diff options
Diffstat (limited to 'compiler/rustc_codegen_llvm/src/intrinsic.rs')
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/intrinsic.rs | 1772 |
1 files changed, 1772 insertions, 0 deletions
diff --git a/compiler/rustc_codegen_llvm/src/intrinsic.rs b/compiler/rustc_codegen_llvm/src/intrinsic.rs new file mode 100644 index 00000000000..ed484185865 --- /dev/null +++ b/compiler/rustc_codegen_llvm/src/intrinsic.rs @@ -0,0 +1,1772 @@ +use crate::abi::{Abi, FnAbi, FnAbiLlvmExt, LlvmType, PassMode}; +use crate::builder::Builder; +use crate::context::CodegenCx; +use crate::llvm; +use crate::type_::Type; +use crate::type_of::LayoutLlvmExt; +use crate::va_arg::emit_va_arg; +use crate::value::Value; + +use rustc_codegen_ssa::base::{compare_simd_types, wants_msvc_seh}; +use rustc_codegen_ssa::common::span_invalid_monomorphization_error; +use rustc_codegen_ssa::common::{IntPredicate, TypeKind}; +use rustc_codegen_ssa::mir::operand::OperandRef; +use rustc_codegen_ssa::mir::place::PlaceRef; +use rustc_codegen_ssa::traits::*; +use rustc_hir as hir; +use rustc_middle::ty::layout::{FnAbiExt, HasTyCtxt}; +use rustc_middle::ty::{self, Ty}; +use rustc_middle::{bug, span_bug}; +use rustc_span::{sym, symbol::kw, Span, Symbol}; +use rustc_target::abi::{self, HasDataLayout, LayoutOf, Primitive}; +use rustc_target::spec::PanicStrategy; + +use std::cmp::Ordering; +use std::iter; + +fn get_simple_intrinsic(cx: &CodegenCx<'ll, '_>, name: Symbol) -> Option<(&'ll Type, &'ll Value)> { + let llvm_name = match name { + sym::sqrtf32 => "llvm.sqrt.f32", + sym::sqrtf64 => "llvm.sqrt.f64", + sym::powif32 => "llvm.powi.f32", + sym::powif64 => "llvm.powi.f64", + sym::sinf32 => "llvm.sin.f32", + sym::sinf64 => "llvm.sin.f64", + sym::cosf32 => "llvm.cos.f32", + sym::cosf64 => "llvm.cos.f64", + sym::powf32 => "llvm.pow.f32", + sym::powf64 => "llvm.pow.f64", + sym::expf32 => "llvm.exp.f32", + sym::expf64 => "llvm.exp.f64", + sym::exp2f32 => "llvm.exp2.f32", + sym::exp2f64 => "llvm.exp2.f64", + sym::logf32 => "llvm.log.f32", + sym::logf64 => "llvm.log.f64", + sym::log10f32 => "llvm.log10.f32", + sym::log10f64 => "llvm.log10.f64", + sym::log2f32 => "llvm.log2.f32", + sym::log2f64 => "llvm.log2.f64", + sym::fmaf32 => "llvm.fma.f32", + sym::fmaf64 => "llvm.fma.f64", + sym::fabsf32 => "llvm.fabs.f32", + sym::fabsf64 => "llvm.fabs.f64", + sym::minnumf32 => "llvm.minnum.f32", + sym::minnumf64 => "llvm.minnum.f64", + sym::maxnumf32 => "llvm.maxnum.f32", + sym::maxnumf64 => "llvm.maxnum.f64", + sym::copysignf32 => "llvm.copysign.f32", + sym::copysignf64 => "llvm.copysign.f64", + sym::floorf32 => "llvm.floor.f32", + sym::floorf64 => "llvm.floor.f64", + sym::ceilf32 => "llvm.ceil.f32", + sym::ceilf64 => "llvm.ceil.f64", + sym::truncf32 => "llvm.trunc.f32", + sym::truncf64 => "llvm.trunc.f64", + sym::rintf32 => "llvm.rint.f32", + sym::rintf64 => "llvm.rint.f64", + sym::nearbyintf32 => "llvm.nearbyint.f32", + sym::nearbyintf64 => "llvm.nearbyint.f64", + sym::roundf32 => "llvm.round.f32", + sym::roundf64 => "llvm.round.f64", + _ => return None, + }; + Some(cx.get_intrinsic(&llvm_name)) +} + +impl IntrinsicCallMethods<'tcx> for Builder<'a, 'll, 'tcx> { + fn codegen_intrinsic_call( + &mut self, + instance: ty::Instance<'tcx>, + fn_abi: &FnAbi<'tcx, Ty<'tcx>>, + args: &[OperandRef<'tcx, &'ll Value>], + llresult: &'ll Value, + span: Span, + ) { + let tcx = self.tcx; + let callee_ty = instance.ty(tcx, ty::ParamEnv::reveal_all()); + + let (def_id, substs) = match *callee_ty.kind() { + ty::FnDef(def_id, substs) => (def_id, substs), + _ => bug!("expected fn item type, found {}", callee_ty), + }; + + let sig = callee_ty.fn_sig(tcx); + let sig = tcx.normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), sig); + let arg_tys = sig.inputs(); + let ret_ty = sig.output(); + let name = tcx.item_name(def_id); + let name_str = &*name.as_str(); + + let llret_ty = self.layout_of(ret_ty).llvm_type(self); + let result = PlaceRef::new_sized(llresult, fn_abi.ret.layout); + + let simple = get_simple_intrinsic(self, name); + let llval = match name { + _ if simple.is_some() => { + let (simple_ty, simple_fn) = simple.unwrap(); + self.call( + simple_ty, + simple_fn, + &args.iter().map(|arg| arg.immediate()).collect::<Vec<_>>(), + None, + ) + } + sym::likely => { + self.call_intrinsic("llvm.expect.i1", &[args[0].immediate(), self.const_bool(true)]) + } + sym::unlikely => self + .call_intrinsic("llvm.expect.i1", &[args[0].immediate(), self.const_bool(false)]), + kw::Try => { + try_intrinsic( + self, + args[0].immediate(), + args[1].immediate(), + args[2].immediate(), + llresult, + ); + return; + } + sym::breakpoint => self.call_intrinsic("llvm.debugtrap", &[]), + sym::va_copy => { + self.call_intrinsic("llvm.va_copy", &[args[0].immediate(), args[1].immediate()]) + } + sym::va_arg => { + match fn_abi.ret.layout.abi { + abi::Abi::Scalar(ref scalar) => { + match scalar.value { + Primitive::Int(..) => { + if self.cx().size_of(ret_ty).bytes() < 4 { + // `va_arg` should not be called on a integer type + // less than 4 bytes in length. If it is, promote + // the integer to a `i32` and truncate the result + // back to the smaller type. + let promoted_result = emit_va_arg(self, args[0], tcx.types.i32); + self.trunc(promoted_result, llret_ty) + } else { + emit_va_arg(self, args[0], ret_ty) + } + } + Primitive::F64 | Primitive::Pointer => { + emit_va_arg(self, args[0], ret_ty) + } + // `va_arg` should never be used with the return type f32. + Primitive::F32 => bug!("the va_arg intrinsic does not work with `f32`"), + } + } + _ => bug!("the va_arg intrinsic does not work with non-scalar types"), + } + } + + sym::volatile_load | sym::unaligned_volatile_load => { + let tp_ty = substs.type_at(0); + let ptr = args[0].immediate(); + let load = if let PassMode::Cast(ty) = fn_abi.ret.mode { + let llty = ty.llvm_type(self); + let ptr = self.pointercast(ptr, self.type_ptr_to(llty)); + self.volatile_load(llty, ptr) + } else { + self.volatile_load(self.layout_of(tp_ty).llvm_type(self), ptr) + }; + let align = if name == sym::unaligned_volatile_load { + 1 + } else { + self.align_of(tp_ty).bytes() as u32 + }; + unsafe { + llvm::LLVMSetAlignment(load, align); + } + self.to_immediate(load, self.layout_of(tp_ty)) + } + sym::volatile_store => { + let dst = args[0].deref(self.cx()); + args[1].val.volatile_store(self, dst); + return; + } + sym::unaligned_volatile_store => { + let dst = args[0].deref(self.cx()); + args[1].val.unaligned_volatile_store(self, dst); + return; + } + sym::prefetch_read_data + | sym::prefetch_write_data + | sym::prefetch_read_instruction + | sym::prefetch_write_instruction => { + let (rw, cache_type) = match name { + sym::prefetch_read_data => (0, 1), + sym::prefetch_write_data => (1, 1), + sym::prefetch_read_instruction => (0, 0), + sym::prefetch_write_instruction => (1, 0), + _ => bug!