| pub mod llvm; |
| mod simd; |
| |
| #[cfg(feature = "master")] |
| use std::iter; |
| |
| #[cfg(feature = "master")] |
| use gccjit::Type; |
| use gccjit::{ComparisonOp, Function, FunctionType, RValue, ToRValue, UnaryOp}; |
| #[cfg(feature = "master")] |
| use rustc_abi::ExternAbi; |
| use rustc_abi::{BackendRepr, HasDataLayout}; |
| use rustc_codegen_ssa::MemFlags; |
| use rustc_codegen_ssa::base::wants_msvc_seh; |
| use rustc_codegen_ssa::common::IntPredicate; |
| use rustc_codegen_ssa::errors::InvalidMonomorphization; |
| use rustc_codegen_ssa::mir::operand::{OperandRef, OperandValue}; |
| use rustc_codegen_ssa::mir::place::{PlaceRef, PlaceValue}; |
| #[cfg(feature = "master")] |
| use rustc_codegen_ssa::traits::MiscCodegenMethods; |
| use rustc_codegen_ssa::traits::{ |
| ArgAbiBuilderMethods, BaseTypeCodegenMethods, BuilderMethods, ConstCodegenMethods, |
| IntrinsicCallBuilderMethods, |
| }; |
| use rustc_middle::bug; |
| #[cfg(feature = "master")] |
| use rustc_middle::ty::layout::FnAbiOf; |
| use rustc_middle::ty::layout::LayoutOf; |
| use rustc_middle::ty::{self, Instance, Ty}; |
| use rustc_span::{Span, Symbol, sym}; |
| use rustc_target::callconv::{ArgAbi, PassMode}; |
| use rustc_target::spec::PanicStrategy; |
| |
| #[cfg(feature = "master")] |
| use crate::abi::FnAbiGccExt; |
| use crate::abi::GccType; |
| use crate::builder::Builder; |
| use crate::common::{SignType, TypeReflection}; |
| use crate::context::CodegenCx; |
| use crate::intrinsic::simd::generic_simd_intrinsic; |
| use crate::type_of::LayoutGccExt; |
| |
| fn get_simple_intrinsic<'gcc, 'tcx>( |
| cx: &CodegenCx<'gcc, 'tcx>, |
| name: Symbol, |
| ) -> Option<Function<'gcc>> { |
| let gcc_name = match name { |
| sym::sqrtf32 => "sqrtf", |
| sym::sqrtf64 => "sqrt", |
| sym::powif32 => "__builtin_powif", |
| sym::powif64 => "__builtin_powi", |
| sym::sinf32 => "sinf", |
| sym::sinf64 => "sin", |
| sym::cosf32 => "cosf", |
| sym::cosf64 => "cos", |
| sym::powf32 => "powf", |
| sym::powf64 => "pow", |
| sym::expf32 => "expf", |
| sym::expf64 => "exp", |
| sym::exp2f32 => "exp2f", |
| sym::exp2f64 => "exp2", |
| sym::logf32 => "logf", |
| sym::logf64 => "log", |
| sym::log10f32 => "log10f", |
| sym::log10f64 => "log10", |
| sym::log2f32 => "log2f", |
| sym::log2f64 => "log2", |
| sym::fmaf32 => "fmaf", |
| sym::fmaf64 => "fma", |
| // FIXME: calling `fma` from libc without FMA target feature uses expensive software emulation |
| sym::fmuladdf32 => "fmaf", // TODO: use gcc intrinsic analogous to llvm.fmuladd.f32 |
| sym::fmuladdf64 => "fma", // TODO: use gcc intrinsic analogous to llvm.fmuladd.f64 |
| sym::fabsf32 => "fabsf", |
| sym::fabsf64 => "fabs", |
| sym::minnumf32 => "fminf", |
| sym::minnumf64 => "fmin", |
| sym::minimumf32 => "fminimumf", |
| sym::minimumf64 => "fminimum", |
| sym::minimumf128 => { |
| // GCC doesn't have the intrinsic we want so we use the compiler-builtins one |
| // https://docs.rs/compiler_builtins/latest/compiler_builtins/math/full_availability/fn.fminimumf128.html |
| let f128_type = cx.type_f128(); |
| return Some(cx.context.new_function( |
| None, |
| FunctionType::Extern, |
| f128_type, |
| &[ |
| cx.context.new_parameter(None, f128_type, "a"), |
| cx.context.new_parameter(None, f128_type, "b"), |
| ], |
| "fminimumf128", |
| false, |
| )); |
| } |
| sym::maxnumf32 => "fmaxf", |
| sym::maxnumf64 => "fmax", |
| sym::maximumf32 => "fmaximumf", |
| sym::maximumf64 => "fmaximum", |
| sym::maximumf128 => { |
| // GCC doesn't have the intrinsic we want so we use the compiler-builtins one |
| // https://docs.rs/compiler_builtins/latest/compiler_builtins/math/full_availability/fn.fmaximumf128.html |
| let f128_type = cx.type_f128(); |
| return Some(cx.context.new_function( |
| None, |
| FunctionType::Extern, |
| f128_type, |
| &[ |
| cx.context.new_parameter(None, f128_type, "a"), |
| cx.context.new_parameter(None, f128_type, "b"), |
| ], |
| "fmaximumf128", |
| false, |
| )); |
| } |
| sym::copysignf32 => "copysignf", |
| sym::copysignf64 => "copysign", |
| sym::floorf32 => "floorf", |
| sym::floorf64 => "floor", |
| sym::ceilf32 => "ceilf", |
| sym::ceilf64 => "ceil", |
| sym::truncf32 => "truncf", |
| sym::truncf64 => "trunc", |
| // We match the LLVM backend and lower this to `rint`. |
| sym::round_ties_even_f32 => "rintf", |
| sym::round_ties_even_f64 => "rint", |
| sym::roundf32 => "roundf", |
| sym::roundf64 => "round", |
| sym::abort => "abort", |
| _ => return None, |
| }; |
| Some(cx.context.get_builtin_function(gcc_name)) |
| } |
| |
| // TODO(antoyo): We can probably remove these and use the fallback intrinsic implementation. |
| fn get_simple_function<'gcc, 'tcx>( |
| cx: &CodegenCx<'gcc, 'tcx>, |
| name: Symbol, |
| ) -> Option<Function<'gcc>> { |
| let (return_type, parameters, func_name) = match name { |
| sym::minimumf32 => { |
| let parameters = [ |
| cx.context.new_parameter(None, cx.float_type, "a"), |
| cx.context.new_parameter(None, cx.float_type, "b"), |
| ]; |
| (cx.float_type, parameters, "fminimumf") |
| } |
| sym::minimumf64 => { |
| let parameters = [ |
| cx.context.new_parameter(None, cx.double_type, "a"), |
| cx.context.new_parameter(None, cx.double_type, "b"), |
| ]; |
| (cx.double_type, parameters, "fminimum") |
| } |
| sym::minimumf128 => { |
| let f128_type = cx.type_f128(); |
| // GCC doesn't have the intrinsic we want so we use the compiler-builtins one |
| // https://docs.rs/compiler_builtins/latest/compiler_builtins/math/full_availability/fn.fminimumf128.html |
| let parameters = [ |
| cx.context.new_parameter(None, f128_type, "a"), |
| cx.context.new_parameter(None, f128_type, "b"), |
| ]; |
| (f128_type, parameters, "fminimumf128") |
| } |
| sym::maximumf32 => { |
| let parameters = [ |
| cx.context.new_parameter(None, cx.float_type, "a"), |
| cx.context.new_parameter(None, cx.float_type, "b"), |
| ]; |
| (cx.float_type, parameters, "fmaximumf") |
| } |
| sym::maximumf64 => { |
| let parameters = [ |
| cx.context.new_parameter(None, cx.double_type, "a"), |
| cx.context.new_parameter(None, cx.double_type, "b"), |
| ]; |
| (cx.double_type, parameters, "fmaximum") |
| } |
| sym::maximumf128 => { |
| let f128_type = cx.type_f128(); |
| // GCC doesn't have the intrinsic we want so we use the compiler-builtins one |
