Gcc 3.4.3 to Gcc 4.8x

Dallman, John john.dallman@siemens.com
Fri Dec 6 10:19:00 GMT 2019

> Good morning!  I’m assisting a client moving from/to the above-referenced versions.  Any known issues with this specific upgrade?

I have not done that specific upgrade. I went from 3.3, to 4.0, to 4.3, to 4.8, with C code. Things I encountered along the way:

Later versions of GCC try much harder to re-use the stack space for variables declared in inner blocks. That means faulty code which uses pointers to variables that have gone out of scope is more likely to actually cause problems with later compilers. The code needs to be fixed.

You may well be able to turn up the optimisation: -O2 did not work well for me with GCC 3.3, but is good on GCC 4.8.

You may get more information if you say what platform(s) you're building for. I was doing 32-bit and 64-bit x86 for the relevant years, except that I dropped 32-bit during the GCC 4.3 period.

John Dallman
Siemens Industry Software Limited is a limited company registered in England and Wales.
Registered number: 3476850.
Registered office: Faraday House, Sir William Siemens Square, Frimley, Surrey, GU16 8QD.

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