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Re: Use __builtin_tgmath in tgmath.h with GCC 8 (bug 21660) [committed]
- From: Szabolcs Nagy <szabolcs dot nagy at arm dot com>
- To: Joseph Myers <joseph at codesourcery dot com>, libc-alpha at sourceware dot org
- Cc: nd at arm dot com
- Date: Fri, 17 Nov 2017 12:11:33 +0000
- Subject: Re: Use __builtin_tgmath in tgmath.h with GCC 8 (bug 21660) [committed]
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> +/* There are two variant implementations of type-generic macros in
> + this file: one for GCC 8 and later, using __builtin_tgmath and
> + where each macro expands each of its arguments only once, and one
> + for older GCC, using other compiler extensions but with macros
> + expanding their arguments many times (so resulting in exponential
> + blowup of the size of expansions when calls to such macros are
> + nested inside arguments to such macros). */
> +
> +#define __HAVE_BUILTIN_TGMATH __GNUC_PREREQ (8, 0)
this breaks the build on trunk toolchains that
lack __builtin_tgmath