diff mbox series

newlib: libc: return back support for AArch64 ILP32

Message ID GV4PR83MB0941E525894BB08010DE642A925EA@GV4PR83MB0941.EURPRD83.prod.outlook.com
State New
Headers
Series newlib: libc: return back support for AArch64 ILP32 |

Commit Message

Radek Barton July 24, 2025, 11:04 a.m. UTC 
  Hello.

As discussed at https://sourceware.org/pipermail/newlib/2025/022045.html, sending a patch reverting removal of AArch64 ILP32 ABI support.

Radek

---
From 0b67661adf790719d91f1ee8be3a737316dfc4d6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Radek=20Barto=C5=88?= <radek.barton@microsoft.com>
Date: Thu, 24 Jul 2025 12:36:02 +0200
Subject: [PATCH] newlib: libc: return back support for AArch64 ILP32
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This patch is returning back support for AArch64 ILP32 ABI that was
removed in de479a54e22e8fcb6262639a8e67fe8b00a27c37 commit but is needed
to ensure source code compatibility with GCC 14.

The change in newlib/libc/machine/aarch64/asmdefs.h makes it
out-of-the-sync with the current upstream implementation in
https://github.com/ARM-software/optimized-routines repository.

Signed-off-by: Radek Bartoň <radek.barton@microsoft.com>
---
 newlib/libc/machine/aarch64/asmdefs.h   | 14 ++++++++++++++
 newlib/libc/machine/aarch64/memchr.S    |  2 ++
 newlib/libc/machine/aarch64/memcmp.S    |  4 ++++
 newlib/libc/machine/aarch64/memcpy.S    |  3 +++
 newlib/libc/machine/aarch64/memrchr.S   |  1 +
 newlib/libc/machine/aarch64/memset.S    |  3 +++
 newlib/libc/machine/aarch64/strchr.S    |  1 +
 newlib/libc/machine/aarch64/strchrnul.S |  1 +
 newlib/libc/machine/aarch64/strcmp.S    |  2 ++
 newlib/libc/machine/aarch64/strcpy.S    |  2 ++
 newlib/libc/machine/aarch64/strlen.S    |  1 +
 newlib/libc/machine/aarch64/strncmp.S   |  3 +++
 newlib/libc/machine/aarch64/strnlen.S   |  2 ++
 newlib/libc/machine/aarch64/strrchr.S   |  1 +
 14 files changed, 40 insertions(+)

Comments

Corinna Vinschen July 24, 2025, 11:07 a.m. UTC | #1 
Joel, can you please test?


