forked from rust-lang/rust
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathcodegen_i128.rs
165 lines (155 loc) · 6.83 KB
/
codegen_i128.rs
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
//! Replaces 128-bit operators with lang item calls where necessary
use crate::prelude::*;
pub(crate) fn maybe_codegen<'tcx>(
fx: &mut FunctionCx<'_, 'tcx, impl Module>,
bin_op: BinOp,
checked: bool,
lhs: CValue<'tcx>,
rhs: CValue<'tcx>,
) -> Option<CValue<'tcx>> {
if lhs.layout().ty != fx.tcx.types.u128 && lhs.layout().ty != fx.tcx.types.i128 {
return None;
}
let lhs_val = lhs.load_scalar(fx);
let rhs_val = rhs.load_scalar(fx);
let is_signed = type_sign(lhs.layout().ty);
match bin_op {
BinOp::BitAnd | BinOp::BitOr | BinOp::BitXor => {
assert!(!checked);
None
}
BinOp::Add | BinOp::Sub if !checked => None,
BinOp::Add => {
let out_ty = fx.tcx.mk_tup([lhs.layout().ty, fx.tcx.types.bool].iter());
return Some(if is_signed {
fx.easy_call("__rust_i128_addo", &[lhs, rhs], out_ty)
} else {
fx.easy_call("__rust_u128_addo", &[lhs, rhs], out_ty)
});
}
BinOp::Sub => {
let out_ty = fx.tcx.mk_tup([lhs.layout().ty, fx.tcx.types.bool].iter());
return Some(if is_signed {
fx.easy_call("__rust_i128_subo", &[lhs, rhs], out_ty)
} else {
fx.easy_call("__rust_u128_subo", &[lhs, rhs], out_ty)
});
}
BinOp::Offset => unreachable!("offset should only be used on pointers, not 128bit ints"),
BinOp::Mul => {
let res = if checked {
let out_ty = fx.tcx.mk_tup([lhs.layout().ty, fx.tcx.types.bool].iter());
if is_signed {
fx.easy_call("__rust_i128_mulo", &[lhs, rhs], out_ty)
} else {
fx.easy_call("__rust_u128_mulo", &[lhs, rhs], out_ty)
}
} else {
let val_ty = if is_signed {
fx.tcx.types.i128
} else {
fx.tcx.types.u128
};
fx.easy_call("__multi3", &[lhs, rhs], val_ty)
};
Some(res)
}
BinOp::Div => {
assert!(!checked);
if is_signed {
Some(fx.easy_call("__divti3", &[lhs, rhs], fx.tcx.types.i128))
} else {
Some(fx.easy_call("__udivti3", &[lhs, rhs], fx.tcx.types.u128))
}
}
BinOp::Rem => {
assert!(!checked);
if is_signed {
Some(fx.easy_call("__modti3", &[lhs, rhs], fx.tcx.types.i128))
} else {
Some(fx.easy_call("__umodti3", &[lhs, rhs], fx.tcx.types.u128))
}
}
BinOp::Lt | BinOp::Le | BinOp::Eq | BinOp::Ge | BinOp::Gt | BinOp::Ne => {
assert!(!checked);
None
}
BinOp::Shl | BinOp::Shr => {
let is_overflow = if checked {
// rhs >= 128
// FIXME support non 128bit rhs
/*let (rhs_lsb, rhs_msb) = fx.bcx.ins().isplit(rhs_val);
let rhs_msb_gt_0 = fx.bcx.ins().icmp_imm(IntCC::NotEqual, rhs_msb, 0);
let rhs_lsb_ge_128 = fx.bcx.ins().icmp_imm(IntCC::SignedGreaterThan, rhs_lsb, 127);
let is_overflow = fx.bcx.ins().bor(rhs_msb_gt_0, rhs_lsb_ge_128);*/
let is_overflow = fx.bcx.ins().bconst(types::B1, false);
Some(fx.bcx.ins().bint(types::I8, is_overflow))
} else {
None
};
// Optimize `val >> 64`, because compiler_builtins uses it to deconstruct an 128bit
// integer into its lsb and msb.
// https://github.com/rust-lang-nursery/compiler-builtins/blob/79a6a1603d5672cbb9187ff41ff4d9b5048ac1cb/src/int/mod.rs#L217
if resolve_value_imm(fx.bcx.func, rhs_val) == Some(64) {
let (lhs_lsb, lhs_msb) = fx.bcx.ins().isplit(lhs_val);
let all_zeros = fx.bcx.ins().iconst(types::I64, 0);
let val = match (bin_op, is_signed) {
(BinOp::Shr, false) => {
let val = fx.bcx.ins().iconcat(lhs_msb, all_zeros);
Some(CValue::by_val(val, fx.layout_of(fx.tcx.types.u128)))
}
(BinOp::Shr, true) => {
let sign = fx.bcx.ins().icmp_imm(IntCC::SignedLessThan, lhs_msb, 0);
let all_ones = fx.bcx.ins().iconst(types::I64, u64::MAX as i64);
let all_sign_bits = fx.bcx.ins().select(sign, all_zeros, all_ones);
let val = fx.bcx.ins().iconcat(lhs_msb, all_sign_bits);
Some(CValue::by_val(val, fx.layout_of(fx.tcx.types.i128)))
}
(BinOp::Shl, _) => {
let val_ty = if is_signed {
fx.tcx.types.i128
} else {
fx.tcx.types.u128
};
let val = fx.bcx.ins().iconcat(all_zeros, lhs_lsb);
Some(CValue::by_val(val, fx.layout_of(val_ty)))
}
_ => None,
};
if let Some(val) = val {
if let Some(is_overflow) = is_overflow {
let out_ty = fx.tcx.mk_tup([lhs.layout().ty, fx.tcx.types.bool].iter());
let val = val.load_scalar(fx);
return Some(CValue::by_val_pair(val, is_overflow, fx.layout_of(out_ty)));
} else {
return Some(val);
}
}
}
let truncated_rhs = clif_intcast(fx, rhs_val, types::I32, false);
let truncated_rhs = CValue::by_val(truncated_rhs, fx.layout_of(fx.tcx.types.u32));
let val = match (bin_op, is_signed) {
(BinOp::Shl, false) => {
fx.easy_call("__ashlti3", &[lhs, truncated_rhs], fx.tcx.types.u128)
}
(BinOp::Shl, true) => {
fx.easy_call("__ashlti3", &[lhs, truncated_rhs], fx.tcx.types.i128)
}
(BinOp::Shr, false) => {
fx.easy_call("__lshrti3", &[lhs, truncated_rhs], fx.tcx.types.u128)
}
(BinOp::Shr, true) => {
fx.easy_call("__ashrti3", &[lhs, truncated_rhs], fx.tcx.types.i128)
}
(_, _) => unreachable!(),
};
if let Some(is_overflow) = is_overflow {
let out_ty = fx.tcx.mk_tup([lhs.layout().ty, fx.tcx.types.bool].iter());
let val = val.load_scalar(fx);
Some(CValue::by_val_pair(val, is_overflow, fx.layout_of(out_ty)))
} else {
Some(val)
}
}
}
}