Altera Nios II C2H Compiler - Manual (Page 104)

4–10 9.1 Altera Corporation
Nios II C2H Compiler User Guide November 2009
Performance
Performance The performance section of the C2H build report details information
about each loop in the accelerated function. For each loop shown, the
report contains the following information:
■ File name and source line number
■ Loop latency
■ Cycles per loop iteration (CPLI)
■ Scheduling information per assignment
■ Scheduling information per state
In the following discussion of information shown in the performance
section, refer to
Example 4–2 .
Example 4–2. CRC32 (Ethernet CRC)
#pragma altera_accelerate connect_variable\
crc_calculation/data to onchipRAM1
#pragma altera_accelerate connect_variable\
crc_calculation/table to onchipRAM2
unsigned long crc_calculation
( unsigned char * _ _ restrict_ _ data,
unsigned long * _ _ restrict_ _ table,
unsigned long length)
{
unsigned long i, crc = 0xFFFFFFFF;
unsigned char lut_addr;
for (i = 0; i < length; i++)
{
lut_addr = (crc & 0xFF) ^ *data++;
crc = (crc >> 8) ^ table[lut_addr];
}
return (crc ^ 0xFFFFFFFF);
}
Source Line Number
The performance section of the build report shows a source line number
for each loop statement. The line number is determined by the beginning
of the loop, which is the source line containing the opening block
delimiter (
{ ). If your coding style places the loop keyword ( do , while , or
for ) on a separate line from the delimiter, the report shows the line where
the delimiter appears.