(), + }; + self.call_intrinsic( + "llvm.prefetch", + &[ + args[0].immediate(), + self.const_i32(rw), + args[1].immediate(), + self.const_i32(cache_type), + ], + ) + } + sym::ctlz + | sym::ctlz_nonzero + | sym::cttz + | sym::cttz_nonzero + | sym::ctpop + | sym::bswap + | sym::bitreverse + | sym::rotate_left + | sym::rotate_right + | sym::saturating_add + | sym::saturating_sub => { + let ty = arg_tys[0]; + match int_type_width_signed(ty, self) { + Some((width, signed)) => match name { + sym::ctlz | sym::cttz => { + let y = self.const_bool(false); + self.call_intrinsic( + &format!("llvm.{}.i{}", name, width), + &[args[0].immediate(), y], + ) + } + sym::ctlz_nonzero | sym::cttz_nonzero => { + let y = self.const_bool(true); + let llvm_name = &format!("llvm.{}.i{}", &name_str[..4], width); + self.call_intrinsic(llvm_name, &[args[0].immediate(), y]) + } + sym::ctpop => self.call_intrinsic( + &format!("llvm.ctpop.i{}", width), + &[args[0].immediate()], + ), + sym::bswap => { + if width == 8 { + args[0].immediate() // byte swap a u8/i8 is just a no-op + } else { + self.call_intrinsic( + &format!("llvm.bswap.i{}", width), + &[args[0].immediate()], + ) + } + } + sym::bitreverse => self.call_intrinsic( + &format!("llvm.bitreverse.i{}", width), + &[args[0].immediate()], + ), + sym::rotate_left | sym::rotate_right => { + let is_left = name == sym::rotate_left; + let val = args[0].immediate(); + let raw_shift = args[1].immediate(); + // rotate = funnel shift with first two args the same + let llvm_name = + &format!("llvm.fsh{}.i{}", if is_left { 'l' } else { 'r' }, width); + self.call_intrinsic(llvm_name, &[val, val, raw_shift]) + } + sym::saturating_add | sym::saturating_sub => { + let is_add = name == sym::saturating_add; + let lhs = args[0].immediate(); + let rhs = args[1].immediate(); + let llvm_name = &format!( + "llvm.{}{}.sat.i{}", + if signed { 's' } else { 'u' }, + if is_add { "add" } else { "sub" }, + width + ); + self.call_intrinsic(llvm_name, &[lhs, rhs]) + } + _ => bug!(), + }, + None => { + span_invalid_monomorphization_error( + tcx.sess, + span, + &format!( + "invalid monomorphization of `{}` intrinsic: \ + expected basic integer type, found `{}`", + name, ty + ), + ); + return; + } + } + } + + sym::raw_eq => { + use abi::Abi::*; + let tp_ty = substs.type_at(0); + let layout = self.layout_of(tp_ty).layout; + let use_integer_compare = match layout.abi { + Scalar(_) | ScalarPair(_, _) => true, + Uninhabited | Vector { .. } => false, + Aggregate { .. } => { + // For rusty ABIs, small aggregates are actually passed + // as `RegKind::Integer` (see `FnAbi::adjust_for_abi`), + // so we re-use that same threshold here. + layout.size <= self.data_layout().pointer_size * 2 + } + }; + + let a = args[0].immediate(); + let b = args[1].immediate(); + if layout.size.bytes() == 0 { + self.const_bool(true) + } else if use_integer_compare { + let integer_ty = self.type_ix(layout.size.bits()); + let ptr_ty = self.type_ptr_to(integer_ty); + let a_ptr = self.bitcast(a, ptr_ty); + let a_val = self.load(integer_ty, a_ptr, layout.align.abi); + let b_ptr = self.bitcast(b, ptr_ty); + let b_val = self.load(integer_ty, b_ptr, layout.align.abi); + self.icmp(IntPredicate::IntEQ, a_val, b_val) + } else { + let i8p_ty = self.type_i8p(); + let a_ptr = self.bitcast(a, i8p_ty); + let b_ptr = self.bitcast(b, i8p_ty); + let n = self.const_usize(layout.size.bytes()); + let cmp = self.call_intrinsic("memcmp", &[a_ptr, b_ptr, n]); + self.icmp(IntPredicate::IntEQ, cmp, self.const_i32(0)) + } + } + + _ if name_str.starts_with("simd_") => { + match generic_simd_intrinsic(self, name, callee_ty, args, ret_ty, llret_ty, span) { + Ok(llval) => llval, + Err(()) => return, + } + } + + _ => bug!("unknown intrinsic '{}'", name), + }; + + if !fn_abi.ret.is_ignore() { + if let PassMode::Cast(ty) = fn_abi.ret.mode { + let ptr_llty = self.type_ptr_to(ty.llvm_type(self)); + let ptr = self.pointercast(result.llval, ptr_llty); + self.store(llval, ptr, result.align); + } else { + OperandRef::from_immediate_or_packed_pair(self, llval, result.layout) + .val + .store(self, result); + } + } + } + + fn abort(&mut self) { + self.call_intrinsic("llvm.trap", &[]); + } + + fn assume(&mut self, val: Self::Value) { + self.call_intrinsic("llvm.assume", &[val]); + } + + fn expect(&mut self, cond: Self::Value, expected: bool) -> Self::Value { + self.call_intrinsic("llvm.expect.i1", &[cond, self.const_bool(expected)]) + } + + fn sideeffect(&mut self) { + // This kind of check would make a ton of sense in the caller, but currently the only + // caller of this function is in `rustc_codegen_ssa`, which is agnostic to whether LLVM + // codegen backend being used, and so is unable to check the LLVM version. + if unsafe { llvm::LLVMRustVersionMajor() } < 12 { + self.call_intrinsic("llvm.sideeffect", &[]); + } + } + + fn va_start(&mut self, va_list: &'ll Value) -> &'ll Value { + self.call_intrinsic("llvm.va_start", &[va_list]) + } + + fn va_end(&mut self, va_list: &'ll Value) -> &'ll Value { + self.call_intrinsic("llvm.va_end", &[va_list]) + } +} + +fn try_intrinsic( + bx: &mut Builder<'a, 'll, 'tcx>, + try_func: &'ll Value, + data: &'ll Value, + catch_func: &'ll Value, + dest: &'ll Value, +) { + if bx.sess().panic_strategy() == PanicStrategy::Abort { + let try_func_ty = bx.type_func(&[bx.type_i8p()], bx.type_void()); + bx.call(try_func_ty, try_func, &[data], None); + // Return 0 unconditionally from the intrinsic call; + // we can never unwind. + let ret_align = bx.tcx().data_layout.i32_align.abi; + bx.store(bx.const_i32(0), dest, ret_align); + } else if wants_msvc_seh(bx.sess()) { + codegen_msvc_try(bx, try_func, data, catch_func, dest); + } else if bx.sess().target.is_like_emscripten { + codegen_emcc_try(bx, try_func, data, catch_func, dest); + } else { + codegen_gnu_try(bx, try_func, data, catch_func, dest); + } +} + +// MSVC's definition of the `rust_try` function. +// +// This implementation uses the new exception handling instructions in LLVM +// which have support in LLVM for SEH on MSVC targets. Although these +// instructions are meant to work for all targets, as of the time of this +// writing, however, LLVM does not recommend the usage of these new instructions +// as the old ones are still more optimized. +fn codegen_msvc_try( + bx: &mut Builder<'a, 'll, 'tcx>, + try_func: &'ll Value, + data: &'ll Value, + catch_func: &'ll Value, + dest: &'ll Value, +) { + let (llty, llfn) = get_rust_try_fn(bx, &mut |mut bx| { + bx.set_personality_fn(bx.eh_personality()); + + let mut normal = bx.build_sibling_block("normal"); + let mut catchswitch = bx.build_sibling_block("catchswitch"); + let mut catchpad_rust = bx.build_sibling_block("catchpad_rust"); + let mut catchpad_foreign = bx.build_sibling_block("catchpad_foreign"); + let mut caught = bx.build_sibling_block("caught"); + + let try_func = llvm::get_param(bx.llfn(), 0); + let data = llvm::get_param(bx.llfn(), 1); + let catch_func = llvm::get_param(bx.llfn(), 2); + + // We're generating an IR snippet that looks like: + // + // declare i32 @rust_try(%try_func, %data, %catch_func) { + // %slot = alloca i8* + // invoke %try_func(%data) to label %normal unwind label %catchswitch + // + // normal: + // ret i32 0 + // + // catchswitch: + // %cs = catchswitch within none [%catchpad_rust, %catchpad_foreign] unwind to caller + // + // catchpad_rust: + // %tok = catchpad within %cs [%type_descriptor, 8, %slot] + // %ptr = load %slot + // call %catch_func(%data, %ptr) + // catchret from %tok to label %caught + // + // catchpad_foreign: + // %tok = catchpad within %cs [null, 64, null] + // call %catch_func(%data, null) + // catchret from %tok to label %caught + // + // caught: + // ret i32 1 + // } + // + // This structure follows the basic usage of throw/try/catch in LLVM. + // For example, compile this C++ snippet to see what LLVM generates: + // + // struct rust_panic { + // rust_panic(const rust_panic&); + // ~rust_panic(); + // + // void* x[2]; + // }; + // + // int __rust_try( + // void (*try_func)(void*), + // void *data, + // void (*catch_func)(void*, void*) noexcept + // ) { + // try { + // try_func(data); + // return 0; + // } catch(rust_panic& a) { + // catch_func(data, &a); + // return 1; + // } catch(...) { + // catch_func(data, NULL); + // return 1; + // } + // } + // + // More information can be found in libstd's seh.rs implementation. + let ptr_align = bx.tcx().data_layout.pointer_align.abi; + let slot = bx.alloca(bx.type_i8p(), ptr_align); + let try_func_ty = bx.type_func(&[bx.type_i8p()], bx.type_void()); + bx.invoke(try_func_ty, try_func, &[data], normal.llbb(), catchswitch.llbb(), None); + + normal.ret(bx.const_i32(0)); + + let cs = catchswitch.catch_switch(None, None, 2); + catchswitch.add_handler(cs, catchpad_rust.llbb()); + catchswitch.add_handler(cs, catchpad_foreign.llbb()); + + // We can't use the TypeDescriptor defined in libpanic_unwind because it + // might be in another DLL and the SEH encoding only supports specifying + // a TypeDescriptor from the current module. + // + // However this isn't an issue since the MSVC runtime uses string + // comparison on the type name to match TypeDescriptors rather than + // pointer equality. + // + // So instead we generate a new TypeDescriptor in each module that uses + // `try` and let the linker merge duplicate definitions in the same + // module. + // + // When modifying, make sure that the type_name string exactly matches + // the one used in src/libpanic_unwind/seh.rs. + let type_info_vtable = bx.declare_global("??_7type_info@@6B@", bx.type_i8p()); + let type_name = bx.const_bytes(b"rust_panic\0"); + let type_info = + bx.const_struct(&[type_info_vtable, bx.const_null(bx.type_i8p()), type_name], false); + let tydesc = bx.declare_global("__rust_panic_type_info", bx.val_ty(type_info)); + unsafe { + llvm::LLVMRustSetLinkage(tydesc, llvm::Linkage::LinkOnceODRLinkage); + llvm::SetUniqueComdat(bx.llmod, tydesc); + llvm::LLVMSetInitializer(tydesc, type_info); + } + + // The flag value of 8 indicates that we are catching the exception by + // reference instead of by value. We can't use catch by value because + // that requires copying the exception object, which we don't support + // since our exception object effectively contains a Box. + // + // Source: MicrosoftCXXABI::getAddrOfCXXCatchHandlerType in clang + let flags = bx.const_i32(8); + let funclet = catchpad_rust.catch_pad(cs, &[tydesc, flags, slot]); + let ptr = catchpad_rust.load(bx.type_i8p(), slot, ptr_align); + let catch_ty = bx.type_func(&[bx.type_i8p(), bx.type_i8p()], bx.type_void()); + catchpad_rust.call(catch_ty, catch_func, &[data, ptr], Some(&funclet)); + catchpad_rust.catch_ret(&funclet, caught.llbb()); + + // The flag value of 64 indicates a "catch-all". + let flags = bx.const_i32(64); + let null = bx.const_null(bx.type_i8p()); + let funclet = catchpad_foreign.catch_pad(cs, &[null, flags, null]); + catchpad_foreign.call(catch_ty, catch_func, &[data, null], Some(&funclet)); + catchpad_foreign.catch_ret(&funclet, caught.llbb()); + + caught.ret(bx.const_i32(1)); + }); + + // Note that no invoke is used here because by definition this function + // can't panic (that's what it's catching). + let ret = bx.call(llty, llfn, &[try_func, data, catch_func], None); + let i32_align = bx.tcx().data_layout.i32_align.abi; + bx.store(ret, dest, i32_align); +} + +// Definition of the standard `try` function for Rust using the GNU-like model +// of exceptions (e.g., the normal semantics of LLVM's `landingpad` and `invoke` +// instructions). +// +// This codegen is a little surprising because we always call a shim +// function instead of inlining the call to `invoke` manually here. This is done +// because in LLVM we're only allowed to have one personality per function +// definition. The call to the `try` intrinsic is being inlined into the +// function calling it, and that function may already have other personality +// functions in play. By calling a shim we're guaranteed that our shim will have +// the right personality function. +fn codegen_gnu_try( + bx: &mut Builder<'a, 'll, 'tcx>, + try_func: &'ll Value, + data: &'ll Value, + catch_func: &'ll Value, + dest: &'ll Value, +) { + let (llty, llfn) = get_rust_try_fn(bx, &mut |mut bx| { + // Codegens the shims described above: + // + // bx: + // invoke %try_func(%data) normal %normal unwind %catch + // + // normal: + // ret 0 + // + // catch: + // (%ptr, _) = landingpad + // call %catch_func(%data, %ptr) + // ret 1 + let mut then = bx.build_sibling_block("then"); + let mut catch = bx.build_sibling_block("catch"); + + let try_func = llvm::get_param(bx.llfn(), 0); + let data = llvm::get_param(bx.llfn(), 1); + let catch_func = llvm::get_param(bx.llfn(), 2); + let try_func_ty = bx.type_func(&[bx.type_i8p()], bx.type_void()); + bx.invoke(try_func_ty, try_func, &[data], then.llbb(), catch.llbb(), None); + then.ret(bx.const_i32(0)); + + // Type indicator for the exception being thrown. + // + // The first value in this tuple is a pointer to the exception object + // being thrown. The second value is a "selector" indicating which of + // the landing pad clauses the exception's type had been matched to. + // rust_try ignores the selector. + let lpad_ty = bx.type_struct(&[bx.type_i8p(), bx.type_i32()], false); + let vals = catch.landing_pad(lpad_ty, bx.eh_personality(), 1); + let tydesc = bx.const_null(bx.type_i8p()); + catch.add_clause(vals, tydesc); + let ptr = catch.extract_value(vals, 0); + let catch_ty = bx.type_func(&[bx.type_i8p(), bx.type_i8p()], bx.type_void()); + catch.call(catch_ty, catch_func, &[data, ptr], None); + catch.ret(bx.const_i32(1)); + }); + + // Note