summaryrefslogtreecommitdiffstats
path: root/compiler/rustc_codegen_cranelift/src/intrinsics/llvm_x86.rs
blob: 7bc161fbe55236a1b03ad08db5a80e274f94d7f8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
//! Emulate x86 LLVM intrinsics

use crate::intrinsics::*;
use crate::prelude::*;

use rustc_middle::ty::subst::SubstsRef;

pub(crate) fn codegen_x86_llvm_intrinsic_call<'tcx>(
    fx: &mut FunctionCx<'_, '_, 'tcx>,
    intrinsic: &str,
    _substs: SubstsRef<'tcx>,
    args: &[mir::Operand<'tcx>],
    ret: CPlace<'tcx>,
    target: Option<BasicBlock>,
) {
    match intrinsic {
        "llvm.x86.sse2.pause" | "llvm.aarch64.isb" => {
            // Spin loop hint
        }

        // Used by `_mm_movemask_epi8` and `_mm256_movemask_epi8`
        "llvm.x86.sse2.pmovmskb.128" | "llvm.x86.avx2.pmovmskb" | "llvm.x86.sse2.movmsk.pd" => {
            intrinsic_args!(fx, args => (a); intrinsic);

            let (lane_count, lane_ty) = a.layout().ty.simd_size_and_type(fx.tcx);
            let lane_ty = fx.clif_type(lane_ty).unwrap();
            assert!(lane_count <= 32);

            let mut res = fx.bcx.ins().iconst(types::I32, 0);

            for lane in (0..lane_count).rev() {
                let a_lane = a.value_lane(fx, lane).load_scalar(fx);

                // cast float to int
                let a_lane = match lane_ty {
                    types::F32 => fx.bcx.ins().bitcast(types::I32, a_lane),
                    types::F64 => fx.bcx.ins().bitcast(types::I64, a_lane),
                    _ => a_lane,
                };

                // extract sign bit of an int
                let a_lane_sign = fx.bcx.ins().ushr_imm(a_lane, i64::from(lane_ty.bits() - 1));

                // shift sign bit into result
                let a_lane_sign = clif_intcast(fx, a_lane_sign, types::I32, false);
                res = fx.bcx.ins().ishl_imm(res, 1);
                res = fx.bcx.ins().bor(res, a_lane_sign);
            }

            let res = CValue::by_val(res, fx.layout_of(fx.tcx.types.i32));
            ret.write_cvalue(fx, res);
        }
        "llvm.x86.sse2.cmp.ps" | "llvm.x86.sse2.cmp.pd" => {
            let (x, y, kind) = match args {
                [x, y, kind] => (x, y, kind),
                _ => bug!("wrong number of args for intrinsic {intrinsic}"),
            };
            let x = codegen_operand(fx, x);
            let y = codegen_operand(fx, y);
            let kind = crate::constant::mir_operand_get_const_val(fx, kind)
                .expect("llvm.x86.sse2.cmp.* kind not const");

            let flt_cc = match kind
                .try_to_bits(Size::from_bytes(1))
                .unwrap_or_else(|| panic!("kind not scalar: {:?}", kind))
            {
                0 => FloatCC::Equal,
                1 => FloatCC::LessThan,
                2 => FloatCC::LessThanOrEqual,
                7 => FloatCC::Ordered,
                3 => FloatCC::Unordered,
                4 => FloatCC::NotEqual,
                5 => FloatCC::UnorderedOrGreaterThanOrEqual,
                6 => FloatCC::UnorderedOrGreaterThan,
                kind => unreachable!("kind {:?}", kind),
            };

            simd_pair_for_each_lane(fx, x, y, ret, &|fx, lane_ty, res_lane_ty, x_lane, y_lane| {
                let res_lane = match lane_ty.kind() {
                    ty::Float(_) => fx.bcx.ins().fcmp(flt_cc, x_lane, y_lane),
                    _ => unreachable!("{:?}", lane_ty),
                };
                bool_to_zero_or_max_uint(fx, res_lane_ty, res_lane)
            });
        }
        "llvm.x86.sse2.psrli.d" => {
            let (a, imm8) = match args {
                [a, imm8] => (a, imm8),
                _ => bug!("wrong number of args for intrinsic {intrinsic}"),
            };
            let a = codegen_operand(fx, a);
            let imm8 = crate::constant::mir_operand_get_const_val(fx, imm8)
                .expect("llvm.x86.sse2.psrli.d imm8 not const");

