rust/compiler/rustc_codegen_llvm/src/intrinsic.rs
2022-06-18 01:09:20 +03:00

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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::{FnAbiOf, HasTyCtxt, LayoutOf};
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, Align, HasDataLayout, Primitive};
use rustc_target::spec::{HasTargetSpec, PanicStrategy};
use std::cmp::Ordering;
use std::iter;
fn get_simple_intrinsic<'ll>(
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<'ll, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'_, '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 ty::FnDef(def_id, substs) = *callee_ty.kind() else {
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 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(scalar) => {
match scalar.primitive() {
Primitive::Int(..) => {
if self.cx().size_of(ret_ty).bytes() < 4 {
// `va_arg` should not be called on an integer type
// less than 4 bytes in length. If it is, promote
// the integer to an `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 => {
let y = self.const_bool(true);
let llvm_name = &format!("llvm.ctlz.i{}", width);
self.call_intrinsic(llvm_name, &[args[0].immediate(), y])
}
sym::cttz_nonzero => {
let y = self.const_bool(true);
let llvm_name = &format!("llvm.cttz.i{}", 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]);
match self.cx.sess().target.arch.as_ref() {
"avr" | "msp430" => self.icmp(IntPredicate::IntEQ, cmp, self.const_i16(0)),
_ => self.icmp(IntPredicate::IntEQ, cmp, self.const_i32(0)),
}
}
}
sym::black_box => {
args[0].val.store(self, result);
// We need to "use" the argument in some way LLVM can't introspect, and on
// targets that support it we can typically leverage inline assembly to do
// this. LLVM's interpretation of inline assembly is that it's, well, a black
// box. This isn't the greatest implementation since it probably deoptimizes
// more than we want, but it's so far good enough.
crate::asm::inline_asm_call(
self,
"",
"r,~{memory}",
&[result.llval],
self.type_void(),
true,
false,
llvm::AsmDialect::Att,
&[span],
false,
None,
)
.unwrap_or_else(|| bug!("failed to generate inline asm call for `black_box`"));
// We have copied the value to `result` already.
return;
}
_ if name.as_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 type_test(&mut self, pointer: Self::Value, typeid: Self::Value) -> Self::Value {
// Test the called operand using llvm.type.test intrinsic. The LowerTypeTests link-time
// optimization pass replaces calls to this intrinsic with code to test type membership.
let i8p_ty = self.type_i8p();
let bitcast = self.bitcast(pointer, i8p_ty);
self.call_intrinsic("llvm.type.test", &[bitcast, typeid])
}
fn type_checked_load(
&mut self,
llvtable: &'ll Value,
vtable_byte_offset: u64,
typeid: &'ll Value,
) -> Self::Value {
let vtable_byte_offset = self.const_i32(vtable_byte_offset as i32);
self.call_intrinsic("llvm.type.checked.load", &[llvtable, vtable_byte_offset, typeid])
}
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<'ll>(
bx: &mut Builder<'_, 'll, '_>,
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.os == "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<'ll>(
bx: &mut Builder<'_, 'll, '_>,
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 normal = bx.append_sibling_block("normal");
let catchswitch = bx.append_sibling_block("catchswitch");
let catchpad_rust = bx.append_sibling_block("catchpad_rust");
let catchpad_foreign = bx.append_sibling_block("catchpad_foreign");
let caught = bx.append_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, catchswitch, None);
bx.switch_to_block(normal);
bx.ret(bx.const_i32(0));
bx.switch_to_block(catchswitch);
let cs = bx.catch_switch(None, None, &[catchpad_rust, catchpad_foreign]);
// 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
bx.switch_to_block(catchpad_rust);
let flags = bx.const_i32(8);
let funclet = bx.catch_pad(cs, &[tydesc, flags, slot]);
let ptr = bx.load(bx.type_i8p(), slot, ptr_align);
let catch_ty = bx.type_func(&[bx.type_i8p(), bx.type_i8p()], bx.type_void());
bx.call(catch_ty, catch_func, &[data, ptr], Some(&funclet));
bx.catch_ret(&funclet, caught);
// The flag value of 64 indicates a "catch-all".
bx.switch_to_block(catchpad_foreign);
let flags = bx.const_i32(64);
let null = bx.const_null(bx.type_i8p());
let funclet = bx.catch_pad(cs, &[null, flags, null]);
bx.call(catch_ty, catch_func, &[data, null], Some(&funclet));
bx.catch_ret(&funclet, caught);
bx.switch_to_block(caught);
bx.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<'ll>(
bx: &mut Builder<'_, 'll, '_>,
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 then = bx.append_sibling_block("then");
let catch = bx.append_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, catch, None);
bx.switch_to_block(then);
bx.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.
