Merge pull request #70 from thecppzoo/jp/swar-demos-arm

SWAR Demos on ARM

Author: thecppzoo

benchmark/atoi-corpus.h

@@ -1,5 +1,5 @@
 #include "atoi.h"
-
+#include "zoo/pp/platform.h"
 #include <vector>
 #include <string>
 #include <cstring>
@@ -119,17 +119,28 @@ struct CorpusStringLength {
     }
 };
 
+
+#if ZOO_CONFIGURED_TO_USE_AVX()
+#define AVX2_STRLEN_CORPUS_X_LIST \
+    X(ZOO_AVX, zoo::avx2_strlen)
+#else
+#define AVX2_STRLEN_CORPUS_X_LIST /* nothing */
+#endif
+
+
 #define STRLEN_CORPUS_X_LIST \
     X(LIBC_STRLEN, strlen) \
     X(ZOO_STRLEN, zoo::c_strLength) \
     X(ZOO_NATURAL_STRLEN, zoo::c_strLength_natural) \
     X(ZOO_MANUAL_STRLEN, zoo::c_strLength_manualComparison) \
-    X(ZOO_AVX, zoo::avx2_strlen) \
-    X(GENERIC_GLIBC_STRLEN, STRLEN_old)
+    X(GENERIC_GLIBC_STRLEN, STRLEN_old) \
+    AVX2_STRLEN_CORPUS_X_LIST
+
 
 #define X(Typename, FunctionToCall) \
     struct Invoke##Typename { int operator()(const char *p) { return FunctionToCall(p); } };
 
 PARSE8BYTES_CORPUS_X_LIST
 STRLEN_CORPUS_X_LIST
+
 #undef X

benchmark/atoi.cpp

@@ -1,7 +1,9 @@
 #include "zoo/swar/SWAR.h"
 #include "zoo/swar/associative_iteration.h"
 
+#if ZOO_CONFIGURED_TO_USE_AVX
 #include <immintrin.h>
+#endif
 
 #include <stdint.h>
 #include <string.h>
@@ -117,6 +119,7 @@ std::size_t c_strLength_manualComparison(const char *s) {
     }
 }
 
+#if ZOO_CONFIGURED_TO_USE_AVX
 size_t avx2_strlen(const char* str) {
     const __m256i zero = _mm256_setzero_si256(); // Vector of 32 zero bytes
     size_t offset = 0;
@@ -140,6 +143,7 @@ size_t avx2_strlen(const char* str) {
     // Unreachable, but included to avoid compiler warnings
     return offset;
 }
+#endif
 
 }
 

benchmark/atoi.h

@@ -9,7 +9,10 @@ namespace zoo {
 std::size_t c_strLength(const char *s);
 std::size_t c_strLength_natural(const char *s);
 std::size_t c_strLength_manualComparison(const char *s);
+
+#if ZOO_CONFIGURED_TO_USE_AVX
 std::size_t avx2_strlen(const char* str);
+#endif
 
 }
 

benchmark/catch2swar-demo.cpp

@@ -36,7 +36,9 @@ TEST_CASE("Atoi benchmarks", "[atoi][swar]") {
     REQUIRE(fromLIBC_STRLEN == fromZOO_NATURAL_STRLEN);
     REQUIRE(fromZOO_NATURAL_STRLEN == fromZOO_MANUAL_STRLEN);
     REQUIRE(fromGENERIC_GLIBC_STRLEN == fromZOO_NATURAL_STRLEN);
+#if ZOO_CONFIGURED_TO_USE_AVX()
     REQUIRE(fromZOO_AVX == fromZOO_STRLEN);
+#endif
 
     auto haveTheRoleOfMemoryBarrier = -1;
     #define X(Type, Fun) \

inc/zoo/pp/platform.h

@@ -1,14 +1,16 @@
 #ifndef ZOO_PLATFORM_MACROS_H
 #define ZOO_PLATFORM_MACROS_H
 
-#ifdef _MSC_VER
+#ifdef __AVX2__
+#define ZOO_CONFIGURED_TO_USE_AVX() 1
+#else
+#define ZOO_CONFIGURED_TO_USE_AVX() 0
+#endif
 
+#ifdef _MSC_VER
 #define MSVC_EMPTY_BASES __declspec(empty_bases)
-
 #else
-
 #define MSVC_EMPTY_BASES
-
 #endif
 
 #endif