Thanks,
Corinna


On Jul 24 11:04, Radek Barton via Newlib wrote:
> Hello.
> 
> As discussed at https://sourceware.org/pipermail/newlib/2025/022045.html, sending a patch reverting removal of AArch64 ILP32 ABI support.
> 
> Radek
> 
> ---
> >From 0b67661adf790719d91f1ee8be3a737316dfc4d6 Mon Sep 17 00:00:00 2001
> From: =?UTF-8?q?Radek=20Barto=C5=88?= <radek.barton@microsoft.com>
> Date: Thu, 24 Jul 2025 12:36:02 +0200
> Subject: [PATCH] newlib: libc: return back support for AArch64 ILP32
> MIME-Version: 1.0
> Content-Type: text/plain; charset=UTF-8
> Content-Transfer-Encoding: 8bit
> 
> This patch is returning back support for AArch64 ILP32 ABI that was
> removed in de479a54e22e8fcb6262639a8e67fe8b00a27c37 commit but is needed
> to ensure source code compatibility with GCC 14.
> 
> The change in newlib/libc/machine/aarch64/asmdefs.h makes it
> out-of-the-sync with the current upstream implementation in
> https://github.com/ARM-software/optimized-routines repository.
> 
> Signed-off-by: Radek Bartoň <radek.barton@microsoft.com>
> ---
>  newlib/libc/machine/aarch64/asmdefs.h   | 14 ++++++++++++++
>  newlib/libc/machine/aarch64/memchr.S    |  2 ++
>  newlib/libc/machine/aarch64/memcmp.S    |  4 ++++
>  newlib/libc/machine/aarch64/memcpy.S    |  3 +++
>  newlib/libc/machine/aarch64/memrchr.S   |  1 +
>  newlib/libc/machine/aarch64/memset.S    |  3 +++
>  newlib/libc/machine/aarch64/strchr.S    |  1 +
>  newlib/libc/machine/aarch64/strchrnul.S |  1 +
>  newlib/libc/machine/aarch64/strcmp.S    |  2 ++
>  newlib/libc/machine/aarch64/strcpy.S    |  2 ++
>  newlib/libc/machine/aarch64/strlen.S    |  1 +
>  newlib/libc/machine/aarch64/strncmp.S   |  3 +++
>  newlib/libc/machine/aarch64/strnlen.S   |  2 ++
>  newlib/libc/machine/aarch64/strrchr.S   |  1 +
>  14 files changed, 40 insertions(+)
> 
> diff --git a/newlib/libc/machine/aarch64/asmdefs.h b/newlib/libc/machine/aarch64/asmdefs.h
> index 6c99fa704..cf156a5a8 100644
> --- a/newlib/libc/machine/aarch64/asmdefs.h
> +++ b/newlib/libc/machine/aarch64/asmdefs.h
> @@ -88,4 +88,18 @@ GNU_PROPERTY (FEATURE_1_AND, FEATURE_1_BTI|FEATURE_1_PAC)
>  
>  #define L(l) .L ## l
>  
> +#ifdef __ILP32__
> +  /* Sanitize padding bits of pointer arguments as per aapcs64 */
> +#define PTR_ARG(n)  mov w##n, w##n
> +#else
> +#define PTR_ARG(n)
> +#endif
> +
> +#ifdef __ILP32__
> +  /* Sanitize padding bits of size arguments as per aapcs64 */
> +#define SIZE_ARG(n)  mov w##n, w##n
> +#else
> +#define SIZE_ARG(n)
> +#endif
> +
>  #endif
> diff --git a/newlib/libc/machine/aarch64/memchr.S b/newlib/libc/machine/aarch64/memchr.S
> index 074a004cf..a0f305e0f 100644
> --- a/newlib/libc/machine/aarch64/memchr.S
> +++ b/newlib/libc/machine/aarch64/memchr.S
> @@ -50,6 +50,8 @@
>   */
>  
>  ENTRY (memchr)
> +	PTR_ARG (0)
> +	SIZE_ARG (2)
>  	/* Do not dereference srcin if no bytes to compare.  */
>  	cbz	cntin, L(zero_length)
>  	/*
> diff --git a/newlib/libc/machine/aarch64/memcmp.S b/newlib/libc/machine/aarch64/memcmp.S
> index 2a9c446bb..18874d321 100644
> --- a/newlib/libc/machine/aarch64/memcmp.S
> +++ b/newlib/libc/machine/aarch64/memcmp.S
> @@ -34,6 +34,10 @@
>  
>  
>  ENTRY (memcmp)
> +	PTR_ARG (0)
> +	PTR_ARG (1)
> +	SIZE_ARG (2)
> +
>  	cmp	limit, 16
>  	b.lo	L(less16)
>  	ldp	data1, data3, [src1]
> diff --git a/newlib/libc/machine/aarch64/memcpy.S b/newlib/libc/machine/aarch64/memcpy.S
> index 252d2452a..248e7843a 100644
> --- a/newlib/libc/machine/aarch64/memcpy.S
> +++ b/newlib/libc/machine/aarch64/memcpy.S
> @@ -58,6 +58,9 @@
>  
>  ENTRY_ALIAS (memmove)
>  ENTRY (memcpy)
> +	PTR_ARG (0)
> +	PTR_ARG (1)
> +	SIZE_ARG (2)
>  	add	srcend, src, count
>  	add	dstend, dstin, count
>  	cmp	count, 128
> diff --git a/newlib/libc/machine/aarch64/memrchr.S b/newlib/libc/machine/aarch64/memrchr.S
> index 2525cf190..ba9915cc3 100644
> --- a/newlib/libc/machine/aarch64/memrchr.S
> +++ b/newlib/libc/machine/aarch64/memrchr.S
> @@ -45,6 +45,7 @@
>     exactly which byte matched.  */
>  
>  ENTRY (memrchr)
> +	PTR_ARG (0)
>  	add	end, srcin, cntin
>  	sub	endm1, end, 1
>  	bic	src, endm1, 15