| // https://docs.rs/compiler_builtins/latest/compiler_builtins/math/full_availability/fn.fmaximumf128.html |
| let parameters = [ |
| cx.context.new_parameter(None, f128_type, "a"), |
| cx.context.new_parameter(None, f128_type, "b"), |
| ]; |
| (f128_type, parameters, "fmaximumf128") |
| } |
| _ => return None, |
| }; |
| Some(cx.context.new_function( |
| None, |
| FunctionType::Extern, |
| return_type, |
| ¶meters, |
| func_name, |
| false, |
| )) |
| } |
| |
| fn get_simple_function_f128<'gcc, 'tcx>( |
| cx: &CodegenCx<'gcc, 'tcx>, |
| name: Symbol, |
| ) -> Option<Function<'gcc>> { |
| if !cx.supports_f128_type { |
| return None; |
| } |
| |
| let f128_type = cx.type_f128(); |
| let func_name = match name { |
| sym::ceilf128 => "ceilf128", |
| sym::floorf128 => "floorf128", |
| sym::truncf128 => "truncf128", |
| sym::roundf128 => "roundf128", |
| sym::round_ties_even_f128 => "roundevenf128", |
| sym::sqrtf128 => "sqrtf128", |
| _ => return None, |
| }; |
| Some(cx.context.new_function( |
| None, |
| FunctionType::Extern, |
| f128_type, |
| &[cx.context.new_parameter(None, f128_type, "a")], |
| func_name, |
| false, |
| )) |
| } |
| |
| fn get_simple_function_f128_2args<'gcc, 'tcx>( |
| cx: &CodegenCx<'gcc, 'tcx>, |
| name: Symbol, |
| ) -> Option<Function<'gcc>> { |
| if !cx.supports_f128_type { |
| return None; |
| } |
| |
| let f128_type = cx.type_f128(); |
| let func_name = match name { |
| sym::maxnumf128 => "fmaxf128", |
| sym::minnumf128 => "fminf128", |
| sym::copysignf128 => "copysignf128", |
| _ => return None, |
| }; |
| Some(cx.context.new_function( |
| None, |
| FunctionType::Extern, |
| f128_type, |
| &[ |
| cx.context.new_parameter(None, f128_type, "a"), |
| cx.context.new_parameter(None, f128_type, "b"), |
| ], |
| func_name, |
| false, |
| )) |
| } |
| |
| fn f16_builtin<'gcc, 'tcx>( |
| cx: &CodegenCx<'gcc, 'tcx>, |
| name: Symbol, |
| args: &[OperandRef<'tcx, RValue<'gcc>>], |
| ) -> RValue<'gcc> { |
| let f32_type = cx.type_f32(); |
| let builtin_name = match name { |
| sym::ceilf16 => "__builtin_ceilf", |
| sym::copysignf16 => "__builtin_copysignf", |
| sym::floorf16 => "__builtin_floorf", |
| sym::fmaf16 => "fmaf", |
| sym::maxnumf16 => "__builtin_fmaxf", |
| sym::minnumf16 => "__builtin_fminf", |
| sym::powf16 => "__builtin_powf", |
| sym::powif16 => { |
| let func = cx.context.get_builtin_function("__builtin_powif"); |
| let arg0 = cx.context.new_cast(None, args[0].immediate(), f32_type); |
| let args = [arg0, args[1].immediate()]; |
| let result = cx.context.new_call(None, func, &args); |
| return cx.context.new_cast(None, result, cx.type_f16()); |
| } |
| sym::roundf16 => "__builtin_roundf", |
| sym::round_ties_even_f16 => "__builtin_rintf", |
| sym::sqrtf16 => "__builtin_sqrtf", |
| sym::truncf16 => "__builtin_truncf", |
| _ => unreachable!(), |
| }; |
| |
| let func = cx.context.get_builtin_function(builtin_name); |
| let args: Vec<_> = |
| args.iter().map(|arg| cx.context.new_cast(None, arg.immediate(), f32_type)).collect(); |
| let result = cx.context.new_call(None, func, &args); |
| cx.context.new_cast(None, result, cx.type_f16()) |
| } |
| |
| impl<'a, 'gcc, 'tcx> IntrinsicCallBuilderMethods<'tcx> for Builder<'a, 'gcc, 'tcx> { |
| fn codegen_intrinsic_call( |
| &mut self, |
| instance: Instance<'tcx>, |
| args: &[OperandRef<'tcx, RValue<'gcc>>], |
| result: PlaceRef<'tcx, RValue<'gcc>>, |
| span: Span, |
| ) -> Result<(), Instance<'tcx>> { |
| let tcx = self.tcx; |
| |
| let name = tcx.item_name(instance.def_id()); |
| let name_str = name.as_str(); |
| let fn_args = instance.args; |
| |
| let simple = get_simple_intrinsic(self, name); |
| // TODO(antoyo): Only call get_simple_function_f128 and get_simple_function_f128_2args when |
| // it is the symbols for the supported f128 builtins. |
| let simple_func = get_simple_function(self, name) |
| .or_else(|| get_simple_function_f128(self, name)) |
| .or_else(|| get_simple_function_f128_2args(self, name)); |
| |
| // FIXME(tempdragon): Re-enable `clippy::suspicious_else_formatting` if the following issue is solved: |
| // https://github.com/rust-lang/rust-clippy/issues/12497 |
| // and leave `else if use_integer_compare` to be placed "as is". |
| #[allow(clippy::suspicious_else_formatting)] |
| let value = match name { |
| _ if simple.is_some() => { |
| let func = simple.expect("simple intrinsic function"); |
| self.cx.context.new_call( |
| self.location, |
| func, |
| &args.iter().map(|arg| arg.immediate()).collect::<Vec<_>>(), |
| ) |
| } |
| _ if simple_func.is_some() => { |
| let func = simple_func.expect("simple function"); |
| self.cx.context.new_call( |
| self.location, |
| func, |
| &args.iter().map(|arg| arg.immediate()).collect::<Vec<_>>(), |
| ) |
| } |
| sym::ceilf16 |
| | sym::copysignf16 |
| | sym::floorf16 |
| | sym::fmaf16 |
| | sym::maxnumf16 |
| | sym::minnumf16 |
| | sym::powf16 |
| | sym::powif16 |
| | sym::roundf16 |
| | sym::round_ties_even_f16 |
| | sym::sqrtf16 |
| | sym::truncf16 => f16_builtin(self, name, args), |
| sym::fmaf128 => { |
| let f128_type = self.cx.type_f128(); |
| let func = self.cx.context.new_function( |
| None, |
| FunctionType::Extern, |
| f128_type, |
| &[ |
| self.cx.context.new_parameter(None, f128_type, "a"), |
| self.cx.context.new_parameter(None, f128_type, "b"), |
| self.cx.context.new_parameter(None, f128_type, "c"), |
| ], |
| "fmaf128", |
| false, |
| ); |
| self.cx.context.new_call( |
| self.location, |
| func, |
| &args.iter().map(|arg| arg.immediate()).collect::<Vec<_>>(), |
| ) |
| } |
| sym::powif128 => { |
| let f128_type = self.cx.type_f128(); |
| let func = self.cx.context.new_function( |
| None, |
| FunctionType::Extern, |
| f128_type, |
| &[ |
| self.cx.context.new_parameter(None, f128_type, "a"), |
| self.cx.context.new_parameter(None, self.int_type, "b"), |
| ], |
| "__powitf2", |
| false, |
| ); |
| self.cx.context.new_call( |
| self.location, |
| func, |
| &args.iter().map(|arg| arg.immediate()).collect::<Vec<_>>(), |
| ) |
| } |
| sym::is_val_statically_known => { |
| let a = args[0].immediate(); |
| let builtin = self.context.get_builtin_function("__builtin_constant_p"); |
| let res = self.context.new_call(None, builtin, &[a]); |
| self.icmp(IntPredicate::IntEQ, res, self.const_i32(0)) |
