AlignmentĪlthough Windows enables the ARM hardware to handle misaligned integer accesses transparently, alignment faults still may be generated in some situations. It may lead to an application fault in user mode, or a bugcheck in kernel mode. If an exception is generated in big-endian mode, the behavior is unpredictable. However, doing so is discouraged because it's dangerous for an application.
Visual arm emulator multiply by 3 code#
The SETEND instruction in the ARM instruction set architecture (ISA) allows even user-mode code to change the current endianness.
Both the MSVC compiler and the Windows runtime always expect little-endian data. Windows on ARM executes in little-endian mode. Platforms that lack integer divide support may incur a performance penalty because these operations have to be trapped and possibly patched. Integer divide support (UDIV/SDIV) is recommended but not required. No run-time support for emulation is provided. The Windows runtime doesn't support emulation of floating-point to enable running on non-VFP hardware.Īdvanced SIMD Extensions (NEON) support, including both integer and floating-point operations, must also be present in hardware.
The VFP must support both single-precision and double-precision floating-point in hardware. Floating-point support in the form of VFPv3-D32 or later must be present in hardware. Windows on ARM always presumes that it's running on an ARMv7 architecture. For more information about the standard ARM EABI, see Application Binary Interface (ABI) for the ARM Architecture (external link). For information about the ARM64 ABI, see Overview of ARM64 ABI conventions. This article highlights key differences between Windows on ARM and the standard. The application binary interface (ABI) for code compiled for Windows on ARM processors is based on the standard ARM EABI.