Hi,
On Mon, Nov 22, 2010 at 2:39 PM, Nicolas Pitre nicolas.pitre@linaro.org wrote:
[...]
I hope there is at least a validation of the IT instructions by the assembler with regards to the condition codes on the following instructions (and vice versa) to make sure they are all coherent, and even so for ARM mode compilation.
In unified syntax, yes; in traditional syntax, no.
When driving gas via GCC, this means that the checking is done only when building for Thumb-2 (since traditional syntax is always used for ARM code generated by GCC, and this probably isn't going to change for now). In traditional syntax, at least some binutils versions totally ignore IT instructions.
However, for code generated by GCC itself (i.e., not inline asm), GCC is supposed to generate the correct IT instructions when generating Thumb-2 code. -mimplicit-it may therefore cause some code generation errors to go unnoticed, particularly where the compiler misses out an IT instruction which it was supposed to insert, but the assembler silently inserts the missing instruction.
Cheers ---Dave