Thumb code size diagnostics
The assembler can issue a warning when it assembles a Thumb instruction to a 32-bit encoding when it could have used a 16-bit encoding.
In Thumb code, some instructions, for example a branch or LDR (PC-relative), can be encoded as a 32-bit or 16-bit instruction. The assembler chooses the size of the encoded instruction.
To enable this warning, use the following command-line option when invoking the assembler:
armasm --diag_warning 1813