Crypto++ 8.4 Free C++ class library of cryptographic schemes

neon_simd.cpp
1
2 // crc_simd.cpp - written and placed in the public domain by
3 // Jeffrey Walton, Uri Blumenthal and Marcel Raad.
4 //
5 // This source file uses intrinsics to gain access to ARMv7a and
6 // ARMv8a NEON instructions. A separate source file is needed
7 // because additional CXXFLAGS are required to enable the
8 // appropriate instructions sets in some build configurations.
9 // For Linux and Unix additional flags are not required.
10
11 #include "pch.h"
12 #include "config.h"
13 #include "stdcpp.h"
14
15 #if (CRYPTOPP_ARM_NEON_HEADER)
16 # include <arm_neon.h>
17 #endif
18
19 #if (CRYPTOPP_ARM_ACLE_HEADER)
20 # include <stdint.h>
21 # include <arm_acle.h>
22 #endif
23
24 #ifdef CRYPTOPP_GNU_STYLE_INLINE_ASSEMBLY
25 # include <signal.h>
26 # include <setjmp.h>
27 #endif
28
29 #ifndef EXCEPTION_EXECUTE_HANDLER
30 # define EXCEPTION_EXECUTE_HANDLER 1
31 #endif
32
33 // Squash MS LNK4221 and libtool warnings
34 extern const char NEON_SIMD_FNAME[] = __FILE__;
35
36 NAMESPACE_BEGIN(CryptoPP)
37
38 #ifdef CRYPTOPP_GNU_STYLE_INLINE_ASSEMBLY
39 extern "C" {
40 typedef void (*SigHandler)(int);
41
42 static jmp_buf s_jmpSIGILL;
43 static void SigIllHandler(int)
44 {
45 longjmp(s_jmpSIGILL, 1);
46 }
47 }
48 #endif // Not CRYPTOPP_MS_STYLE_INLINE_ASSEMBLY
49
50 bool CPU_ProbeARMv7()
51 {
52 #if defined(__aarch32__) || defined(__aarch64__) || defined(_M_ARM64)
53 return false;
54 #elif defined(CRYPTOPP_NO_CPU_FEATURE_PROBES)
55 return false;
56 #elif CRYPTOPP_ARM_NEON_AVAILABLE
57 # if defined(CRYPTOPP_MS_STYLE_INLINE_ASSEMBLY)
58 volatile bool result = true;
59 __try
60 {
61 // Modern MS hardware is ARMv7
62 result = true;
63 }
64 __except (EXCEPTION_EXECUTE_HANDLER)
65 {
66 return false;
67 }
68 return result;
69 # else
70 // longjmp and clobber warnings. Volatile is required.
71 // http://github.com/weidai11/cryptopp/issues/24 and http://stackoverflow.com/q/7721854
72 volatile bool result = true;
73
74 volatile SigHandler oldHandler = signal(SIGILL, SigIllHandler);
75 if (oldHandler == SIG_ERR)
76 return false;
77
78 volatile sigset_t oldMask;
79 if (sigprocmask(0, NULLPTR, (sigset_t*)&oldMask))
80 {
81 signal(SIGILL, oldHandler);
82 return false;
83 }
84
85 if (setjmp(s_jmpSIGILL))
86 result = false;
87 else
88 {
89
90 #if 0
91 // ARMv7 added movt and movw
92 int a;
93 asm volatile("movw %0,%1 \n"
94 "movt %0,%1 \n"
95 : "=r"(a) : "i"(0x1234));
96
97 00000010 <_Z5test2v>: // ARM
98 10: e3010234 movw r0, #4660 ; 0x1234
99 14: e3410234 movt r0, #4660 ; 0x1234
100 18: e12fff1e bx lr
101
102 0000001c <_Z5test3v>: // Thumb
103 1c: f241 2034 movw r0, #4660 ; 0x1234
104 20: f2c1 2034 movt r0, #4660 ; 0x1234
105 24: e12fff1e bx lr
106 #endif
107
108 unsigned int a;
109 asm volatile (
110 #if defined(__thumb__)
111 ".inst.n 0xf241, 0x2034 \n\t" // movw r0, 0x1234
112 ".inst.n 0xf2c1, 0x2034 \n\t" // movt r0, 0x1234
113 "mov %0, r0 \n\t" // mov [a], r0
114 #else
115 ".inst 0xe3010234 \n\t" // movw r0, 0x1234
116 ".inst 0xe3410234 \n\t" // movt r0, 0x1234
117 "mov %0, r0 \n\t" // mov [a], r0
118 #endif
119 : "=r" (a) : : "r0");
120
121 result = (a == 0x12341234);
122 }
123
124 sigprocmask(SIG_SETMASK, (sigset_t*)&oldMask, NULLPTR);
125 signal(SIGILL, oldHandler);
126 return result;
127 # endif
128 #else
129 return false;
130 #endif // CRYPTOPP_ARM_NEON_AVAILABLE
131 }
132
133 bool CPU_ProbeNEON()
134 {
135 #if defined(__aarch32__) || defined(__aarch64__) || defined(_M_ARM64)
136 return true;
137 #elif defined(CRYPTOPP_NO_CPU_FEATURE_PROBES)
138 return false;
139 #elif CRYPTOPP_ARM_NEON_AVAILABLE
140 # if defined(CRYPTOPP_MS_STYLE_INLINE_ASSEMBLY)
141 volatile bool result = true;
142 __try
143 {
144 uint32x4_t x = vdupq_n_u32(1);
145 uint32x4_t y = vshlq_n_u32(x, 4);
146
147 word32 z[4]; vst1q_u32(z, y);
148 return (z[0] & z[1] & z[2] & z[3]) == 16;
149 }
150 __except (EXCEPTION_EXECUTE_HANDLER)
151 {
152 return false;
153 }
154 return result;
155 # else
156 // longjmp and clobber warnings. Volatile is required.
157 // http://github.com/weidai11/cryptopp/issues/24 and http://stackoverflow.com/q/7721854
158 volatile bool result = true;
159
160 volatile SigHandler oldHandler = signal(SIGILL, SigIllHandler);
161 if (oldHandler == SIG_ERR)
162 return false;
163
164 volatile sigset_t oldMask;
165 if (sigprocmask(0, NULLPTR, (sigset_t*)&oldMask))
166 {
167 signal(SIGILL, oldHandler);
168 return false;
169 }
170
171 if (setjmp(s_jmpSIGILL))
172 result = false;
173 else
174 {
175 // This is risky... When we hand encode the instructions
176 // for vmov.u32 and vshl.u32 we get a SIGILL. Apparently
177 // we need more than just the instructions. Using
178 // intrinsics introduces the risk because the whole
179 // file gets built with ISA options, and the higher ISA
180 // may escape the try block with the SIGILL guard.
181 uint32x4_t x = vdupq_n_u32(1);
182 uint32x4_t y = vshlq_n_u32(x, 4);
183
184 word32 z[4]; vst1q_u32(z, y);
185 result = (z[0] & z[1] & z[2] & z[3]) == 16;
186 }
187
188 sigprocmask(SIG_SETMASK, (sigset_t*)&oldMask, NULLPTR);
189 signal(SIGILL, oldHandler);
190 return result;
191 # endif
192 #else
193 return false;
194 #endif // CRYPTOPP_ARM_NEON_AVAILABLE
195 }
196
197 NAMESPACE_END
pch.h
Precompiled header file.
word32
unsigned int word32
32-bit unsigned datatype
Definition: config_int.h:62
stdcpp.h
Common C++ header files.
CryptoPP
Crypto++ library namespace.
config.h
Library configuration file.