that no invoke is used here because by definition this function + // can't panic (that's what it's catching). + let ret = bx.call(llty, llfn, &[try_func, data, catch_func], None); + let i32_align = bx.tcx().data_layout.i32_align.abi; + bx.store(ret, dest, i32_align); +} + +// Variant of codegen_gnu_try used for emscripten where Rust panics are +// implemented using C++ exceptions. Here we use exceptions of a specific type +// (`struct rust_panic`) to represent Rust panics. +fn codegen_emcc_try( + bx: &mut Builder<'a, 'll, 'tcx>, + try_func: &'ll Value, + data: &'ll Value, + catch_func: &'ll Value, + dest: &'ll Value, +) { + let (llty, llfn) = get_rust_try_fn(bx, &mut |mut bx| { + // Codegens the shims described above: + // + // bx: + // invoke %try_func(%data) normal %normal unwind %catch + // + // normal: + // ret 0 + // + // catch: + // (%ptr, %selector) = landingpad + // %rust_typeid = @llvm.eh.typeid.for(@_ZTI10rust_panic) + // %is_rust_panic = %selector == %rust_typeid + // %catch_data = alloca { i8*, i8 } + // %catch_data[0] = %ptr + // %catch_data[1] = %is_rust_panic + // call %catch_func(%data, %catch_data) + // ret 1 + let mut then = bx.build_sibling_block("then"); + let mut catch = bx.build_sibling_block("catch"); + + let try_func = llvm::get_param(bx.llfn(), 0); + let data = llvm::get_param(bx.llfn(), 1); + let catch_func = llvm::get_param(bx.llfn(), 2); + let try_func_ty = bx.type_func(&[bx.type_i8p()], bx.type_void()); + bx.invoke(try_func_ty, try_func, &[data], then.llbb(), catch.llbb(), None); + then.ret(bx.const_i32(0)); + + // Type indicator for the exception being thrown. + // + // The first value in this tuple is a pointer to the exception object + // being thrown. The second value is a "selector" indicating which of + // the landing pad clauses the exception's type had been matched to. + let tydesc = bx.eh_catch_typeinfo(); + let lpad_ty = bx.type_struct(&[bx.type_i8p(), bx.type_i32()], false); + let vals = catch.landing_pad(lpad_ty, bx.eh_personality(), 2); + catch.add_clause(vals, tydesc); + catch.add_clause(vals, bx.const_null(bx.type_i8p())); + let ptr = catch.extract_value(vals, 0); + let selector = catch.extract_value(vals, 1); + + // Check if the typeid we got is the one for a Rust panic. + let rust_typeid = catch.call_intrinsic("llvm.eh.typeid.for", &[tydesc]); + let is_rust_panic = catch.icmp(IntPredicate::IntEQ, selector, rust_typeid); + let is_rust_panic = catch.zext(is_rust_panic, bx.type_bool()); + + // We need to pass two values to catch_func (ptr and is_rust_panic), so + // create an alloca and pass a pointer to that. + let ptr_align = bx.tcx().data_layout.pointer_align.abi; + let i8_align = bx.tcx().data_layout.i8_align.abi; + let catch_data_type = bx.type_struct(&[bx.type_i8p(), bx.type_bool()], false); + let catch_data = catch.alloca(catch_data_type, ptr_align); + let catch_data_0 = catch.inbounds_gep( + catch_data_type, + catch_data, + &[bx.const_usize(0), bx.const_usize(0)], + ); + catch.store(ptr, catch_data_0, ptr_align); + let catch_data_1 = catch.inbounds_gep( + catch_data_type, + catch_data, + &[bx.const_usize(0), bx.const_usize(1)], + ); + catch.store(is_rust_panic, catch_data_1, i8_align); + let catch_data = catch.bitcast(catch_data, bx.type_i8p()); + + let catch_ty = bx.type_func(&[bx.type_i8p(), bx.type_i8p()], bx.type_void()); + catch.call(catch_ty, catch_func, &[data, catch_data], None); + catch.ret(bx.const_i32(1)); + }); + + // Note that no invoke is used here because by definition this function + // can't panic (that's what it's catching). + let ret = bx.call(llty, llfn, &[try_func, data, catch_func], None); + let i32_align = bx.tcx().data_layout.i32_align.abi; + bx.store(ret, dest, i32_align); +} + +// Helper function to give a Block to a closure to codegen a shim function. +// This is currently primarily used for the `try` intrinsic functions above. +fn gen_fn<'ll, 'tcx>( + cx: &CodegenCx<'ll, 'tcx>, + name: &str, + rust_fn_sig: ty::PolyFnSig<'tcx>, + codegen: &mut dyn FnMut(Builder<'_, 'll, 'tcx>), +) -> (&'ll Type, &'ll Value) { + let fn_abi = FnAbi::of_fn_ptr(cx, rust_fn_sig, &[]); + let llty = fn_abi.llvm_type(cx); + let llfn = cx.declare_fn(name, &fn_abi); + cx.set_frame_pointer_type(llfn); + cx.apply_target_cpu_attr(llfn); + // FIXME(eddyb) find a nicer way to do this. + unsafe { llvm::LLVMRustSetLinkage(llfn, llvm::Linkage::InternalLinkage) }; + let llbb = Builder::append_block(cx, llfn, "entry-block"); + let bx = Builder::build(cx, llbb); + codegen(bx); + (llty, llfn) +} + +// Helper function used to get a handle to the `__rust_try` function used to +// catch exceptions. +// +// This function is only generated once and is then cached. +fn get_rust_try_fn<'ll, 'tcx>( + cx: &CodegenCx<'ll, 'tcx>, + codegen: &mut dyn FnMut(Builder<'_, 'll, 'tcx>), +) -> (&'ll Type, &'ll Value) { + if let Some(llfn) = cx.rust_try_fn.get() { + return llfn; + } + + // Define the type up front for the signature of the rust_try function. + let tcx = cx.tcx; + let i8p = tcx.mk_mut_ptr(tcx.types.i8); + // `unsafe fn(*mut i8) -> ()` + let try_fn_ty = tcx.mk_fn_ptr(ty::Binder::dummy(tcx.mk_fn_sig( + iter::once(i8p), + tcx.mk_unit(), + false, + hir::Unsafety::Unsafe, + Abi::Rust, + ))); + // `unsafe fn(*mut i8, *mut i8) -> ()` + let catch_fn_ty = tcx.mk_fn_ptr(ty::Binder::dummy(tcx.mk_fn_sig( + [i8p, i8p].iter().cloned(), + tcx.mk_unit(), + false, + hir::Unsafety::Unsafe, + Abi::Rust, + ))); + // `unsafe fn(unsafe fn(*mut i8) -> (), *mut i8, unsafe fn(*mut i8, *mut i8) -> ()) -> i32` + let rust_fn_sig = ty::Binder::dummy(cx.tcx.mk_fn_sig( + vec![try_fn_ty, i8p, catch_fn_ty].into_iter(), + tcx.types.i32, + false, + hir::Unsafety::Unsafe, + Abi::Rust, + )); + let rust_try = gen_fn(cx, "__rust_try", rust_fn_sig, codegen); + cx.rust_try_fn.set(Some(rust_try)); + rust_try +} + +fn generic_simd_intrinsic( + bx: &mut Builder<'a, 'll, 'tcx>, + name: Symbol, + callee_ty: Ty<'tcx>, + args: &[OperandRef<'tcx, &'ll Value>], + ret_ty: Ty<'tcx>, + llret_ty: &'ll Type, + span: Span, +) -> Result<&'ll Value, ()> { + // macros for error handling: + macro_rules! emit_error { + ($msg: tt) => { + emit_error!($msg, ) + }; + ($msg: tt, $($fmt: tt)*) => { + span_invalid_monomorphization_error( + bx.sess(), span, + &format!(concat!("invalid monomorphization of `{}` intrinsic: ", $msg), + name, $($fmt)*)); + } + } + + macro_rules! return_error { + ($($fmt: tt)*) => { + { + emit_error!($($fmt)*); + return Err(()); + } + } + } + + macro_rules! require { + ($cond: expr, $($fmt: tt)*) => { + if !$cond { + return_error!($($fmt)*); + } + }; + } + + macro_rules! require_simd { + ($ty: expr, $position: expr) => { + require!