> diff --git a/newlib/libc/machine/aarch64/memset.S b/newlib/libc/machine/aarch64/memset.S
> index 5bf4851f3..ca76439a9 100644
> --- a/newlib/libc/machine/aarch64/memset.S
> +++ b/newlib/libc/machine/aarch64/memset.S
> @@ -25,6 +25,9 @@
>  #define zva_val	x5
>  
>  ENTRY (memset)
> +	PTR_ARG (0)
> +	SIZE_ARG (2)
> +
>  	dup	v0.16B, valw
>  	add	dstend, dstin, count
>  
> diff --git a/newlib/libc/machine/aarch64/strchr.S b/newlib/libc/machine/aarch64/strchr.S
> index a4e089b99..500d9aff2 100644
> --- a/newlib/libc/machine/aarch64/strchr.S
> +++ b/newlib/libc/machine/aarch64/strchr.S
> @@ -54,6 +54,7 @@
>  /* Locals and temporaries.  */
>  
>  ENTRY (strchr)
> +	PTR_ARG (0)
>  	/* Magic constant 0xc0300c03 to allow us to identify which lane
>  	   matches the requested byte.  Even bits are set if the character
>  	   matches, odd bits if either the char is NUL or matches.  */
> diff --git a/newlib/libc/machine/aarch64/strchrnul.S b/newlib/libc/machine/aarch64/strchrnul.S
> index 4d6093be7..ceaf4dca1 100644
> --- a/newlib/libc/machine/aarch64/strchrnul.S
> +++ b/newlib/libc/machine/aarch64/strchrnul.S
> @@ -50,6 +50,7 @@
>  /* Locals and temporaries.  */
>  
>  ENTRY (strchrnul)
> +	PTR_ARG (0)
>  	/* Magic constant 0x40100401 to allow us to identify which lane
>  	   matches the termination condition.  */
>  	mov	wtmp2, #0x0401
> diff --git a/newlib/libc/machine/aarch64/strcmp.S b/newlib/libc/machine/aarch64/strcmp.S
> index 1d85da432..691a1760e 100644
> --- a/newlib/libc/machine/aarch64/strcmp.S
> +++ b/newlib/libc/machine/aarch64/strcmp.S
> @@ -54,6 +54,8 @@
>  
>  
>  ENTRY (strcmp)
> +	PTR_ARG (0)
> +	PTR_ARG (1)
>  	sub	off2, src2, src1
>  	mov	zeroones, REP8_01
>  	and	tmp, src1, 7
> diff --git a/newlib/libc/machine/aarch64/strcpy.S b/newlib/libc/machine/aarch64/strcpy.S
> index 1f5f70792..57c46f390 100644
> --- a/newlib/libc/machine/aarch64/strcpy.S
> +++ b/newlib/libc/machine/aarch64/strcpy.S
> @@ -55,6 +55,8 @@
>     exactly which byte matched.  */
>  
>  ENTRY (STRCPY)
> +	PTR_ARG (0)
> +	PTR_ARG (1)
>  	bic	src, srcin, 15
>  	ld1	{vdata.16b}, [src]
>  	cmeq	vhas_nul.16b, vdata.16b, 0
> diff --git a/newlib/libc/machine/aarch64/strlen.S b/newlib/libc/machine/aarch64/strlen.S
> index a3345a3ab..68a6f357c 100644
> --- a/newlib/libc/machine/aarch64/strlen.S
> +++ b/newlib/libc/machine/aarch64/strlen.S
> @@ -78,6 +78,7 @@
>     character, return the length, if not, continue in the main loop.  */
>  
>  ENTRY (strlen)
> +	PTR_ARG (0)
>  	and	tmp1, srcin, MIN_PAGE_SIZE - 1
>  	cmp	tmp1, MIN_PAGE_SIZE - 32
>  	b.hi	L(page_cross)
> diff --git a/newlib/libc/machine/aarch64/strncmp.S b/newlib/libc/machine/aarch64/strncmp.S
> index 6b1994ef5..373695503 100644
> --- a/newlib/libc/machine/aarch64/strncmp.S
> +++ b/newlib/libc/machine/aarch64/strncmp.S
> @@ -58,6 +58,9 @@
>  #endif
>  
>  ENTRY (strncmp)
> +	PTR_ARG (0)
> +	PTR_ARG (1)
> +	SIZE_ARG (2)
>  	cbz	limit, L(ret0)
>  	eor	tmp1, src1, src2
>  	mov	zeroones, #REP8_01
> diff --git a/newlib/libc/machine/aarch64/strnlen.S b/newlib/libc/machine/aarch64/strnlen.S
> index dc9fcb2fd..091002e0b 100644
> --- a/newlib/libc/machine/aarch64/strnlen.S
> +++ b/newlib/libc/machine/aarch64/strnlen.S
> @@ -39,6 +39,8 @@
>     identifies the first zero byte.  */
>  
>  ENTRY (strnlen)
> +	PTR_ARG (0)
> +	SIZE_ARG (1)
>  	bic	src, srcin, 15
>  	cbz	cntin, L(nomatch)
>  	ld1	{vdata.16b}, [src]
> diff --git a/newlib/libc/machine/aarch64/strrchr.S b/newlib/libc/machine/aarch64/strrchr.S
> index 67013e39d..b0574228b 100644
> --- a/newlib/libc/machine/aarch64/strrchr.S
> +++ b/newlib/libc/machine/aarch64/strrchr.S
> @@ -58,6 +58,7 @@
>     identify exactly which byte is causing the termination, and why.  */
>  
>  ENTRY (strrchr)
> +	PTR_ARG (0)
>  	/* Magic constant 0x40100401 to allow us to identify which lane
>  	   matches the requested byte.  Magic constant 0x80200802 used
>  	   similarly for NUL termination.  */
> -- 
> 2.50.1.vfs.0.0
>
Joel Sherrill July 24, 2025, 2:41 p.m. UTC | #2 
Yes. I will test. It may be tomorrow before results pop out.

