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Benno Schulenberg wrote: |
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> Although I agree with your reasoning above, you are contradicting |
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> yourself in the following two statements: |
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> |
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>> At least, it's no more broken under -Os than under -O2. |
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>> [...] benefits of using -Os over -O2 are minimal |
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>> compared against the possible problems it might cause. |
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> |
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> If -Os is no more broken than -O2, then it shouldn't cause any extra |
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> problems. :) |
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True, this is a contradiction, but only in the sense that I failed to |
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distinguish between the general case of "most things" that used to break |
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under -Os don't break anymore, vs. the specific cases where the two |
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settings actually do differ. Obviously, O2 and Os are using a different |
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set of optimizations. In most cases the code is the same, so if there's |
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a problem with the resulting code, it's probably not the compiler's |
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fault. But there are always going to be corner cases where some extra |
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space-saving optimization does something unintended, or exposes some |
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bug, that O2 does not. |
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--K |
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-- |
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