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057c93b64e0fba69a347a088217df70a64396516
wasmtime/cranelift/codegen/src/isa/aarch64/lower_inst.rs
Andrew Brown 057c93b64e Add unarrow instruction with x86 implementation 
Adds a shared `unarrow` instruction in order to lower the Wasm SIMD specification's unsigned narrowing (see https://github.com/WebAssembly/simd/blob/master/proposals/simd/SIMD.md#integer-to-integer-narrowing). Additionally, this commit implements the instruction for x86 using PACKUSWB and PACKUSDW for the applicable encodings.
2020-07-02 09:35:45 -07:00

2371 lines
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//! Lower a single Cranelift instruction into vcode.
use crate::binemit::CodeOffset;
use crate::ir::condcodes::FloatCC;
use crate::ir::types::*;
use crate::ir::Inst as IRInst;
use crate::ir::{InstructionData, Opcode, TrapCode};
use crate::machinst::lower::*;
use crate::machinst::*;
use crate::CodegenResult;
use crate::isa::aarch64::abi::*;
use crate::isa::aarch64::inst::*;
use regalloc::RegClass;
use alloc::boxed::Box;
use alloc::vec::Vec;
use core::convert::TryFrom;
use smallvec::SmallVec;
use super::lower::*;
/// Actually codegen an instruction's results into registers.
pub(crate) fn lower_insn_to_regs<C: LowerCtx<I = Inst>>(
ctx: &mut C,
insn: IRInst,
) -> CodegenResult<()> {
let op = ctx.data(insn).opcode();
let inputs: SmallVec<[InsnInput; 4]> = (0..ctx.num_inputs(insn))
.map(|i| InsnInput { insn, input: i })
.collect();
let outputs: SmallVec<[InsnOutput; 2]> = (0..ctx.num_outputs(insn))
.map(|i| InsnOutput { insn, output: i })
.collect();
let ty = if outputs.len() > 0 {
Some(ctx.output_ty(insn, 0))
} else {
None
};
match op {
Opcode::Iconst | Opcode::Bconst | Opcode::Null => {
let value = ctx.get_constant(insn).unwrap();
let rd = get_output_reg(ctx, outputs[0]);
lower_constant_u64(ctx, rd, value);
}
Opcode::F32const => {
let value = f32::from_bits(ctx.get_constant(insn).unwrap() as u32);
let rd = get_output_reg(ctx, outputs[0]);
lower_constant_f32(ctx, rd, value);
}
Opcode::F64const => {
let value = f64::from_bits(ctx.get_constant(insn).unwrap());
let rd = get_output_reg(ctx, outputs[0]);
lower_constant_f64(ctx, rd, value);
}
Opcode::Iadd => {
let rd = get_output_reg(ctx, outputs[0]);
let rn = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
let rm = put_input_in_rse_imm12(ctx, inputs[1], NarrowValueMode::None);
let ty = ty.unwrap();
let alu_op = choose_32_64(ty, ALUOp::Add32, ALUOp::Add64);
ctx.emit(alu_inst_imm12(alu_op, rd, rn, rm));
}
Opcode::Isub => {
let rd = get_output_reg(ctx, outputs[0]);
let rn = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
let rm = put_input_in_rse_imm12(ctx, inputs[1], NarrowValueMode::None);
let ty = ty.unwrap();
let alu_op = choose_32_64(ty, ALUOp::Sub32, ALUOp::Sub64);
ctx.emit(alu_inst_imm12(alu_op, rd, rn, rm));
}
Opcode::UaddSat | Opcode::SaddSat => {
// We use the vector instruction set's saturating adds (UQADD /
// SQADD), which require vector registers.
let is_signed = op == Opcode::SaddSat;
let narrow_mode = if is_signed {
NarrowValueMode::SignExtend64
} else {
NarrowValueMode::ZeroExtend64
};
let alu_op = if is_signed {
VecALUOp::SQAddScalar
} else {
VecALUOp::UQAddScalar
};
let va = ctx.alloc_tmp(RegClass::V128, I128);
let vb = ctx.alloc_tmp(RegClass::V128, I128);
let ra = put_input_in_reg(ctx, inputs[0], narrow_mode);
let rb = put_input_in_reg(ctx, inputs[1], narrow_mode);
let rd = get_output_reg(ctx, outputs[0]);
ctx.emit(Inst::MovToVec64 { rd: va, rn: ra });
ctx.emit(Inst::MovToVec64 { rd: vb, rn: rb });
ctx.emit(Inst::VecRRR {
rd: va,
rn: va.to_reg(),
rm: vb.to_reg(),
alu_op,
ty: I64,
});
ctx.emit(Inst::MovFromVec {
rd,
rn: va.to_reg(),
idx: 0,
ty: I64,
});
}
Opcode::UsubSat | Opcode::SsubSat => {
let is_signed = op == Opcode::SsubSat;
let narrow_mode = if is_signed {
NarrowValueMode::SignExtend64
} else {
NarrowValueMode::ZeroExtend64
};
let alu_op = if is_signed {
VecALUOp::SQSubScalar
} else {
VecALUOp::UQSubScalar
};
let va = ctx.alloc_tmp(RegClass::V128, I128);
let vb = ctx.alloc_tmp(RegClass::V128, I128);
let ra = put_input_in_reg(ctx, inputs[0], narrow_mode);
let rb = put_input_in_reg(ctx, inputs[1], narrow_mode);
let rd = get_output_reg(ctx, outputs[0]);
ctx.emit(Inst::MovToVec64 { rd: va, rn: ra });
ctx.emit(Inst::MovToVec64 { rd: vb, rn: rb });
ctx.emit(Inst::VecRRR {
rd: va,
rn: va.to_reg(),
rm: vb.to_reg(),
alu_op,
ty: I64,
});
ctx.emit(Inst::MovFromVec {
rd,
rn: va.to_reg(),
idx: 0,
ty: I64,
});
}
Opcode::Ineg => {
let rd = get_output_reg(ctx, outputs[0]);
let rn = zero_reg();
let rm = put_input_in_rse_imm12(ctx, inputs[0], NarrowValueMode::None);
let ty = ty.unwrap();
let alu_op = choose_32_64(ty, ALUOp::Sub32, ALUOp::Sub64);
ctx.emit(alu_inst_imm12(alu_op, rd, rn, rm));
}
Opcode::Imul => {
let rd = get_output_reg(ctx, outputs[0]);
let rn = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
let rm = put_input_in_reg(ctx, inputs[1], NarrowValueMode::None);
let ty = ty.unwrap();
let alu_op = choose_32_64(ty, ALUOp::MAdd32, ALUOp::MAdd64);
ctx.emit(Inst::AluRRRR {
alu_op,
rd,
rn,
rm,
ra: zero_reg(),
});
}
Opcode::Umulhi | Opcode::Smulhi => {
let rd = get_output_reg(ctx, outputs[0]);
let is_signed = op == Opcode::Smulhi;
let input_ty = ctx.input_ty(insn, 0);
assert!(ctx.input_ty(insn, 1) == input_ty);
assert!(ctx.output_ty(insn, 0) == input_ty);
match input_ty {
I64 => {
let rn = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
let rm = put_input_in_reg(ctx, inputs[1], NarrowValueMode::None);
let ra = zero_reg();
let alu_op = if is_signed {
ALUOp::SMulH
} else {
ALUOp::UMulH
};
ctx.emit(Inst::AluRRRR {
alu_op,
rd,
rn,
rm,
ra,
});
}
I32 | I16 | I8 => {
let narrow_mode = if is_signed {
NarrowValueMode::SignExtend64
} else {
NarrowValueMode::ZeroExtend64
};
let rn = put_input_in_reg(ctx, inputs[0], narrow_mode);
let rm = put_input_in_reg(ctx, inputs[1], narrow_mode);
let ra = zero_reg();
ctx.emit(Inst::AluRRRR {
alu_op: ALUOp::MAdd64,
rd,
rn,
rm,
ra,
});
let shift_op = if is_signed {
ALUOp::Asr64
} else {
ALUOp::Lsr64
};
let shift_amt = match input_ty {
I32 => 32,
I16 => 16,
I8 => 8,
_ => unreachable!(),
};
ctx.emit(Inst::AluRRImmShift {
alu_op: shift_op,
rd,
rn: rd.to_reg(),
immshift: ImmShift::maybe_from_u64(shift_amt).unwrap(),
});
}
_ => {
panic!("Unsupported argument type for umulhi/smulhi: {}", input_ty);
}
}
}
Opcode::Udiv | Opcode::Sdiv | Opcode::Urem | Opcode::Srem => {
let is_signed = match op {
Opcode::Udiv | Opcode::Urem => false,
Opcode::Sdiv | Opcode::Srem => true,
_ => unreachable!(),
};
let is_rem = match op {
Opcode::Udiv | Opcode::Sdiv => false,
Opcode::Urem | Opcode::Srem => true,
_ => unreachable!(),
};
let narrow_mode = if is_signed {
NarrowValueMode::SignExtend64
} else {
NarrowValueMode::ZeroExtend64
};
// TODO: Add SDiv32 to implement 32-bit directly, rather
// than extending the input.
let div_op = if is_signed {
ALUOp::SDiv64
} else {
ALUOp::UDiv64
};
let rd = get_output_reg(ctx, outputs[0]);
let rn = put_input_in_reg(ctx, inputs[0], narrow_mode);
let rm = put_input_in_reg(ctx, inputs[1], narrow_mode);
// The div instruction does not trap on divide by zero or signed overflow
// so checks are inserted below.
