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Date: Mon, 4 Jul 2011 23:38:30 +0100
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From: Peter Maydell <peter.maydell@linaro.org>
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Subject: Re: [Qemu-devel] [PATCH 2/3] Add fno-strict-overflow
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To: Raghavendra D Prabhu <raghu.prabhu13@gmail.com>
Cc: Raghavendra D Prabhu <rprabhu@wnohang.net>, qemu-devel@nongnu.org, kvm@vger.kernel.org

On 4 July 2011 23:00, Raghavendra D Prabhu <raghu.prabhu13@gmail.com> wrote:
> This is to avoid gcc optimizating out the comparison in assert,
> due to assumption of signed overflow being undefined by default (-Werror=strict-overflow).

>--- a/Makefile.hw
>+++ b/Makefile.hw
>@@ -9,7 +9,7 @@ include $(SRC_PATH)/rules.mak
>
> $(call set-vpath, $(SRC_PATH):$(SRC_PATH)/hw)
>
> -QEMU_CFLAGS+=-I.. -I$(SRC_PATH)/fpu
> +QEMU_CFLAGS+=-I.. -I$(SRC_PATH)/fpu -fno-strict-overflow

Can you give a more detailed description of the problem this is trying
to solve? I think it would be nicer if we could remove the assumptions
about signed overflows instead, if that's practical.

(Also, if we do want to add this compiler flag then it ought to be
done in configure I think, as we do for -fno-strict-aliasing.)

-- PMM