Assembler User GuidePreface Overview of the Assembler Overview of the ARM Architecture Structure of Assembly Language Modules Writing ARM Assembly Language Condition Codes Using the Assembler armasm command-line syntax Specify command-line options with an environment v Using stdin to input source code to the assembler Built-in variables and constants Identifying versions of armasm in source code Diagnostic messages Interlocks diagnostics Automatic IT block generation Thumb branch target alignment Thumb code size diagnostics ARM and Thumb instruction portability diagnostics Instruction width diagnostics Two pass assembler diagnostics Conditional assembly Using the C preprocessor Address alignment Instruction width selection in Thumb Symbols, Literals, Expressions, and Operators VFP Programming Assembler Command-line Options ARM and Thumb Instructions VFP Instructions Directives Reference Via File Syntax
Automatic IT block generation
6.8 Automatic IT block generation
The assembler can automatically insert an IT block for conditional instructions in Thumb code, without requiring the use of explicit IT instructions.
If you write the following code:
AREA x, CODE THUMB MOVNE r0,r1 NOP IT NE MOVNE r0,r1 END
the assembler generates the following instructions:
IT NE MOVNE r0,r1 NOP IT NE MOVNE r0,r1
You can receive warning messages about this automatic generation of
armasm --diag_warning 1763
of your data.