From: Richard Earnshaw <Richard.Earnshaw@foss.arm.com>
To: Bernhard Krug <b.krug@elektronenpumpe.de>, newlib@sourceware.org
Subject: Re: [PATCH] libc: arm: setjmp jmp_buf exagerated size
Date: Wed, 15 Feb 2023 16:12:04 +0000 [thread overview]
Message-ID: <bf2a0e40-c6ec-ae6d-84b5-22a5e39b7f12@foss.arm.com> (raw)
In-Reply-To: <DBB0ABD2-604D-4B6D-953F-76F154266601@elektronenpumpe.de>
On 15/02/2023 11:09, Bernhard Krug wrote:
> Patch sets correct jmp_buf size for armv6-m conforming to implementation in setjmp.S
>
> FYI a table of cortex architectures:
> __ARM_ARCH_6M__ cortex-m0/m0+/m1 no fpu option
> __ARM_ARCH_7M__ cortex-m3 no fpu option
> __ARM_ARCH_7EM__ cortex-m4 optional fpu
> check using __ARM_FP
I don't think it's as simple as this. The ABI supports three variants,
two of which are call compatible.
hard-float (where you must have hardware FP)
soft (where you haven't got any hardware FP)
softfp (where you have hardware FP but need to inter-operate with code
that doesnt).
soft and softfp are call compatible and so any jump-bufs created need to
support saving and restoring the FP context.
I guess a configure-time option to disable support for softfp might be
an option, but the default needs to ensure things are compatible.
R.
next prev parent reply other threads:[~2023-02-15 16:12 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-14 22:47 Bernhard Krug
2023-02-15 11:09 ` [PATCH] " Bernhard Krug
2023-02-15 15:56 ` Bernhard Krug
2023-02-15 16:05 ` Bernhard Krug
2023-02-15 16:12 ` Richard Earnshaw [this message]
2023-02-15 16:40 ` Bernhard Krug
2023-02-15 17:01 ` Richard Earnshaw
2023-02-15 17:14 ` Bernhard Krug
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