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Add memory barrier to limiting the effect of the optimizer on inline implementation

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Patrick Pelissier committed 2019-02-16 23:20:36 +01:00
1 parent b00d6a9655
commit 91ae3fd4f2
1 file changed
+49 -1
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bench/bench-string.cpp
+49 -1
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@@ -45,7 +45,6 @@
* The idea is to measure the performance empty constructors, char * * The idea is to measure the performance empty constructors, char *
* constructors, assignment, concatenation and scanning. * constructors, assignment, concatenation and scanning.
* *
* This benchmark may be unfair to non-inline string libraries.
*/ */
#include <stdio.h> #include <stdio.h>
@@ -84,6 +83,17 @@ extern "C" {
#define TEST_SECONDS (5) #define TEST_SECONDS (5)
/*
* This macro puts a memory barrier and prevents the optimizer from
* optimizing too much the inline functions and literraly breaking
* the benchmark by doing nothing.
*/
#ifdef __GNUC__
#define BARRIER() asm volatile("": : :"memory")
#else
#define BARRIER() (void) 0
#endif
bool print_csv = false; bool print_csv = false;
int timeTest (double &res, int (*testfn) (int count), int count) { int timeTest (double &res, int (*testfn) (int count), int count) {
@@ -124,6 +134,7 @@ int testSTL_emptyCtor (int count) {
int i, c = 0; int i, c = 0;
for (i=0; i < count; i++) { for (i=0; i < count; i++) {
std::string b; std::string b;
BARRIER();
c += b.length () ^ i; c += b.length () ^ i;
} }
return c; return c;
@@ -133,6 +144,7 @@ int testSTL_nonemptyCtor (int count) {
int i, c = 0; int i, c = 0;
for (i=0; i < count; i++) { for (i=0; i < count; i++) {
std::string b (TESTSTRING1); std::string b (TESTSTRING1);
BARRIER();
c += b.length () ^ i; c += b.length () ^ i;
} }
return c; return c;
@@ -144,6 +156,7 @@ int testSTL_cstrAssignment (int count) {
for (i=0; i < count; i++) { for (i=0; i < count; i++) {
b = TESTSTRING1; b = TESTSTRING1;
BARRIER();
c += b.length () ^ i; c += b.length () ^ i;
} }
return c; return c;
@@ -157,6 +170,7 @@ int testSTL_extraction (int count) {
c += b[(i & 7)]; c += b[(i & 7)];
c += b[(i & 7) ^ 8]; c += b[(i & 7) ^ 8];
c += b.c_str()[(i & 7) ^ 4] ^ i; c += b.c_str()[(i & 7) ^ 4] ^ i;
BARRIER();
} }
return c; return c;
} }
@@ -169,6 +183,7 @@ int i, c = 0;
c += b.find ('.'); c += b.find ('.');
c += b.find ("123"); c += b.find ("123");
c += b.find_first_of ("sm") ^i; c += b.find_first_of ("sm") ^i;
BARRIER();
} }
return c; return c;
} }
@@ -183,6 +198,7 @@ int testSTL_concat (int count) {
for (i=0; i < 250; i++) { for (i=0; i < 250; i++) {
accum += a; accum += a;
accum += "!!"; accum += "!!";
BARRIER();
c += accum.length() ^i; c += accum.length() ^i;
} }
} }
@@ -197,6 +213,7 @@ int testSTL_replace (int count) {
a.replace (11, 4, "XXXXXX"); a.replace (11, 4, "XXXXXX");
a.replace (23, 2, "XXXXXX"); a.replace (23, 2, "XXXXXX");