($ty.is_simd(), "expected SIMD {} type, found non-SIMD `{}`", $position, $ty) + }; + } + + let tcx = bx.tcx(); + let sig = + tcx.normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), callee_ty.fn_sig(tcx)); + let arg_tys = sig.inputs(); + let name_str = &*name.as_str(); + + if name == sym::simd_select_bitmask { + let in_ty = arg_tys[0]; + let m_len = match in_ty.kind() { + // Note that this `.unwrap()` crashes for isize/usize, that's sort + // of intentional as there's not currently a use case for that. + ty::Int(i) => i.bit_width().unwrap(), + ty::Uint(i) => i.bit_width().unwrap(), + _ => return_error!("`{}` is not an integral type", in_ty), + }; + require_simd!(arg_tys[1], "argument"); + let (v_len, _) = arg_tys[1].simd_size_and_type(bx.tcx()); + require!( + // Allow masks for vectors with fewer than 8 elements to be + // represented with a u8 or i8. + m_len == v_len || (m_len == 8 && v_len < 8), + "mismatched lengths: mask length `{}` != other vector length `{}`", + m_len, + v_len + ); + let i1 = bx.type_i1(); + let im = bx.type_ix(v_len); + let i1xn = bx.type_vector(i1, v_len); + let m_im = bx.trunc(args[0].immediate(), im); + let m_i1s = bx.bitcast(m_im, i1xn); + return Ok(bx.select(m_i1s, args[1].immediate(), args[2].immediate())); + } + + // every intrinsic below takes a SIMD vector as its first argument + require_simd!(arg_tys[0], "input"); + let in_ty = arg_tys[0]; + + let comparison = match name { + sym::simd_eq => Some(hir::BinOpKind::Eq), + sym::simd_ne => Some(hir::BinOpKind::Ne), + sym::simd_lt => Some(hir::BinOpKind::Lt), + sym::simd_le => Some(hir::BinOpKind::Le), + sym::simd_gt => Some(hir::BinOpKind::Gt), + sym::simd_ge => Some(hir::BinOpKind::Ge), + _ => None, + }; + + let (in_len, in_elem) = arg_tys[0].simd_size_and_type(bx.tcx()); + if let Some(cmp_op) = comparison { + require_simd!(ret_ty, "return"); + + let (out_len, out_ty) = ret_ty.simd_size_and_type(bx.tcx()); + require!( + in_len == out_len, + "expected return type with length {} (same as input type `{}`), \ + found `{}` with length {}", + in_len, + in_ty, + ret_ty, + out_len + ); + require!( + bx.type_kind(bx.element_type(llret_ty)) == TypeKind::Integer, + "expected return type with integer elements, found `{}` with non-integer `{}`", + ret_ty, + out_ty + ); + + return Ok(compare_simd_types( + bx, + args[0].immediate(), + args[1].immediate(), + in_elem, + llret_ty, + cmp_op, + )); + } + + if let Some(stripped) = name_str.strip_prefix("simd_shuffle") { + let n: u64 = stripped.parse().unwrap_or_else(|_| { + span_bug!(span, "bad `simd_shuffle` instruction only caught in codegen?") + }); + + require_simd!(ret_ty, "return"); + + let (out_len, out_ty) = ret_ty.simd_size_and_type(bx.tcx()); + require!( + out_len == n, + "expected return type of length {}, found `{}` with length {}", + n, + ret_ty, + out_len + ); + require!( + in_elem == out_ty, + "expected return element type `{}` (element of input `{}`), \ + found `{}` with element type `{}`", + in_elem, + in_ty, + ret_ty, + out_ty + ); + + let total_len = u128::from(in_len) * 2; + + let vector = args[2].immediate(); + + let indices: Option<Vec<_>> = (0..n) + .map(|i| { + let arg_idx = i; + let val = bx.const_get_elt(vector, i as u64); + match bx.const_to_opt_u128(val, true) { + None => { + emit_error!("shuffle index #{} is not a constant", arg_idx); + None + } + Some(idx) if idx >= total_len => { + emit_error!( + "shuffle index #{} is out of bounds (limit {})", + arg_idx, + total_len + ); + None + } + Some(idx) => Some(bx.const_i32(idx as i32)), + } + }) + .collect(); + let indices = match indices { + Some(i) => i, + None => return Ok(bx.const_null(llret_ty)), + }; + + return Ok(bx.shuffle_vector( + args[0].immediate(), + args[1].immediate(), + bx.const_vector(&indices), + )); + } + + if name == sym::simd_insert { + require!( + in_elem == arg_tys[2], + "expected inserted type `{}` (element of input `{}`), found `{}`", + in_elem, + in_ty, + arg_tys[2] + ); + return Ok(bx.insert_element( + args[0].immediate(), + args[2].immediate(), + args[1].immediate(), + )); + } + if name == sym::simd_extract { + require!( + ret_ty == in_elem, + "expected return type `{}` (element of input `{}`), found `{}`", + in_elem, + in_ty, + ret_ty + ); + return Ok(bx.extract_element(args[0].immediate(), args[1].immediate())); + } + + if name == sym::simd_select { + let m_elem_ty = in_elem; + let m_len = in_len; + require_simd!(arg_tys[1], "argument"); + let (v_len, _) = arg_tys[1].simd_size_and_type(bx.tcx()); + require!( + m_len == v_len, + "mismatched lengths: mask length `{}` != other vector length `{}`", + m_len, + v_len + ); + match m_elem_ty.kind() { + ty::Int(_) => {} + _ => return_error!("mask element type is `{}`, expected `i_`", m_elem_ty), + } + // truncate the mask to a vector of i1s + let i1 = bx.type_i1(); + let i1xn = bx.type_vector(i1, m_len as u64); + let m_i1s = bx.trunc(args[0].immediate(), i1xn); + return Ok(bx.select(m_i1s, args[1].immediate(), args[2].immediate())); + } + + if name == sym::simd_bitmask { + // The `fn simd_bitmask(vector) -> unsigned integer` intrinsic takes a + // vector mask and returns an unsigned integer containing the most + // significant bit (MSB) of each lane. + + // If the vector has less than 8 lanes, an u8 is returned with zeroed + // trailing bits. + let expected_int_bits = in_len.max(8); + match ret_ty.kind() { + ty::Uint(i) if i.bit_width() == Some(expected_int_bits) => (), + _ => return_error!("bitmask `{}`, expected `u{}`", ret_ty, expected_int_bits), + } + + // Integer vector <i{in_bitwidth} x in_len>: + let (i_xn, in_elem_bitwidth) = match in_elem.kind() { + ty::Int(i) => ( + args[0].immediate(), + i.bit_width().unwrap_or_else(|| bx.data_layout().pointer_size.bits()), + ), + ty::Uint(i) => ( + args[0].immediate(), + i.bit_width().unwrap_or_else(|| bx.data_layout().pointer_size.bits()), + ), + _ => return_error!( + "vector argument `{}`'s element type `{}`, expected integer element type", + in_ty, + in_elem + ), + }; + + // Shift the MSB to the right by "in_elem_bitwidth - 1" into the first bit position. + let shift_indices = + vec![ + bx.cx.const_int(bx.type_ix(in_elem_bitwidth), (in_elem_bitwidth - 1) as _); + in_len as _ + ]; + let i_xn_msb = bx.lshr(i_xn, bx.const_vector(shift_indices.as_slice())); + // Truncate vector to an <i1 x N> + let i1xn = bx.trunc(i_xn_msb, bx.type_vector(bx.type_i1(), in_len)); + // Bitcast <i1 x N> to iN: + let i_ = bx.bitcast(i1xn, bx.type_ix(in_len)); + // Zero-extend iN to the bitmask type: + return Ok(bx.zext(i_, bx.type_ix(expected_int_bits))); + } + + fn simd_simple_float_intrinsic( + name: Symbol, + in_elem: &::rustc_middle::ty::TyS<'_>, + in_ty: &::rustc_middle::ty::TyS<'_>, + in_len: u64, + bx: &mut Builder<'a, 'll, 'tcx>, + span: Span, + args: &[OperandRef<'tcx, &'ll Value>], + ) -> Result<&'ll Value, ()> { + macro_rules! emit_error { + ($msg: tt) => { + emit_error!