1438 "riscv64" => llvm_util::get_version() < (13, 0, 0),
1448 ) -> Option<&'ll Value> {
1449 if !self.fptoint_sat_broken_in_llvm() {
1450 let src_ty = self.cx.val_ty(val);
1451 let (float_ty, int_ty, vector_length) = if self.cx.type_kind(src_ty) == TypeKind::Vector
1453 assert_eq!(self.cx.vector_length(src_ty), self.cx.vector_length(dest_ty));
1455 self.cx.element_type(src_ty),
1456 self.cx.element_type(dest_ty),
1457 Some(self.cx.vector_length(src_ty)),
1460 (src_ty, dest_ty, None)
1462 let float_width = self.cx.float_width(float_ty);
1463 let int_width = self.cx.int_width(int_ty);
1465 let instr = if signed { "fptosi" } else { "fptoui" };
1466 let name = if let Some(vector_length) = vector_length {
1468 "llvm.{}.sat.v{}i{}.v{}f{}",
1469 instr, vector_length, int_width, vector_length, float_width
1472 format!("llvm.{}.sat.i{}.f{}", instr, int_width, float_width)
1475 self.declare_cfn(&name, llvm::UnnamedAddr::No, self.type_func(&[src_ty], dest_ty));
1476 Some(self.call(self.type_func(&[src_ty], dest_ty), f, &[val], None))