            simd_for_each_lane(fx, a, ret, &|fx, _lane_ty, _res_lane_ty, lane| match imm8
                .try_to_bits(Size::from_bytes(4))
                .unwrap_or_else(|| panic!("imm8 not scalar: {:?}", imm8))
            {
                imm8 if imm8 < 32 => fx.bcx.ins().ushr_imm(lane, i64::from(imm8 as u8)),
                _ => fx.bcx.ins().iconst(types::I32, 0),
            });
        }
        "llvm.x86.sse2.pslli.d" => {
            let (a, imm8) = match args {
                [a, imm8] => (a, imm8),
                _ => bug!("wrong number of args for intrinsic {intrinsic}"),
            };
            let a = codegen_operand(fx, a);
            let imm8 = crate::constant::mir_operand_get_const_val(fx, imm8)
                .expect("llvm.x86.sse2.psrli.d imm8 not const");

            simd_for_each_lane(fx, a, ret, &|fx, _lane_ty, _res_lane_ty, lane| match imm8
                .try_to_bits(Size::from_bytes(4))
                .unwrap_or_else(|| panic!("imm8 not scalar: {:?}", imm8))
            {
                imm8 if imm8 < 32 => fx.bcx.ins().ishl_imm(lane, i64::from(imm8 as u8)),
                _ => fx.bcx.ins().iconst(types::I32, 0),
            });
        }
        "llvm.x86.sse2.storeu.dq" => {
            intrinsic_args!(fx, args => (mem_addr, a); intrinsic);
            let mem_addr = mem_addr.load_scalar(fx);

            // FIXME correctly handle the unalignment
            let dest = CPlace::for_ptr(Pointer::new(mem_addr), a.layout());
            dest.write_cvalue(fx, a);
        }
        "llvm.x86.addcarry.64" => {
            intrinsic_args!(fx, args => (c_in, a, b); intrinsic);
            let c_in = c_in.load_scalar(fx);

            llvm_add_sub(fx, BinOp::Add, ret, c_in, a, b);
        }
        "llvm.x86.subborrow.64" => {
            intrinsic_args!(fx, args => (b_in, a, b); intrinsic);
            let b_in = b_in.load_scalar(fx);

            llvm_add_sub(fx, BinOp::Sub, ret, b_in, a, b);
        }
        _ => {
            fx.tcx.sess.warn(&format!(
                "unsupported x86 llvm intrinsic {}; replacing with trap",
                intrinsic
            ));
            crate::trap::trap_unimplemented(fx, intrinsic);
            return;
        }
    }

    let dest = target.expect("all llvm intrinsics used by stdlib should return");
    let ret_block = fx.get_block(dest);
    fx.bcx.ins().jump(ret_block, &[]);
}

// llvm.x86.avx2.vperm2i128
// llvm.x86.ssse3.pshuf.b.128
// llvm.x86.avx2.pshuf.b
// llvm.x86.avx2.psrli.w
// llvm.x86.sse2.psrli.w

fn llvm_add_sub<'tcx>(
    fx: &mut FunctionCx<'_, '_, 'tcx>,
    bin_op: BinOp,
    ret: CPlace<'tcx>,
    cb_in: Value,
    a: CValue<'tcx>,
    b: CValue<'tcx>,
) {
    assert_eq!(
        a.layout().ty,
        fx.tcx.types.u64,
        "llvm.x86.addcarry.64/llvm.x86.subborrow.64 second operand must be u64"
    );
    assert_eq!(
        b.layout().ty,
        fx.tcx.types.u64,
        "llvm.x86.addcarry.64/llvm.x86.subborrow.64 third operand must be u64"
    );

    // c + carry -> c + first intermediate carry or borrow respectively
    let int0 = crate::num::codegen_checked_int_binop(fx, bin_op, a, b);
    let c = int0.value_field(fx, mir::Field::new(0));
    let cb0 = int0.value_field(fx, mir::Field::new(1)).load_scalar(fx);

    // c + carry -> c + second intermediate carry or borrow respectively
    let cb_in_as_u64 = fx.bcx.ins().uextend(types::I64, cb_in);
    let cb_in_as_u64 = CValue::by_val(cb_in_as_u64, fx.layout_of(fx.tcx.types.u64));
    let int1 = crate::num::codegen_checked_int_binop(fx, bin_op, c, cb_in_as_u64);
    let (c, cb1) = int1.load_scalar_pair(fx);

    // carry0 | carry1 -> carry or borrow respectively
    let cb_out = fx.bcx.ins().bor(cb0, cb1);

    let layout = fx.layout_of(fx.tcx.mk_tup([fx.tcx.types.u8, fx.tcx.types.u64].iter()));
    let val = CValue::by_val_pair(cb_out, c, layout);
    ret.write_cvalue(fx, val);
}