| } |
| sym::catch_unwind => { |
| try_intrinsic( |
| self, |
| args[0].immediate(), |
| args[1].immediate(), |
| args[2].immediate(), |
| result, |
| ); |
| return Ok(()); |
| } |
| sym::breakpoint => { |
| unimplemented!(); |
| } |
| sym::va_copy => { |
| unimplemented!(); |
| } |
| sym::va_arg => { |
| unimplemented!(); |
| } |
| |
| sym::volatile_load | sym::unaligned_volatile_load => { |
| let ptr = args[0].immediate(); |
| let load = self.volatile_load(result.layout.gcc_type(self), ptr); |
| // TODO(antoyo): set alignment. |
| if let BackendRepr::Scalar(scalar) = result.layout.backend_repr { |
| self.to_immediate_scalar(load, scalar) |
| } else { |
| load |
| } |
| } |
| sym::volatile_store => { |
| let dst = args[0].deref(self.cx()); |
| args[1].val.volatile_store(self, dst); |
| return Ok(()); |
| } |
| sym::unaligned_volatile_store => { |
| let dst = args[0].deref(self.cx()); |
| args[1].val.unaligned_volatile_store(self, dst); |
| return Ok(()); |
| } |
| sym::prefetch_read_data |
| | sym::prefetch_write_data |
| | sym::prefetch_read_instruction |
| | sym::prefetch_write_instruction => { |
| unimplemented!(); |
| } |
| 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 => { |
| match int_type_width_signed(args[0].layout.ty, self) { |
| Some((width, signed)) => match name { |
| sym::ctlz | sym::cttz => { |
| let func = self.current_func(); |
| let then_block = func.new_block("then"); |
| let else_block = func.new_block("else"); |
| let after_block = func.new_block("after"); |
| |
| let arg = args[0].immediate(); |
| let result = func.new_local(None, self.u32_type, "zeros"); |
| let zero = self.cx.gcc_zero(arg.get_type()); |
| let cond = self.gcc_icmp(IntPredicate::IntEQ, arg, zero); |
| self.llbb().end_with_conditional(None, cond, then_block, else_block); |
| |
| let zero_result = self.cx.gcc_uint(self.u32_type, width); |
| then_block.add_assignment(None, result, zero_result); |
| then_block.end_with_jump(None, after_block); |
| |
| // NOTE: since jumps were added in a place |
| // count_leading_zeroes() does not expect, the current block |
| // in the state need to be updated. |
| self.switch_to_block(else_block); |
| |
| let zeros = match name { |
| sym::ctlz => self.count_leading_zeroes(width, arg), |
| sym::cttz => self.count_trailing_zeroes(width, arg), |
| _ => unreachable!(), |
| }; |
| self.llbb().add_assignment(None, result, zeros); |
| self.llbb().end_with_jump(None, after_block); |
| |
| // NOTE: since jumps were added in a place rustc does not |
| // expect, the current block in the state need to be updated. |
| self.switch_to_block(after_block); |
| |
| result.to_rvalue() |
| } |
| sym::ctlz_nonzero => self.count_leading_zeroes(width, args[0].immediate()), |
| sym::cttz_nonzero => self.count_trailing_zeroes(width, args[0].immediate()), |
| sym::ctpop => self.pop_count(args[0].immediate()), |
| sym::bswap => { |
| if width == 8 { |
| args[0].immediate() // byte swap a u8/i8 is just a no-op |
| } else { |
| self.gcc_bswap(args[0].immediate(), width) |
| } |
| } |
| sym::bitreverse => self.bit_reverse(width, args[0].immediate()), |
| sym::rotate_left | sym::rotate_right => { |
| // TODO(antoyo): implement using algorithm from: |
| // https://blog.regehr.org/archives/1063 |
| // for other platforms. |
| let is_left = name == sym::rotate_left; |
| let val = args[0].immediate(); |
| let raw_shift = args[1].immediate(); |
| if is_left { |
| self.rotate_left(val, raw_shift, width) |
| } else { |
| self.rotate_right(val, raw_shift, width) |
| } |
| } |
| sym::saturating_add => self.saturating_add( |
| args[0].immediate(), |
| args[1].immediate(), |
| signed, |
| width, |
| ), |
| sym::saturating_sub => self.saturating_sub( |
| args[0].immediate(), |
| args[1].immediate(), |
| signed, |
| width, |
| ), |
| _ => bug!(), |
| }, |
| None => { |
| tcx.dcx().emit_err(InvalidMonomorphization::BasicIntegerType { |
| span, |
| name, |
| ty: args[0].layout.ty, |
| }); |
| return Ok(()); |
| } |
| } |
| } |
| |
| sym::raw_eq => { |
| use rustc_abi::BackendRepr::*; |
| let tp_ty = fn_args.type_at(0); |
| let layout = self.layout_of(tp_ty).layout; |
| let _use_integer_compare = match layout.backend_repr() { |
| Scalar(_) | ScalarPair(_, _) => true, |
| SimdVector { .. } => false, |
| Memory { .. } => { |
| // 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()); // FIXME(antoyo): LLVM creates an integer of 96 bits for [i32; 3], but gcc doesn't support this, so it creates an integer of 128 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 void_ptr_type = self.context.new_type::<*const ()>(); |
| let a_ptr = self.bitcast(a, void_ptr_type); |
| let b_ptr = self.bitcast(b, void_ptr_type); |
| let n = self.context.new_cast( |
| None, |
| self.const_usize(layout.size().bytes()), |
| self.sizet_type, |
| ); |
| let builtin = self.context.get_builtin_function("memcmp"); |
| let cmp = self.context.new_call(None, builtin, &[a_ptr, b_ptr, n]); |
| self.icmp(IntPredicate::IntEQ, cmp, self.const_i32(0)) |
| } |
| } |
| |
| sym::compare_bytes => { |
| let a = args[0].immediate(); |
| let b = args[1].immediate(); |
| let n = args[2].immediate(); |
| |
| let void_ptr_type = self.context.new_type::<*const ()>(); |
| let a_ptr = self.bitcast(a, void_ptr_type); |
| let b_ptr = self.bitcast(b, void_ptr_type); |
| |
| // Here we assume that the `memcmp` provided by the target is a NOP for size 0. |
| let builtin = self.context.get_builtin_function("memcmp"); |
| let cmp = self.context.new_call(None, builtin, &[a_ptr, b_ptr, n]); |
| self.sext(cmp, self.type_ix(32)) |
| } |
| |
| sym::black_box => { |
| args[0].val.store(self, result); |
| |
| let block = self.llbb(); |
| let extended_asm = block.add_extended_asm(None, ""); |
| extended_asm.add_input_operand(None, "r", result.val.llval); |
| extended_asm.add_clobber("memory"); |
| extended_asm.set_volatile_flag(true); |
| |
| // We have copied the value to `result` already. |
| return Ok(()); |
| } |
| |
| sym::ptr_mask => { |
| let usize_type = self.context.new_type::<usize>(); |
| let void_ptr_type = self.context.new_type::<*const ()>(); |
| |
| let ptr = args[0].immediate(); |
| let mask = args[1].immediate(); |
| |
| let addr = self.bitcast(ptr, usize_type); |
| let masked = self.and(addr, mask); |
