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-rw-r--r--compiler/rustc_codegen_gcc/src/intrinsic/mod.rs1134
1 files changed, 1134 insertions, 0 deletions
diff --git a/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs b/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs
new file mode 100644
index 000000000..5fbdedac0
--- /dev/null
+++ b/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs
@@ -0,0 +1,1134 @@
+pub mod llvm;
+mod simd;
+
+use gccjit::{ComparisonOp, Function, RValue, ToRValue, Type, UnaryOp, FunctionType};
+use rustc_codegen_ssa::MemFlags;
+use rustc_codegen_ssa::base::wants_msvc_seh;
+use rustc_codegen_ssa::common::{IntPredicate, span_invalid_monomorphization_error};
+use rustc_codegen_ssa::mir::operand::{OperandRef, OperandValue};
+use rustc_codegen_ssa::mir::place::PlaceRef;
+use rustc_codegen_ssa::traits::{ArgAbiMethods, BaseTypeMethods, BuilderMethods, ConstMethods, IntrinsicCallMethods};
+use rustc_middle::bug;
+use rustc_middle::ty::{self, Instance, Ty};
+use rustc_middle::ty::layout::LayoutOf;
+use rustc_span::{Span, Symbol, symbol::kw, sym};
+use rustc_target::abi::HasDataLayout;
+use rustc_target::abi::call::{ArgAbi, FnAbi, PassMode};
+use rustc_target::spec::PanicStrategy;
+
+use crate::abi::GccType;
+use crate::builder::Builder;
+use crate::common::{SignType, TypeReflection};
+use crate::context::CodegenCx;
+use crate::type_of::LayoutGccExt;
+use crate::intrinsic::simd::generic_simd_intrinsic;
+
+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",
+ sym::fabsf32 => "fabsf",
+ sym::fabsf64 => "fabs",
+ sym::minnumf32 => "fminf",
+ sym::minnumf64 => "fmin",
+ sym::maxnumf32 => "fmaxf",
+ sym::maxnumf64 => "fmax",
+ sym::copysignf32 => "copysignf",
+ sym::copysignf64 => "copysign",
+ sym::floorf32 => "floorf",
+ sym::floorf64 => "floor",
+ sym::ceilf32 => "ceilf",
+ sym::ceilf64 => "ceil",
+ sym::truncf32 => "truncf",
+ sym::truncf64 => "trunc",
+ sym::rintf32 => "rintf",
+ sym::rintf64 => "rint",
+ sym::nearbyintf32 => "nearbyintf",
+ sym::nearbyintf64 => "nearbyint",
+ sym::roundf32 => "roundf",
+ sym::roundf64 => "round",
+ sym::abort => "abort",
+ _ => return None,
+ };
+ Some(cx.context.get_builtin_function(&gcc_name))
+}
+
+impl<'a, 'gcc, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
+ fn codegen_intrinsic_call(&mut self, instance: Instance<'tcx>, fn_abi: &FnAbi<'tcx, Ty<'tcx>>, args: &[OperandRef<'tcx, RValue<'gcc>>], llresult: RValue<'gcc>, span: Span) {
+ let tcx = self.tcx;
+ let callee_ty = instance.ty(tcx, ty::ParamEnv::reveal_all());
+
+ let (def_id, substs) = match *callee_ty.kind() {
+ ty::FnDef(def_id, substs) => (def_id, substs),
+ _ => bug!("expected fn item type, found {}", callee_ty),
+ };
+
+ let sig = callee_ty.fn_sig(tcx);
+ let sig = tcx.normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), sig);
+ let arg_tys = sig.inputs();
+ let ret_ty = sig.output();
+ let name = tcx.item_name(def_id);
+ let name_str = name.as_str();
+
+ let llret_ty = self.layout_of(ret_ty).gcc_type(self, true);
+ 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() => {
+ // FIXME(antoyo): remove this cast when the API supports function.
