HI, Ruoyao, Thanks indeed for your help! Best regards, Dingjun ________________________________ From: Xi Ruoyao <xry111@xxxxxxxxxxx> Sent: Tuesday, September 26, 2023 3:38 AM To: David Brown <david.brown@xxxxxxxxxxxx>; gcc-help@xxxxxxxxxxx <gcc-help@xxxxxxxxxxx> Cc: Dingjun Chen <Dingjun.Chen@xxxxxxxxxxxxxxxxxxx> Subject: Re: where to download g++ 32 bit compiler? External Email Warning: Do not click any links or open any attachments unless you trust the sender and know the content is safe. From Geotech IT. On Mon, 2023-09-25 at 19:50 +0200, David Brown wrote: > You don't need a 32-bit compiler to build 32-bit applications - you can > happily use a 64-bit compiler with a 32-bit target. If you are > targeting x86 (I'm guessing you are, since you did not specify), you use > the "-m32" flag to generate 32-bit code. A caveat here: -m32 does not necessarily imply -march=i686. So if you build something with a x86_64 compiler and -m32, there is no guarantee that the object code can run correctly on a "pure" 32-bit x86 CPU. In previous GCC releases the documentation did not mention this caveat and might puzzle people. Some distros are using --with-arch-32=i686 configuring GCC to imply - march=i686 with -m32, but it's not the default of vanilla GCC. -- Xi Ruoyao <xry111@xxxxxxxxxxx> School of Aerospace Science and Technology, Xidian University