| self.bitcast(masked, void_ptr_type) |
| } |
| |
| _ if name_str.starts_with("simd_") => { |
| match generic_simd_intrinsic( |
| self, |
| name, |
| args, |
| result.layout.ty, |
| result.layout.gcc_type(self), |
| span, |
| ) { |
| Ok(value) => value, |
| Err(()) => return Ok(()), |
| } |
| } |
| |
| // Fall back to default body |
| _ => return Err(Instance::new_raw(instance.def_id(), instance.args)), |
| }; |
| |
| if result.layout.ty.is_bool() { |
| let val = self.from_immediate(value); |
| self.store_to_place(val, result.val); |
| } else if !result.layout.ty.is_unit() { |
| self.store_to_place(value, result.val); |
| } |
| Ok(()) |
| } |
| |
| fn abort(&mut self) { |
| let func = self.context.get_builtin_function("abort"); |
| let func: RValue<'gcc> = unsafe { std::mem::transmute(func) }; |
| self.call(self.type_void(), None, None, func, &[], None, None); |
| } |
| |
| fn assume(&mut self, value: Self::Value) { |
| // TODO(antoyo): switch to assume when it exists. |
| // Or use something like this: |
| // #define __assume(cond) do { if (!(cond)) __builtin_unreachable(); } while (0) |
| self.expect(value, true); |
| } |
| |
| fn expect(&mut self, cond: Self::Value, _expected: bool) -> Self::Value { |
| // TODO(antoyo) |
| cond |
| } |
| |
| fn type_checked_load( |
| &mut self, |
| _vtable: Self::Value, |
| _vtable_byte_offset: u64, |
| _typeid: Self::Value, |
| ) -> Self::Value { |
| // Unsupported. |
| self.context.new_rvalue_from_int(self.int_type, 0) |
| } |
| |
| fn va_start(&mut self, _va_list: RValue<'gcc>) -> RValue<'gcc> { |
| unimplemented!(); |
| } |
| |
| fn va_end(&mut self, _va_list: RValue<'gcc>) -> RValue<'gcc> { |
| unimplemented!(); |
| } |
| } |
| |
| impl<'a, 'gcc, 'tcx> ArgAbiBuilderMethods<'tcx> for Builder<'a, 'gcc, 'tcx> { |
| fn store_fn_arg( |
| &mut self, |
| arg_abi: &ArgAbi<'tcx, Ty<'tcx>>, |
| idx: &mut usize, |
| dst: PlaceRef<'tcx, Self::Value>, |
| ) { |
| arg_abi.store_fn_arg(self, idx, dst) |
| } |
| |
| fn store_arg( |
| &mut self, |
| arg_abi: &ArgAbi<'tcx, Ty<'tcx>>, |
| val: RValue<'gcc>, |
| dst: PlaceRef<'tcx, RValue<'gcc>>, |
| ) { |
| arg_abi.store(self, val, dst) |
| } |
| } |
| |
| pub trait ArgAbiExt<'gcc, 'tcx> { |
| fn store( |
| &self, |
| bx: &mut Builder<'_, 'gcc, 'tcx>, |
| val: RValue<'gcc>, |
| dst: PlaceRef<'tcx, RValue<'gcc>>, |
| ); |
| fn store_fn_arg( |
| &self, |
| bx: &mut Builder<'_, 'gcc, 'tcx>, |
| idx: &mut usize, |
| dst: PlaceRef<'tcx, RValue<'gcc>>, |
| ); |
| } |
| |
| impl<'gcc, 'tcx> ArgAbiExt<'gcc, 'tcx> for ArgAbi<'tcx, Ty<'tcx>> { |
| /// Stores a direct/indirect value described by this ArgAbi into a |
| /// place for the original Rust type of this argument/return. |
| /// Can be used for both storing formal arguments into Rust variables |
| /// or results of call/invoke instructions into their destinations. |
| fn store( |
| &self, |
| bx: &mut Builder<'_, 'gcc, 'tcx>, |
| val: RValue<'gcc>, |
| dst: PlaceRef<'tcx, RValue<'gcc>>, |
| ) { |
| if self.is_ignore() { |
| return; |
| } |
| if self.is_sized_indirect() { |
| OperandValue::Ref(PlaceValue::new_sized(val, self.layout.align.abi)).store(bx, dst) |
| } else if self.is_unsized_indirect() { |
| bug!("unsized `ArgAbi` must be handled through `store_fn_arg`"); |
| } else if let PassMode::Cast { ref cast, .. } = self.mode { |
| // FIXME(eddyb): Figure out when the simpler Store is safe, clang |
| // uses it for i16 -> {i8, i8}, but not for i24 -> {i8, i8, i8}. |
| let can_store_through_cast_ptr = false; |
| if can_store_through_cast_ptr { |
| let cast_ptr_llty = bx.type_ptr_to(cast.gcc_type(bx)); |
| let cast_dst = bx.pointercast(dst.val.llval, cast_ptr_llty); |
| bx.store(val, cast_dst, self.layout.align.abi); |
| } else { |
| // The actual return type is a struct, but the ABI |
| // adaptation code has cast it into some scalar type. The |
| // code that follows is the only reliable way I have |
| // found to do a transform like i64 -> {i32,i32}. |
| // Basically we dump the data onto the stack then memcpy it. |
| // |
| // Other approaches I tried: |
| // - Casting rust ret pointer to the foreign type and using Store |
| // is (a) unsafe if size of foreign type > size of rust type and |
| // (b) runs afoul of strict aliasing rules, yielding invalid |
| // assembly under -O (specifically, the store gets removed). |
| // - Truncating foreign type to correct integral type and then |
| // bitcasting to the struct type yields invalid cast errors. |
| |
| // We instead thus allocate some scratch space... |
| let scratch_size = cast.size(bx); |
| let scratch_align = cast.align(bx); |
| let scratch = bx.alloca(scratch_size, scratch_align); |
| bx.lifetime_start(scratch, scratch_size); |
| |
| // ... where we first store the value... |
| rustc_codegen_ssa::mir::store_cast(bx, cast, val, scratch, scratch_align); |
| |
| // ... and then memcpy it to the intended destination. |
| bx.memcpy( |
| dst.val.llval, |
| self.layout.align.abi, |
| scratch, |
| scratch_align, |
| bx.const_usize(self.layout.size.bytes()), |
| MemFlags::empty(), |
| ); |
| |
| bx.lifetime_end(scratch, scratch_size); |
| } |
| } else { |
| OperandValue::Immediate(val).store(bx, dst); |
| } |
| } |
| |
| fn store_fn_arg<'a>( |
| &self, |
| bx: &mut Builder<'a, 'gcc, 'tcx>, |
| idx: &mut usize, |
| dst: PlaceRef<'tcx, RValue<'gcc>>, |
| ) { |
| let mut next = || { |
| let val = bx.current_func().get_param(*idx as i32); |
| *idx += 1; |
| val.to_rvalue() |
| }; |
| match self.mode { |
| PassMode::Ignore => {} |
| PassMode::Pair(..) => { |
| OperandValue::Pair(next(), next()).store(bx, dst); |
| } |
| PassMode::Indirect { meta_attrs: Some(_), .. } => { |
| let place_val = PlaceValue { |
| llval: next(), |
| llextra: Some(next()), |
| align: self.layout.align.abi, |
| }; |
| OperandValue::Ref(place_val).store(bx, dst); |
| } |
| PassMode::Direct(_) |
| | PassMode::Indirect { meta_attrs: None, .. } |
| | PassMode::Cast { .. } => { |
| let next_arg = next(); |
| self.store(bx, next_arg, dst); |
| } |
| } |
| } |
| } |
| |
| fn int_type_width_signed<'gcc, 'tcx>( |
| ty: Ty<'tcx>, |
| cx: &CodegenCx<'gcc, 'tcx>, |
| ) -> Option<(u64, bool)> { |
| match *ty.kind() { |
| ty::Int(t) => Some(( |
| match t { |
| rustc_middle::ty::IntTy::Isize => u64::from(cx.tcx.sess.target.pointer_width), |
