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64 bit assignment on a 32 bit platform
- From: kum <a dot kumaresh at gmail dot com>
- To: gcc-help at gcc dot gnu dot org
- Date: Mon, 29 Oct 2007 15:37:04 +0530
- Subject: 64 bit assignment on a 32 bit platform
Hi,
UINT64 a64; // UINT64 has been typedefed as long long unsigned int
UINT32 a32, b32;
a32 = x; // some value
b32 = y; // some value
a64 = a32 * b32;
a64 += a32 + b32;
Is it necessary to type-cast both a32 and b32 to yield correct 64 bit
results? Without casting, I find that addition (even if the result
overflows) works while the multiplication does not. Is there a
compiler option to make this work without casting? I am using gcc
4.1.1 on an xscale platform.
Thank you all,
kumaresh