a.replace ( 4, 8, "XX"); a.replace ( 4, 8, "XX");
BARRIER();
c += a.length () ^ j; c += a.length () ^ j;
} }
return c; return c;
@@ -209,6 +226,7 @@ int testCBS_emptyCtor (int count) {
int i, c = 0; int i, c = 0;
for (i=0; i < count; i++) { for (i=0; i < count; i++) {
CBString b; CBString b;
BARRIER();
c += b.length ()^i; c += b.length ()^i;
} }
return c; return c;
@@ -218,6 +236,7 @@ int testCBS_nonemptyCtor (int count) {
int i, c = 0; int i, c = 0;
for (i=0; i < count; i++) { for (i=0; i < count; i++) {
CBString b (TESTSTRING1); CBString b (TESTSTRING1);
BARRIER();
c += b.length () ^i; c += b.length () ^i;
} }
return c; return c;
@@ -229,6 +248,7 @@ int testCBS_cstrAssignment (int count) {
for (i=0; i < count; i++) { for (i=0; i < count; i++) {
b = TESTSTRING1; b = TESTSTRING1;
BARRIER();
c += b.length () ^i; c += b.length () ^i;
} }
return c; return c;
@@ -242,6 +262,7 @@ int testCBS_extraction (int count) {
c += b[(i & 7)]; c += b[(i & 7)];
c += b[(i & 7) ^ 8]; c += b[(i & 7) ^ 8];
c += ((const char *)b)[(i & 7) ^ 4] ^i; c += ((const char *)b)[(i & 7) ^ 4] ^i;
BARRIER();
} }
return c; return c;
} }
@@ -254,6 +275,7 @@ int testCBS_scan (int count) {
c += b.find ('.'); c += b.find ('.');
c += b.find ("123"); c += b.find ("123");
c += b.findchr ("sm") ^i; c += b.findchr ("sm") ^i;
BARRIER();
} }
return c; return c;
} }
@@ -268,6 +290,7 @@ int testCBS_concat (int count) {
for (i=0; i < 250; i++) { for (i=0; i < 250; i++) {
accum += a; accum += a;
accum += "!!"; accum += "!!";
BARRIER();
c+= accum.length() ^i; c+= accum.length() ^i;
} }
} }
@@ -282,6 +305,7 @@ int testCBS_replace (int count) {
a.replace (11, 4, "XXXXXX"); a.replace (11, 4, "XXXXXX");
a.replace (23, 2, "XXXXXX"); a.replace (23, 2, "XXXXXX");
a.replace ( 4, 8, "XX"); a.replace ( 4, 8, "XX");
BARRIER();
c += a.length () ^j; c += a.length () ^j;
} }
return c; return c;
@@ -293,6 +317,7 @@ int testSRT_emptyCtor (int count) {
int i, c = 0; int i, c = 0;
for (c=i=0; i < count; i++) { for (c=i=0; i < count; i++) {
srt_string *b = ss_alloc(0); srt_string *b = ss_alloc(0);
BARRIER();
c += ss_size(b) ^i; c += ss_size(b) ^i;
ss_free(&b); ss_free(&b);
} }
@@ -303,6 +328,7 @@ int testSRT_nonemptyCtor (int count) {
int i, c = 0; int i, c = 0;
for (c=i=0; i < count; i++) { for (c=i=0; i < count; i++) {
srt_string *b = ss_dup_c(TESTSTRING1); srt_string *b = ss_dup_c(TESTSTRING1);
BARRIER();
c += ss_size(b) ^i; c += ss_size(b) ^i;
ss_free(&b); ss_free(&b);
} }
@@ -314,6 +340,7 @@ int testSRT_cstrAssignment (int count) {
srt_string *b = ss_alloc(0); srt_string *b = ss_alloc(0);
for (c=i=0; i < count; i++) { for (c=i=0; i < count; i++) {
ss_cpy_cn(&b, TESTSTRING1, strlen(TESTSTRING1)); ss_cpy_cn(&b, TESTSTRING1, strlen(TESTSTRING1));
BARRIER();
c += ss_size(b) ^i; c += ss_size(b) ^i;
} }
ss_free(&b); ss_free(&b);
@@ -327,6 +354,7 @@ int testSRT_extraction (int count) {
c += ss_at(b,(i & 7)); c += ss_at(b,(i & 7));
c += ss_at(b,(i & 7) ^ 8); c += ss_at(b,(i & 7) ^ 8);