//
// div rd, rn, rm
ctx.emit(Inst::AluRRR {
alu_op: div_op,
rd,
rn,
rm,
});
if is_rem {
// Remainder (rn % rm) is implemented as:
//
// tmp = rn / rm
// rd = rn - (tmp*rm)
//
// use 'rd' for tmp and you have:
//
// div rd, rn, rm ; rd = rn / rm
// cbnz rm, #8 ; branch over trap
// udf ; divide by zero
// msub rd, rd, rm, rn ; rd = rn - rd * rm
// Check for divide by 0.
let branch_size = 8;
ctx.emit(Inst::OneWayCondBr {
target: BranchTarget::ResolvedOffset(branch_size),
kind: CondBrKind::NotZero(rm),
});
let trap_info = (ctx.srcloc(insn), TrapCode::IntegerDivisionByZero);
ctx.emit(Inst::Udf { trap_info });
ctx.emit(Inst::AluRRRR {
alu_op: ALUOp::MSub64,
rd: rd,
rn: rd.to_reg(),
rm: rm,
ra: rn,
});
} else {
if div_op == ALUOp::SDiv64 {
// cbz rm, #20
// cmn rm, 1
// ccmp rn, 1, #nzcv, eq
// b.vc 12
// udf ; signed overflow
// udf ; divide by zero
// Check for divide by 0.
let branch_size = 20;
ctx.emit(Inst::OneWayCondBr {
target: BranchTarget::ResolvedOffset(branch_size),
kind: CondBrKind::Zero(rm),
});
// Check for signed overflow. The only case is min_value / -1.
let ty = ty.unwrap();
// The following checks must be done in 32-bit or 64-bit, depending
// on the input type. Even though the initial div instruction is
// always done in 64-bit currently.
let size = InstSize::from_ty(ty);
// Check RHS is -1.
ctx.emit(Inst::AluRRImm12 {
alu_op: choose_32_64(ty, ALUOp::AddS32, ALUOp::AddS64),
rd: writable_zero_reg(),
rn: rm,
imm12: Imm12::maybe_from_u64(1).unwrap(),
});
// Check LHS is min_value, by subtracting 1 and branching if
// there is overflow.
ctx.emit(Inst::CCmpImm {
size,
rn,
imm: UImm5::maybe_from_u8(1).unwrap(),
nzcv: NZCV::new(false, false, false, false),
cond: Cond::Eq,
});
ctx.emit(Inst::OneWayCondBr {
target: BranchTarget::ResolvedOffset(12),
kind: CondBrKind::Cond(Cond::Vc),
});
let trap_info = (ctx.srcloc(insn), TrapCode::IntegerOverflow);
ctx.emit(Inst::Udf { trap_info });
} else {
// cbnz rm, #8
// udf ; divide by zero
// Check for divide by 0.
let branch_size = 8;
ctx.emit(Inst::OneWayCondBr {
target: BranchTarget::ResolvedOffset(branch_size),
kind: CondBrKind::NotZero(rm),
});
}
let trap_info = (ctx.srcloc(insn), TrapCode::IntegerDivisionByZero);
ctx.emit(Inst::Udf { trap_info });
}
}
Opcode::Uextend | Opcode::Sextend => {
let output_ty = ty.unwrap();
let input_ty = ctx.input_ty(insn, 0);
let from_bits = ty_bits(input_ty) as u8;
let to_bits = ty_bits(output_ty) as u8;
let to_bits = std::cmp::max(32, to_bits);
assert!(from_bits <= to_bits);
if from_bits < to_bits {
let signed = op == Opcode::Sextend;
// If we reach this point, we weren't able to incorporate the extend as
// a register-mode on another instruction, so we have a 'None'
// narrow-value/extend mode here, and we emit the explicit instruction.
let rn = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
let rd = get_output_reg(ctx, outputs[0]);
ctx.emit(Inst::Extend {
rd,
rn,
signed,
from_bits,
to_bits,
});
}
}
Opcode::Bnot => {
let rd = get_output_reg(ctx, outputs[0]);
let ty = ty.unwrap();
if ty_bits(ty) < 128 {
let rm = put_input_in_rs_immlogic(ctx, inputs[0], NarrowValueMode::None);
let alu_op = choose_32_64(ty, ALUOp::OrrNot32, ALUOp::OrrNot64);
// NOT rd, rm ==> ORR_NOT rd, zero, rm
ctx.emit(alu_inst_immlogic(alu_op, rd, zero_reg(), rm));
} else {
let rm = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
ctx.emit(Inst::VecMisc {
op: VecMisc2::Not,
rd,
rn: rm,
ty,
});
}
}
Opcode::Band
| Opcode::Bor
| Opcode::Bxor
| Opcode::BandNot
| Opcode::BorNot
| Opcode::BxorNot => {
let rd = get_output_reg(ctx, outputs[0]);
let ty = ty.unwrap();
if ty_bits(ty) < 128 {
let rn = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
let rm = put_input_in_rs_immlogic(ctx, inputs[1], NarrowValueMode::None);
let alu_op = match op {
Opcode::Band => choose_32_64(ty, ALUOp::And32, ALUOp::And64),
Opcode::Bor => choose_32_64(ty, ALUOp::Orr32, ALUOp::Orr64),
Opcode::Bxor => choose_32_64(ty, ALUOp::Eor32, ALUOp::Eor64),
Opcode::BandNot => choose_32_64(ty, ALUOp::AndNot32, ALUOp::AndNot64),
Opcode::BorNot => choose_32_64(ty, ALUOp::OrrNot32, ALUOp::OrrNot64),
Opcode::BxorNot => choose_32_64(ty, ALUOp::EorNot32, ALUOp::EorNot64),
_ => unreachable!(),
};
ctx.emit(alu_inst_immlogic(alu_op, rd, rn, rm));
} else {
let alu_op = match op {
Opcode::Band => VecALUOp::And,
Opcode::BandNot => VecALUOp::Bic,
Opcode::Bor => VecALUOp::Orr,
Opcode::Bxor => VecALUOp::Eor,
_ => unreachable!(),
};
let rn = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
let rm = put_input_in_reg(ctx, inputs[1], NarrowValueMode::None);
let rd = get_output_reg(ctx, outputs[0]);
ctx.emit(Inst::VecRRR {
alu_op,
rd,
rn,
rm,
ty,
});
}
}
Opcode::Ishl | Opcode::Ushr | Opcode::Sshr => {
let ty = ty.unwrap();
let size = InstSize::from_bits(ty_bits(ty));
let narrow_mode = match (op, size) {
(Opcode::Ishl, _) => NarrowValueMode::None,
(Opcode::Ushr, InstSize::Size64) => NarrowValueMode::ZeroExtend64,
(Opcode::Ushr, InstSize::Size32) => NarrowValueMode::ZeroExtend32,
(Opcode::Sshr, InstSize::Size64) => NarrowValueMode::SignExtend64,
(Opcode::Sshr, InstSize::Size32) => NarrowValueMode::SignExtend32,
_ => unreachable!(),
};
let rd = get_output_reg(ctx, outputs[0]);
let rn = put_input_in_reg(ctx, inputs[0], narrow_mode);
let rm = put_input_in_reg_immshift(ctx, inputs[1], ty_bits(ty));
let alu_op = match op {
Opcode::Ishl => choose_32_64(ty, ALUOp::Lsl32, ALUOp::Lsl64),
Opcode::Ushr => choose_32_64(ty, ALUOp::Lsr32, ALUOp::Lsr64),
Opcode::Sshr => choose_32_64(ty, ALUOp::Asr32, ALUOp::Asr64),
_ => unreachable!(),
};
ctx.emit(alu_inst_immshift(alu_op, rd, rn, rm));
}
Opcode::Rotr | Opcode::Rotl => {
// aarch64 doesn't have a left-rotate instruction, but a left rotation of K places is
// effectively a right rotation of N - K places, if N is the integer's bit size. We
// implement left rotations with this trick.
//
// For a 32-bit or 64-bit rotate-right, we can use the ROR instruction directly.
//
// For a < 32-bit rotate-right, we synthesize this as:
//
// rotr rd, rn, rm
//
// =>
//
// zero-extend rn, <32-or-64>
// and tmp_masked_rm, rm, <bitwidth - 1>
// sub tmp1, tmp_masked_rm, <bitwidth>
// sub tmp1, zero, tmp1 ; neg
// lsr tmp2, rn, tmp_masked_rm
// lsl rd, rn, tmp1
// orr rd, rd, tmp2
//
// For a constant amount, we can instead do:
//
// zero-extend rn, <32-or-64>
// lsr tmp2, rn, #<shiftimm>
// lsl rd, rn, <bitwidth - shiftimm>
// orr rd, rd, tmp2
let is_rotl = op == Opcode::Rotl;
let ty = ty.unwrap();
let ty_bits_size = ty_bits(ty) as u8;
let rd = get_output_reg(ctx, outputs[0]);
let rn = put_input_in_reg(
ctx,
inputs[0],
if ty_bits_size <= 32 {
NarrowValueMode::ZeroExtend32
} else {
NarrowValueMode::ZeroExtend64
},
);
let rm = put_input_in_reg_immshift(ctx, inputs[1], ty_bits(ty));
if ty_bits_size == 32 || ty_bits_size == 64 {
let alu_op = choose_32_64(ty, ALUOp::RotR32, ALUOp::RotR64);
match rm {
ResultRegImmShift::ImmShift(mut immshift) => {
if is_rotl {
immshift.imm = ty_bits_size.wrapping_sub(immshift.value());
}
immshift.imm &= ty_bits_size - 1;
ctx.emit(Inst::AluRRImmShift {
alu_op,
rd,
rn,
immshift,
});
}
ResultRegImmShift::Reg(rm) => {
let rm = if is_rotl {
// Really ty_bits_size - rn, but the upper bits of the result are
// ignored (because of the implicit masking done by the instruction),
// so this is equivalent to negating the input.
let alu_op = choose_32_64(ty, ALUOp::Sub32, ALUOp::Sub64);
let tmp = ctx.alloc_tmp(RegClass::I64, ty);
ctx.emit(Inst::AluRRR {
alu_op,
rd: tmp,
rn: zero_reg(),
rm,
});
tmp.to_reg()
} else {
rm
};
ctx.emit(Inst::AluRRR { alu_op, rd, rn, rm });
}
}
} else {
debug_assert!(ty_bits_size < 32);
match rm {
ResultRegImmShift::Reg(reg) => {
let reg = if is_rotl {
// Really ty_bits_size - rn, but the upper bits of the result are
// ignored (because of the implicit masking done by the instruction),
// so this is equivalent to negating the input.
let tmp = ctx.alloc_tmp(RegClass::I64, I32);
ctx.emit(Inst::AluRRR {
alu_op: ALUOp::Sub32,
rd: tmp,
rn: zero_reg(),
rm: reg,
});
tmp.to_reg()
} else {
reg
};
// Explicitly mask the rotation count.