($msg, ) + }; + ($msg: tt, $($fmt: tt)*) => { + span_invalid_monomorphization_error( + bx.sess(), span, + &format!(concat!("invalid monomorphization of `{}` intrinsic: ", $msg), + name, $($fmt)*)); + } + } + macro_rules! return_error { + ($($fmt: tt)*) => { + { + emit_error!($($fmt)*); + return Err(()); + } + } + } + + let (elem_ty_str, elem_ty) = if let ty::Float(f) = in_elem.kind() { + let elem_ty = bx.cx.type_float_from_ty(*f); + match f.bit_width() { + 32 => ("f32", elem_ty), + 64 => ("f64", elem_ty), + _ => { + return_error!( + "unsupported element type `{}` of floating-point vector `{}`", + f.name_str(), + in_ty + ); + } + } + } else { + return_error!("`{}` is not a floating-point type", in_ty); + }; + + let vec_ty = bx.type_vector(elem_ty, in_len); + + let (intr_name, fn_ty) = match name { + sym::simd_ceil => ("ceil", bx.type_func(&[vec_ty], vec_ty)), + sym::simd_fabs => ("fabs", bx.type_func(&[vec_ty], vec_ty)), + sym::simd_fcos => ("cos", bx.type_func(&[vec_ty], vec_ty)), + sym::simd_fexp2 => ("exp2", bx.type_func(&[vec_ty], vec_ty)), + sym::simd_fexp => ("exp", bx.type_func(&[vec_ty], vec_ty)), + sym::simd_flog10 => ("log10", bx.type_func(&[vec_ty], vec_ty)), + sym::simd_flog2 => ("log2", bx.type_func(&[vec_ty], vec_ty)), + sym::simd_flog => ("log", bx.type_func(&[vec_ty], vec_ty)), + sym::simd_floor => ("floor", bx.type_func(&[vec_ty], vec_ty)), + sym::simd_fma => ("fma", bx.type_func(&[vec_ty, vec_ty, vec_ty], vec_ty)), + sym::simd_fpowi => ("powi", bx.type_func(&[vec_ty, bx.type_i32()], vec_ty)), + sym::simd_fpow => ("pow", bx.type_func(&[vec_ty, vec_ty], vec_ty)), + sym::simd_fsin => ("sin", bx.type_func(&[vec_ty], vec_ty)), + sym::simd_fsqrt => ("sqrt", bx.type_func(&[vec_ty], vec_ty)), + sym::simd_round => ("round", bx.type_func(&[vec_ty], vec_ty)), + sym::simd_trunc => ("trunc", bx.type_func(&[vec_ty], vec_ty)), + _ => return_error!("unrecognized intrinsic `{}`", name), + }; + let llvm_name = &format!("llvm.{0}.v{1}{2}", intr_name, in_len, elem_ty_str); + let f = bx.declare_cfn(&llvm_name, llvm::UnnamedAddr::No, fn_ty); + let c = + bx.call(fn_ty, f, &args.iter().map(|arg| arg.immediate()).collect::<Vec<_>>(), None); + Ok(c) + } + + if std::matches!( + name, + sym::simd_ceil + | sym::simd_fabs + | sym::simd_fcos + | sym::simd_fexp2 + | sym::simd_fexp + | sym::simd_flog10 + | sym::simd_flog2 + | sym::simd_flog + | sym::simd_floor + | sym::simd_fma + | sym::simd_fpow + | sym::simd_fpowi + | sym::simd_fsin + | sym::simd_fsqrt + | sym::simd_round + | sym::simd_trunc + ) { + return simd_simple_float_intrinsic(name, in_elem, in_ty, in_len, bx, span, args); + } + + // FIXME: use: + // https://github.com/llvm-mirror/llvm/blob/master/include/llvm/IR/Function.h#L182 + // https://github.com/llvm-mirror/llvm/blob/master/include/llvm/IR/Intrinsics.h#L81 + fn llvm_vector_str(elem_ty: Ty<'_>, vec_len: u64, no_pointers: usize) -> String { + let p0s: String = "p0".repeat(no_pointers); + match *elem_ty.kind() { + ty::Int(v) => format!("v{}{}i{}", vec_len, p0s, v.bit_width().unwrap()), + ty::Uint(v) => format!("v{}{}i{}", vec_len, p0s, v.bit_width().unwrap()), + ty::Float(v) => format!("v{}{}f{}", vec_len, p0s, v.bit_width()), + _ => unreachable!(), + } + } + + fn llvm_vector_ty( + cx: &CodegenCx<'ll, '_>, + elem_ty: Ty<'_>, + vec_len: u64, + mut no_pointers: usize, + ) -> &'ll Type { + // FIXME: use cx.layout_of(ty).llvm_type() ? + let mut elem_ty = match *elem_ty.kind() { + ty::Int(v) => cx.type_int_from_ty(v), + ty::Uint(v) => cx.type_uint_from_ty(v), + ty::Float(v) => cx.type_float_from_ty(v), + _ => unreachable!(), + }; + while no_pointers > 0 { + elem_ty = cx.type_ptr_to(elem_ty); + no_pointers -= 1; + } + cx.type_vector(elem_ty, vec_len) + } + + if name == sym::simd_gather { + // simd_gather(values: <N x T>, pointers: <N x *_ T>, + // mask: <N x i{M}>) -> <N x T> + // * N: number of elements in the input vectors + // * T: type of the element to load + // * M: any integer width is supported, will be truncated to i1 + + // All types must be simd vector types + require_simd!(in_ty, "first"); + require_simd!(arg_tys[1], "second"); + require_simd!(arg_tys[2], "third"); + require_simd!(ret_ty, "return"); + + // Of the same length: + let (out_len, _) = arg_tys[1].simd_size_and_type(bx.tcx()); + let (out_len2, _) = arg_tys[2].simd_size_and_type(bx.tcx()); + require!( + in_len == out_len, + "expected {} argument with length {} (same as input type `{}`), \ + found `{}` with length {}", + "second", + in_len, + in_ty, + arg_tys[1], + out_len + ); + require!( + in_len == out_len2, + "expected {} argument with length {} (same as input type `{}`), \ + found `{}` with length {}", + "third", + in_len, + in_ty, + arg_tys[2], + out_len2 + ); + + // The return type must match the first argument type + require!(ret_ty == in_ty, "expected return type `{}`, found `{}`", in_ty, ret_ty); + + // This counts how many pointers + fn ptr_count(t: Ty<'_>) -> usize { + match t.kind() { + ty::RawPtr(p) => 1 + ptr_count(p.ty), + _ => 0, + } + } + + // Non-ptr type + fn non_ptr(t: Ty<'_>) -> Ty<'_> { + match t.kind() { + ty::RawPtr(p) => non_ptr(p.ty), + _ => t, + } + } + + // The second argument must be a simd vector with an element type that's a pointer + // to the element type of the first argument + let (_, element_ty0) = arg_tys[0].simd_size_and_type(bx.tcx()); + let (_, element_ty1) = arg_tys[1].simd_size_and_type(bx.tcx()); + let (pointer_count, underlying_ty) = match element_ty1.kind() { + ty::RawPtr(p) if p.ty == in_elem => (ptr_count(element_ty1), non_ptr(element_ty1)), + _ => { + require!( + false, + "expected element type `{}` of second argument `{}` \ + to be a pointer to the element type `{}` of the first \ + argument `{}`, found `{}` != `*_ {}`", + element_ty1, + arg_tys[1], + in_elem, + in_ty, + element_ty1, + in_elem + ); + unreachable!(); + } + }; + assert!(pointer_count > 0); + assert_eq!(pointer_count - 1, ptr_count(element_ty0)); + assert_eq!(underlying_ty, non_ptr(element_ty0)); + + // The element type of the third argument must be a signed integer type of any width: + let (_, element_ty2) = arg_tys[2].simd_size_and_type(bx.tcx()); + match element_ty2.kind() { + ty::Int(_) => (), + _ => { + require!( + false, + "expected element type `{}` of third argument `{}` \ + to be a signed integer type", + element_ty2, + arg_tys[2] + ); + } + } + + // Alignment of T, must be a constant integer value: + let alignment_ty = bx.type_i32(); + let alignment = bx.const_i32(bx.align_of(in_elem).bytes() as i32); + + // Truncate the mask vector to a vector of i1s: + let (mask, mask_ty) = { + let i1 = bx.type_i1(); + let i1xn = bx.type_vector(i1, in_len); + (bx.trunc(args[2].immediate(), i1xn), i1xn) + }; + + // Type of the vector of pointers: + let llvm_pointer_vec_ty = llvm_vector_ty(bx, underlying_ty, in_len, pointer_count); + let llvm_pointer_vec_str = llvm_vector_str(underlying_ty, in_len, pointer_count); + + // Type of the vector of elements: + let llvm_elem_vec_ty = llvm_vector_ty(bx, underlying_ty, in_len, pointer_count - 1); + let llvm_elem_vec_str = llvm_vector_str(underlying_ty, in_len, pointer_count - 1); + + let llvm_intrinsic = + format!