+ let func = unsafe { std::mem::transmute(simple.expect("simple")) };
+ self.call(self.type_void(), func, &args.iter().map(|arg| arg.immediate()).collect::<Vec<_>>(), None)
+ },
+ sym::likely => {
+ self.expect(args[0].immediate(), true)
+ }
+ sym::unlikely => {
+ self.expect(args[0].immediate(), false)
+ }
+ kw::Try => {
+ try_intrinsic(
+ self,
+ args[0].immediate(),
+ args[1].immediate(),
+ args[2].immediate(),
+ llresult,
+ );
+ return;
+ }
+ sym::breakpoint => {
+ unimplemented!();
+ }
+ sym::va_copy => {
+ unimplemented!();
+ }
+ sym::va_arg => {
+ unimplemented!();
+ }
+
+ sym::volatile_load | sym::unaligned_volatile_load => {
+ let tp_ty = substs.type_at(0);
+ let mut ptr = args[0].immediate();
+ if let PassMode::Cast(ty) = fn_abi.ret.mode {
+ ptr = self.pointercast(ptr, self.type_ptr_to(ty.gcc_type(self)));
+ }
+ let load = self.volatile_load(ptr.get_type(), ptr);
+ // TODO(antoyo): set alignment.
+ 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 => {
+ 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 => {
+ let ty = arg_tys[0];
+ match int_type_width_signed(ty, self) {
+ Some((width, signed)) => match name {
+ sym::ctlz | sym::cttz => {
+ let func = self.current_func.borrow().expect("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, arg.get_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(arg.get_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 => {
+ span_invalid_monomorphization_error(
+ tcx.sess,
+ span,
+ &format!(
+ "invalid monomorphization of `{}` intrinsic: \
+ expected basic integer type, found `{}`",
+ name, ty
+ ),
+ );
+ return;
+ }
+ }
+ }
+
+ sym::raw_eq => {
+ use rustc_target::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()); // 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::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.llval);
+ extended_asm.add_clobber("memory");
+ extended_asm.set_volatile_flag(true);
+
+ // We have copied the value to `result` already.
+ return;
+ }
+
+ _ if name_str.starts_with("simd_") => {
+ match generic_simd_intrinsic(self, name, callee_ty, args, ret_ty, llret_ty, span) {
+ Ok(llval) => llval,
+ Err(()) => return,
+ }
+ }
+
+ _ => bug!("unknown intrinsic '{}'", name),
+ };
+
+ if !fn_abi.ret.is_ignore() {
+ if let PassMode::Cast(ty) = fn_abi.ret.mode {
+ let ptr_llty = self.type_ptr_to(ty.gcc_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) {
+ let func = self.context.get_builtin_function("abort");
+ let func: RValue<'gcc> = unsafe { std::mem::transmute(func) };
+ self.call(self.type_void(), func, &[], 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_test(&mut self, _pointer: Self::Value, _typeid: Self::Value) -> Self::Value {
+ // Unsupported.
+ self.context.new_rvalue_from_int(self.int_type, 0)
+ }
+
+ fn type_checked_load(
+ &mut self,
+ _llvtable: 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> ArgAbiMethods<'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)
+ }
+
+ fn arg_memory_ty(&self, arg_abi: &ArgAbi<'tcx, Ty<'tcx>>) -> Type<'gcc> {
+ arg_abi.memory_ty(self)
+ }
+}
+
+pub trait ArgAbiExt<'gcc, 'tcx> {
+ fn memory_ty(&self, cx: &CodegenCx<'gcc, 'tcx>) -> Type<'gcc>;
+ 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>> {
+ /// Gets the LLVM type for a place of the original Rust type of
+ /// this argument/return, i.e., the result of `type_of::type_of`.
+ fn memory_ty(&self, cx: &CodegenCx<'gcc, 'tcx>) -> Type<'gcc> {
+ self.layout.gcc_type(cx, true)
+ }
+
+ /// 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(val, None, 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(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.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 llscratch = bx.alloca(cast.gcc_type(bx), scratch_align);
+ bx.lifetime_start(llscratch, scratch_size);
+
+ // ... where we first store the value...
+ bx.store(val, llscratch, scratch_align);
+
+ // ... and then memcpy it to the intended destination.