let tmp_masked_rm = ctx.alloc_tmp(RegClass::I64, I32);
ctx.emit(Inst::AluRRImmLogic {
alu_op: ALUOp::And32,
rd: tmp_masked_rm,
rn: reg,
imml: ImmLogic::maybe_from_u64((ty_bits_size - 1) as u64, I32).unwrap(),
});
let tmp_masked_rm = tmp_masked_rm.to_reg();
let tmp1 = ctx.alloc_tmp(RegClass::I64, I32);
let tmp2 = ctx.alloc_tmp(RegClass::I64, I32);
ctx.emit(Inst::AluRRImm12 {
alu_op: ALUOp::Sub32,
rd: tmp1,
rn: tmp_masked_rm,
imm12: Imm12::maybe_from_u64(ty_bits_size as u64).unwrap(),
});
ctx.emit(Inst::AluRRR {
alu_op: ALUOp::Sub32,
rd: tmp1,
rn: zero_reg(),
rm: tmp1.to_reg(),
});
ctx.emit(Inst::AluRRR {
alu_op: ALUOp::Lsr32,
rd: tmp2,
rn,
rm: tmp_masked_rm,
});
ctx.emit(Inst::AluRRR {
alu_op: ALUOp::Lsl32,
rd,
rn,
rm: tmp1.to_reg(),
});
ctx.emit(Inst::AluRRR {
alu_op: ALUOp::Orr32,
rd,
rn: rd.to_reg(),
rm: tmp2.to_reg(),
});
}
ResultRegImmShift::ImmShift(mut immshift) => {
if is_rotl {
immshift.imm = ty_bits_size.wrapping_sub(immshift.value());
}
immshift.imm &= ty_bits_size - 1;
let tmp1 = ctx.alloc_tmp(RegClass::I64, I32);
ctx.emit(Inst::AluRRImmShift {
alu_op: ALUOp::Lsr32,
rd: tmp1,
rn,
immshift: immshift.clone(),
});
let amount = immshift.value() & (ty_bits_size - 1);
let opp_shift =
ImmShift::maybe_from_u64(ty_bits_size as u64 - amount as u64).unwrap();
ctx.emit(Inst::AluRRImmShift {
alu_op: ALUOp::Lsl32,
rd,
rn,
immshift: opp_shift,
});
ctx.emit(Inst::AluRRR {
alu_op: ALUOp::Orr32,
rd,
rn: rd.to_reg(),
rm: tmp1.to_reg(),
});
}
}
}
}
Opcode::Bitrev | Opcode::Clz | Opcode::Cls | Opcode::Ctz => {
let rd = get_output_reg(ctx, outputs[0]);
let needs_zext = match op {
Opcode::Bitrev | Opcode::Ctz => false,
Opcode::Clz | Opcode::Cls => true,
_ => unreachable!(),
};
let ty = ty.unwrap();
let narrow_mode = if needs_zext && ty_bits(ty) == 64 {
NarrowValueMode::ZeroExtend64
} else if needs_zext {
NarrowValueMode::ZeroExtend32
} else {
NarrowValueMode::None
};
let rn = put_input_in_reg(ctx, inputs[0], narrow_mode);
let op_ty = match ty {
I8 | I16 | I32 => I32,
I64 => I64,
_ => panic!("Unsupported type for Bitrev/Clz/Cls"),
};
let bitop = match op {
Opcode::Clz | Opcode::Cls | Opcode::Bitrev => BitOp::from((op, op_ty)),
Opcode::Ctz => BitOp::from((Opcode::Bitrev, op_ty)),
_ => unreachable!(),
};
ctx.emit(Inst::BitRR { rd, rn, op: bitop });
// Both bitrev and ctz use a bit-reverse (rbit) instruction; ctz to reduce the problem
// to a clz, and bitrev as the main operation.
if op == Opcode::Bitrev || op == Opcode::Ctz {
// Reversing an n-bit value (n < 32) with a 32-bit bitrev instruction will place
// the reversed result in the highest n bits, so we need to shift them down into
// place.
let right_shift = match ty {
I8 => Some(24),
I16 => Some(16),
I32 => None,
I64 => None,
_ => panic!("Unsupported type for Bitrev"),
};
if let Some(s) = right_shift {
ctx.emit(Inst::AluRRImmShift {
alu_op: ALUOp::Lsr32,
rd,
rn: rd.to_reg(),
immshift: ImmShift::maybe_from_u64(s).unwrap(),
});
}
}
if op == Opcode::Ctz {
ctx.emit(Inst::BitRR {
op: BitOp::from((Opcode::Clz, op_ty)),
rd,
rn: rd.to_reg(),
});
}
}
Opcode::Popcnt => {
// Lower popcount using the following algorithm:
//
// x -= (x >> 1) & 0x5555555555555555
// x = (x & 0x3333333333333333) + ((x >> 2) & 0x3333333333333333)
// x = (x + (x >> 4)) & 0x0f0f0f0f0f0f0f0f
// x += x << 8
// x += x << 16
// x += x << 32
// x >> 56
let ty = ty.unwrap();
let rd = get_output_reg(ctx, outputs[0]);
// FIXME(#1537): zero-extend 8/16/32-bit operands only to 32 bits,
// and fix the sequence below to work properly for this.
let narrow_mode = NarrowValueMode::ZeroExtend64;
let rn = put_input_in_reg(ctx, inputs[0], narrow_mode);
let tmp = ctx.alloc_tmp(RegClass::I64, I64);
// If this is a 32-bit Popcnt, use Lsr32 to clear the top 32 bits of the register, then
// the rest of the code is identical to the 64-bit version.
// lsr [wx]d, [wx]n, #1
ctx.emit(Inst::AluRRImmShift {
alu_op: choose_32_64(ty, ALUOp::Lsr32, ALUOp::Lsr64),
rd: rd,
rn: rn,
immshift: ImmShift::maybe_from_u64(1).unwrap(),
});
// and xd, xd, #0x5555555555555555
ctx.emit(Inst::AluRRImmLogic {
alu_op: ALUOp::And64,
rd: rd,
rn: rd.to_reg(),
imml: ImmLogic::maybe_from_u64(0x5555555555555555, I64).unwrap(),
});
// sub xd, xn, xd
ctx.emit(Inst::AluRRR {
alu_op: ALUOp::Sub64,
rd: rd,
rn: rn,
rm: rd.to_reg(),
});
// and xt, xd, #0x3333333333333333
ctx.emit(Inst::AluRRImmLogic {
alu_op: ALUOp::And64,
rd: tmp,
rn: rd.to_reg(),
imml: ImmLogic::maybe_from_u64(0x3333333333333333, I64).unwrap(),
});
// lsr xd, xd, #2
ctx.emit(Inst::AluRRImmShift {
alu_op: ALUOp::Lsr64,
rd: rd,
rn: rd.to_reg(),
immshift: ImmShift::maybe_from_u64(2).unwrap(),
});
// and xd, xd, #0x3333333333333333
ctx.emit(Inst::AluRRImmLogic {
alu_op: ALUOp::And64,
rd: rd,
rn: rd.to_reg(),
imml: ImmLogic::maybe_from_u64(0x3333333333333333, I64).unwrap(),
});
// add xt, xd, xt
ctx.emit(Inst::AluRRR {
alu_op: ALUOp::Add64,
rd: tmp,
rn: rd.to_reg(),
rm: tmp.to_reg(),
});
// add xt, xt, xt LSR #4
ctx.emit(Inst::AluRRRShift {
alu_op: ALUOp::Add64,
rd: tmp,
rn: tmp.to_reg(),
rm: tmp.to_reg(),
shiftop: ShiftOpAndAmt::new(
ShiftOp::LSR,
ShiftOpShiftImm::maybe_from_shift(4).unwrap(),
),
});
// and xt, xt, #0x0f0f0f0f0f0f0f0f
ctx.emit(Inst::AluRRImmLogic {
alu_op: ALUOp::And64,
rd: tmp,
rn: tmp.to_reg(),
imml: ImmLogic::maybe_from_u64(0x0f0f0f0f0f0f0f0f, I64).unwrap(),
});
// add xt, xt, xt, LSL #8
ctx.emit(Inst::AluRRRShift {
alu_op: ALUOp::Add64,
rd: tmp,
rn: tmp.to_reg(),
rm: tmp.to_reg(),
shiftop: ShiftOpAndAmt::new(
ShiftOp::LSL,
ShiftOpShiftImm::maybe_from_shift(8).unwrap(),
),
});
// add xt, xt, xt, LSL #16
ctx.emit(Inst::AluRRRShift {
alu_op: ALUOp::Add64,
rd: tmp,
rn: tmp.to_reg(),
rm: tmp.to_reg(),
shiftop: ShiftOpAndAmt::new(
ShiftOp::LSL,
ShiftOpShiftImm::maybe_from_shift(16).unwrap(),
),
});
// add xt, xt, xt, LSL #32
ctx.emit(Inst::AluRRRShift {
alu_op: ALUOp::Add64,
rd: tmp,
rn: tmp.to_reg(),
rm: tmp.to_reg(),
shiftop: ShiftOpAndAmt::new(
ShiftOp::LSL,
ShiftOpShiftImm::maybe_from_shift(32).unwrap(),
),
});
// lsr xd, xt, #56
ctx.emit(Inst::AluRRImmShift {
alu_op: ALUOp::Lsr64,
rd: rd,
rn: tmp.to_reg(),
immshift: ImmShift::maybe_from_u64(56).unwrap(),
});
}
Opcode::Load
| Opcode::Uload8
| Opcode::Sload8
| Opcode::Uload16
| Opcode::Sload16
| Opcode::Uload32
| Opcode::Sload32
| Opcode::LoadComplex
| Opcode::Uload8Complex
| Opcode::Sload8Complex
| Opcode::Uload16Complex
| Opcode::Sload16Complex
| Opcode::Uload32Complex
| Opcode::Sload32Complex
| Opcode::Sload8x8
| Opcode::Uload8x8
| Opcode::Sload16x4
| Opcode::Uload16x4
| Opcode::Sload32x2
| Opcode::Uload32x2 => {
let off = ldst_offset(ctx.data(insn)).unwrap();
let elem_ty = match op {
Opcode::Sload8 | Opcode::Uload8 | Opcode::Sload8Complex | Opcode::Uload8Complex => {
I8
}
Opcode::Sload16
| Opcode::Uload16
| Opcode::Sload16Complex
| Opcode::Uload16Complex => I16,
Opcode::Sload32
| Opcode::Uload32
| Opcode::Sload32Complex
| Opcode::Uload32Complex => I32,
Opcode::Load | Opcode::LoadComplex => ctx.output_ty(insn, 0),
Opcode::Sload8x8 | Opcode::Uload8x8 => I8X8,
Opcode::Sload16x4 | Opcode::Uload16x4 => I16X4,
Opcode::Sload32x2 | Opcode::Uload32x2 => I32X2,
_ => unreachable!(),
};
let sign_extend = match op {
Opcode::Sload8
| Opcode::Sload8Complex
| Opcode::Sload16
| Opcode::Sload16Complex
| Opcode::Sload32
| Opcode::Sload32Complex => true,
_ => false,
};
let is_float = ty_is_float(elem_ty);
let mem = lower_address(ctx, elem_ty, &inputs[..], off);
let rd = get_output_reg(ctx, outputs[0]);
let memflags = ctx.memflags(insn).expect("memory flags");
let srcloc = if !memflags.notrap() {
Some(ctx.srcloc(insn))
} else {
None
};
ctx.emit(match (ty_bits(elem_ty), sign_extend, is_float) {
(1, _, _) => Inst::ULoad8 { rd, mem, srcloc },
(8, false, _) => Inst::ULoad8 { rd, mem, srcloc },
(8, true, _) => Inst::SLoad8 { rd, mem, srcloc },
(16, false, _) => Inst::ULoad16 { rd, mem, srcloc },
(16, true, _) => Inst::SLoad16 { rd, mem, srcloc },
(32, false, false) => Inst::ULoad32 { rd, mem, srcloc },
(32, true, false) => Inst::SLoad32 { rd, mem, srcloc },
(32, _, true) => Inst::FpuLoad32 { rd, mem, srcloc },
(64, _, false) => Inst::ULoad64 { rd, mem, srcloc },
// Note that we treat some of the vector loads as scalar floating-point loads,
// which is correct in a little endian environment.