("llvm.masked.gather.{}.{}", llvm_elem_vec_str, llvm_pointer_vec_str); + let fn_ty = bx.type_func( + &[llvm_pointer_vec_ty, alignment_ty, mask_ty, llvm_elem_vec_ty], + llvm_elem_vec_ty, + ); + let f = bx.declare_cfn(&llvm_intrinsic, llvm::UnnamedAddr::No, fn_ty); + let v = + bx.call(fn_ty, f, &[args[1].immediate(), alignment, mask, args[0].immediate()], None); + return Ok(v); + } + + if name == sym::simd_scatter { + // simd_scatter(values: <N x T>, pointers: <N x *mut T>, + // mask: <N x i{M}>) -> () + // * N: number of elements in the input vectors + // * T: type of the element to load + // * M: any integer width is supported, will be truncated to i1 + + // All types must be simd vector types + require_simd!(in_ty, "first"); + require_simd!(arg_tys[1], "second"); + require_simd!(arg_tys[2], "third"); + + // Of the same length: + let (element_len1, _) = arg_tys[1].simd_size_and_type(bx.tcx()); + let (element_len2, _) = arg_tys[2].simd_size_and_type(bx.tcx()); + require!( + in_len == element_len1, + "expected {} argument with length {} (same as input type `{}`), \ + found `{}` with length {}", + "second", + in_len, + in_ty, + arg_tys[1], + element_len1 + ); + require!( + in_len == element_len2, + "expected {} argument with length {} (same as input type `{}`), \ + found `{}` with length {}", + "third", + in_len, + in_ty, + arg_tys[2], + element_len2 + ); + + // This counts how many pointers + fn ptr_count(t: Ty<'_>) -> usize { + match t.kind() { + ty::RawPtr(p) => 1 + ptr_count(p.ty), + _ => 0, + } + } + + // Non-ptr type + fn non_ptr(t: Ty<'_>) -> Ty<'_> { + match t.kind() { + ty::RawPtr(p) => non_ptr(p.ty), + _ => t, + } + } + + // The second argument must be a simd vector with an element type that's a pointer + // to the element type of the first argument + let (_, element_ty0) = arg_tys[0].simd_size_and_type(bx.tcx()); + let (_, element_ty1) = arg_tys[1].simd_size_and_type(bx.tcx()); + let (_, element_ty2) = arg_tys[2].simd_size_and_type(bx.tcx()); + let (pointer_count, underlying_ty) = match element_ty1.kind() { + ty::RawPtr(p) if p.ty == in_elem && p.mutbl == hir::Mutability::Mut => { + (ptr_count(element_ty1), non_ptr(element_ty1)) + } + _ => { + require!( + false, + "expected element type `{}` of second argument `{}` \ + to be a pointer to the element type `{}` of the first \ + argument `{}`, found `{}` != `*mut {}`", + element_ty1, + arg_tys[1], + in_elem, + in_ty, + element_ty1, + in_elem + ); + unreachable!(); + } + }; + assert!(pointer_count > 0); + assert_eq!(pointer_count - 1, ptr_count(element_ty0)); + assert_eq!(underlying_ty, non_ptr(element_ty0)); + + // The element type of the third argument must be a signed integer type of any width: + match element_ty2.kind() { + ty::Int(_) => (), + _ => { + require!( + false, + "expected element type `{}` of third argument `{}` \ + be a signed integer type", + element_ty2, + arg_tys[2] + ); + } + } + + // Alignment of T, must be a constant integer value: + let alignment_ty = bx.type_i32(); + let alignment = bx.const_i32(bx.align_of(in_elem).bytes() as i32); + + // Truncate the mask vector to a vector of i1s: + let (mask, mask_ty) = { + let i1 = bx.type_i1(); + let i1xn = bx.type_vector(i1, in_len); + (bx.trunc(args[2].immediate(), i1xn), i1xn) + }; + + let ret_t = bx.type_void(); + + // Type of the vector of pointers: + let llvm_pointer_vec_ty = llvm_vector_ty(bx, underlying_ty, in_len, pointer_count); + let llvm_pointer_vec_str = llvm_vector_str(underlying_ty, in_len, pointer_count); + + // Type of the vector of elements: + let llvm_elem_vec_ty = llvm_vector_ty(bx, underlying_ty, in_len, pointer_count - 1); + let llvm_elem_vec_str = llvm_vector_str(underlying_ty, in_len, pointer_count - 1); + + let llvm_intrinsic = + format!("llvm.masked.scatter.{}.{}", llvm_elem_vec_str, llvm_pointer_vec_str); + let fn_ty = + bx.type_func(&[llvm_elem_vec_ty, llvm_pointer_vec_ty, alignment_ty, mask_ty], ret_t); + let f = bx.declare_cfn(&llvm_intrinsic, llvm::UnnamedAddr::No, fn_ty); + let v = + bx.call(fn_ty, f, &[args[0].immediate(), args[1].immediate(), alignment, mask], None); + return Ok(v); + } + + macro_rules! arith_red { + ($name:ident : $integer_reduce:ident, $float_reduce:ident, $ordered:expr, $op:ident, + $identity:expr) => { + if name == sym::$name { + require!( + ret_ty == in_elem, + "expected return type `{}` (element of input `{}`), found `{}`", + in_elem, + in_ty, + ret_ty + ); + return match in_elem.kind() { + ty::Int(_) | ty::Uint(_) => { + let r = bx.$integer_reduce(args[0].immediate()); + if $ordered { + // if overflow occurs, the result is the + // mathematical result modulo 2^n: + Ok(bx.$op(args[1].immediate(), r)) + } else { + Ok(bx.$integer_reduce(args[0].immediate())) + } + } + ty::Float(f) => { + let acc = if $ordered { + // ordered arithmetic reductions take an accumulator + args[1].immediate() + } else { + // unordered arithmetic reductions use the identity accumulator + match f.bit_width() { + 32 => bx.const_real(bx.type_f32(), $identity), + 64 => bx.const_real(bx.type_f64(), $identity), + v => return_error!( + r#" +unsupported {} from `{}` with element `{}` of size `{}` to `{}`"#, + sym::$name, + in_ty, + in_elem, + v, + ret_ty + ), + } + }; + Ok(bx.$float_reduce(acc, args[0].immediate())) + } + _ => return_error!( + "unsupported {} from `{}` with element `{}` to `{}`", + sym::$name, + in_ty, + in_elem, + ret_ty + ), + }; + } + }; + } + + arith_red!(simd_reduce_add_ordered: vector_reduce_add, vector_reduce_fadd, true, add, 0.0); + arith_red!(simd_reduce_mul_ordered: vector_reduce_mul, vector_reduce_fmul, true, mul, 1.0); + arith_red!( + simd_reduce_add_unordered: vector_reduce_add, + vector_reduce_fadd_fast, + false, + add, + 0.0 + ); + arith_red!( + simd_reduce_mul_unordered: vector_reduce_mul, + vector_reduce_fmul_fast, + false, + mul, + 1.0 + ); + + macro_rules! minmax_red { + ($name:ident: $int_red:ident, $float_red:ident) => { + if name == sym::$name { + require!( + ret_ty == in_elem, + "expected return type `{}` (element of input `{}`), found `{}`", + in_elem, + in_ty, + ret_ty + ); + return match in_elem.kind() { + ty::Int(_i) => Ok(bx.$int_red(args[0].immediate(), true)), + ty::Uint(_u) => Ok(bx.$int_red(args[0].immediate(), false)), + ty::Float(_f) => Ok(bx.$float_red(args[0].immediate())), + _ => return_error!( + "unsupported {} from `{}` with element `{}` to `{}`", + sym::$name, + in_ty, + in_elem, + ret_ty + ), + }; + } + }; + } + + minmax_red!(simd_reduce_min: vector_reduce_min, vector_reduce_fmin); + minmax_red!