+ bx.memcpy(
+ dst.llval,
+ self.layout.align.abi,
+ llscratch,
+ scratch_align,
+ bx.const_usize(self.layout.size.bytes()),
+ MemFlags::empty(),
+ );
+
+ bx.lifetime_end(llscratch, 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 { extra_attrs: Some(_), .. } => {
+ OperandValue::Ref(next(), Some(next()), self.layout.align.abi).store(bx, dst);
+ },
+ PassMode::Direct(_) | PassMode::Indirect { extra_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 => {
+ // First step.
+ let left = self.and(value, context.new_rvalue_from_int(typ, 0xF0));
+ let left = self.lshr(left, context.new_rvalue_from_int(typ, 4));
+ let right = self.and(value, context.new_rvalue_from_int(typ, 0x0F));
+ let right = self.shl(right, context.new_rvalue_from_int(typ, 4));
+ let step1 = self.or(left, right);
+
+ // Second step.
+ let left = self.and(step1, context.new_rvalue_from_int(typ, 0xCC));
+ let left = self.lshr(left, context.new_rvalue_from_int(typ, 2));
+ let right = self.and(step1, context.new_rvalue_from_int(typ, 0x33));
+ let right = self.shl(right, context.new_rvalue_from_int(typ, 2));
+ let step2 = self.or(left, right);
+
+ // Third step.
+ let left = self.and(step2, context.new_rvalue_from_int(typ, 0xAA));
+ let left = self.lshr(left, context.new_rvalue_from_int(typ, 1));
+ let right = self.and(step2, context.new_rvalue_from_int(typ, 0x55));
+ let right = self.shl(right, context.new_rvalue_from_int(typ, 1));
+ let step3 = self.or(left, right);
+
+ step3
+ },
+ 16 => {
+ // First step.
+ let left = self.and(value, context.new_rvalue_from_int(typ, 0x5555));
+ let left = self.shl(left, context.new_rvalue_from_int(typ, 1));
+ let right = self.and(value, context.new_rvalue_from_int(typ, 0xAAAA));
+ let right = self.lshr(right, context.new_rvalue_from_int(typ, 1));
+ let step1 = self.or(left, right);
+
+ // Second step.
+ let left = self.and(step1, context.new_rvalue_from_int(typ, 0x3333));
+ let left = self.shl(left, context.new_rvalue_from_int(typ, 2));
+ let right = self.and(step1, context.new_rvalue_from_int(typ, 0xCCCC));
+ let right = self.lshr(right, context.new_rvalue_from_int(typ, 2));
+ let step2 = self.or(left, right);
+
+ // Third step.
+ let left = self.and(step2, context.new_rvalue_from_int(typ, 0x0F0F));
+ let left = self.shl(left, context.new_rvalue_from_int(typ, 4));
+ let right = self.and(step2, context.new_rvalue_from_int(typ, 0xF0F0));
+ let right = self.lshr(right, context.new_rvalue_from_int(typ, 4));
+ let step3 = self.or(left, right);
+
+ // Fourth step.
+ let left = self.and(step3, context.new_rvalue_from_int(typ, 0x00FF));
+ let left = self.shl(left, context.new_rvalue_from_int(typ, 8));
+ let right = self.and(step3, context.new_rvalue_from_int(typ, 0xFF00));
+ let right = self.lshr(right, context.new_rvalue_from_int(typ, 8));
+ let step4 = self.or(left, right);
+
+ step4
+ },
+ 32 => {
+ // TODO(antoyo): Refactor with other implementations.
+ // First step.
+ let left = self.and(value, context.new_rvalue_from_long(typ, 0x55555555));
+ let left = self.shl(left, context.new_rvalue_from_long(typ, 1));
+ let right = self.and(value, context.new_rvalue_from_long(typ, 0xAAAAAAAA));
+ let right = self.lshr(right, context.new_rvalue_from_long(typ, 1));
+ let step1 = self.or(left, right);
+
+ // Second step.
+ let left = self.and(step1, context.new_rvalue_from_long(typ, 0x33333333));
+ let left = self.shl(left, context.new_rvalue_from_long(typ, 2));
+ let right = self.and(step1, context.new_rvalue_from_long(typ, 0xCCCCCCCC));
+ let right = self.lshr(right, context.new_rvalue_from_long(typ, 2));
+ let step2 = self.or(left, right);
+
+ // Third step.
