Hello,
I would like to report a C6x 7.4.2 (and earlier) compiler bug, which seems related to the (fixed) SDSCM00044775 one.
You'll find test code and compiler options in the attached file. The function "TestFilt8A" compiles in a bad way with option -o2 only (bad SPLOOP configuration).
Jakez
// cl6x v7.4.2
// ok with Compiler Options=-g -q -o0 --silicon_version=6740
// ok with Compiler Options=-g -q -o1 --silicon_version=6740
// error with Compiler Options=-g -q -o2 --silicon_version=6740
// ok with Compiler Options=-g -q -o3 --silicon_version=6740
typedef unsigned char uint8_t;
#define LOG2_BPP_MAX 3
#define BUFF_SIZE 0x100
#define BPP_MAX (1<<(LOG2_BPP_MAX))
// unsigned bpp : => bad SPLOOP code with -o2
static void TestFilt8A( uint8_t *pBuff, int n, unsigned int bpp )
{ int i;
uint8_t *rp = pBuff + bpp;
for ( i = n - bpp; (i>0); i-- )
{ *rp = (*rp + *( rp - bpp )) & 0xFF;
rp++;
}
}
// signed bpp : always ok
static void TestFilt8B( uint8_t *pBuff, int n, int bpp )
{ int i;
uint8_t *rp = pBuff + bpp;
for ( i = n - bpp; (i>0); i-- )
{ *rp = (*rp + *( rp - bpp )) & 0xFF;
rp++;
}
}
int TestFilter( int bpp )
{ static uint8_t pBuff8A[BUFF_SIZE];
static uint8_t pBuff8B[BUFF_SIZE];
int i;
int err = 0;
for ( i=0; (i<BUFF_SIZE); i++ )
pBuff8B[i] = pBuff8A[i] = (uint8_t)(i & 0xFF);
TestFilt8A( pBuff8A, BUFF_SIZE, bpp );
TestFilt8B( pBuff8B, BUFF_SIZE, bpp );
for ( i=0; (i<BUFF_SIZE); i++ )
if ( pBuff8A[i] != pBuff8B[i] )
err++;
return err;
}
// return !=0 if error detected
int main( void )
{ int bpp;
int err = 0;
for (bpp = 1; (bpp < BPP_MAX); bpp++ )
err += TestFilter( bpp );
return err;
}
