Certainly I've seen compiler bugs. 1) Borland Turbo Pascal, where code would not execute correctly in the presence of a comment near the top of a loop. Deletin

Certainly I've seen compiler bugs. 1) Borland Turbo Pascal, where code would not execute correctly in the presence of a comment near the top of a loop. Deleting the comment caused the correct loop execution. 2) Texas Instruments DSP C-compiler sometimes failed to unroll loops correctly. Certain loop forms needed to be avoided as a result. 3) Recently I've been working on a C-compiler written in Golang, and the grammar definition was raw enough that it definitely had bugs. The bugs were fortunately obvious in that it would refuse to compile valid C code. Of course, 99.98% bugs were mine.