+ let left = self.and(step2, context.new_rvalue_from_long(typ, 0x0F0F0F0F));
+ let left = self.shl(left, context.new_rvalue_from_long(typ, 4));
+ let right = self.and(step2, context.new_rvalue_from_long(typ, 0xF0F0F0F0));
+ let right = self.lshr(right, context.new_rvalue_from_long(typ, 4));
+ let step3 = self.or(left, right);
+
+ // Fourth step.
+ let left = self.and(step3, context.new_rvalue_from_long(typ, 0x00FF00FF));
+ let left = self.shl(left, context.new_rvalue_from_long(typ, 8));
+ let right = self.and(step3, context.new_rvalue_from_long(typ, 0xFF00FF00));
+ let right = self.lshr(right, context.new_rvalue_from_long(typ, 8));
+ let step4 = self.or(left, right);
+
+ // Fifth step.
+ let left = self.and(step4, context.new_rvalue_from_long(typ, 0x0000FFFF));
+ let left = self.shl(left, context.new_rvalue_from_long(typ, 16));
+ let right = self.and(step4, context.new_rvalue_from_long(typ, 0xFFFF0000));
+ let right = self.lshr(right, context.new_rvalue_from_long(typ, 16));
+ let step5 = self.or(left, right);
+
+ step5
+ },
+ 64 => {
+ // First step.
+ let left = self.shl(value, context.new_rvalue_from_long(typ, 32));
+ let right = self.lshr(value, context.new_rvalue_from_long(typ, 32));
+ let step1 = self.or(left, right);
+
+ // Second step.
+ let left = self.and(step1, context.new_rvalue_from_long(typ, 0x0001FFFF0001FFFF));
+ let left = self.shl(left, context.new_rvalue_from_long(typ, 15));
+ let right = self.and(step1, context.new_rvalue_from_long(typ, 0xFFFE0000FFFE0000u64 as i64)); // TODO(antoyo): transmute the number instead?
+ let right = self.lshr(right, context.new_rvalue_from_long(typ, 17));
+ let step2 = self.or(left, right);
+
+ // Third step.
+ let left = self.lshr(step2, context.new_rvalue_from_long(typ, 10));
+ let left = self.xor(step2, left);
+ let temp = self.and(left, context.new_rvalue_from_long(typ, 0x003F801F003F801F));
+
+ let left = self.shl(temp, context.new_rvalue_from_long(typ, 10));
+ let left = self.or(temp, left);
+ let step3 = self.xor(left, step2);
+
+ // Fourth step.
+ let left = self.lshr(step3, context.new_rvalue_from_long(typ, 4));
+ let left = self.xor(step3, left);
+ let temp = self.and(left, context.new_rvalue_from_long(typ, 0x0E0384210E038421));
+
+ let left = self.shl(temp, context.new_rvalue_from_long(typ, 4));
+ let left = self.or(temp, left);
+ let step4 = self.xor(left, step3);
+
+ // Fifth step.
+ let left = self.lshr(step4, context.new_rvalue_from_long(typ, 2));
+ let left = self.xor(step4, left);
+ let temp = self.and(left, context.new_rvalue_from_long(typ, 0x2248884222488842));
+
+ let left = self.shl(temp, context.new_rvalue_from_long(typ, 2));
+ let left = self.or(temp, left);
+ let step5 = self.xor(left, step4);
+
+ step5
+ },
+ 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)
+ },
+ _ => {
+ 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 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_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(None, first_elem, first_value);
+
+ let second_elem = self.context.new_array_access(None, result, one);
+ let cast = self.gcc_int_cast(self.context.new_call(None, clzll, &[low]), arg_type);
+ let second_value = self.add(cast, sixty_four);
+ self.llbb()
+ .add_assignment(None, second_elem, second_value);
+
+ let third_elem = self.context.new_array_access(None, result, two);
+ let third_value = self.const_uint(arg_type, 128);
+ self.llbb()
+ .add_assignment(None, third_elem, third_value);
+
+ let not_high = self.context.new_unary_op(None, UnaryOp::LogicalNegate, self.u64_type, high);
+ let not_low = self.context.new_unary_op(None, 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(None, index, self.i32_type);
+
+ let res = self.context.new_array_access(None, result, index);
+
+ return self.gcc_int_cast(res.to_rvalue(), arg_type);
+ }
+ else {
+ let count_leading_zeroes = self.context.get_builtin_function("__builtin_clzll");
