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Another strict-alias puzzle with (unsigned) char ptrs
- From: Adam Dickmeiss <adam at indexdata dot dk>
- To: gcc-help at gcc dot gnu dot org
- Date: Tue, 26 Sep 2006 23:02:44 +0200
- Subject: Another strict-alias puzzle with (unsigned) char ptrs
The program below prints 1 or 0 depending on GCC version and
-O2/-fstrict-aliasing being present or not. With proper optimizations
enabled, 0 is printed. Otherwise, 1 is printed.
So just to understand: strict aliases also take effect for
signed/unsigned char pointers?
/ Adam
#include <stdio.h>
static void decode_ptr(const unsigned char **src)
{
(*src)++;
}
int main(int argc, char **argv)
{
const char *src0 = "";
const char *src = src0;
decode_ptr(&src);
printf("sz = %lld\n", (long long)(src - src0));
}