Was (wer) ist single assignment - definition

INTERMEDIATE REPRESENTATION (IR) IN WHICH EACH VARIABLE IS ASSIGNED EXACTLY ONCE, AND EVERY VARIABLE IS DEFINED BEFORE IT IS USED

SSA form; SSA Form; SSA (compilers); SSAF; Static single assignment; Single static assignment; SSA optimisation algorithm; Static single-assignment representation; Static single assignment representation; Static Single Assignment; Static Single Assignment form; SSA (computing); Static single assignment form

single assignment

<programming> A property of variables in a {functional language}. If a variable is only assigned a value once then an instance of that variable is thereafter semantically equivalent to the value. SISAL is an example of a language with this property. See also zero assignment. (2003-12-22)

Static single-assignment form

In compiler design, static single assignment form (often abbreviated as SSA form or simply SSA) is a property of an intermediate representation (IR), which requires that each variable be assigned exactly once, and every variable be defined before it is used. Existing variables in the original IR are split into versions, new variables typically indicated by the original name with a subscript in textbooks, so that every definition gets its own version.

https://en.wikipedia.org/wiki/Static_single-assignment_form

Static single assignment form

https://en.wikipedia.org/wiki/Static_single_assignment_form

Wikipedia

Static single-assignment form

In compiler design, static single assignment form (often abbreviated as SSA form or simply SSA) is a property of an intermediate representation (IR) that requires each variable to be assigned exactly once and defined before it is used. Existing variables in the original IR are split into versions, new variables typically indicated by the original name with a subscript in textbooks, so that every definition gets its own version. In SSA form, use-def chains are explicit and each contains a single element.

SSA was proposed by Barry K. Rosen, Mark N. Wegman, and F. Kenneth Zadeck in 1988. Zadeck shared a brief history of how SSA came into being in his presentation The Development of Static Single Assignment Form at the "Static Single-Assignment Form Seminar" conducted at the Saarland University. Ron Cytron, Jeanne Ferrante and the previous three researchers at IBM developed an algorithm that can compute the SSA form efficiently.

One can expect to find SSA in a compiler for Fortran, C, C++, or Java (Android Runtime); whereas in functional language compilers, such as those for Scheme and ML, continuation-passing style (CPS) is generally used. SSA is formally equivalent to a well-behaved subset of CPS excluding non-local control flow, which does not occur when CPS is used as intermediate representation. So optimizations and transformations formulated in terms of one immediately apply to the other.

https://en.wikipedia.org/wiki/Static single-assignment form

Aussprachebeispiele für single assignment

1. Single Assignment, you know, compiler technique. And one of her employees had built a parser.

Coders at Work _ Peter Seibel _ Talks at Google

Beispiele aus Textkorpus für single assignment

1. Non–existent before a series of labour market reforms in the 1''0s, temporary and single–assignment contracts now cover more than 35 per cent of all jobs in Spain, against a European average of 12 per cent.