+ let arg = self.context.new_cast(None, 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(None, count_leading_zeroes, &[arg]) - diff;
+ return self.context.new_cast(None, res, arg_type);
+ };
+ let count_leading_zeroes = self.context.get_builtin_function(count_leading_zeroes);
+ let res = self.context.new_call(None, count_leading_zeroes, &[arg]);
+ self.context.new_cast(None, res, arg_type)
+ }
+
+ fn count_trailing_zeroes(&mut self, _width: u64, arg: RValue<'gcc>) -> RValue<'gcc> {
+ let result_type = arg.get_type();
+ let arg =
+ if result_type.is_signed(self.cx) {
+ let new_type = result_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(None, result, zero);
+ let first_value = self.gcc_int_cast(self.context.new_call(None, ctzll, &[low]), arg_type);
+ self.llbb()
+ .add_assignment(None, first_elem, first_value);
+
+ let second_elem = self.context.new_array_access(None, result, one);
+ let second_value = self.gcc_add(self.gcc_int_cast(self.context.new_call(None, ctzll, &[high]), arg_type), sixty_four);
+ self.llbb()
+ .add_assignment(None, second_elem, second_value);
+
+ let third_elem = self.context.new_array_access(None, result, two);
+ let third_value = self.gcc_int(arg_type, 128);
+ self.llbb()
+ .add_assignment(None, third_elem, third_value);
+
+ let not_low = self.context.new_unary_op(None, UnaryOp::LogicalNegate, self.u64_type, low);
+ let not_high = self.context.new_unary_op(None, 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(None, index, self.i32_type);
+
+ let res = self.context.new_array_access(None, 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(None, 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(None, UnaryOp::BitwiseNegate, arg_type, arg);
+ let cond = self.context.new_comparison(None, ComparisonOp::Equals, masked, mask);
+ let diff = diff * self.context.new_cast(None, cond, self.int_type);
+ let res = self.context.new_call(None, count_trailing_zeroes, &[casted_arg]) - diff;
+ return self.context.new_cast(None, 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(None, arg, expected_type)
+ }
+ else {
+ arg
+ };
+ let res = self.context.new_call(None, count_trailing_zeroes, &[arg]);
+ self.context.new_cast(None, 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 = value.get_type();
+ let value_type = result_type.to_unsigned(self.cx);
+
+ let value =
+ if result_type.is_signed(self.cx) {
+ self.gcc_int_cast(value, value_type)
+ }
+ else {
+ value
+ };
+
+ if value_type.is_u128(&self.cx) {
+ // TODO(antoyo): implement in the normal algorithm below to have a more efficient
+ // implementation (that does not require a call to __popcountdi2).
+ let popcount = self.context.get_builtin_function("__builtin_popcountll");
+ 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.context.new_call(None, popcount, &[high]);
+ let low = self.gcc_int_cast(value, self.cx.ulonglong_type);
+ let low = self.context.new_call(None, popcount, &[low]);
+ let res = high + low;
+ return self.gcc_int_cast(res, result_type);
+ }
+
+ // First step.
+ let mask = self.context.new_rvalue_from_long(value_type, 0x5555555555555555);
+ let left = value & mask;
+ let shifted = value >> self.context.new_rvalue_from_int(value_type, 1);
+ let right = shifted & mask;
+ let value = left + right;
+
+ // Second step.
+ let mask = self.context.new_rvalue_from_long(value_type, 0x3333333333333333);
+ let left = value & mask;
+ let shifted = value >> self.context.new_rvalue_from_int(value_type, 2);
+ let right = shifted & mask;
+ let value = left + right;
+
+ // Third step.
+ let mask = self.context.new_rvalue_from_long(value_type, 0x0F0F0F0F0F0F0F0F);
+ let left = value & mask;
+ let shifted = value >> self.context.new_rvalue_from_int(value_type, 4);
+ let right = shifted & mask;
+ let value = left + right;
+
+ if value_type.is_u8(&self.cx) {
+ return self.context.new_cast(None, value, result_type);
+ }
+
+ // Fourth step.
