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Using the Inline and Embedded Assemblers of the AR
Compiler support for inline assembly language
Inline assembler support in the compiler
Restrictions on inline assembler support in the co
Inline assembly language syntax with the __asm key
Inline assembly language syntax with the asm keywo
Inline assembler rules for compiler keywords __asm
Restrictions on inline assembly operations in C an
Inline assembler register restrictions in C and C+
Inline assembler processor mode restrictions in C
Inline assembler Thumb instruction set restriction
Inline assembler Vector Floating-Point (VFP) restr
Inline assembler instruction restrictions in C and
Miscellaneous inline assembler restrictions in C a
Inline assembler and register access in C and C++
Inline assembler and the # constant expression spe
Inline assembler and instruction expansion in C an
Expansion of inline assembler instructions that us
Expansion of inline assembler load and store instr
Inline assembler effect on processor condition fla
Inline assembler operands in C and C++ code
Inline assembler expression operands in C and C++
Inline assembler register list operands in C and C
Inline assembler intermediate operands in C and C+
Inline assembler function calls and branches in C
Behavior of BL and SVC without optional lists in C
Inline assembler BL and SVC input parameter list i
Inline assembler BL and SVC output value list in C
Inline assembler BL and SVC corrupted register lis
Inline assembler branches and labels in C and C++
Inline assembler and virtual registers
Embedded assembler support in the compiler
Embedded assembler syntax in C and C++
Effect of compiler ARM and Thumb states on embedde
Restrictions on embedded assembly language functio
Compiler generation of embedded assembly language
Access to C and C++ compile-time constant expressi
Differences between expressions in embedded assemb
Manual overload resolution in embedded assembler
__offsetof_base keyword for related base classes i
Compiler-supported keywords for calling class memb
__mcall_is_virtual(D, f)
__mcall_is_in_vbase(D, f)
__mcall_offsetof_vbase(D, f)
__mcall_this_offset(D, f)
__vcall_offsetof_vfunc(D, f)
Calling nonstatic member functions in embedded ass
Calling a nonvirtual member function
Calling a virtual member function
Legacy inline assembler that accesses sp, lr, or p
Accessing sp (r13), lr (r14), and pc (r15) in lega
Differences in compiler support of inline and embe
Compiler User Guide
Differences in compiler support of inline and embedded assembly code
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| Home > Using the Inline and Embedded Assemblers of the ARM Compiler > Differences in compiler support of inline and embedded assembly code | |||
There are differences between the ways inline and embedded assembly are compiled:
Inline assembly code uses a high level of processor abstraction, and is integrated with the C and C++ code during code generation. Therefore, the compiler optimizes the C and C++ code and the assembly code together.
Unlike inline assembly code, embedded assembly code is assembled separately from the C and C++ code to produce a compiled object that is then combined with the object from the compilation of the C or C++ source.
Inline assembly code can be inlined by the compiler, but embedded assembly code cannot be inlined, either implicitly or explicitly.
Table 20 summarizes the main differences between inline assembler and embedded assembler.
Table 20. Differences between inline and embedded assembler
| Feature | Embedded assembler | Inline assembler |
|---|---|---|
| Instruction set | ARM and Thumb. | ARM on all processors. Thumb on processors with Thumb-2 technology. |
| ARM assembler directives | All supported. | None supported. |
| ARMv6 instructions | All supported. | Supports most instructions, with some exceptions,
for example |
| ARMv7 instructions | All supported. | Supports most instructions. |
| VFP instructions | All supported. | VFPv2 only. |
| C/C++ expressions | Constant expressions only. | Full C/C++ expressions. |
| Optimization of assembly code | No optimization. | Full optimization. |
| Inlining | Never. | Possible. |
| Register access | Specified physical registers are used. You
can also use PC, LR and SP. | Uses virtual registers. Using |
| Return instructions | You must add them in your code. | Generated automatically. (The BX, BXJ, and BLX instructions
are not supported.) |
BKPT instruction | Supported directly. | Not supported. |
See also- Concepts
| Copyright © 2007-2008, 2011-2012 ARM. All rights reserved. | ARM DUI 0375D |
| Non-Confidential | ID062912 |
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| Home > Using the Inline and Embedded Assemblers of the ARM Compiler > Differences in compiler support of inline and embedded assembly code |
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