c += ss_at(b,(i & 7) ^ 4) ^i; c += ss_at(b,(i & 7) ^ 4) ^i;
BARRIER();
} }
ss_free(&b); ss_free(&b);
return c; return c;
@@ -340,6 +368,7 @@ int testSRT_scan (int count) {
c += ss_find_cn (b, 0, "123", strlen("123")); c += ss_find_cn (b, 0, "123", strlen("123"));
//c += ss_pbrk (b, 0, "sm") ^i; //c += ss_pbrk (b, 0, "sm") ^i;
c += ss_findb (b, 0) ^i; c += ss_findb (b, 0) ^i;
BARRIER();
} }
ss_free(&b); ss_free(&b);
return c; return c;
@@ -356,6 +385,7 @@ int testSRT_concat (int count) {
for (i=0; i < 250; i++) { for (i=0; i < 250; i++) {
ss_cat(&accum, a, NULL); ss_cat(&accum, a, NULL);
ss_cat_c(&accum, "!!", NULL); ss_cat_c(&accum, "!!", NULL);
BARRIER();
c += ss_size(accum) ^i; c += ss_size(accum) ^i;
} }
} }
@@ -372,6 +402,7 @@ int testMLIB_emptyCtor (int count) {
for (c=i=0; i < count; i++) { for (c=i=0; i < count; i++) {
string_t b; string_t b;
string_init(b); string_init(b);
BARRIER();
c += string_size(b) ^i; c += string_size(b) ^i;
string_clear(b); string_clear(b);
} }
@@ -383,6 +414,7 @@ int testMLIB_nonemptyCtor (int count) {
for (c=i=0; i < count; i++) { for (c=i=0; i < count; i++) {
string_t b; string_t b;
string_init_set_str(b, TESTSTRING1); string_init_set_str(b, TESTSTRING1);
BARRIER();
c += string_size(b) ^i; c += string_size(b) ^i;
string_clear(b); string_clear(b);
} }
@@ -395,6 +427,7 @@ int testMLIB_cstrAssignment (int count) {
string_init(b); string_init(b);
for (c=i=0; i < count; i++) { for (c=i=0; i < count; i++) {
string_set_str(b, TESTSTRING1); string_set_str(b, TESTSTRING1);
BARRIER();
c += string_size(b) ^i; c += string_size(b) ^i;
} }
string_clear(b); string_clear(b);
@@ -411,6 +444,7 @@ int testMLIB_extraction (int count) {
c += string_get_char(b, (i & 7)); c += string_get_char(b, (i & 7));
c += string_get_char(b, (i & 7) ^ 8); c += string_get_char(b, (i & 7) ^ 8);
c += string_get_char(b, (i & 7) ^ 4) ^i; c += string_get_char(b, (i & 7) ^ 4) ^i;
BARRIER();
} }
string_clear(b); string_clear(b);
return c; return c;
@@ -425,6 +459,7 @@ int testMLIB_scan (int count) {
c += string_search_char (b, '.'); c += string_search_char (b, '.');
c += string_search_str (b, "123"); c += string_search_str (b, "123");
c += string_search_pbrk (b, "sm") ^i; c += string_search_pbrk (b, "sm") ^i;
BARRIER();
} }
string_clear(b); string_clear(b);
return c; return c;
@@ -442,6 +477,7 @@ int testMLIB_concat (int count) {
for (i=0; i < 250; i++) { for (i=0; i < 250; i++) {
string_cat(accum, a); string_cat(accum, a);
string_cat_str(accum, "!!"); string_cat_str(accum, "!!");
BARRIER();
c += string_size(accum) ^i; c += string_size(accum) ^i;
} }
} }
@@ -459,6 +495,7 @@ int testMLIB_replace (int count) {
string_replace_at(a, 11, 4, "XXXXXX"); string_replace_at(a, 11, 4, "XXXXXX");
string_replace_at(a, 23, 2, "XXXXXX"); string_replace_at(a, 23, 2, "XXXXXX");
string_replace_at(a, 4, 8, "XX"); string_replace_at(a, 4, 8, "XX");
BARRIER();
c += string_size(a) ^j; c += string_size(a) ^j;
} }
@@ -473,6 +510,7 @@ int testSDS_emptyCtor (int count) {
