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Code sizes

There are many sources on the web telling you how to write small C code. But different versions of gcc produce different code sizes. I made a small test with different gcc-versions:

gcc 3.2.3 (exactly: "gcc (GCC) 3.2.3 20030502 (Red Hat Linux 3.2.3-54)")
gcc 3.3.3 (exactly: "gcc (GCC) 3.3.3 20040412 (Red Hat Linux 3.3.3-7)")
gcc 3.3.5 (exactly: "gcc (GCC) 3.3.6-hammer 20050117 (prerelease)")
gcc 3.3.6 (original GNU code)
gcc 3.4.6 (exactly: "gcc (GCC) 3.4.6 20060404 (Red Hat 3.4.6-3)")
gcc 4.1.0 (exactly: "gcc (GCC) 4.1.0 20060304 (Red Hat 4.1.0-3)")

With each gcc I built the dietlibc-0.30 with standard dietlibc options/flags and got the following file sizes of bin-i386/dietlibc.a:

gcc 3.2.3: 681214
gcc 3.3.3: 631384
gcc 3.3.5: 631336
gcc 3.3.6: 631504
gcc 3.4.6: 627568
gcc 4.1.0: 627204

Then I used each compiled dietlibc with each gcc to compile some small tools. The executables were stripped ("strip -s -R .note -R .comment"). The matrix values are the sums of the tools file sizes:

	diet323	diet333	diet335	diet336	diet346	diet410
gcc323	26300	24060	24140	24204	24172	26180
gcc333	24108	23816	23904	23816	23940	25896
gcc335	24120	23828	23916	23828	23952	25908
gcc336	24280	24016	24112	24016	24176	26124
gcc346	24172	23880	23968	23880	23972	25960
gcc410	24356	24064	24152	24064	24188	26144

Short note about the old-fashioned gcc-2.95.3: The file sizes I got with it are even inferior to gcc-3.2.3 and nearly bad as gcc-4.1.0.

A last test shows file sizes when compiling a tool with gcc-3.4.6:

diet -Os gcc -Os; strip	3776
diet -Os gcc -Os	7358
diet gcc -Os	7418
diet gcc -O2	7578
gcc -Os	7730
gcc -O2	7854
gcc -O2 -g	13966
gcc -Os -static	550334

Last note: With sstrip or elftrunc (dietlibc contrib) you can strip symbols and section headers from ELF executables to get smaller files.