r254574 - PR17381: Treat undefined behavior during expression evaluation as an unmodeled

[Robinson, Paul via cfe-commits]

Okay, I'll bite:  so what *does* UINT128_MAX actually convert to?

From: cfe-commits [mailto:cfe-commits-bounces at lists.llvm.org] On Behalf Of Richard Smith via cfe-commits
Sent: Tuesday, December 08, 2015 10:52 AM
To: Joerg Sonnenberger; cfe-commits
Subject: Re: r254574 - PR17381: Treat undefined behavior during expression evaluation as an unmodeled

On Tue, Dec 8, 2015 at 2:13 AM, Joerg Sonnenberger via cfe-commits <cfe-commits at lists.llvm.org<mailto:cfe-commits at lists.llvm.org>> wrote:
On Mon, Dec 07, 2015 at 01:32:14PM -0800, Richard Smith via cfe-commits wrote:
> C11 6.3.1.5/1<http://6.3.1.5/1>: "If the value being converted is outside the range of values
> that can be represented, the behavior is undefined."

The value of 1e100 can be represented as +inf, even if not precisely.

Only if +inf is in the range of representable values, which, as already noted, is problematic.

This is a bit different from non-IEEE math like VAX, that doesn't have
infinities.

Joerg
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