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PtxUtils.cuh
1 /**
2 * Copyright (c) 2015-present, Facebook, Inc.
3 * All rights reserved.
4 *
5 * This source code is licensed under the BSD+Patents license found in the
6 * LICENSE file in the root directory of this source tree.
7 */
8
9
10 #pragma once
11
12 #include <cuda.h>
13
14 namespace faiss { namespace gpu {
15
16 __device__ __forceinline__
17 unsigned int getBitfield(unsigned int val, int pos, int len) {
18 unsigned int ret;
19 asm("bfe.u32 %0, %1, %2, %3;" : "=r"(ret) : "r"(val), "r"(pos), "r"(len));
20 return ret;
21 }
22
23 __device__ __forceinline__
24 unsigned long getBitfield(unsigned long val, int pos, int len) {
25 unsigned long ret;
26 asm("bfe.u64 %0, %1, %2, %3;" : "=l"(ret) : "l"(val), "r"(pos), "r"(len));
27 return ret;
28 }
29
30 __device__ __forceinline__
31 unsigned int setBitfield(unsigned int val,
32 unsigned int toInsert, int pos, int len) {
33 unsigned int ret;
34 asm("bfi.b32 %0, %1, %2, %3, %4;" :
35 "=r"(ret) : "r"(toInsert), "r"(val), "r"(pos), "r"(len));
36 return ret;
37 }
38
39 __device__ __forceinline__ int getLaneId() {
40 int laneId;
41 asm("mov.s32 %0, %laneid;" : "=r"(laneId) );
42 return laneId;
43 }
44
45 __device__ __forceinline__ unsigned getLaneMaskLt() {
46 unsigned mask;
47 asm("mov.u32 %0, %%lanemask_lt;" : "=r"(mask));
48 return mask;
49 }
50
51 __device__ __forceinline__ unsigned getLaneMaskLe() {
52 unsigned mask;
53 asm("mov.u32 %0, %%lanemask_le;" : "=r"(mask));
54 return mask;
55 }
56
57 __device__ __forceinline__ unsigned getLaneMaskGt() {
58 unsigned mask;
59 asm("mov.u32 %0, %%lanemask_gt;" : "=r"(mask));
60 return mask;
61 }
62
63 __device__ __forceinline__ unsigned getLaneMaskGe() {
64 unsigned mask;
65 asm("mov.u32 %0, %%lanemask_ge;" : "=r"(mask));
66 return mask;
67 }
68
69 __device__ __forceinline__ void namedBarrierWait(int name, int numThreads) {
70 asm volatile("bar.sync %0, %1;" : : "r"(name), "r"(numThreads) : "memory");
71 }
72
73 __device__ __forceinline__ void namedBarrierArrived(int name, int numThreads) {
74 asm volatile("bar.arrive %0, %1;" : : "r"(name), "r"(numThreads) : "memory");
75 }
76
77 // FIXME: prefetch does nothing (in SASS) on Maxwell
78 __device__ __forceinline__ void prefetchL2(const void *p) {
79 asm volatile("prefetch.global.L2 [%0];" : : "l"(p));
80 }
81
82 __device__ __forceinline__ void prefetchL1(const void *p) {
83 asm volatile("prefetch.global.L1 [%0];" : : "l"(p));
84 }
85
86 } } // namespace