Editing C++ (section)

====Variations across compilers====
Different C++ compilers implement inline assembly in distinct ways.

* GCC ([[GNU Compiler Collection]]) and [[Clang]]:<ref>{{Cite web |title=Extended Asm (Using the GNU Compiler Collection) |url=https://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html |website=GCC Online Documentation |publisher=GNU Project |access-date=1 April 2025}}</ref> Use the GCC extended inline assembly syntax. Using <syntaxhighlight lang="C++" inline>__asm__</syntaxhighlight> keyword instead of <syntaxhighlight lang="C++" inline>asm</syntaxhighlight> when writing code that can be compiled with <syntaxhighlight lang="C++" inline>-ansi</syntaxhighlight> and <syntaxhighlight lang="C++" inline>-std</syntaxhighlight> options, which allows specifying input/output operands and clobbered registers. This approach is widely adopted, including by Intel<ref name="IntelInlineAssembly">Intel Corporation. "[https://www.intel.com/content/www/us/en/docs/cpp-compiler/developer-guide-reference/2021-9/inline-assembly.html Inline Assembly]". ''Intel® C++ Compiler Classic Developer Guide and Reference'', Version 2021.9. Retrieved 1 April 2025.</ref> and IBM<ref name="IBMInlineAssembly">IBM. "[https://www.ibm.com/docs/en/xl-c-aix/13.1.3?topic=statements-inline-assembly-extension Inline assembly statements (IBM extension)]". ''IBM Documentation''. Retrieved 1 April 2025.</ref> compilers.
* MSVC ([[Microsoft Visual C++]]): The inline assembler is built into the compiler. Previously supported inline assembly via the <syntaxhighlight lang="C++" inline>__asm</syntaxhighlight> keyword, but this support has been removed in 64-bit mode, requiring separate .asm modules instead.<ref>{{Cite web |title=Inline Assembler Overview |url=https://learn.microsoft.com/en-us/cpp/assembler/inline/inline-assembler-overview?view=msvc-170 |website=Microsoft Learn |publisher=Microsoft |access-date=1 April 2025}}</ref>
* TI ARM Clang and Embedded Compilers:<ref>{{Cite web |title=Interfacing C and C++ With Assembly Language |url=https://software-dl.ti.com/codegen/docs/tiarmclang/compiler_tools_user_guide/compiler_manual/runtime_environment/interfacing-c-and-c-with-assembly-language-stdz0544217.html#interfacing-c-and-c-with-assembly-language |website=Texas Instruments |publisher=Texas Instruments Incorporated |date=23 February 2025 |access-date=1 April 2025}}</ref> Some embedded system compilers, like Texas Instruments' TI Arm Clang, allow inline assembly but impose stricter rules to avoid conflicts with register conventions and calling conventions.