(simd_reduce_max: vector_reduce_max, vector_reduce_fmax); + + minmax_red!(simd_reduce_min_nanless: vector_reduce_min, vector_reduce_fmin_fast); + minmax_red!(simd_reduce_max_nanless: vector_reduce_max, vector_reduce_fmax_fast); + + macro_rules! bitwise_red { + ($name:ident : $red:ident, $boolean:expr) => { + if name == sym::$name { + let input = if !$boolean { + require!( + ret_ty == in_elem, + "expected return type `{}` (element of input `{}`), found `{}`", + in_elem, + in_ty, + ret_ty + ); + args[0].immediate() + } else { + match in_elem.kind() { + ty::Int(_) | ty::Uint(_) => {} + _ => return_error!( + "unsupported {} from `{}` with element `{}` to `{}`", + sym::$name, + in_ty, + in_elem, + ret_ty + ), + } + + // boolean reductions operate on vectors of i1s: + let i1 = bx.type_i1(); + let i1xn = bx.type_vector(i1, in_len as u64); + bx.trunc(args[0].immediate(), i1xn) + }; + return match in_elem.kind() { + ty::Int(_) | ty::Uint(_) => { + let r = bx.$red(input); + Ok(if !$boolean { r } else { bx.zext(r, bx.type_bool()) }) + } + _ => return_error!( + "unsupported {} from `{}` with element `{}` to `{}`", + sym::$name, + in_ty, + in_elem, + ret_ty + ), + }; + } + }; + } + + bitwise_red!(simd_reduce_and: vector_reduce_and, false); + bitwise_red!(simd_reduce_or: vector_reduce_or, false); + bitwise_red!(simd_reduce_xor: vector_reduce_xor, false); + bitwise_red!(simd_reduce_all: vector_reduce_and, true); + bitwise_red!(simd_reduce_any: vector_reduce_or, true); + + if name == sym::simd_cast { + require_simd!(ret_ty, "return"); + let (out_len, out_elem) = ret_ty.simd_size_and_type(bx.tcx()); + require!( + in_len == out_len, + "expected return type with length {} (same as input type `{}`), \ + found `{}` with length {}", + in_len, + in_ty, + ret_ty, + out_len + ); + // casting cares about nominal type, not just structural type + if in_elem == out_elem { + return Ok(args[0].immediate()); + } + + enum Style { + Float, + Int(/* is signed? */ bool), + Unsupported, + } + + let (in_style, in_width) = match in_elem.kind() { + // vectors of pointer-sized integers should've been + // disallowed before here, so this unwrap is safe. + ty::Int(i) => (Style::Int(true), i.bit_width().unwrap()), + ty::Uint(u) => (Style::Int(false), u.bit_width().unwrap()), + ty::Float(f) => (Style::Float, f.bit_width()), + _ => (Style::Unsupported, 0), + }; + let (out_style, out_width) = match out_elem.kind() { + ty::Int(i) => (Style::Int(true), i.bit_width().unwrap()), + ty::Uint(u) => (Style::Int(false), u.bit_width().unwrap()), + ty::Float(f) => (Style::Float, f.bit_width()), + _ => (Style::Unsupported, 0), + }; + + match (in_style, out_style) { + (Style::Int(in_is_signed), Style::Int(_)) => { + return Ok(match in_width.cmp(&out_width) { + Ordering::Greater => bx.trunc(args[0].immediate(), llret_ty), + Ordering::Equal => args[0].immediate(), + Ordering::Less => { + if in_is_signed { + bx.sext(args[0].immediate(), llret_ty) + } else { + bx.zext(args[0].immediate(), llret_ty) + } + } + }); + } + (Style::Int(in_is_signed), Style::Float) => { + return Ok(if in_is_signed { + bx.sitofp(args[0].immediate(), llret_ty) + } else { + bx.uitofp(args[0].immediate(), llret_ty) + }); + } + (Style::Float, Style::Int(out_is_signed)) => { + return Ok(if out_is_signed { + bx.fptosi(args[0].immediate(), llret_ty) + } else { + bx.fptoui(args[0].immediate(), llret_ty) + }); + } + (Style::Float, Style::Float) => { + return Ok(match in_width.cmp(&out_width) { + Ordering::Greater => bx.fptrunc(args[0].immediate(), llret_ty), + Ordering::Equal => args[0].immediate(), + Ordering::Less => bx.fpext(args[0].immediate(), llret_ty), + }); + } + _ => { /* Unsupported. Fallthrough. */ } + } + require!( + false, + "unsupported cast from `{}` with element `{}` to `{}` with element `{}`", + in_ty, + in_elem, + ret_ty, + out_elem + ); + } + macro_rules! arith_binary { + ($($name: ident: $($($p: ident),* => $call: ident),*;)*) => { + $(if name == sym::$name { + match in_elem.kind() { + $($(ty::$p(_))|* => { + return Ok(bx.$call(args[0].immediate(), args[1].immediate())) + })* + _ => {}, + } + require!(false, + "unsupported operation on `{}` with element `{}`", + in_ty, + in_elem) + })* + } + } + arith_binary! { + simd_add: Uint, Int => add, Float => fadd; + simd_sub: Uint, Int => sub, Float => fsub; + simd_mul: Uint, Int => mul, Float => fmul; + simd_div: Uint => udiv, Int => sdiv, Float => fdiv; + simd_rem: Uint => urem, Int => srem, Float => frem; + simd_shl: Uint, Int => shl; + simd_shr: Uint => lshr, Int => ashr; + simd_and: Uint, Int => and; + simd_or: Uint, Int => or; + simd_xor: Uint, Int => xor; + simd_fmax: Float => maxnum; + simd_fmin: Float => minnum; + + } + macro_rules! arith_unary { + ($($name: ident: $($($p: ident),* => $call: ident),*;)*) => { + $(if name == sym::$name { + match in_elem.kind() { + $($(ty::$p(_))|* => { + return Ok(bx.$call(args[0].immediate())) + })* + _ => {}, + } + require!(false, + "unsupported operation on `{}` with element `{}`", + in_ty, + in_elem) + })* + } + } + arith_unary! { + simd_neg: Int => neg, Float => fneg; + } + + if name == sym::simd_saturating_add || name == sym::simd_saturating_sub { + let lhs = args[0].immediate(); + let rhs = args[1].immediate(); + let is_add = name == sym::simd_saturating_add; + let ptr_bits = bx.tcx().data_layout.pointer_size.bits() as _; + let (signed, elem_width, elem_ty) = match *in_elem.kind() { + ty::Int(i) => (true, i.bit_width().unwrap_or(ptr_bits), bx.cx.type_int_from_ty(i)), + ty::Uint(i) => (false, i.bit_width().unwrap_or(ptr_bits), bx.cx.type_uint_from_ty(i)), + _ => { + return_error!( + "expected element type `{}` of vector type `{}` \ + to be a signed or unsigned integer type", + arg_tys[0].simd_size_and_type(bx.tcx()).1, + arg_tys[0] + ); + } + }; + let llvm_intrinsic = &format!( + "llvm.{}{}.sat.v{}i{}", + if signed { 's' } else { 'u' }, + if is_add { "add" } else { "sub" }, + in_len, + elem_width + ); + let vec_ty = bx.cx.type_vector(elem_ty, in_len as u64); + + let fn_ty = bx.type_func(&[vec_ty, vec_ty], vec_ty); + let f = bx.declare_cfn(&llvm_intrinsic, llvm::UnnamedAddr::No, fn_ty); + let v = bx.call(fn_ty, f, &[lhs, rhs], None); + return Ok(v); + } + + span_bug!(span, "unknown SIMD intrinsic"); +} + +// Returns the width of an int Ty, and if it's signed or not +// Returns None if the type is not an integer +// FIXME: there’s multiple of this functions, investigate using some of the already existing +// stuffs. +fn int_type_width_signed(ty: Ty<'_>, cx: &CodegenCx<'_, '_>) -> Option<(u64, bool)> { + match ty.kind() { + ty::Int(t) => { + Some((t.bit_width().unwrap_or(u64::from(cx.tcx.sess.target.pointer_width)), true)) + } + ty::Uint(t) => { + Some((t.bit_width().unwrap_or(u64::from(cx.tcx.sess.target.pointer_width)), false)) + } + _ => None, + } +} |