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Re: gcc 3.3 / i386 / -O2 question
Steven Bosscher wrote:
Hah, but there you are. Define "non-altering-semantic-option"
for something that according to the standard does not *have*
semantics.
Reminds me of a famous exchange in the discussion of Algol-68
semantics at one meeting. Someone asked Charles Lindsay what
undefined meant. He replied that it could mean anything, up
to and including "unimaginable chaos". Geerhardt Goos then
enquired (in a rather emphatic manner) "But how can I implement
unimaginable chaos in my compiler?") :-)
One interesting paragraph in the Algol-68 report specifies that
at any point in the execution of the program, further elaboration
of the program can be "interrupted", and that if such an
interrupt occurs, further semantics are undefined.
Sounds a bit drastic, until you learn that the paragraph derived
from a discussion of what the situation was if an earthquake
occurred during the execution of a program, causing the
computer to be destroyed. Operating in a formal mode, the
committee decided that they could not have a specification
that would require conforming compilers to ensure against
the possibility of earthquakes :-)