(64, _, true) => Inst::FpuLoad64 { rd, mem, srcloc },
(128, _, _) => Inst::FpuLoad128 { rd, mem, srcloc },
_ => panic!("Unsupported size in load"),
});
let vec_extend = match op {
Opcode::Sload8x8 => Some(VecExtendOp::Sxtl8),
Opcode::Uload8x8 => Some(VecExtendOp::Uxtl8),
Opcode::Sload16x4 => Some(VecExtendOp::Sxtl16),
Opcode::Uload16x4 => Some(VecExtendOp::Uxtl16),
Opcode::Sload32x2 => Some(VecExtendOp::Sxtl32),
Opcode::Uload32x2 => Some(VecExtendOp::Uxtl32),
_ => None,
};
if let Some(t) = vec_extend {
ctx.emit(Inst::VecExtend {
t,
rd,
rn: rd.to_reg(),
});
}
}
Opcode::Store
| Opcode::Istore8
| Opcode::Istore16
| Opcode::Istore32
| Opcode::StoreComplex
| Opcode::Istore8Complex
| Opcode::Istore16Complex
| Opcode::Istore32Complex => {
let off = ldst_offset(ctx.data(insn)).unwrap();
let elem_ty = match op {
Opcode::Istore8 | Opcode::Istore8Complex => I8,
Opcode::Istore16 | Opcode::Istore16Complex => I16,
Opcode::Istore32 | Opcode::Istore32Complex => I32,
Opcode::Store | Opcode::StoreComplex => ctx.input_ty(insn, 0),
_ => unreachable!(),
};
let is_float = ty_is_float(elem_ty);
let mem = lower_address(ctx, elem_ty, &inputs[1..], off);
let rd = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
let memflags = ctx.memflags(insn).expect("memory flags");
let srcloc = if !memflags.notrap() {
Some(ctx.srcloc(insn))
} else {
None
};
ctx.emit(match (ty_bits(elem_ty), is_float) {
(1, _) | (8, _) => Inst::Store8 { rd, mem, srcloc },
(16, _) => Inst::Store16 { rd, mem, srcloc },
(32, false) => Inst::Store32 { rd, mem, srcloc },
(32, true) => Inst::FpuStore32 { rd, mem, srcloc },
(64, false) => Inst::Store64 { rd, mem, srcloc },
(64, true) => Inst::FpuStore64 { rd, mem, srcloc },
(128, _) => Inst::FpuStore128 { rd, mem, srcloc },
_ => panic!("Unsupported size in store"),
});
}
Opcode::StackAddr => {
let (stack_slot, offset) = match *ctx.data(insn) {
InstructionData::StackLoad {
opcode: Opcode::StackAddr,
stack_slot,
offset,
} => (stack_slot, offset),
_ => unreachable!(),
};
let rd = get_output_reg(ctx, outputs[0]);
let offset: i32 = offset.into();
let inst = ctx
.abi()
.stackslot_addr(stack_slot, u32::try_from(offset).unwrap(), rd);
ctx.emit(inst);
}
Opcode::StackLoad | Opcode::StackStore => {
panic!("Direct stack memory access not supported; should not be used by Wasm");
}
Opcode::HeapAddr => {
panic!("heap_addr should have been removed by legalization!");
}
Opcode::TableAddr => {
panic!("table_addr should have been removed by legalization!");
}
Opcode::ConstAddr => unimplemented!(),
Opcode::Nop => {
// Nothing.
}
Opcode::Select | Opcode::Selectif | Opcode::SelectifSpectreGuard => {
let cond = if op == Opcode::Select {
let (cmp_op, narrow_mode) = if ty_bits(ctx.input_ty(insn, 0)) > 32 {
(ALUOp::SubS64, NarrowValueMode::ZeroExtend64)
} else {
(ALUOp::SubS32, NarrowValueMode::ZeroExtend32)
};
let rcond = put_input_in_reg(ctx, inputs[0], narrow_mode);
// cmp rcond, #0
ctx.emit(Inst::AluRRR {
alu_op: cmp_op,
rd: writable_zero_reg(),
rn: rcond,
rm: zero_reg(),
});
Cond::Ne
} else {
let condcode = inst_condcode(ctx.data(insn)).unwrap();
let cond = lower_condcode(condcode);
let is_signed = condcode_is_signed(condcode);
// Verification ensures that the input is always a
// single-def ifcmp.
let ifcmp_insn = maybe_input_insn(ctx, inputs[0], Opcode::Ifcmp).unwrap();
lower_icmp_or_ifcmp_to_flags(ctx, ifcmp_insn, is_signed);
cond
};
// csel.COND rd, rn, rm
let rd = get_output_reg(ctx, outputs[0]);
let rn = put_input_in_reg(ctx, inputs[1], NarrowValueMode::None);
let rm = put_input_in_reg(ctx, inputs[2], NarrowValueMode::None);
let ty = ctx.output_ty(insn, 0);
let bits = ty_bits(ty);
if ty_is_float(ty) && bits == 32 {
ctx.emit(Inst::FpuCSel32 { cond, rd, rn, rm });
} else if ty_is_float(ty) && bits == 64 {
ctx.emit(Inst::FpuCSel64 { cond, rd, rn, rm });
} else {
ctx.emit(Inst::CSel { cond, rd, rn, rm });
}
}
Opcode::Bitselect => {
let ty = ty.unwrap();
if ty_bits(ty) < 128 {
let tmp = ctx.alloc_tmp(RegClass::I64, I64);
let rd = get_output_reg(ctx, outputs[0]);
let rcond = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
let rn = put_input_in_reg(ctx, inputs[1], NarrowValueMode::None);
let rm = put_input_in_reg(ctx, inputs[2], NarrowValueMode::None);
// AND rTmp, rn, rcond
ctx.emit(Inst::AluRRR {
alu_op: ALUOp::And64,
rd: tmp,
rn,
rm: rcond,
});
// BIC rd, rm, rcond
ctx.emit(Inst::AluRRR {
alu_op: ALUOp::AndNot64,
rd,
rn: rm,
rm: rcond,
});
// ORR rd, rd, rTmp
ctx.emit(Inst::AluRRR {
alu_op: ALUOp::Orr64,
rd,
rn: rd.to_reg(),
rm: tmp.to_reg(),
});
} else {
let rcond = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
let rn = put_input_in_reg(ctx, inputs[1], NarrowValueMode::None);
let rm = put_input_in_reg(ctx, inputs[2], NarrowValueMode::None);
let rd = get_output_reg(ctx, outputs[0]);
ctx.emit(Inst::gen_move(rd, rcond, ty));
ctx.emit(Inst::VecRRR {
alu_op: VecALUOp::Bsl,
rd,
rn,
rm,
ty,
});
}
}
Opcode::Trueif => {
let condcode = inst_condcode(ctx.data(insn)).unwrap();
let cond = lower_condcode(condcode);
let is_signed = condcode_is_signed(condcode);
// Verification ensures that the input is always a
// single-def ifcmp.
let ifcmp_insn = maybe_input_insn(ctx, inputs[0], Opcode::Ifcmp).unwrap();
lower_icmp_or_ifcmp_to_flags(ctx, ifcmp_insn, is_signed);
let rd = get_output_reg(ctx, outputs[0]);
ctx.emit(Inst::CSet { rd, cond });
}
Opcode::Trueff => {
let condcode = inst_fp_condcode(ctx.data(insn)).unwrap();
let cond = lower_fp_condcode(condcode);
let ffcmp_insn = maybe_input_insn(ctx, inputs[0], Opcode::Ffcmp).unwrap();
lower_fcmp_or_ffcmp_to_flags(ctx, ffcmp_insn);
let rd = get_output_reg(ctx, outputs[0]);
ctx.emit(Inst::CSet { rd, cond });
}
Opcode::IsNull | Opcode::IsInvalid => {
panic!("Reference types not supported");
}
Opcode::Copy => {
let rd = get_output_reg(ctx, outputs[0]);
let rn = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
let ty = ctx.input_ty(insn, 0);
ctx.emit(Inst::gen_move(rd, rn, ty));
}
Opcode::Bint | Opcode::Breduce | Opcode::Bextend | Opcode::Ireduce => {
// All of these ops are simply a move from a zero-extended source.
// Here is why this works, in each case:
//
// - Bint: Bool-to-int. We always represent a bool as a 0 or 1, so we
// merely need to zero-extend here.
//
// - Breduce, Bextend: changing width of a boolean. We represent a
// bool as a 0 or 1, so again, this is a zero-extend / no-op.
//
// - Ireduce: changing width of an integer. Smaller ints are stored
// with undefined high-order bits, so we can simply do a copy.
let rn = put_input_in_reg(ctx, inputs[0], NarrowValueMode::ZeroExtend64);
let rd = get_output_reg(ctx, outputs[0]);
let ty = ctx.input_ty(insn, 0);
ctx.emit(Inst::gen_move(rd, rn, ty));
}
Opcode::Bmask => {
// Bool is {0, 1}, so we can subtract from 0 to get all-1s.
let rd = get_output_reg(ctx, outputs[0]);
let rm = put_input_in_reg(ctx, inputs[0], NarrowValueMode::ZeroExtend64);
ctx.emit(Inst::AluRRR {
alu_op: ALUOp::Sub64,
rd,
rn: zero_reg(),
rm,
});
}
Opcode::Bitcast => {
let rd = get_output_reg(ctx, outputs[0]);
let ity = ctx.input_ty(insn, 0);
let oty = ctx.output_ty(insn, 0);
match (ty_is_float(ity), ty_is_float(oty)) {
(true, true) => {
let narrow_mode = if ty_bits(ity) <= 32 && ty_bits(oty) <= 32 {
NarrowValueMode::ZeroExtend32
} else {
NarrowValueMode::ZeroExtend64
};
let rm = put_input_in_reg(ctx, inputs[0], narrow_mode);
ctx.emit(Inst::gen_move(rd, rm, oty));
}
(false, false) => {
let rm = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
ctx.emit(Inst::gen_move(rd, rm, oty));
}
(false, true) => {
let rn = put_input_in_reg(ctx, inputs[0], NarrowValueMode::ZeroExtend64);
ctx.emit(Inst::MovToVec64 { rd, rn });
}
(true, false) => {
let rn = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
ctx.emit(Inst::MovFromVec {
rd,
rn,
idx: 0,
ty: I64,
});
}
}
}
Opcode::FallthroughReturn | Opcode::Return => {
for (i, input) in inputs.iter().enumerate() {
// N.B.: according to the AArch64 ABI, the top bits of a register
// (above the bits for the value's type) are undefined, so we
// need not extend the return values.
let reg = put_input_in_reg(ctx, *input, NarrowValueMode::None);
let retval_reg = ctx.retval(i);
let ty = ctx.input_ty(insn, i);
ctx.emit(Inst::gen_move(retval_reg, reg, ty));
}
// N.B.: the Ret itself is generated by the ABI.
