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Ten minutes to compile a simple c++ function
- To: gcc-bugs at gcc dot gnu dot org
- Subject: Ten minutes to compile a simple c++ function
- From: Kelley Cook <kelleycook at yahoo dot com>
- Date: Thu, 15 Jun 2000 13:58:54 -0700 (PDT)
- Cc: Robert <robert dot melchers at drives dot eurotherm dot co dot uk>
- Reply-To: KelleyCook at attglobal dot net
I just checked and the same thing happens under current CVS on i686.
Forwarding to gcc-bugs ...
---------- FWD from gcc@gcc.gnu.org ----
I posted this earlier but had little response, I have tidied up the
example code and tried the same code with gcc version 2.96 20000612
(experimental) sh-elf with the same results. The compiler takes an
excessive time to compile the function below, I have placed the timings
at the end.
with the following cmdline:
sh-elf-gcc -c mux.cc
The same file compiles fine with:
sh-elf-gcc -c -xc mux.cc
splitting the OR into 2 parts also fixes the problem also the same file
compiles fine with "sh-coff-gcc version 2.95.2 19991024 (release)"
I hope this helps someone.
Robert <robert.melchers@drives.eurotherm.co.uk>
/* --- Start of file mux.cc --- */
#ifndef __cplusplus
typedef char bool; /* needed for 'c' build */
#endif /* !__cplusplus */
bool in0 ;
bool in1 ;
bool in2 ;
bool in3 ;
bool in4 ;
bool in5 ;
bool in6 ;
bool in7 ;
bool in8 ;
bool in9 ;
bool in10;
bool in11;
bool in12;
bool in13;
bool in14;
bool in15;
unsigned int output;
void mux(void)
{
output =
(in0 ? 0x0001 : 0) |
(in1 ? 0x0002 : 0) |
(in2 ? 0x0004 : 0) |
(in3 ? 0x0008 : 0) |
(in4 ? 0x0010 : 0) |
(in5 ? 0x0020 : 0) |
(in6 ? 0x0040 : 0) |
(in7 ? 0x0080 : 0) |
(in8 ? 0x0100 : 0) |
(in9 ? 0x0200 : 0) |
(in10 ? 0x0400 : 0) |
(in11 ? 0x0800 : 0) |
(in12 ? 0x1000 : 0) |
(in13 ? 0x2000 : 0) |
(in14 ? 0x4000 : 0) |
(in15 ? 0x8000 : 0) ;
}
/* --- END OF FILE --- */
Times for c++ compile
---------------------
//d/605plus/code/app_fb/fb_mux [1072] ../../_tools/gtime.exe -v
sh-elf-gcc -c mux.cc
Command being timed: "sh-elf-gcc -c mux.cc"
User time (seconds): 208.42
System time (seconds): 0.17
Percent of CPU this job got: 92%
Elapsed (wall clock) time (h:mm:ss or m:ss): 3:44.95
Average shared text size (kbytes): 0
Average unshared data size (kbytes): 0
Average stack size (kbytes): 0
Average total size (kbytes): 0
Maximum resident set size (kbytes): 0
Average resident set size (kbytes): 0
Major (requiring I/O) page faults: 0
Minor (reclaiming a frame) page faults: 0
Voluntary context switches: 0
Involuntary context switches: 0
Swaps: 0
File system inputs: 0
File system outputs: 0
Socket messages sent: 0
Socket messages received: 0
Signals delivered: 3
Page size (bytes): 4096
Exit status: 0
Times for c compile
--------------------
//d/605plus/code/app_fb/fb_mux [1072] ../../_tools/gtime.exe -v
sh-elf-gcc -c -xc mux.cc
Command being timed: "sh-elf-gcc -c -xc mux.cc"
User time (seconds): 0.19
System time (seconds): 0.17
Percent of CPU this job got: 74%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:00.48
Average shared text size (kbytes): 0
Average unshared data size (kbytes): 0
Average stack size (kbytes): 0
Average total size (kbytes): 0
Maximum resident set size (kbytes): 0
Average resident set size (kbytes): 0
Major (requiring I/O) page faults: 0
Minor (reclaiming a frame) page faults: 0
Voluntary context switches: 0
Involuntary context switches: 0
Swaps: 0
File system inputs: 0
File system outputs: 0
Socket messages sent: 0
Socket messages received: 0
Signals delivered: 3
Page size (bytes): 4096
Exit status: 0
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