+ let mask = self.context.new_rvalue_from_long(value_type, 0x00FF00FF00FF00FF);
+ let left = value & mask;
+ let shifted = value >> self.context.new_rvalue_from_int(value_type, 8);
+ let right = shifted & mask;
+ let value = left + right;
+
+ if value_type.is_u16(&self.cx) {
+ return self.context.new_cast(None, value, result_type);
+ }
+
+ // Fifth step.
+ let mask = self.context.new_rvalue_from_long(value_type, 0x0000FFFF0000FFFF);
+ let left = value & mask;
+ let shifted = value >> self.context.new_rvalue_from_int(value_type, 16);
+ let right = shifted & mask;
+ let value = left + right;
+
+ if value_type.is_u32(&self.cx) {
+ return self.context.new_cast(None, value, result_type);
+ }
+
+ // Sixth step.
+ let mask = self.context.new_rvalue_from_long(value_type, 0x00000000FFFFFFFF);
+ let left = value & mask;
+ let shifted = value >> self.context.new_rvalue_from_int(value_type, 32);
+ let right = shifted & mask;
+ let value = left + right;
+
+ self.context.new_cast(None, value, 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.borrow().expect("func");
+ let res = func.new_local(None, 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(None)], None)
+ }
+ else {
+ let func_name =
+ match width {
+ 128 => "__rust_i128_addo",
+ _ => unreachable!(),
+ };
+ let param_a = self.context.new_parameter(None, result_type, "a");
+ let param_b = self.context.new_parameter(None, result_type, "b");
+ let result_field = self.context.new_field(None, result_type, "result");
+ let overflow_field = self.context.new_field(None, self.bool_type, "overflow");
+ let return_type = self.context.new_struct_type(None, "result_overflow", &[result_field, overflow_field]);
+ let func = self.context.new_function(None, FunctionType::Extern, return_type.as_type(), &[param_a, param_b], func_name, false);
+ let result = self.context.new_call(None, func, &[lhs, rhs]);
+ let overflow = result.access_field(None, overflow_field);
+ let int_result = result.access_field(None, result_field);
+ self.llbb().add_assignment(None, 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(None, res, self.gcc_int_cast(self.gcc_add(shifted, int_max), result_type));
+ then_block.end_with_jump(None, after_block);
+
+ self.llbb().end_with_conditional(None, 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)
+ }
+ }
+
+ // 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.borrow().expect("func");
+ let res = func.new_local(None, 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(None)], None)
+ }
+ else {
+ let func_name =
+ match width {
+ 128 => "__rust_i128_subo",
+ _ => unreachable!(),
+ };
+ let param_a = self.context.new_parameter(None, result_type, "a");
+ let param_b = self.context.new_parameter(None, result_type, "b");
+ let result_field = self.context.new_field(None, result_type, "result");
+ let overflow_field = self.context.new_field(None, self.bool_type, "overflow");
+ let return_type = self.context.new_struct_type(None, "result_overflow", &[result_field, overflow_field]);
+ let func = self.context.new_function(None, FunctionType::Extern, return_type.as_type(), &[param_a, param_b], func_name, false);
+ let result = self.context.new_call(None, func, &[lhs, rhs]);
+ let overflow = result.access_field(None, overflow_field);
+ let int_result = result.access_field(None, result_field);
+ self.llbb().add_assignment(None, 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(None, res, self.gcc_int_cast(self.gcc_add(shifted, int_max), result_type));
+ then_block.end_with_jump(None, after_block);
+
+ self.llbb().end_with_conditional(None, 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<'gcc, 'tcx>(bx: &mut Builder<'_, 'gcc, 'tcx>, try_func: RValue<'gcc>, data: RValue<'gcc>, _catch_func: RValue<'gcc>, dest: RValue<'gcc>) {
+ // NOTE: the `|| true` here is to use the panic=abort strategy with panic=unwind too
+ if bx.sess().panic_strategy() == PanicStrategy::Abort || true {
+ // TODO(bjorn3): Properly implement unwinding and remove the `|| true` once this is done.
+ bx.call(bx.type_void(), 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()) {
+ unimplemented!();
+ }
+ else {
+ unimplemented!();
+ }
+}