}
Opcode::Ifcmp | Opcode::Ffcmp => {
// An Ifcmp/Ffcmp must always be seen as a use of a brif/brff or trueif/trueff
// instruction. This will always be the case as long as the IR uses an Ifcmp/Ffcmp from
// the same block, or a dominating block. In other words, it cannot pass through a BB
// param (phi). The flags pass of the verifier will ensure this.
panic!("Should never reach ifcmp as isel root!");
}
Opcode::Icmp => {
let condcode = inst_condcode(ctx.data(insn)).unwrap();
let cond = lower_condcode(condcode);
let is_signed = condcode_is_signed(condcode);
let rd = get_output_reg(ctx, outputs[0]);
let ty = ctx.input_ty(insn, 0);
let bits = ty_bits(ty);
let narrow_mode = match (bits <= 32, is_signed) {
(true, true) => NarrowValueMode::SignExtend32,
(true, false) => NarrowValueMode::ZeroExtend32,
(false, true) => NarrowValueMode::SignExtend64,
(false, false) => NarrowValueMode::ZeroExtend64,
};
let rn = put_input_in_reg(ctx, inputs[0], narrow_mode);
if ty_bits(ty) < 128 {
let alu_op = choose_32_64(ty, ALUOp::SubS32, ALUOp::SubS64);
let rm = put_input_in_rse_imm12(ctx, inputs[1], narrow_mode);
ctx.emit(alu_inst_imm12(alu_op, writable_zero_reg(), rn, rm));
ctx.emit(Inst::CondSet { cond, rd });
} else {
let rm = put_input_in_reg(ctx, inputs[1], narrow_mode);
lower_vector_compare(ctx, rd, rn, rm, ty, cond)?;
}
}
Opcode::Fcmp => {
let condcode = inst_fp_condcode(ctx.data(insn)).unwrap();
let cond = lower_fp_condcode(condcode);
let ty = ctx.input_ty(insn, 0);
let rn = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
let rm = put_input_in_reg(ctx, inputs[1], NarrowValueMode::None);
let rd = get_output_reg(ctx, outputs[0]);
if ty_bits(ty) < 128 {
match ty_bits(ty) {
32 => {
ctx.emit(Inst::FpuCmp32 { rn, rm });
}
64 => {
ctx.emit(Inst::FpuCmp64 { rn, rm });
}
_ => panic!("Bad float size"),
}
ctx.emit(Inst::CondSet { cond, rd });
} else {
lower_vector_compare(ctx, rd, rn, rm, ty, cond)?;
}
}
Opcode::JumpTableEntry | Opcode::JumpTableBase => {
panic!("Should not appear: we handle BrTable directly");
}
Opcode::Debugtrap => {
ctx.emit(Inst::Brk);
}
Opcode::Trap | Opcode::ResumableTrap => {
let trap_info = (ctx.srcloc(insn), inst_trapcode(ctx.data(insn)).unwrap());
ctx.emit(Inst::Udf { trap_info })
}
Opcode::Trapif | Opcode::Trapff => {
let trap_info = (ctx.srcloc(insn), inst_trapcode(ctx.data(insn)).unwrap());
let cond = if maybe_input_insn(ctx, inputs[0], Opcode::IaddIfcout).is_some() {
let condcode = inst_condcode(ctx.data(insn)).unwrap();
let cond = lower_condcode(condcode);
// The flags must not have been clobbered by any other
// instruction between the iadd_ifcout and this instruction, as
// verified by the CLIF validator; so we can simply use the
// flags here.
cond
} else if op == Opcode::Trapif {
let condcode = inst_condcode(ctx.data(insn)).unwrap();
let cond = lower_condcode(condcode);
let is_signed = condcode_is_signed(condcode);
// Verification ensures that the input is always a single-def ifcmp.
let ifcmp_insn = maybe_input_insn(ctx, inputs[0], Opcode::Ifcmp).unwrap();
lower_icmp_or_ifcmp_to_flags(ctx, ifcmp_insn, is_signed);
cond
} else {
let condcode = inst_fp_condcode(ctx.data(insn)).unwrap();
let cond = lower_fp_condcode(condcode);
// Verification ensures that the input is always a
// single-def ffcmp.
let ffcmp_insn = maybe_input_insn(ctx, inputs[0], Opcode::Ffcmp).unwrap();
lower_fcmp_or_ffcmp_to_flags(ctx, ffcmp_insn);
cond
};
// Branch around the break instruction with inverted cond. Go straight to lowered
// one-target form; this is logically part of a single-in single-out template lowering.
let cond = cond.invert();
ctx.emit(Inst::OneWayCondBr {
target: BranchTarget::ResolvedOffset(8),
kind: CondBrKind::Cond(cond),
});
ctx.emit(Inst::Udf { trap_info })
}
Opcode::Safepoint => {
panic!("safepoint support not implemented!");
}
Opcode::Trapz | Opcode::Trapnz | Opcode::ResumableTrapnz => {
panic!("trapz / trapnz / resumable_trapnz should have been removed by legalization!");
}
Opcode::FuncAddr => {
let rd = get_output_reg(ctx, outputs[0]);
let (extname, _) = ctx.call_target(insn).unwrap();
let extname = extname.clone();
let loc = ctx.srcloc(insn);
ctx.emit(Inst::LoadExtName {
rd,
name: Box::new(extname),
srcloc: loc,
offset: 0,
});
}
Opcode::GlobalValue => {
panic!("global_value should have been removed by legalization!");
}
Opcode::SymbolValue => {
let rd = get_output_reg(ctx, outputs[0]);
let (extname, _, offset) = ctx.symbol_value(insn).unwrap();
let extname = extname.clone();
let loc = ctx.srcloc(insn);
ctx.emit(Inst::LoadExtName {
rd,
name: Box::new(extname),
srcloc: loc,
offset,
});
}
Opcode::Call | Opcode::CallIndirect => {
let loc = ctx.srcloc(insn);
let (mut abi, inputs) = match op {
Opcode::Call => {
let (extname, dist) = ctx.call_target(insn).unwrap();
let extname = extname.clone();
let sig = ctx.call_sig(insn).unwrap();
assert!(inputs.len() == sig.params.len());
assert!(outputs.len() == sig.returns.len());
(
AArch64ABICall::from_func(sig, &extname, dist, loc)?,
&inputs[..],
)
}
Opcode::CallIndirect => {
let ptr = put_input_in_reg(ctx, inputs[0], NarrowValueMode::ZeroExtend64);
let sig = ctx.call_sig(insn).unwrap();
assert!(inputs.len() - 1 == sig.params.len());
assert!(outputs.len() == sig.returns.len());
(AArch64ABICall::from_ptr(sig, ptr, loc, op)?, &inputs[1..])
}
_ => unreachable!(),
};
abi.emit_stack_pre_adjust(ctx);
assert!(inputs.len() == abi.num_args());
for (i, input) in inputs.iter().enumerate() {
let arg_reg = put_input_in_reg(ctx, *input, NarrowValueMode::None);
abi.emit_copy_reg_to_arg(ctx, i, arg_reg);
}
abi.emit_call(ctx);
for (i, output) in outputs.iter().enumerate() {
let retval_reg = get_output_reg(ctx, *output);
abi.emit_copy_retval_to_reg(ctx, i, retval_reg);
}
abi.emit_stack_post_adjust(ctx);
}
Opcode::GetPinnedReg => {
let rd = get_output_reg(ctx, outputs[0]);
ctx.emit(Inst::mov(rd, xreg(PINNED_REG)));
}
Opcode::SetPinnedReg => {
let rm = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
ctx.emit(Inst::mov(writable_xreg(PINNED_REG), rm));
}
Opcode::Spill
| Opcode::Fill
| Opcode::FillNop
| Opcode::Regmove
| Opcode::CopySpecial
| Opcode::CopyToSsa
| Opcode::CopyNop
| Opcode::AdjustSpDown
| Opcode::AdjustSpUpImm
| Opcode::AdjustSpDownImm
| Opcode::IfcmpSp
| Opcode::Regspill
| Opcode::Regfill => {
panic!("Unused opcode should not be encountered.");
}
Opcode::Jump
| Opcode::Fallthrough
| Opcode::Brz
| Opcode::Brnz
| Opcode::BrIcmp
| Opcode::Brif
| Opcode::Brff
| Opcode::IndirectJumpTableBr
| Opcode::BrTable => {
panic!("Branch opcode reached non-branch lowering logic!");
}
Opcode::Vconst => {
let value = output_to_const_f128(ctx, outputs[0]).unwrap();
let rd = get_output_reg(ctx, outputs[0]);
lower_constant_f128(ctx, rd, value);
}
Opcode::RawBitcast => {
let rm = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
let rd = get_output_reg(ctx, outputs[0]);
let ty = ctx.input_ty(insn, 0);
ctx.emit(Inst::gen_move(rd, rm, ty));
}
Opcode::Extractlane => {
if let InstructionData::BinaryImm8 { imm, .. } = ctx.data(insn) {
let idx = *imm;
let rd = get_output_reg(ctx, outputs[0]);
let rn = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
let ty = ty.unwrap();
if ty_is_int(ty) {
ctx.emit(Inst::MovFromVec { rd, rn, idx, ty });
// Plain moves are faster on some processors.
} else if idx == 0 {
ctx.emit(Inst::gen_move(rd, rn, ty));
} else {
ctx.emit(Inst::FpuMoveFromVec { rd, rn, idx, ty });
}
} else {
unreachable!();
}
}
Opcode::Splat => {
let rn = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
let rd = get_output_reg(ctx, outputs[0]);
let ty = ctx.input_ty(insn, 0);
let inst = if ty_is_int(ty) {
Inst::VecDup { rd, rn, ty }
} else {
Inst::VecDupFromFpu { rd, rn, ty }
};
ctx.emit(inst);
}
Opcode::VanyTrue | Opcode::VallTrue => {
let rd = get_output_reg(ctx, outputs[0]);
let rm = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
let tmp = ctx.alloc_tmp(RegClass::V128, ty.unwrap());
// This operation is implemented by using umaxp or uminv to
// create a scalar value, which is then compared against zero.