bx.switch_to_block(catch);
let lpad_ty = bx.type_struct(&[bx.type_i8p(), bx.type_i32()], false);
let vals = bx.landing_pad(lpad_ty, bx.eh_personality(), 1);
let tydesc = bx.const_null(bx.type_i8p());
bx.add_clause(vals, tydesc);
let ptr = bx.extract_value(vals, 0);
let catch_ty = bx.type_func(&[bx.type_i8p(), bx.type_i8p()], bx.type_void());
bx.call(catch_ty, catch_func, &[data, ptr], None);
bx.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<'ll>(
bx: &mut Builder<'_, 'll, '_>,
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 then = bx.append_sibling_block("then");
let catch = bx.append_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, catch, None);
bx.switch_to_block(then);
bx.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.
bx.switch_to_block(catch);
let tydesc = bx.eh_catch_typeinfo();
let lpad_ty = bx.type_struct(&[bx.type_i8p(), bx.type_i32()], false);
let vals = bx.landing_pad(lpad_ty, bx.eh_personality(), 2);
bx.add_clause(vals, tydesc);
bx.add_clause(vals, bx.const_null(bx.type_i8p()));
let ptr = bx.extract_value(vals, 0);
let selector = bx.extract_value(vals, 1);
// Check if the typeid we got is the one for a Rust panic.
let rust_typeid = bx.call_intrinsic("llvm.eh.typeid.for", &[tydesc]);
let is_rust_panic = bx.icmp(IntPredicate::IntEQ, selector, rust_typeid);
let is_rust_panic = bx.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 = bx.alloca(catch_data_type, ptr_align);
let catch_data_0 =
bx.inbounds_gep(catch_data_type, catch_data, &[bx.const_usize(0), bx.const_usize(0)]);
bx.store(ptr, catch_data_0, ptr_align);
let catch_data_1 =
bx.inbounds_gep(catch_data_type, catch_data, &[bx.const_usize(0), bx.const_usize(1)]);
bx.store(is_rust_panic, catch_data_1, i8_align);
let catch_data = bx.bitcast(catch_data, bx.type_i8p());
let catch_ty = bx.type_func(&[bx.type_i8p(), bx.type_i8p()], bx.type_void());
bx.call(catch_ty, catch_func, &[data, catch_data], None);
bx.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 = cx.fn_abi_of_fn_ptr(rust_fn_sig, ty::List::empty());
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(
[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<'ll, 'tcx>(
bx: &mut Builder<'_, '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:
#[allow(unused_macro_rules)]
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();
if name == sym::simd_select_bitmask {
require_simd!(arg_tys[1], "argument");
let (len, _) = arg_tys[1].simd_size_and_type(bx.tcx());
let expected_int_bits = (len.max(8) - 1).next_power_of_two();
let expected_bytes = len / 8 + ((len % 8 > 0) as u64);
let mask_ty = arg_tys[0];
let mask = match mask_ty.kind() {
ty::Int(i) if i.bit_width() == Some(expected_int_bits) => args[0].immediate(),
ty::Uint(i) if i.bit_width() == Some(expected_int_bits) => args[0].immediate(),
ty::Array(elem, len)
if matches!(elem.kind(), ty::Uint(ty::UintTy::U8))
&& len.try_eval_usize(bx.tcx, ty::ParamEnv::reveal_all())
== Some(expected_bytes) =>
{
let place = PlaceRef::alloca(bx, args[0].layout);
args[0].val.store(bx, place);
let int_ty = bx.type_ix(expected_bytes * 8);
let ptr = bx.pointercast(place.llval, bx.cx.type_ptr_to(int_ty));
bx.load(int_ty, ptr, Align::ONE)
}
_ => return_error!(
"invalid bitmask `{}`, expected `u{}` or `[u8; {}]`",
mask_ty,
expected_int_bits,
expected_bytes
),
};
let i1 = bx.type_i1();
let im = bx.type_ix(len);
let i1xn = bx.type_vector(i1, len);
let m_im = bx.trunc(mask, 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.as_str().strip_prefix("simd_shuffle") {
// If this intrinsic is the older "simd_shuffleN" form, simply parse the integer.
// If there is no suffix, use the index array length.
let n: u64 = if stripped.is_empty() {
// Make sure this is actually an array, since typeck only checks the length-suffixed
// version of this intrinsic.
match args[2].layout.ty.kind() {
ty::Array(ty, len) if matches!(ty.kind(), ty::Uint(ty::UintTy::U32)) => {
len.try_eval_usize(bx.cx.tcx, ty::ParamEnv::reveal_all()).unwrap_or_else(|| {
span_bug!(span, "could not evaluate shuffle index array length")
})
}
_ => return_error!(
"simd_shuffle index must be an array of `u32`, got `{}`",
args[2].layout.ty
),
}
} else {
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 Some(indices) = indices else {
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 the most significant bit (MSB) of each lane in the form
// of either:
// * an unsigned integer
// * an array of `u8`
// If the vector has less than 8 lanes, a u8 is returned with zeroed trailing bits.
