From: Marc Glisse <marc.glisse@inria.fr>
To: Vishal Subramanyam <vishalsubramanyam@outlook.com>
Cc: "gcc-help@gcc.gnu.org" <gcc-help@gcc.gnu.org>
Subject: Re: Pure/const function not getting executed as the first operand to logical OR ( || ) (C++)
Date: Sun, 23 Jan 2022 12:25:38 +0100 (CET) [thread overview]
Message-ID: <4f40d38e-dc36-ada8-d116-4020b5c84cfc@hippo.saclay.inria.fr> (raw)
In-Reply-To: <MA1PR0101MB15597BF355EA66AD9677C032B55D9@MA1PR0101MB1559.INDPRD01.PROD.OUTLOOK.COM>
On Sun, 23 Jan 2022, Vishal Subramanyam via Gcc-help wrote:
> is there a specific name for the type of optimization where the compiler simply decides to drop the return value.
Gcc handles this as part of dead code elimination (among others). A
simpler example would be
int main(){ 1/0; }
which does not crash either.
If you want to make your function func opaque to the optimizers, you may
be interested in __attribute__((noipa)). Using volatile would also avoid
some optimizations.
--
Marc Glisse
next prev parent reply other threads:[~2022-01-23 11:25 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-23 8:37 Vishal Subramanyam
2022-01-23 9:12 ` Xi Ruoyao
[not found] ` <MA1PR0101MB15596E34BCF3E684A1468974B55D9@MA1PR0101MB1559.INDPRD01.PROD.OUTLOOK.COM>
2022-01-23 9:58 ` Fw: " Vishal Subramanyam
2022-01-23 10:02 ` Xi Ruoyao
2022-01-23 10:50 ` Vishal Subramanyam
2022-01-23 11:25 ` Marc Glisse [this message]
2022-01-23 12:24 ` Vishal Subramanyam
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