| rustc_middle::ty::IntTy::I8 => 8, |
| rustc_middle::ty::IntTy::I16 => 16, |
| rustc_middle::ty::IntTy::I32 => 32, |
| rustc_middle::ty::IntTy::I64 => 64, |
| rustc_middle::ty::IntTy::I128 => 128, |
| }, |
| true, |
| )), |
| ty::Uint(t) => Some(( |
| match t { |
| rustc_middle::ty::UintTy::Usize => u64::from(cx.tcx.sess.target.pointer_width), |
| rustc_middle::ty::UintTy::U8 => 8, |
| rustc_middle::ty::UintTy::U16 => 16, |
| rustc_middle::ty::UintTy::U32 => 32, |
| rustc_middle::ty::UintTy::U64 => 64, |
| rustc_middle::ty::UintTy::U128 => 128, |
| }, |
| false, |
| )), |
| _ => None, |
| } |
| } |
| |
| impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> { |
| fn bit_reverse(&mut self, width: u64, value: RValue<'gcc>) -> RValue<'gcc> { |
| let result_type = value.get_type(); |
| let typ = result_type.to_unsigned(self.cx); |
| |
| let value = |
| if result_type.is_signed(self.cx) { self.gcc_int_cast(value, typ) } else { value }; |
| |
| let context = &self.cx.context; |
| let result = match width { |
| 8 | 16 | 32 | 64 => { |
| let mask = ((1u128 << width) - 1) as u64; |
| let (m0, m1, m2) = if width > 16 { |
| ( |
| context.new_rvalue_from_long(typ, (0x5555555555555555u64 & mask) as i64), |
| context.new_rvalue_from_long(typ, (0x3333333333333333u64 & mask) as i64), |
| context.new_rvalue_from_long(typ, (0x0f0f0f0f0f0f0f0fu64 & mask) as i64), |
| ) |
| } else { |
| ( |
| context.new_rvalue_from_int(typ, (0x5555u64 & mask) as i32), |
| context.new_rvalue_from_int(typ, (0x3333u64 & mask) as i32), |
| context.new_rvalue_from_int(typ, (0x0f0fu64 & mask) as i32), |
| ) |
| }; |
| let one = context.new_rvalue_from_int(typ, 1); |
| let two = context.new_rvalue_from_int(typ, 2); |
| let four = context.new_rvalue_from_int(typ, 4); |
| |
| // First step. |
| let left = self.lshr(value, one); |
| let left = self.and(left, m0); |
| let right = self.and(value, m0); |
| let right = self.shl(right, one); |
| let step1 = self.or(left, right); |
| |
| // Second step. |
| let left = self.lshr(step1, two); |
| let left = self.and(left, m1); |
| let right = self.and(step1, m1); |
| let right = self.shl(right, two); |
| let step2 = self.or(left, right); |
| |
| // Third step. |
| let left = self.lshr(step2, four); |
| let left = self.and(left, m2); |
| let right = self.and(step2, m2); |
| let right = self.shl(right, four); |
| let step3 = self.or(left, right); |
| |
| // Fourth step. |
| if width == 8 { step3 } else { self.gcc_bswap(step3, width) } |
| } |
| 128 => { |
| // TODO(antoyo): find a more efficient implementation? |
| let sixty_four = self.gcc_int(typ, 64); |
| let right_shift = self.gcc_lshr(value, sixty_four); |
| let high = self.gcc_int_cast(right_shift, self.u64_type); |
| let low = self.gcc_int_cast(value, self.u64_type); |
| |
| let reversed_high = self.bit_reverse(64, high); |
| let reversed_low = self.bit_reverse(64, low); |
| |
| let new_low = self.gcc_int_cast(reversed_high, typ); |
| let new_high = self.shl(self.gcc_int_cast(reversed_low, typ), sixty_four); |
| |
| self.gcc_or(new_low, new_high, self.location) |
| } |
| _ => { |
| panic!("cannot bit reverse with width = {}", width); |
| } |
| }; |
| |
| self.gcc_int_cast(result, result_type) |
| } |
| |
| fn count_leading_zeroes(&mut self, width: u64, arg: RValue<'gcc>) -> RValue<'gcc> { |
| // TODO(antoyo): use width? |
| let arg_type = arg.get_type(); |
| let result_type = self.u32_type; |
| let arg = if arg_type.is_signed(self.cx) { |
| let new_type = arg_type.to_unsigned(self.cx); |
| self.gcc_int_cast(arg, new_type) |
| } else { |
| arg |
| }; |
| let arg_type = arg.get_type(); |
| let count_leading_zeroes = |
| // TODO(antoyo): write a new function Type::is_compatible_with(&Type) and use it here |
| // instead of using is_uint(). |
| if arg_type.is_uchar(self.cx) || arg_type.is_ushort(self.cx) || arg_type.is_uint(self.cx) { |
| "__builtin_clz" |
| } |
| else if arg_type.is_ulong(self.cx) { |
| "__builtin_clzl" |
| } |
| else if arg_type.is_ulonglong(self.cx) { |
| "__builtin_clzll" |
| } |
| else if width == 128 { |
| // Algorithm from: https://stackoverflow.com/a/28433850/389119 |
| let array_type = self.context.new_array_type(None, arg_type, 3); |
| let result = self.current_func() |
| .new_local(None, array_type, "count_loading_zeroes_results"); |
| |
| let sixty_four = self.const_uint(arg_type, 64); |
| let shift = self.lshr(arg, sixty_four); |
| let high = self.gcc_int_cast(shift, self.u64_type); |
| let low = self.gcc_int_cast(arg, self.u64_type); |
| |
| let zero = self.context.new_rvalue_zero(self.usize_type); |
| let one = self.context.new_rvalue_one(self.usize_type); |
| let two = self.context.new_rvalue_from_long(self.usize_type, 2); |
| |
| let clzll = self.context.get_builtin_function("__builtin_clzll"); |
| |
| let first_elem = self.context.new_array_access(None, result, zero); |
| let first_value = self.gcc_int_cast(self.context.new_call(None, clzll, &[high]), arg_type); |
| self.llbb() |
| .add_assignment(self.location, first_elem, first_value); |
| |
| let second_elem = self.context.new_array_access(self.location, result, one); |
| let cast = self.gcc_int_cast(self.context.new_call(self.location, clzll, &[low]), arg_type); |
| let second_value = self.add(cast, sixty_four); |
| self.llbb() |
| .add_assignment(self.location, second_elem, second_value); |
| |
| let third_elem = self.context.new_array_access(self.location, result, two); |
| let third_value = self.const_uint(arg_type, 128); |
| self.llbb() |
| .add_assignment(self.location, third_elem, third_value); |
| |
| let not_high = self.context.new_unary_op(self.location, UnaryOp::LogicalNegate, self.u64_type, high); |
| let not_low = self.context.new_unary_op(self.location, UnaryOp::LogicalNegate, self.u64_type, low); |
| let not_low_and_not_high = not_low & not_high; |
| let index = not_high + not_low_and_not_high; |
| // NOTE: the following cast is necessary to avoid a GIMPLE verification failure in |
| // gcc. |
| // TODO(antoyo): do the correct verification in libgccjit to avoid an error at the |
| // compilation stage. |
| let index = self.context.new_cast(self.location, index, self.i32_type); |
| |
| let res = self.context.new_array_access(self.location, result, index); |
| |