//
// The bit order of the result depends on the byte endianness, LSB-first for little
// endian and MSB-first for big endian.
let expected_int_bits = in_len.max(8);
let expected_bytes = expected_int_bits / 8 + ((expected_int_bits % 8 > 0) as u64);
// 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));
match ret_ty.kind() {
ty::Uint(i) if i.bit_width() == Some(expected_int_bits) => {
// Zero-extend iN to the bitmask type:
return Ok(bx.zext(i_, bx.type_ix(expected_int_bits)));
}
ty::Array(elem, len)
if matches!(elem.kind(), ty::Uint(ty::UintTy::U8))
&& len.try_eval_usize(bx.tcx, ty::ParamEnv::reveal_all())
== Some(expected_bytes) =>
{
// Zero-extend iN to the array length:
let ze = bx.zext(i_, bx.type_ix(expected_bytes * 8));
// Convert the integer to a byte array
let ptr = bx.alloca(bx.type_ix(expected_bytes * 8), Align::ONE);
bx.store(ze, ptr, Align::ONE);
let array_ty = bx.type_array(bx.type_i8(), expected_bytes);
let ptr = bx.pointercast(ptr, bx.cx.type_ptr_to(array_ty));
return Ok(bx.load(array_ty, ptr, Align::ONE));
}
_ => return_error!(
"cannot return `{}`, expected `u{}` or `[u8; {}]`",
ret_ty,
expected_int_bits,
expected_bytes
),
}
}
fn simd_simple_float_intrinsic<'ll, 'tcx>(
name: Symbol,
in_elem: Ty<'_>,
in_ty: Ty<'_>,
in_len: u64,
bx: &mut Builder<'_, 'll, 'tcx>,
span: Span,
args: &[OperandRef<'tcx, &'ll Value>],
) -> Result<&'ll Value, ()> {
#[allow(unused_macro_rules)]
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,
bx: &Builder<'_, '_, '_>,
) -> String {
let p0s: String = "p0".repeat(no_pointers);
match *elem_ty.kind() {
ty::Int(v) => format!(
"v{}{}i{}",
vec_len,
p0s,
// Normalize to prevent crash if v: IntTy::Isize
v.normalize(bx.target_spec().pointer_width).bit_width().unwrap()
),
ty::Uint(v) => format!(
"v{}{}i{}",
vec_len,
p0s,
// Normalize to prevent crash if v: UIntTy::Usize
v.normalize(bx.target_spec().pointer_width).bit_width().unwrap()
),
ty::Float(v) => format!("v{}{}f{}", vec_len, p0s, v.bit_width()),
_ => unreachable!(),
}
}
fn llvm_vector_ty<'ll>(
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, bx);
// 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, bx);
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, bx);
// 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, bx);
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 || name == sym::simd_as {
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.normalize(bx.tcx().sess.target.pointer_width).bit_width().unwrap(),
),
ty::Uint(u) => (
Style::Int(false),
u.normalize(bx.tcx().sess.target.pointer_width).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.normalize(bx.tcx().sess.target.pointer_width).bit_width().unwrap(),
),
ty::Uint(u) => (
Style::Int(false),
u.normalize(bx.tcx().sess.target.pointer_width).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(match (out_is_signed, name == sym::simd_as) {
(false, false) => bx.fptoui(args[0].immediate(), llret_ty),
(true, false) => bx.fptosi(args[0].immediate(), llret_ty),
(_, true) => bx.cast_float_to_int(out_is_signed, 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_arith_offset {
// This also checks that the first operand is a ptr type.
let pointee = in_elem.builtin_deref(true).unwrap_or_else(|| {
span_bug!(span, "must be called with a vector of pointer types as first argument")
});
let layout = bx.layout_of(pointee.ty);
let ptrs = args[0].immediate();
// The second argument must be a ptr-sized integer.
// (We don't care about the signedness, this is wrapping anyway.)
let (_offsets_len, offsets_elem) = arg_tys[1].simd_size_and_type(bx.tcx());
if !matches!(offsets_elem.kind(), ty::Int(ty::IntTy::Isize) | ty::Uint(ty::UintTy::Usize)) {
span_bug!(
span,
"must be called with a vector of pointer-sized integers as second argument"
);
}
let offsets = args[1].immediate();
return Ok(bx.gep(bx.backend_type(layout), ptrs, &[offsets]));
}
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: theres 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,
}
}