for (c=i=0; i < count; i++) { for (c=i=0; i < count; i++) {
sds b; sds b;
b = sdsempty(); b = sdsempty();
BARRIER();
c += sdslen(b) ^ i; c += sdslen(b) ^ i;
sdsfree(b); sdsfree(b);
} }
@@ -484,6 +522,7 @@ int testSDS_nonemptyCtor (int count) {
for (c=i=0; i < count; i++) { for (c=i=0; i < count; i++) {
sds b; sds b;
b = sdsnew(TESTSTRING1); b = sdsnew(TESTSTRING1);
BARRIER();
c += sdslen(b) ^i; c += sdslen(b) ^i;
sdsfree(b); sdsfree(b);
} }
@@ -496,6 +535,7 @@ int testSDS_cstrAssignment (int count) {
b = sdsempty(); b = sdsempty();
for (c=i=0; i < count; i++) { for (c=i=0; i < count; i++) {
b = sdscpy(b, TESTSTRING1); b = sdscpy(b, TESTSTRING1);
BARRIER();
c += sdslen(b) ^i; c += sdslen(b) ^i;
} }
sdsfree(b); sdsfree(b);
@@ -512,6 +552,7 @@ int testSDS_extraction (int count) {
c += b[(i & 7)]; c += b[(i & 7)];
c += b[(i & 7) ^ 8]; c += b[(i & 7) ^ 8];
c += b[(i & 7) ^ 4] ^i; c += b[(i & 7) ^ 4] ^i;
BARRIER();
} }
sdsfree(b); sdsfree(b);
return c; return c;
@@ -526,6 +567,7 @@ int testSDS_scan (int count) {
c += (intptr_t) strchr(b, '.'); c += (intptr_t) strchr(b, '.');
c += (intptr_t) strstr (b, "123"); c += (intptr_t) strstr (b, "123");
c += (intptr_t) strpbrk (b, "sm") ^i; c += (intptr_t) strpbrk (b, "sm") ^i;
BARRIER();
} }
sdsfree(b); sdsfree(b);
return c; return c;
@@ -543,6 +585,7 @@ int testSDS_concat (int count) {
for (i=0; i < 250; i++) { for (i=0; i < 250; i++) {
accum = sdscat(accum, a); accum = sdscat(accum, a);
accum = sdscat(accum, "!!"); accum = sdscat(accum, "!!");
BARRIER();
c += sdslen(accum) ^i; c += sdslen(accum) ^i;
} }
} }
@@ -561,6 +604,7 @@ int testRAPIDSTRING_emptyCtor (int count) {
for (c=i=0; i < count; i++) { for (c=i=0; i < count; i++) {
rapidstring b; rapidstring b;
rs_init(&b); rs_init(&b);
BARRIER();
c += rs_len(&b) ^i; c += rs_len(&b) ^i;
rs_free(&b); rs_free(&b);
} }
@@ -572,6 +616,7 @@ int testRAPIDSTRING_nonemptyCtor (int count) {
for (c=i=0; i < count; i++) { for (c=i=0; i < count; i++) {
rapidstring b; rapidstring b;
rs_init_w(&b, TESTSTRING1); rs_init_w(&b, TESTSTRING1);
BARRIER();
c += rs_len(&b) ^i; c += rs_len(&b) ^i;
rs_free(&b); rs_free(&b);
} }
@@ -584,6 +629,7 @@ int testRAPIDSTRING_cstrAssignment (int count) {
rs_init(&b); rs_init(&b);
for (c=i=0; i < count; i++) { for (c=i=0; i < count; i++) {
rs_cpy(&b, TESTSTRING1); rs_cpy(&b, TESTSTRING1);
BARRIER();
c += rs_len(&b) ^i; c += rs_len(&b) ^i;
} }
rs_free(&b); rs_free(&b);
@@ -600,6 +646,7 @@ int testRAPIDSTRING_extraction (int count) {
c += rs_data_c(&b)[i & 7]; c += rs_data_c(&b)[i & 7];
c += rs_data_c(&b)[(i & 7) ^ 8]; c += rs_data_c(&b)[(i & 7) ^ 8];
c += rs_data_c(&b)[(i & 7) ^ 4] ^i; c += rs_data_c(&b)[(i & 7) ^ 4] ^i;
BARRIER();
} }
rs_free(&b); rs_free(&b);
return c; return c;
@@ -618,6 +665,7 @@ int testRAPIDSTRING_concat (int count) {
for (i=0; i < 250; i++) { for (i=0; i < 250; i++) {
rs_cat_rs(&accum, &a); rs_cat_rs(&accum, &a);
rs_cat(&accum, "!!"); rs_cat(&accum, "!!");
BARRIER();
c += rs_len(&accum) ^i; c += rs_len(&accum) ^i;
} }
} }