| return self.gcc_int_cast(res.to_rvalue(), result_type); |
| } |
| else { |
| let count_leading_zeroes = self.context.get_builtin_function("__builtin_clzll"); |
| let arg = self.context.new_cast(self.location, arg, self.ulonglong_type); |
| let diff = self.ulonglong_type.get_size() as i64 - arg_type.get_size() as i64; |
| let diff = self.context.new_rvalue_from_long(self.int_type, diff * 8); |
| let res = self.context.new_call(self.location, count_leading_zeroes, &[arg]) - diff; |
| return self.context.new_cast(self.location, res, result_type); |
| }; |
| let count_leading_zeroes = self.context.get_builtin_function(count_leading_zeroes); |
| let res = self.context.new_call(self.location, count_leading_zeroes, &[arg]); |
| self.context.new_cast(self.location, res, result_type) |
| } |
| |
| fn count_trailing_zeroes(&mut self, _width: u64, arg: RValue<'gcc>) -> RValue<'gcc> { |
| let arg_type = arg.get_type(); |
| let result_type = self.u32_type; |
| let arg = if arg_type.is_signed(self.cx) { |
| let new_type = arg_type.to_unsigned(self.cx); |
| self.gcc_int_cast(arg, new_type) |
| } else { |
| arg |
| }; |
| let arg_type = arg.get_type(); |
| let (count_trailing_zeroes, expected_type) = |
| // TODO(antoyo): write a new function Type::is_compatible_with(&Type) and use it here |
| // instead of using is_uint(). |
| if arg_type.is_uchar(self.cx) || arg_type.is_ushort(self.cx) || arg_type.is_uint(self.cx) { |
| // NOTE: we don't need to & 0xFF for uchar because the result is undefined on zero. |
| ("__builtin_ctz", self.cx.uint_type) |
| } |
| else if arg_type.is_ulong(self.cx) { |
| ("__builtin_ctzl", self.cx.ulong_type) |
| } |
| else if arg_type.is_ulonglong(self.cx) { |
| ("__builtin_ctzll", self.cx.ulonglong_type) |
| } |
| else if arg_type.is_u128(self.cx) { |
| // Adapted from the algorithm to count leading zeroes from: https://stackoverflow.com/a/28433850/389119 |
| let array_type = self.context.new_array_type(None, arg_type, 3); |
| let result = self.current_func() |
| .new_local(None, array_type, "count_loading_zeroes_results"); |
| |
| let sixty_four = self.gcc_int(arg_type, 64); |
| let shift = self.gcc_lshr(arg, sixty_four); |
| let high = self.gcc_int_cast(shift, self.u64_type); |
| let low = self.gcc_int_cast(arg, self.u64_type); |
| |
| let zero = self.context.new_rvalue_zero(self.usize_type); |
| let one = self.context.new_rvalue_one(self.usize_type); |
| let two = self.context.new_rvalue_from_long(self.usize_type, 2); |
| |
| let ctzll = self.context.get_builtin_function("__builtin_ctzll"); |
| |
| let first_elem = self.context.new_array_access(self.location, result, zero); |
| let first_value = self.gcc_int_cast(self.context.new_call(self.location, ctzll, &[low]), arg_type); |
| self.llbb() |
| .add_assignment(self.location, first_elem, first_value); |
| |
| let second_elem = self.context.new_array_access(self.location, result, one); |
| let second_value = self.gcc_add(self.gcc_int_cast(self.context.new_call(self.location, ctzll, &[high]), arg_type), sixty_four); |
| self.llbb() |
| .add_assignment(self.location, second_elem, second_value); |
| |
| let third_elem = self.context.new_array_access(self.location, result, two); |
| let third_value = self.gcc_int(arg_type, 128); |
| self.llbb() |
| .add_assignment(self.location, third_elem, third_value); |
| |
| let not_low = self.context.new_unary_op(self.location, UnaryOp::LogicalNegate, self.u64_type, low); |
| let not_high = self.context.new_unary_op(self.location, UnaryOp::LogicalNegate, self.u64_type, high); |
| let not_low_and_not_high = not_low & not_high; |
| let index = not_low + not_low_and_not_high; |
| // NOTE: the following cast is necessary to avoid a GIMPLE verification failure in |
| // gcc. |
| // TODO(antoyo): do the correct verification in libgccjit to avoid an error at the |
| // compilation stage. |
| let index = self.context.new_cast(self.location, index, self.i32_type); |
| |
| let res = self.context.new_array_access(self.location, result, index); |
| |
| return self.gcc_int_cast(res.to_rvalue(), result_type); |
| } |
| else { |
| let count_trailing_zeroes = self.context.get_builtin_function("__builtin_ctzll"); |
| let arg_size = arg_type.get_size(); |
| let casted_arg = self.context.new_cast(self.location, arg, self.ulonglong_type); |
| let byte_diff = self.ulonglong_type.get_size() as i64 - arg_size as i64; |
| let diff = self.context.new_rvalue_from_long(self.int_type, byte_diff * 8); |
| let mask = self.context.new_rvalue_from_long(arg_type, -1); // To get the value with all bits set. |
| let masked = mask & self.context.new_unary_op(self.location, UnaryOp::BitwiseNegate, arg_type, arg); |
| let cond = self.context.new_comparison(self.location, ComparisonOp::Equals, masked, mask); |
| let diff = diff * self.context.new_cast(self.location, cond, self.int_type); |
| let res = self.context.new_call(self.location, count_trailing_zeroes, &[casted_arg]) - diff; |
| return self.context.new_cast(self.location, res, result_type); |
| }; |
| let count_trailing_zeroes = self.context.get_builtin_function(count_trailing_zeroes); |
| let arg = if arg_type != expected_type { |
| self.context.new_cast(self.location, arg, expected_type) |
| } else { |
| arg |
| }; |
| let res = self.context.new_call(self.location, count_trailing_zeroes, &[arg]); |
| self.context.new_cast(self.location, res, result_type) |
| } |
| |
| fn pop_count(&mut self, value: RValue<'gcc>) -> RValue<'gcc> { |
| // TODO(antoyo): use the optimized version with fewer operations. |
| let result_type = self.u32_type; |
| let arg_type = value.get_type(); |
| let value_type = arg_type.to_unsigned(self.cx); |
| |
| let value = |
| if arg_type.is_signed(self.cx) { self.gcc_int_cast(value, value_type) } else { value }; |
| |
| // only break apart 128-bit ints if they're not natively supported |
| // TODO(antoyo): remove this if/when native 128-bit integers land in libgccjit |
| if value_type.is_u128(self.cx) && !self.cx.supports_128bit_integers { |
| let sixty_four = self.gcc_int(value_type, 64); |
| let right_shift = self.gcc_lshr(value, sixty_four); |
| let high = self.gcc_int_cast(right_shift, self.cx.ulonglong_type); |
| let high = self.pop_count(high); |
| let low = self.gcc_int_cast(value, self.cx.ulonglong_type); |
