Editing QEMU (section)

===Tiny Code Generator===
The Tiny Code Generator (TCG) aims to remove the shortcoming of relying on a particular version of [[GNU Compiler Collection|GCC]] or any [[compiler]], instead incorporating the compiler into other tasks performed by QEMU at run time. The whole translation task thus consists of two parts: [[basic block]]s of target code (''TBs'') being rewritten in ''TCG ops'' – a kind of machine-independent intermediate notation, and subsequently this notation being compiled for the host's architecture by TCG. Optional optimization passes are performed between them, for a [[just-in-time compiler]] (JIT) mode.

TCG requires dedicated code written to support every architecture it runs on, so that the JIT knows what to translate the ''TCG ops'' to. If no dedicated JIT code is available for the architecture, TCG falls back to a slow [[Interpreter (computing)|interpreter]] mode called TCG Interpreter (TCI). It also requires updating the target code to use TCG ops instead of the old ''DynGen'' ops.{{Clarify|reason=This appears to be a unique usage of the jargon "dyngen", researching this term, it appears to be more commonly used in the cellular simulation space.|date=December 2024}}

Starting with QEMU Version 0.10.0, TCG ships with the QEMU stable release. It replaces ''DynGen'', which relied on GCC 3.x to work.<ref name="DhNAG3">{{cite web |title=[Qemu-devel] ANNOUNCE: Release 0.10.0 of QEMU |url=http://lists.gnu.org/archive/html/qemu-devel/2009-03/msg00154.html |website=lists.gnu.org}}</ref><ref name="8NZ3y3">{{cite web |last1=Filardo |first1=Nathaniel |date=September 11, 2007 |title=Porting QEMU to Plan 9: QEMU Internals and Port Strategy |url=http://gsoc.cat-v.org/people/nwf/paper-strategy-plus.pdf |website=gsoc.cat-v.org}} -- a review of how the old dyngen worked</ref>