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Re: [Qemu-devel] [PATCH v2] sparc32 : Signed integer division overflow
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From: |
Richard Henderson |
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Subject: |
Re: [Qemu-devel] [PATCH v2] sparc32 : Signed integer division overflow |
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Date: |
Thu, 20 Mar 2014 09:15:40 -0700 |
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User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.3.0 |
On 03/19/2014 03:29 PM, Olivier Danet wrote:
> + if ((int32_t) x0 != x0) {
> + x0 = x0 < 0 ? 0x80000000 : 0x7fffffff;
> + overflow = 1;
> + }
Actually, there's an existing bug here that we might as well fix.
## ... the 32-bit result is sign-extended to 64 bits and
## written into register R[rd].
That 0x80000000 is not going to promote properly to 64-bits. We might as well
go ahead and use INT32_MIN and INT32_MAX here at the same time.
r~