FC3 x86_64 math functions slowdown

Hi all

in two identically configured machines running SuSe 9.1 and FC3.

of tan() and tanf().

The following table summarizes the results .

                             glibc 2.3.3    glibc 2.3.5

 f1 = expf(f2)       0.07    0.03    0.07    0.27 !!! (same here)

 f1 = cos(f2)        0.05    0.06    0.05    0.06
 f1 = cosf(f2)       0.05    0.06    0.05    0.06
 f1 = cosl(f2)       0.05    0.06    0.06    0.06

 f1 = sqrt(f2)       0.02    0.01    0.02    0.01
 f1 = sqrtf(f2)      0.02    0.01    0.02    0.01





SYSTEM INFO OF THE TEST MACHINES :

System 1 : Suse 9.1 (x86-64)

galactix # uname -a

galactix # rpm -q glibc
glibc-2.3.3-63

galactix # cat /proc/cpuinfo

processor       : 0
vendor_id       : AuthenticAMD
cpu family      : 15
model           : 5
model name      : AMD Opteron(tm) Processor 246
stepping        : 8
cpu MHz         : 1992.158
cache size      : 1024 KB
fpu             : yes
fpu_exception   : yes
cpuid level     : 1
wp              : yes

pat pse36 clflush mmx fxsr sse sse2 sys call nix mmxext elm 3dnowext 3now
bogomips        : 3915.77
TLB size        : 1088 4K pages
clflush size    : 64
address sizes   : 40 bits physical, 48 bits virtual
power management: ts ttp

System 2 : FC3 (x86-64)

neron # uname -a

x86_64 x86_64 GNU/Linux

neron # rpm -q glibc
glibc-2.3.5-0.fc3.1

neron # cat /proc/cpuinfo

processor       : 0
vendor_id       : AuthenticAMD
cpu family      : 15
model           : 5
model name      : AMD Opteron(tm) Processor 246
stepping        : 8
cpu MHz         : 1994.595
cache size      : 1024 KB
fpu             : yes
fpu_exception   : yes
cpuid level     : 1
wp              : yes

pat pse36 clflush mmx fxsr sse sse2 pni syscall nx mmxext lm 3dnowext 3dnow
bogomips        : 3923.96
TLB size        : 1088 4K pages
clflush size    : 64
cache_alignment : 64
address sizes   : 40 bits physical, 48 bits virtual
power management: ts ttp



SOURCE CODE OF BENCHMARKING PROGRAM

galactix # cat metro.c

----------------- CUT HERE --------------------
#include <stdio.h>
#include <limits.h>
#include <math.h>
#include <string.h>
#include <stdlib.h>

#define BASEN 50000000
#define WARNRANGE 0.4

struct stacknode {
       int val;
       struct stacknode *next;
};
typedef struct stacknode *Stackp;
Stackp  stackroot;

void push(int i)
{
       Stackp p;

       p = (Stackp) malloc(sizeof(struct stacknode));
       p->val = i;
       p->next = stackroot;
       stackroot = p;
}

int pop()
{
       Stackp p;
       int     i;

       p = stackroot;
       i = stackroot->val;
       stackroot = stackroot->next;
       free(p);
       return i;
}

#include <time.h>

int jobclicks()
{
       return (int) clock();
}

#define quoted(TEXT) #TEXT
/*#define quoted(TEXT) "TEXT"*/

#define loop1(CODE) loop1ctr++; \
       for (i = 0; i < n; i++) { CODE; } \
       loop1next = jobclicks(); \
       thisclicks = loop1next - loop1start; \
       sumclicks += thisclicks; \
       if (thisclicks < minclicks) minclicks = thisclicks; \
       if (thisclicks > maxclicks) maxclicks = thisclicks; \
       printf("%7d ", loop1next - loop1start); \
       loop1start = loop1next;

#define loop(CODE) printf("  %-30s", quoted(CODE)); \
       minclicks = INT_MAX; maxclicks = -1; sumclicks = 0; \
       loop1ctr = 0; \
       loop1start = jobclicks(); \
       loop1(CODE) \
       loop1(CODE) \
       i0 = i1 + i2 + i3; \
       loop1(CODE) \
       i0 = i1 + i2 + i3 - i1 - i2 - i3; \
       loop1(CODE) \
       i0 = i1 + i2 + i3 + i1*i2 + i2*i3 + i1*i3; \
       loop1(CODE) \
       queststr = ""; \
       if (loop1ctr * (maxclicks - minclicks) > WARNRANGE *  sumclicks) \
               queststr = "?"; \

       printf("%10.2f%s\n", lastmics - basemics, queststr);

#define title(TEXT) printf("%s (n=%d)\n", TEXT, n);

/* The experiment */

int sum1(int a) { return a; }
int sum2(int a, int b) { return a + b; }
int sum3(int a, int b, int c) { return a + b + c; }

int main()
{
       int     loop1start, loop1next, loop1ctr;
       double  lastmics, basemics;
       int     minclicks, maxclicks, sumclicks, thisclicks, startclicks;
       int     i, n, basen;
       volatile int    i0, i1, i2, i3, i4;
       volatile float  f0, f1, f2, f3;
       int     *v;
       char    *queststr;
       char    s[100];
       char    fname[20];
       FILE    *fp;
       char    s0123456789[] = "0123456789";
       char    sa123456789[] = "a123456789";
       char    s12345[] = "12345";
       char    s123_45[] = "123.45";
       char    sd[] = "%d";
       char    sdn[] = "%d\n";
       char    sf[] = "%f";
       char    sf62[] = "%f6.2";

       setbuf(stdout, (char *) 0);     /* No buffering to watch output */

       printf("   Mics/N\n");
       startclicks = jobclicks();

       basen = BASEN;
       n = basen;
       title("Null Loop")
       i0 = i1 = i2 = i3 = 5;
       f0 = f1 = f2 = f3 = 5.0;
       basemics = 0.0;
       loop({})
       basemics = lastmics;

       n = basen/10;
/*      n = basen;*/
       title("Math Functions");
       f2 = 5.0;
       loop(f1 = log(f2))
       loop(f1 = logf(f2))
       loop(f1 = tan(f2))
       loop(f1 = tanf(f2))
       loop(f1 = exp(f2))
       loop(f1 = expf(f2))
       loop(f1 = sin(f2))
       loop(f1 = sinf(f2))
       loop(f1 = cos(f2))
       loop(f1 = cosf(f2))
       loop(f1 = cosl(f2))
       loop(f1 = sqrt(f2))
       loop(f1 = sqrtf(f2))

       return 0;
}
--------- CUT HERE --------


Hope its helpful

  D. Angelis