| let low = self.pop_count(low); |
| let res = high + low; |
| return self.gcc_int_cast(res, result_type); |
| } |
| |
| // Use Wenger's algorithm for population count, gcc's seems to play better with it |
| // for (int counter = 0; value != 0; counter++) { |
| // value &= value - 1; |
| // } |
| let func = self.current_func(); |
| let loop_head = func.new_block("head"); |
| let loop_body = func.new_block("body"); |
| let loop_tail = func.new_block("tail"); |
| |
| let counter_type = self.int_type; |
| let counter = self.current_func().new_local(None, counter_type, "popcount_counter"); |
| let val = self.current_func().new_local(None, value_type, "popcount_value"); |
| let zero = self.gcc_zero(counter_type); |
| self.llbb().add_assignment(self.location, counter, zero); |
| self.llbb().add_assignment(self.location, val, value); |
| self.br(loop_head); |
| |
| // check if value isn't zero |
| self.switch_to_block(loop_head); |
| let zero = self.gcc_zero(value_type); |
| let cond = self.gcc_icmp(IntPredicate::IntNE, val.to_rvalue(), zero); |
| self.cond_br(cond, loop_body, loop_tail); |
| |
| // val &= val - 1; |
| self.switch_to_block(loop_body); |
| let one = self.gcc_int(value_type, 1); |
| let sub = self.gcc_sub(val.to_rvalue(), one); |
| let op = self.gcc_and(val.to_rvalue(), sub); |
| loop_body.add_assignment(self.location, val, op); |
| |
| // counter += 1 |
| let one = self.gcc_int(counter_type, 1); |
| let op = self.gcc_add(counter.to_rvalue(), one); |
| loop_body.add_assignment(self.location, counter, op); |
| self.br(loop_head); |
| |
| // end of loop |
| self.switch_to_block(loop_tail); |
| self.gcc_int_cast(counter.to_rvalue(), result_type) |
| } |
| |
| // Algorithm from: https://blog.regehr.org/archives/1063 |
| fn rotate_left( |
| &mut self, |
| value: RValue<'gcc>, |
| shift: RValue<'gcc>, |
| width: u64, |
| ) -> RValue<'gcc> { |
| let max = self.const_uint(shift.get_type(), width); |
| let shift = self.urem(shift, max); |
| let lhs = self.shl(value, shift); |
| let result_neg = self.neg(shift); |
| let result_and = self.and(result_neg, self.const_uint(shift.get_type(), width - 1)); |
| let rhs = self.lshr(value, result_and); |
| self.or(lhs, rhs) |
| } |
| |
| // Algorithm from: https://blog.regehr.org/archives/1063 |
| fn rotate_right( |
| &mut self, |
| value: RValue<'gcc>, |
| shift: RValue<'gcc>, |
| width: u64, |
| ) -> RValue<'gcc> { |
| let max = self.const_uint(shift.get_type(), width); |
| let shift = self.urem(shift, max); |
| let lhs = self.lshr(value, shift); |
| let result_neg = self.neg(shift); |
| let result_and = self.and(result_neg, self.const_uint(shift.get_type(), width - 1)); |
| let rhs = self.shl(value, result_and); |
| self.or(lhs, rhs) |
| } |
| |
| fn saturating_add( |
| &mut self, |
| lhs: RValue<'gcc>, |
| rhs: RValue<'gcc>, |
| signed: bool, |
| width: u64, |
| ) -> RValue<'gcc> { |
| let result_type = lhs.get_type(); |
| if signed { |
| // Based on algorithm from: https://stackoverflow.com/a/56531252/389119 |
| let func = self.current_func(); |
| let res = func.new_local(self.location, result_type, "saturating_sum"); |
| let supports_native_type = self.is_native_int_type(result_type); |
| let overflow = if supports_native_type { |
| let func_name = match width { |
| 8 => "__builtin_add_overflow", |
| 16 => "__builtin_add_overflow", |
| 32 => "__builtin_sadd_overflow", |
| 64 => "__builtin_saddll_overflow", |
| 128 => "__builtin_add_overflow", |
| _ => unreachable!(), |
| }; |
| let overflow_func = self.context.get_builtin_function(func_name); |
| self.overflow_call(overflow_func, &[lhs, rhs, res.get_address(self.location)], None) |
| } else { |
| let func_name = match width { |
| 128 => "__rust_i128_addo", |
| _ => unreachable!(), |
| }; |
| let (int_result, overflow) = |
| self.operation_with_overflow(func_name, lhs, rhs, width); |
| self.llbb().add_assignment(self.location, res, int_result); |
| overflow |
| }; |
| |
| let then_block = func.new_block("then"); |
| let after_block = func.new_block("after"); |
| |
| // Return `result_type`'s maximum or minimum value on overflow |
| // NOTE: convert the type to unsigned to have an unsigned shift. |
| let unsigned_type = result_type.to_unsigned(self.cx); |
| let shifted = self.gcc_lshr( |
| self.gcc_int_cast(lhs, unsigned_type), |
| self.gcc_int(unsigned_type, width as i64 - 1), |
| ); |
| let uint_max = self.gcc_not(self.gcc_int(unsigned_type, 0)); |
| let int_max = self.gcc_lshr(uint_max, self.gcc_int(unsigned_type, 1)); |
| then_block.add_assignment( |
| self.location, |
| res, |
| self.gcc_int_cast(self.gcc_add(shifted, int_max), result_type), |
| ); |
| then_block.end_with_jump(self.location, after_block); |
| |
| self.llbb().end_with_conditional(self.location, overflow, then_block, after_block); |
| |
| // NOTE: since jumps were added in a place rustc does not |
| // expect, the current block in the state need to be updated. |
| self.switch_to_block(after_block); |
| |
| res.to_rvalue() |
| } else { |
| // Algorithm from: http://locklessinc.com/articles/sat_arithmetic/ |
| let res = self.gcc_add(lhs, rhs); |
| let cond = self.gcc_icmp(IntPredicate::IntULT, res, lhs); |
| let value = self.gcc_neg(self.gcc_int_cast(cond, result_type)); |
| self.gcc_or(res, value, self.location) |
| } |
| } |
| |
| // Algorithm from: https://locklessinc.com/articles/sat_arithmetic/ |
| fn saturating_sub( |
| &mut self, |
| lhs: RValue<'gcc>, |
| rhs: RValue<'gcc>, |
| signed: bool, |
| width: u64, |
| ) -> RValue<'gcc> { |
| let result_type = lhs.get_type(); |
| if signed { |
| // Based on algorithm from: https://stackoverflow.com/a/56531252/389119 |
| let func = self.current_func(); |
| let res = func.new_local(self.location, result_type, "saturating_diff"); |
| let supports_native_type = self.is_native_int_type(result_type); |
| let overflow = if supports_native_type { |
| let func_name = match width { |
| 8 => "__builtin_sub_overflow", |
| 16 => "__builtin_sub_overflow", |
| 32 => "__builtin_ssub_overflow", |
| 64 => "__builtin_ssubll_overflow", |
| 128 => "__builtin_sub_overflow", |
| _ => unreachable!(), |
| }; |
| let overflow_func = self.context.get_builtin_function(func_name); |
| self.overflow_call(overflow_func, &[lhs, rhs, res.get_address(self.location)], None) |