//
// umaxp vn.16b, vm.16, vm.16 / uminv bn, vm.16b
// mov xm, vn.d[0]
// cmp xm, #0
// cset xm, ne
let input_ty = ctx.input_ty(insn, 0);
if op == Opcode::VanyTrue {
ctx.emit(Inst::VecRRR {
alu_op: VecALUOp::Umaxp,
rd: tmp,
rn: rm,
rm: rm,
ty: input_ty,
});
} else {
ctx.emit(Inst::VecLanes {
op: VecLanesOp::Uminv,
rd: tmp,
rn: rm,
ty: input_ty,
});
};
ctx.emit(Inst::MovFromVec {
rd,
rn: tmp.to_reg(),
idx: 0,
ty: I64,
});
ctx.emit(Inst::AluRRImm12 {
alu_op: ALUOp::SubS64,
rd: writable_zero_reg(),
rn: rd.to_reg(),
imm12: Imm12::zero(),
});
ctx.emit(Inst::CSet { rd, cond: Cond::Ne });
}
Opcode::Shuffle
| Opcode::Vsplit
| Opcode::Vconcat
| Opcode::Vselect
| Opcode::Insertlane
| Opcode::ScalarToVector
| Opcode::Swizzle
| Opcode::Uload8x8Complex
| Opcode::Sload8x8Complex
| Opcode::Uload16x4Complex
| Opcode::Sload16x4Complex
| Opcode::Uload32x2Complex
| Opcode::Sload32x2Complex => {
// TODO
panic!("Vector ops not implemented.");
}
Opcode::Isplit | Opcode::Iconcat => panic!("Vector ops not supported."),
Opcode::Imax | Opcode::Imin | Opcode::Umin | Opcode::Umax => {
panic!("Vector ops not supported.")
}
Opcode::Fadd | Opcode::Fsub | Opcode::Fmul | Opcode::Fdiv | Opcode::Fmin | Opcode::Fmax => {
let bits = ty_bits(ctx.output_ty(insn, 0));
let fpu_op = match (op, bits) {
(Opcode::Fadd, 32) => FPUOp2::Add32,
(Opcode::Fadd, 64) => FPUOp2::Add64,
(Opcode::Fsub, 32) => FPUOp2::Sub32,
(Opcode::Fsub, 64) => FPUOp2::Sub64,
(Opcode::Fmul, 32) => FPUOp2::Mul32,
(Opcode::Fmul, 64) => FPUOp2::Mul64,
(Opcode::Fdiv, 32) => FPUOp2::Div32,
(Opcode::Fdiv, 64) => FPUOp2::Div64,
(Opcode::Fmin, 32) => FPUOp2::Min32,
(Opcode::Fmin, 64) => FPUOp2::Min64,
(Opcode::Fmax, 32) => FPUOp2::Max32,
(Opcode::Fmax, 64) => FPUOp2::Max64,
_ => panic!("Unknown op/bits combination"),
};
let rn = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
let rm = put_input_in_reg(ctx, inputs[1], NarrowValueMode::None);
let rd = get_output_reg(ctx, outputs[0]);
ctx.emit(Inst::FpuRRR { fpu_op, rd, rn, rm });
}
Opcode::Sqrt | Opcode::Fneg | Opcode::Fabs | Opcode::Fpromote | Opcode::Fdemote => {
let bits = ty_bits(ctx.output_ty(insn, 0));
let fpu_op = match (op, bits) {
(Opcode::Sqrt, 32) => FPUOp1::Sqrt32,
(Opcode::Sqrt, 64) => FPUOp1::Sqrt64,
(Opcode::Fneg, 32) => FPUOp1::Neg32,
(Opcode::Fneg, 64) => FPUOp1::Neg64,
(Opcode::Fabs, 32) => FPUOp1::Abs32,
(Opcode::Fabs, 64) => FPUOp1::Abs64,
(Opcode::Fpromote, 32) => panic!("Cannot promote to 32 bits"),
(Opcode::Fpromote, 64) => FPUOp1::Cvt32To64,
(Opcode::Fdemote, 32) => FPUOp1::Cvt64To32,
(Opcode::Fdemote, 64) => panic!("Cannot demote to 64 bits"),
_ => panic!("Unknown op/bits combination"),
};
let rn = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
let rd = get_output_reg(ctx, outputs[0]);
ctx.emit(Inst::FpuRR { fpu_op, rd, rn });
}
Opcode::Ceil | Opcode::Floor | Opcode::Trunc | Opcode::Nearest => {
let bits = ty_bits(ctx.output_ty(insn, 0));
let op = match (op, bits) {
(Opcode::Ceil, 32) => FpuRoundMode::Plus32,
(Opcode::Ceil, 64) => FpuRoundMode::Plus64,
(Opcode::Floor, 32) => FpuRoundMode::Minus32,
(Opcode::Floor, 64) => FpuRoundMode::Minus64,
(Opcode::Trunc, 32) => FpuRoundMode::Zero32,
(Opcode::Trunc, 64) => FpuRoundMode::Zero64,
(Opcode::Nearest, 32) => FpuRoundMode::Nearest32,
(Opcode::Nearest, 64) => FpuRoundMode::Nearest64,
_ => panic!("Unknown op/bits combination"),
};
let rn = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
let rd = get_output_reg(ctx, outputs[0]);
ctx.emit(Inst::FpuRound { op, rd, rn });
}
Opcode::Fma => {
let bits = ty_bits(ctx.output_ty(insn, 0));
let fpu_op = match bits {
32 => FPUOp3::MAdd32,
64 => FPUOp3::MAdd64,
_ => panic!("Unknown op size"),
};
let rn = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
let rm = put_input_in_reg(ctx, inputs[1], NarrowValueMode::None);
let ra = put_input_in_reg(ctx, inputs[2], NarrowValueMode::None);
let rd = get_output_reg(ctx, outputs[0]);
ctx.emit(Inst::FpuRRRR {
fpu_op,
rn,
rm,
ra,
rd,
});
}
Opcode::Fcopysign => {
// Copy the sign bit from inputs[1] to inputs[0]. We use the following sequence:
//
// This is a scalar Fcopysign.
// This uses scalar NEON operations for 64-bit and vector operations (2S) for 32-bit.
//
// mov vd, vn
// ushr vtmp, vm, #63 / #31
// sli vd, vtmp, #63 / #31
let ty = ctx.output_ty(insn, 0);
let bits = ty_bits(ty) as u8;
assert!(bits == 32 || bits == 64);
let rn = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
let rm = put_input_in_reg(ctx, inputs[1], NarrowValueMode::None);
let rd = get_output_reg(ctx, outputs[0]);
let tmp = ctx.alloc_tmp(RegClass::V128, F64);
// Copy LHS to rd.
ctx.emit(Inst::FpuMove64 { rd, rn });
// Copy the sign bit to the lowest bit in tmp.
let imm = FPURightShiftImm::maybe_from_u8(bits - 1, bits).unwrap();
ctx.emit(Inst::FpuRRI {
fpu_op: choose_32_64(ty, FPUOpRI::UShr32(imm), FPUOpRI::UShr64(imm)),
rd: tmp,
rn: rm,
});
// Insert the bit from tmp into the sign bit of rd.
let imm = FPULeftShiftImm::maybe_from_u8(bits - 1, bits).unwrap();
ctx.emit(Inst::FpuRRI {
fpu_op: choose_32_64(ty, FPUOpRI::Sli32(imm), FPUOpRI::Sli64(imm)),
rd,
rn: tmp.to_reg(),
});
}
Opcode::FcvtToUint | Opcode::FcvtToSint => {
let in_bits = ty_bits(ctx.input_ty(insn, 0));
let out_bits = ty_bits(ctx.output_ty(insn, 0));
let signed = op == Opcode::FcvtToSint;
let op = match (signed, in_bits, out_bits) {
(false, 32, 32) => FpuToIntOp::F32ToU32,
(true, 32, 32) => FpuToIntOp::F32ToI32,
(false, 32, 64) => FpuToIntOp::F32ToU64,
(true, 32, 64) => FpuToIntOp::F32ToI64,
(false, 64, 32) => FpuToIntOp::F64ToU32,
(true, 64, 32) => FpuToIntOp::F64ToI32,
(false, 64, 64) => FpuToIntOp::F64ToU64,
(true, 64, 64) => FpuToIntOp::F64ToI64,
_ => panic!("Unknown input/output-bits combination"),
};
let rn = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
let rd = get_output_reg(ctx, outputs[0]);
// First, check the output: it's important to carry the NaN conversion before the
// in-bounds conversion, per wasm semantics.
// Check that the input is not a NaN.
if in_bits == 32 {
ctx.emit(Inst::FpuCmp32 { rn, rm: rn });
} else {
ctx.emit(Inst::FpuCmp64 { rn, rm: rn });
}
ctx.emit(Inst::OneWayCondBr {
target: BranchTarget::ResolvedOffset(8),
kind: CondBrKind::Cond(lower_fp_condcode(FloatCC::Ordered)),
});
let trap_info = (ctx.srcloc(insn), TrapCode::BadConversionToInteger);
ctx.emit(Inst::Udf { trap_info });
let tmp = ctx.alloc_tmp(RegClass::V128, I128);
// Check that the input is in range, with "truncate towards zero" semantics. This means
// we allow values that are slightly out of range:
// - for signed conversions, we allow values strictly greater than INT_MIN-1 (when this
// can be represented), and strictly less than INT_MAX+1 (when this can be
// represented).
// - for unsigned conversions, we allow values strictly greater than -1, and strictly
// less than UINT_MAX+1 (when this can be represented).
if in_bits == 32 {
// From float32.
let (low_bound, low_cond, high_bound) = match (signed, out_bits) {
(true, 32) => (
i32::min_value() as f32, // I32_MIN - 1 isn't precisely representable as a f32.
FloatCC::GreaterThanOrEqual,
i32::max_value() as f32 + 1.,
),
(true, 64) => (
i64::min_value() as f32, // I64_MIN - 1 isn't precisely representable as a f32.
