Page:AITR-474.djvu/50

 The construction [foo] indicates the creation of a closure for foo in the current environment. This will actually require additional instructions, but we shall ignore the mechanics of this for now since analysis will remove the need for the construction in this case. The fact that the only references to the variables Rl, RZ, and R3 are function calls can be detected and the unnecessary LOAD instructions eliminated. (Once again, this would actually be determined ahead of time, and no LOAD instructions would be generated in the first place. All of this is determined by a general pre-analysis, rather than a peephole post-pass.) Moreover, a GOTO to a tag which immediately follows the GOTO can be eliminated.