| } else { |
| let func_name = match width { |
| 128 => "__rust_i128_subo", |
| _ => unreachable!(), |
| }; |
| let (int_result, overflow) = |
| self.operation_with_overflow(func_name, lhs, rhs, width); |
| self.llbb().add_assignment(self.location, res, int_result); |
| overflow |
| }; |
| |
| let then_block = func.new_block("then"); |
| let after_block = func.new_block("after"); |
| |
| // Return `result_type`'s maximum or minimum value on overflow |
| // NOTE: convert the type to unsigned to have an unsigned shift. |
| let unsigned_type = result_type.to_unsigned(self.cx); |
| let shifted = self.gcc_lshr( |
| self.gcc_int_cast(lhs, unsigned_type), |
| self.gcc_int(unsigned_type, width as i64 - 1), |
| ); |
| let uint_max = self.gcc_not(self.gcc_int(unsigned_type, 0)); |
| let int_max = self.gcc_lshr(uint_max, self.gcc_int(unsigned_type, 1)); |
| then_block.add_assignment( |
| self.location, |
| res, |
| self.gcc_int_cast(self.gcc_add(shifted, int_max), result_type), |
| ); |
| then_block.end_with_jump(self.location, after_block); |
| |
| self.llbb().end_with_conditional(self.location, overflow, then_block, after_block); |
| |
| // NOTE: since jumps were added in a place rustc does not |
| // expect, the current block in the state need to be updated. |
| self.switch_to_block(after_block); |
| |
| res.to_rvalue() |
| } else { |
| let res = self.gcc_sub(lhs, rhs); |
| let comparison = self.gcc_icmp(IntPredicate::IntULE, res, lhs); |
| let value = self.gcc_neg(self.gcc_int_cast(comparison, result_type)); |
| self.gcc_and(res, value) |
| } |
| } |
| } |
| |
| fn try_intrinsic<'a, 'b, 'gcc, 'tcx>( |
| bx: &'b mut Builder<'a, 'gcc, 'tcx>, |
| try_func: RValue<'gcc>, |
| data: RValue<'gcc>, |
| _catch_func: RValue<'gcc>, |
| dest: PlaceRef<'tcx, RValue<'gcc>>, |
| ) { |
| if bx.sess().panic_strategy() == PanicStrategy::Abort { |
| bx.call(bx.type_void(), None, None, try_func, &[data], None, None); |
| // Return 0 unconditionally from the intrinsic call; |
| // we can never unwind. |
| OperandValue::Immediate(bx.const_i32(0)).store(bx, dest); |
| } else { |
| if wants_msvc_seh(bx.sess()) { |
| unimplemented!(); |
| } |
| #[cfg(feature = "master")] |
| codegen_gnu_try(bx, try_func, data, _catch_func, dest); |
| #[cfg(not(feature = "master"))] |
| unimplemented!(); |
| } |
| } |
| |
| // 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. |
| #[cfg(feature = "master")] |
| fn codegen_gnu_try<'gcc, 'tcx>( |
| bx: &mut Builder<'_, 'gcc, 'tcx>, |
| try_func: RValue<'gcc>, |
| data: RValue<'gcc>, |
| catch_func: RValue<'gcc>, |
| dest: PlaceRef<'tcx, RValue<'gcc>>, |
| ) { |
| let cx: &CodegenCx<'gcc, '_> = bx.cx; |
| let (llty, func) = get_rust_try_fn(cx, &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 func = bx.current_func(); |
| let try_func = func.get_param(0).to_rvalue(); |
| let data = func.get_param(1).to_rvalue(); |
| let catch_func = func.get_param(2).to_rvalue(); |
| let try_func_ty = bx.type_func(&[bx.type_i8p()], bx.type_void()); |
| |
| let current_block = bx.block; |
| |
| bx.switch_to_block(then); |
| bx.ret(bx.const_i32(0)); |
| |
| // Type indicator for the exception being thrown. |
| // |
| // The value is a pointer to the exception object |
| // being thrown. |
| bx.switch_to_block(catch); |
| bx.set_personality_fn(bx.eh_personality()); |
| |
| let eh_pointer_builtin = bx.cx.context.get_target_builtin_function("__builtin_eh_pointer"); |
| let zero = bx.cx.context.new_rvalue_zero(bx.int_type); |
| let ptr = bx.cx.context.new_call(None, eh_pointer_builtin, &[zero]); |
| let catch_ty = bx.type_func(&[bx.type_i8p(), bx.type_i8p()], bx.type_void()); |
| bx.call(catch_ty, None, None, catch_func, &[data, ptr], None, None); |
| bx.ret(bx.const_i32(1)); |
| |
| // NOTE: the blocks must be filled before adding the try/catch, otherwise gcc will not |
| // generate a try/catch. |
| // FIXME(antoyo): add a check in the libgccjit API to prevent this. |
| bx.switch_to_block(current_block); |
| bx.invoke(try_func_ty, None, None, try_func, &[data], then, catch, None, None); |
| }); |
| |
| let func = unsafe { std::mem::transmute::<Function<'gcc>, RValue<'gcc>>(func) }; |
| |
| // 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, None, None, func, &[try_func, data, catch_func], None, None); |
| OperandValue::Immediate(ret).store(bx, dest); |
| } |
| |
| // 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. |
| #[cfg(feature = "master")] |
| fn get_rust_try_fn<'a, 'gcc, 'tcx>( |
| cx: &'a CodegenCx<'gcc, 'tcx>, |
| codegen: &mut dyn FnMut(Builder<'a, 'gcc, 'tcx>), |
| ) -> (Type<'gcc>, Function<'gcc>) { |
| 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 = Ty::new_mut_ptr(tcx, tcx.types.i8); |
| // `unsafe fn(*mut i8) -> ()` |
| let try_fn_ty = Ty::new_fn_ptr( |
| tcx, |
| ty::Binder::dummy(tcx.mk_fn_sig( |
| iter::once(i8p), |
| tcx.types.unit, |
| false, |
| rustc_hir::Safety::Unsafe, |
| ExternAbi::Rust, |
| )), |
| ); |
| // `unsafe fn(*mut i8, *mut i8) -> ()` |
| let catch_fn_ty = Ty::new_fn_ptr( |
| tcx, |
| ty::Binder::dummy(tcx.mk_fn_sig( |
| [i8p, i8p].iter().cloned(), |
| tcx.types.unit, |
| false, |
| rustc_hir::Safety::Unsafe, |
| ExternAbi::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], |
| tcx.types.i32, |
| false, |
| rustc_hir::Safety::Unsafe, |
| ExternAbi::Rust, |
| )); |
| let rust_try = gen_fn(cx, "__rust_try", rust_fn_sig, codegen); |
| cx.rust_try_fn.set(Some(rust_try)); |
| rust_try |
| } |
| |
| // 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. |
| #[cfg(feature = "master")] |
| fn gen_fn<'a, 'gcc, 'tcx>( |
| cx: &'a CodegenCx<'gcc, 'tcx>, |
| name: &str, |
| rust_fn_sig: ty::PolyFnSig<'tcx>, |
| codegen: &mut dyn FnMut(Builder<'a, 'gcc, 'tcx>), |
| ) -> (Type<'gcc>, Function<'gcc>) { |
| let fn_abi = cx.fn_abi_of_fn_ptr(rust_fn_sig, ty::List::empty()); |
| let return_type = fn_abi.gcc_type(cx).return_type; |
| // FIXME(eddyb) find a nicer way to do this. |
| cx.linkage.set(FunctionType::Internal); |
| let func = cx.declare_fn(name, fn_abi); |
| cx.set_frame_pointer_type(func); |
| cx.apply_target_cpu_attr(func); |
| let block = Builder::append_block(cx, func, "entry-block"); |
| let bx = Builder::build(cx, block); |
| codegen(bx); |
| (return_type, func) |
| } |
