core/stdarch/crates/core_arch/src/x86/
tbm.rs

1//! Trailing Bit Manipulation (TBM) instruction set.
2//!
3//! The reference is [AMD64 Architecture Programmer's Manual, Volume 3:
4//! General-Purpose and System Instructions][amd64_ref].
5//!
6//! [Wikipedia][wikipedia_bmi] provides a quick overview of the available
7//! instructions.
8//!
9//! [amd64_ref]: http://support.amd.com/TechDocs/24594.pdf
10//! [wikipedia_bmi]:
11//! https://en.wikipedia.org/wiki/Bit_Manipulation_Instruction_Sets#ABM_.28Advanced_Bit_Manipulation.29
12
13#[cfg(test)]
14use stdarch_test::assert_instr;
15
16unsafe extern "C" {
17    #[link_name = "llvm.x86.tbm.bextri.u32"]
18    fn bextri_u32(a: u32, control: u32) -> u32;
19}
20
21/// Extracts bits of `a` specified by `control` into
22/// the least significant bits of the result.
23///
24/// Bits `[7,0]` of `control` specify the index to the first bit in the range to
25/// be extracted, and bits `[15,8]` specify the length of the range. For any bit
26/// position in the specified range that lie beyond the MSB of the source operand,
27/// zeroes will be written. If the range is empty, the result is zero.
28#[inline]
29#[target_feature(enable = "tbm")]
30#[cfg_attr(test, assert_instr(bextr, CONTROL = 0x0404))]
31#[rustc_legacy_const_generics(1)]
32#[stable(feature = "simd_x86_updates", since = "1.82.0")]
33pub unsafe fn _bextri_u32<const CONTROL: u32>(a: u32) -> u32 {
34    static_assert_uimm_bits!(CONTROL, 16);
35    unsafe { bextri_u32(a, CONTROL) }
36}
37
38/// Clears all bits below the least significant zero bit of `x`.
39///
40/// If there is no zero bit in `x`, it returns zero.
41#[inline]
42#[target_feature(enable = "tbm")]
43#[cfg_attr(test, assert_instr(blcfill))]
44#[stable(feature = "simd_x86", since = "1.27.0")]
45pub unsafe fn _blcfill_u32(x: u32) -> u32 {
46    x & (x.wrapping_add(1))
47}
48
49/// Sets all bits of `x` to 1 except for the least significant zero bit.
50///
51/// If there is no zero bit in `x`, it sets all bits.
52#[inline]
53#[target_feature(enable = "tbm")]
54#[cfg_attr(test, assert_instr(blci))]
55#[stable(feature = "simd_x86", since = "1.27.0")]
56pub unsafe fn _blci_u32(x: u32) -> u32 {
57    x | !x.wrapping_add(1)
58}
59
60/// Sets the least significant zero bit of `x` and clears all other bits.
61///
62/// If there is no zero bit in `x`, it returns zero.
63#[inline]
64#[target_feature(enable = "tbm")]
65#[cfg_attr(test, assert_instr(blcic))]
66#[stable(feature = "simd_x86", since = "1.27.0")]
67pub unsafe fn _blcic_u32(x: u32) -> u32 {
68    !x & x.wrapping_add(1)
69}
70
71/// Sets the least significant zero bit of `x` and clears all bits above
72/// that bit.
73///
74/// If there is no zero bit in `x`, it sets all the bits.
75#[inline]
76#[target_feature(enable = "tbm")]
77#[cfg_attr(test, assert_instr(blcmsk))]
78#[stable(feature = "simd_x86", since = "1.27.0")]
79pub unsafe fn _blcmsk_u32(x: u32) -> u32 {
80    x ^ x.wrapping_add(1)
81}
82
83/// Sets the least significant zero bit of `x`.
84///
85/// If there is no zero bit in `x`, it returns `x`.
86#[inline]
87#[target_feature(enable = "tbm")]
88#[cfg_attr(test, assert_instr(blcs))]
89#[stable(feature = "simd_x86", since = "1.27.0")]
90pub unsafe fn _blcs_u32(x: u32) -> u32 {
91    x | x.wrapping_add(1)
92}
93
94/// Sets all bits of `x` below the least significant one.
95///
96/// If there is no set bit in `x`, it sets all the bits.
97#[inline]
98#[target_feature(enable = "tbm")]
99#[cfg_attr(test, assert_instr(blsfill))]
100#[stable(feature = "simd_x86", since = "1.27.0")]
101pub unsafe fn _blsfill_u32(x: u32) -> u32 {
102    x | x.wrapping_sub(1)
103}
104
105/// Clears least significant bit and sets all other bits.
106///
107/// If there is no set bit in `x`, it sets all the bits.