FloatCC::GreaterThanOrEqual,
i64::max_value() as f32 + 1.,
),
(false, 32) => (-1., FloatCC::GreaterThan, u32::max_value() as f32 + 1.),
(false, 64) => (-1., FloatCC::GreaterThan, u64::max_value() as f32 + 1.),
_ => panic!("Unknown input/output-bits combination"),
};
// >= low_bound
lower_constant_f32(ctx, tmp, low_bound);
ctx.emit(Inst::FpuCmp32 {
rn,
rm: tmp.to_reg(),
});
ctx.emit(Inst::OneWayCondBr {
target: BranchTarget::ResolvedOffset(8),
kind: CondBrKind::Cond(lower_fp_condcode(low_cond)),
});
let trap_info = (ctx.srcloc(insn), TrapCode::IntegerOverflow);
ctx.emit(Inst::Udf { trap_info });
// <= high_bound
lower_constant_f32(ctx, tmp, high_bound);
ctx.emit(Inst::FpuCmp32 {
rn,
rm: tmp.to_reg(),
});
ctx.emit(Inst::OneWayCondBr {
target: BranchTarget::ResolvedOffset(8),
kind: CondBrKind::Cond(lower_fp_condcode(FloatCC::LessThan)),
});
let trap_info = (ctx.srcloc(insn), TrapCode::IntegerOverflow);
ctx.emit(Inst::Udf { trap_info });
} else {
// From float64.
let (low_bound, low_cond, high_bound) = match (signed, out_bits) {
(true, 32) => (
i32::min_value() as f64 - 1.,
FloatCC::GreaterThan,
i32::max_value() as f64 + 1.,
),
(true, 64) => (
i64::min_value() as f64, // I64_MIN - 1 is not precisely representable as an i64.
FloatCC::GreaterThanOrEqual,
i64::max_value() as f64 + 1.,
),
(false, 32) => (-1., FloatCC::GreaterThan, u32::max_value() as f64 + 1.),
(false, 64) => (-1., FloatCC::GreaterThan, u64::max_value() as f64 + 1.),
_ => panic!("Unknown input/output-bits combination"),
};
// >= low_bound
lower_constant_f64(ctx, tmp, low_bound);
ctx.emit(Inst::FpuCmp64 {
rn,
rm: tmp.to_reg(),
});
ctx.emit(Inst::OneWayCondBr {
target: BranchTarget::ResolvedOffset(8),
kind: CondBrKind::Cond(lower_fp_condcode(low_cond)),
});
let trap_info = (ctx.srcloc(insn), TrapCode::IntegerOverflow);
ctx.emit(Inst::Udf { trap_info });
// <= high_bound
lower_constant_f64(ctx, tmp, high_bound);
ctx.emit(Inst::FpuCmp64 {
rn,
rm: tmp.to_reg(),
});
ctx.emit(Inst::OneWayCondBr {
target: BranchTarget::ResolvedOffset(8),
kind: CondBrKind::Cond(lower_fp_condcode(FloatCC::LessThan)),
});
let trap_info = (ctx.srcloc(insn), TrapCode::IntegerOverflow);
ctx.emit(Inst::Udf { trap_info });
};
// Do the conversion.
ctx.emit(Inst::FpuToInt { op, rd, rn });
}
Opcode::FcvtFromUint | Opcode::FcvtFromSint => {
let in_bits = ty_bits(ctx.input_ty(insn, 0));
let out_bits = ty_bits(ctx.output_ty(insn, 0));
let signed = op == Opcode::FcvtFromSint;
let op = match (signed, in_bits, out_bits) {
(false, 32, 32) => IntToFpuOp::U32ToF32,
(true, 32, 32) => IntToFpuOp::I32ToF32,
(false, 32, 64) => IntToFpuOp::U32ToF64,
(true, 32, 64) => IntToFpuOp::I32ToF64,
(false, 64, 32) => IntToFpuOp::U64ToF32,
(true, 64, 32) => IntToFpuOp::I64ToF32,
(false, 64, 64) => IntToFpuOp::U64ToF64,
(true, 64, 64) => IntToFpuOp::I64ToF64,
_ => panic!("Unknown input/output-bits combination"),
};
let narrow_mode = match (signed, in_bits) {
(false, 32) => NarrowValueMode::ZeroExtend32,
(true, 32) => NarrowValueMode::SignExtend32,
(false, 64) => NarrowValueMode::ZeroExtend64,
(true, 64) => NarrowValueMode::SignExtend64,
_ => panic!("Unknown input size"),
};
let rn = put_input_in_reg(ctx, inputs[0], narrow_mode);
let rd = get_output_reg(ctx, outputs[0]);
ctx.emit(Inst::IntToFpu { op, rd, rn });
}
Opcode::FcvtToUintSat | Opcode::FcvtToSintSat => {
let in_ty = ctx.input_ty(insn, 0);
let in_bits = ty_bits(in_ty);
let out_ty = ctx.output_ty(insn, 0);
let out_bits = ty_bits(out_ty);
let out_signed = op == Opcode::FcvtToSintSat;
let rn = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
let rd = get_output_reg(ctx, outputs[0]);
// FIMM Vtmp1, u32::MAX or u64::MAX or i32::MAX or i64::MAX
// FMIN Vtmp2, Vin, Vtmp1
// FIMM Vtmp1, 0 or 0 or i32::MIN or i64::MIN
// FMAX Vtmp2, Vtmp2, Vtmp1
// (if signed) FIMM Vtmp1, 0
// FCMP Vin, Vin
// FCSEL Vtmp2, Vtmp1, Vtmp2, NE // on NaN, select 0
// convert Rout, Vtmp2
assert!(in_bits == 32 || in_bits == 64);
assert!(out_bits == 32 || out_bits == 64);
let min: f64 = match (out_bits, out_signed) {
(32, true) => std::i32::MIN as f64,
(32, false) => 0.0,
(64, true) => std::i64::MIN as f64,
(64, false) => 0.0,
_ => unreachable!(),
};
let max = match (out_bits, out_signed) {
(32, true) => std::i32::MAX as f64,
(32, false) => std::u32::MAX as f64,
(64, true) => std::i64::MAX as f64,
(64, false) => std::u64::MAX as f64,
_ => unreachable!(),
};
let rtmp1 = ctx.alloc_tmp(RegClass::V128, in_ty);
let rtmp2 = ctx.alloc_tmp(RegClass::V128, in_ty);
if in_bits == 32 {
ctx.emit(Inst::LoadFpuConst32 {
rd: rtmp1,
const_data: max as f32,
});
} else {
ctx.emit(Inst::LoadFpuConst64 {
rd: rtmp1,
const_data: max,
});
}
ctx.emit(Inst::FpuRRR {
fpu_op: choose_32_64(in_ty, FPUOp2::Min32, FPUOp2::Min64),
rd: rtmp2,
rn: rn,
rm: rtmp1.to_reg(),
});
if in_bits == 32 {
ctx.emit(Inst::LoadFpuConst32 {
rd: rtmp1,
const_data: min as f32,
});
} else {
ctx.emit(Inst::LoadFpuConst64 {
rd: rtmp1,
const_data: min,
});
}
ctx.emit(Inst::FpuRRR {
fpu_op: choose_32_64(in_ty, FPUOp2::Max32, FPUOp2::Max64),
rd: rtmp2,
rn: rtmp2.to_reg(),
rm: rtmp1.to_reg(),
});
if out_signed {
if in_bits == 32 {
ctx.emit(Inst::LoadFpuConst32 {
rd: rtmp1,
const_data: 0.0,
});
} else {
ctx.emit(Inst::LoadFpuConst64 {
rd: rtmp1,
const_data: 0.0,
});
}
}
if in_bits == 32 {
ctx.emit(Inst::FpuCmp32 { rn: rn, rm: rn });
ctx.emit(Inst::FpuCSel32 {
rd: rtmp2,
rn: rtmp1.to_reg(),
rm: rtmp2.to_reg(),
cond: Cond::Ne,
});
} else {
ctx.emit(Inst::FpuCmp64 { rn: rn, rm: rn });
ctx.emit(Inst::FpuCSel64 {
rd: rtmp2,
rn: rtmp1.to_reg(),
rm: rtmp2.to_reg(),
cond: Cond::Ne,
});
}
let cvt = match (in_bits, out_bits, out_signed) {
(32, 32, false) => FpuToIntOp::F32ToU32,
(32, 32, true) => FpuToIntOp::F32ToI32,
(32, 64, false) => FpuToIntOp::F32ToU64,
(32, 64, true) => FpuToIntOp::F32ToI64,
(64, 32, false) => FpuToIntOp::F64ToU32,
(64, 32, true) => FpuToIntOp::F64ToI32,
(64, 64, false) => FpuToIntOp::F64ToU64,
(64, 64, true) => FpuToIntOp::F64ToI64,
_ => unreachable!(),
};
ctx.emit(Inst::FpuToInt {
op: cvt,
rd,
rn: rtmp2.to_reg(),
});
}
Opcode::IaddIfcout => {
// This is a two-output instruction that is needed for the
// legalizer's explicit heap-check sequence, among possible other
// uses. Its second output is a flags output only ever meant to
// check for overflow using the
// `backend.unsigned_add_overflow_condition()` condition.
//
// Note that the CLIF validation will ensure that no flag-setting
// operation comes between this IaddIfcout and its use (e.g., a
// Trapif). Thus, we can rely on implicit communication through the
// processor flags rather than explicitly generating flags into a
// register. We simply use the variant of the add instruction that
// sets flags (`adds`) here.
// Ensure that the second output isn't directly called for: it
// should only be used by a flags-consuming op, which will directly
// understand this instruction and merge the comparison.
assert!(!ctx.is_reg_needed(insn, ctx.get_output(insn, 1).to_reg()));
// Now handle the iadd as above, except use an AddS opcode that sets
// flags.
let rd = get_output_reg(ctx, outputs[0]);
let rn = put_input_in_reg(ctx, inputs[0], NarrowValueMode::None);
let rm = put_input_in_rse_imm12(ctx, inputs[1], NarrowValueMode::None);
let ty = ty.unwrap();
let alu_op = choose_32_64(ty, ALUOp::AddS32, ALUOp::AddS64);
ctx.emit(alu_inst_imm12(alu_op, rd, rn, rm));
}
Opcode::IaddImm
| Opcode::ImulImm
| Opcode::UdivImm
| Opcode::SdivImm
| Opcode::UremImm
| Opcode::SremImm
| Opcode::IrsubImm
| Opcode::IaddCin
| Opcode::IaddIfcin
| Opcode::IaddCout
| Opcode::IaddCarry
| Opcode::IaddIfcarry
| Opcode::IsubBin
| Opcode::IsubIfbin
| Opcode::IsubBout
| Opcode::IsubIfbout
| Opcode::IsubBorrow
| Opcode::IsubIfborrow
| Opcode::BandImm
| Opcode::BorImm
| Opcode::BxorImm
| Opcode::RotlImm
| Opcode::RotrImm
| Opcode::IshlImm
| Opcode::UshrImm
| Opcode::SshrImm
| Opcode::IcmpImm
| Opcode::IfcmpImm => {
panic!("ALU+imm and ALU+carry ops should not appear here!");
}
#[cfg(feature = "x86")]
Opcode::X86Udivmodx
| Opcode::X86Sdivmodx
| Opcode::X86Umulx
| Opcode::X86Smulx
| Opcode::X86Cvtt2si
| Opcode::X86Fmin
| Opcode::X86Fmax
| Opcode::X86Push
| Opcode::X86Pop
| Opcode::X86Bsr
| Opcode::X86Bsf
| Opcode::X86Pblendw
| Opcode::X86Pshufd
| Opcode::X86Pshufb
| Opcode::X86Pextr
| Opcode::X86Pinsr
| Opcode::X86Insertps
| Opcode::X86Movsd
| Opcode::X86Movlhps
| Opcode::X86Psll
| Opcode::X86Psrl
| Opcode::X86Psra
| Opcode::X86Ptest
| Opcode::X86Pmaxs
| Opcode::X86Pmaxu
| Opcode::X86Pmins
| Opcode::X86Pminu
| Opcode::X86Pmullq
| Opcode::X86Pmuludq
| Opcode::X86Punpckh
| Opcode::X86Punpckl
| Opcode::X86Vcvtudq2ps
| Opcode::X86ElfTlsGetAddr
| Opcode::X86MachoTlsGetAddr => {
panic!("x86-specific opcode in supposedly arch-neutral IR!");
}
Opcode::AvgRound => unimplemented!(),
Opcode::Iabs => unimplemented!(),
Opcode::Snarrow | Opcode::Unarrow => unimplemented!(),
Opcode::TlsValue => unimplemented!(),
}
Ok(())
}
pub(crate) fn lower_branch<C: LowerCtx<I = Inst>>(
ctx: &mut C,
branches: &[IRInst],
targets: &[MachLabel],
fallthrough: Option<MachLabel>,
) -> CodegenResult<()> {
// A block should end with at most two branches. The first may be a
// conditional branch; a conditional branch can be followed only by an
// unconditional branch or fallthrough. Otherwise, if only one branch,
// it may be an unconditional branch, a fallthrough, a return, or a
// trap. These conditions are verified by `is_ebb_basic()` during the
// verifier pass.
assert!(branches.len() <= 2);
if branches.len() == 2 {
// Must be a conditional branch followed by an unconditional branch.
let op0 = ctx.data(branches[0]).opcode();
let op1 = ctx.data(branches[1]).opcode();
assert!(op1 == Opcode::Jump || op1 == Opcode::Fallthrough);
let taken = BranchTarget::Label(targets[0]);
let not_taken = match op1 {
Opcode::Jump => BranchTarget::Label(targets[1]),
Opcode::Fallthrough => BranchTarget::Label(fallthrough.unwrap()),
_ => unreachable!(), // assert above.
};
match op0 {
Opcode::Brz | Opcode::Brnz => {
let flag_input = InsnInput {
insn: branches[0],
input: 0,
};
if let Some(icmp_insn) =
maybe_input_insn_via_conv(ctx, flag_input, Opcode::Icmp, Opcode::Bint)
{
let condcode = inst_condcode(ctx.data(icmp_insn)).unwrap();
let cond = lower_condcode(condcode);
let is_signed = condcode_is_signed(condcode);
let negated = op0 == Opcode::Brz;
let cond = if negated { cond.invert() } else { cond };
lower_icmp_or_ifcmp_to_flags(ctx, icmp_insn, is_signed);
ctx.emit(Inst::CondBr {
taken,
not_taken,
kind: CondBrKind::Cond(cond),
});
} else if let Some(fcmp_insn) =
maybe_input_insn_via_conv(ctx, flag_input, Opcode::Fcmp, Opcode::Bint)
{
let condcode = inst_fp_condcode(ctx.data(fcmp_insn)).unwrap();
let cond = lower_fp_condcode(condcode);
let negated = op0 == Opcode::Brz;
let cond = if negated { cond.invert() } else { cond };
lower_fcmp_or_ffcmp_to_flags(ctx, fcmp_insn);
ctx.emit(Inst::CondBr {
taken,
not_taken,
kind: CondBrKind::Cond(cond),
});
} else {
let rt = put_input_in_reg(
ctx,
InsnInput {
insn: branches[0],
input: 0,
},
NarrowValueMode::ZeroExtend64,
);
let kind = match op0 {
Opcode::Brz => CondBrKind::Zero(rt),
Opcode::Brnz => CondBrKind::NotZero(rt),
_ => unreachable!(),
};
ctx.emit(Inst::CondBr {
taken,
not_taken,
kind,
});
}
}
Opcode::BrIcmp => {
let condcode = inst_condcode(ctx.data(branches[0])).unwrap();
let cond = lower_condcode(condcode);
let kind = CondBrKind::Cond(cond);
let is_signed = condcode_is_signed(condcode);
let ty = ctx.input_ty(branches[0], 0);
let bits = ty_bits(ty);
let narrow_mode = match (bits <= 32, is_signed) {
(true, true) => NarrowValueMode::SignExtend32,
(true, false) => NarrowValueMode::ZeroExtend32,
(false, true) => NarrowValueMode::SignExtend64,
(false, false) => NarrowValueMode::ZeroExtend64,
};
let rn = put_input_in_reg(
ctx,
InsnInput {
insn: branches[0],
input: 0,
},
narrow_mode,
);
let rm = put_input_in_rse_imm12(
ctx,
InsnInput {
insn: branches[0],
input: 1,
},
narrow_mode,
);
let alu_op = choose_32_64(ty, ALUOp::SubS32, ALUOp::SubS64);
let rd = writable_zero_reg();
ctx.emit(alu_inst_imm12(alu_op, rd, rn, rm));
ctx.emit(Inst::CondBr {
taken,
not_taken,
kind,
});
}
Opcode::Brif => {
let condcode = inst_condcode(ctx.data(branches[0])).unwrap();
let cond = lower_condcode(condcode);
let kind = CondBrKind::Cond(cond);
let is_signed = condcode_is_signed(condcode);
let flag_input = InsnInput {
insn: branches[0],
input: 0,
};
if let Some(ifcmp_insn) = maybe_input_insn(ctx, flag_input, Opcode::Ifcmp) {
lower_icmp_or_ifcmp_to_flags(ctx, ifcmp_insn, is_signed);
ctx.emit(Inst::CondBr {
taken,
not_taken,
kind,
});
} else {
// If the ifcmp result is actually placed in a
// register, we need to move it back into the flags.
let rn = put_input_in_reg(ctx, flag_input, NarrowValueMode::None);
ctx.emit(Inst::MovToNZCV { rn });
ctx.emit(Inst::CondBr {
taken,
not_taken,
kind,
});
}
}
Opcode::Brff => {
let condcode = inst_fp_condcode(ctx.data(branches[0])).unwrap();
let cond = lower_fp_condcode(condcode);
let kind = CondBrKind::Cond(cond);
let flag_input = InsnInput {
insn: branches[0],
input: 0,
};
if let Some(ffcmp_insn) = maybe_input_insn(ctx, flag_input, Opcode::Ffcmp) {
lower_fcmp_or_ffcmp_to_flags(ctx, ffcmp_insn);
ctx.emit(Inst::CondBr {
taken,
not_taken,
kind,
});
} else {
// If the ffcmp result is actually placed in a
// register, we need to move it back into the flags.
let rn = put_input_in_reg(ctx, flag_input, NarrowValueMode::None);
ctx.emit(Inst::MovToNZCV { rn });
ctx.emit(Inst::CondBr {
taken,
not_taken,
kind,
});
}
}
_ => unimplemented!(),
}
} else {
// Must be an unconditional branch or an indirect branch.
let op = ctx.data(branches[0]).opcode();
match op {
Opcode::Jump | Opcode::Fallthrough => {
assert!(branches.len() == 1);
// In the Fallthrough case, the machine-independent driver
// fills in `targets[0]` with our fallthrough block, so this
// is valid for both Jump and Fallthrough.
ctx.emit(Inst::Jump {
dest: BranchTarget::Label(targets[0]),
});
}
Opcode::BrTable => {
// Expand `br_table index, default, JT` to:
//
// emit_island // this forces an island at this point
// // if the jumptable would push us past
// // the deadline
// subs idx, #jt_size
// b.hs default
// adr vTmp1, PC+16
// ldr vTmp2, [vTmp1, idx, lsl #2]
// add vTmp2, vTmp2, vTmp1
// br vTmp2
// [jumptable offsets relative to JT base]
let jt_size = targets.len() - 1;
assert!(jt_size <= std::u32::MAX as usize);
ctx.emit(Inst::EmitIsland {
needed_space: 4 * (6 + jt_size) as CodeOffset,
});
let ridx = put_input_in_reg(
ctx,
InsnInput {
insn: branches[0],
input: 0,
},
NarrowValueMode::ZeroExtend32,
);
let rtmp1 = ctx.alloc_tmp(RegClass::I64, I32);
let rtmp2 = ctx.alloc_tmp(RegClass::I64, I32);
// Bounds-check and branch to default.
if let Some(imm12) = Imm12::maybe_from_u64(jt_size as u64) {
ctx.emit(Inst::AluRRImm12 {
alu_op: ALUOp::SubS32,
rd: writable_zero_reg(),
rn: ridx,
imm12,
});
} else {
lower_constant_u64(ctx, rtmp1, jt_size as u64);
ctx.emit(Inst::AluRRR {
alu_op: ALUOp::SubS32,
rd: writable_zero_reg(),
rn: ridx,
rm: rtmp1.to_reg(),
});
}
let default_target = BranchTarget::Label(targets[0]);
ctx.emit(Inst::OneWayCondBr {
target: default_target.clone(),
kind: CondBrKind::Cond(Cond::Hs), // unsigned >=
});
// Emit the compound instruction that does:
//
// adr rA, jt
// ldrsw rB, [rA, rIndex, UXTW 2]
// add rA, rA, rB
// br rA
// [jt entries]
//
// This must be *one* instruction in the vcode because
// we cannot allow regalloc to insert any spills/fills
// in the middle of the sequence; otherwise, the ADR's
// PC-rel offset to the jumptable would be incorrect.
// (The alternative is to introduce a relocation pass
// for inlined jumptables, which is much worse, IMHO.)
let jt_targets: Vec<BranchTarget> = targets
.iter()
.skip(1)
.map(|bix| BranchTarget::Label(*bix))
.collect();
let targets_for_term: Vec<MachLabel> = targets.to_vec();
ctx.emit(Inst::JTSequence {
ridx,
rtmp1,
rtmp2,
info: Box::new(JTSequenceInfo {
targets: jt_targets,
targets_for_term: targets_for_term,
}),
});
}
_ => panic!("Unknown branch type!"),
}
}
Ok(())
}
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