108#[inline]
109#[target_feature(enable = "tbm")]
110#[cfg_attr(test, assert_instr(blsic))]
111#[stable(feature = "simd_x86", since = "1.27.0")]
112pub unsafe fn _blsic_u32(x: u32) -> u32 {
113    !x | x.wrapping_sub(1)
114}
115
116/// Clears all bits below the least significant zero of `x` and sets all other
117/// bits.
118///
119/// If the least significant bit of `x` is `0`, it sets all bits.
120#[inline]
121#[target_feature(enable = "tbm")]
122#[cfg_attr(test, assert_instr(t1mskc))]
123#[stable(feature = "simd_x86", since = "1.27.0")]
124pub unsafe fn _t1mskc_u32(x: u32) -> u32 {
125    !x | x.wrapping_add(1)
126}
127
128/// Sets all bits below the least significant one of `x` and clears all other
129/// bits.
130///
131/// If the least significant bit of `x` is 1, it returns zero.
132#[inline]
133#[target_feature(enable = "tbm")]
134#[cfg_attr(test, assert_instr(tzmsk))]
135#[stable(feature = "simd_x86", since = "1.27.0")]
136pub unsafe fn _tzmsk_u32(x: u32) -> u32 {
137    !x & x.wrapping_sub(1)
138}
139
140#[cfg(test)]
141mod tests {
142    use stdarch_test::simd_test;
143
144    use crate::core_arch::x86::*;
145
146    #[simd_test(enable = "tbm")]
147    unsafe fn test_bextri_u32() {
148        assert_eq!(_bextri_u32::<0x0404>(0b0101_0000u32), 0b0000_0101u32);
149    }
150
151    #[simd_test(enable = "tbm")]
152    unsafe fn test_blcfill_u32() {
153        assert_eq!(_blcfill_u32(0b0101_0111u32), 0b0101_0000u32);
154        assert_eq!(_blcfill_u32(0b1111_1111u32), 0u32);
155    }
156
157    #[simd_test(enable = "tbm")]
158    unsafe fn test_blci_u32() {
159        assert_eq!(
160            _blci_u32(0b0101_0000u32),
161            0b1111_1111_1111_1111_1111_1111_1111_1110u32
162        );
163        assert_eq!(
164            _blci_u32(0b1111_1111u32),
165            0b1111_1111_1111_1111_1111_1110_1111_1111u32
166        );
167    }
168
169    #[simd_test(enable = "tbm")]
170    unsafe fn test_blcic_u32() {
171        assert_eq!(_blcic_u32(0b0101_0001u32), 0b0000_0010u32);
172        assert_eq!(_blcic_u32(0b1111_1111u32), 0b1_0000_0000u32);
173    }
174
175    #[simd_test(enable = "tbm")]
176    unsafe fn test_blcmsk_u32() {
177        assert_eq!(_blcmsk_u32(0b0101_0001u32), 0b0000_0011u32);
178        assert_eq!(_blcmsk_u32(0b1111_1111u32), 0b1_1111_1111u32);
179    }
180
181    #[simd_test(enable = "tbm")]
182    unsafe fn test_blcs_u32() {
183        assert_eq!(_blcs_u32(0b0101_0001u32), 0b0101_0011u32);
184        assert_eq!(_blcs_u32(0b1111_1111u32), 0b1_1111_1111u32);
185    }
186
187    #[simd_test(enable = "tbm")]
188    unsafe fn test_blsfill_u32() {
189        assert_eq!(_blsfill_u32(0b0101_0100u32), 0b0101_0111u32);
190        assert_eq!(
191            _blsfill_u32(0u32),
192            0b1111_1111_1111_1111_1111_1111_1111_1111u32
193        );
194    }
195
196    #[simd_test(enable = "tbm")]
197    unsafe fn test_blsic_u32() {
198        assert_eq!(
199            _blsic_u32(0b0101_0100u32),
200            0b1111_1111_1111_1111_1111_1111_1111_1011u32
201        );
202        assert_eq!(
203            _blsic_u32(0u32),
204            0b1111_1111_1111_1111_1111_1111_1111_1111u32
205        );
206    }
207
208    #[simd_test(enable = "tbm")]
209    unsafe fn test_t1mskc_u32() {
210        assert_eq!(
211            _t1mskc_u32(0b0101_0111u32),
212            0b1111_1111_1111_1111_1111_1111_1111_1000u32
213        );
214        assert_eq!(
215            _t1mskc_u32(0u32),
216            0b1111_1111_1111_1111_1111_1111_1111_1111u32
217        );
218    }
219
220    #[simd_test(enable = "tbm")]
221    unsafe fn test_tzmsk_u32() {
222        assert_eq!(_tzmsk_u32(0b0101_1000u32), 0b0000_0111u32);
223        assert_eq!(_tzmsk_u32(0b0101_1001u32), 0b0000_0000u32);
224    }
225}
core/stdarch/crates/core_arch/src/x86/tbm.rs

core/stdarch/crates/core_arch/src/x86/
tbm.rs