Also ip32 is still in GCC 15. It is not the usual --enable-obsolete as the
nios2
requires in gcc 14. You needed to add   -Wno-error=deprecated to the target
CFLAGS. Different but works fine.

Thanks.

--joel

On Thu, Jul 24, 2025 at 6:07 AM Corinna Vinschen <vinschen@redhat.com>
wrote:

> Joel, can you please test?
>
>
> Thanks,
> Corinna
>
>
> On Jul 24 11:04, Radek Barton via Newlib wrote:
> > Hello.
> >
> > As discussed at https://sourceware.org/pipermail/newlib/2025/022045.html,
> sending a patch reverting removal of AArch64 ILP32 ABI support.
> >
> > Radek
> >
> > ---
> > >From 0b67661adf790719d91f1ee8be3a737316dfc4d6 Mon Sep 17 00:00:00 2001
> > From: =?UTF-8?q?Radek=20Barto=C5=88?= <radek.barton@microsoft.com>
> > Date: Thu, 24 Jul 2025 12:36:02 +0200
> > Subject: [PATCH] newlib: libc: return back support for AArch64 ILP32
> > MIME-Version: 1.0
> > Content-Type: text/plain; charset=UTF-8
> > Content-Transfer-Encoding: 8bit
> >
> > This patch is returning back support for AArch64 ILP32 ABI that was
> > removed in de479a54e22e8fcb6262639a8e67fe8b00a27c37 commit but is needed
> > to ensure source code compatibility with GCC 14.
> >
> > The change in newlib/libc/machine/aarch64/asmdefs.h makes it
> > out-of-the-sync with the current upstream implementation in
> > https://github.com/ARM-software/optimized-routines repository.
> >
> > Signed-off-by: Radek Bartoň <radek.barton@microsoft.com>
> > ---
> >  newlib/libc/machine/aarch64/asmdefs.h   | 14 ++++++++++++++
> >  newlib/libc/machine/aarch64/memchr.S    |  2 ++
> >  newlib/libc/machine/aarch64/memcmp.S    |  4 ++++
> >  newlib/libc/machine/aarch64/memcpy.S    |  3 +++
> >  newlib/libc/machine/aarch64/memrchr.S   |  1 +
> >  newlib/libc/machine/aarch64/memset.S    |  3 +++
> >  newlib/libc/machine/aarch64/strchr.S    |  1 +
> >  newlib/libc/machine/aarch64/strchrnul.S |  1 +
> >  newlib/libc/machine/aarch64/strcmp.S    |  2 ++
> >  newlib/libc/machine/aarch64/strcpy.S    |  2 ++
> >  newlib/libc/machine/aarch64/strlen.S    |  1 +
> >  newlib/libc/machine/aarch64/strncmp.S   |  3 +++
> >  newlib/libc/machine/aarch64/strnlen.S   |  2 ++
> >  newlib/libc/machine/aarch64/strrchr.S   |  1 +
> >  14 files changed, 40 insertions(+)
> >
> > diff --git a/newlib/libc/machine/aarch64/asmdefs.h
> b/newlib/libc/machine/aarch64/asmdefs.h
> > index 6c99fa704..cf156a5a8 100644
> > --- a/newlib/libc/machine/aarch64/asmdefs.h
> > +++ b/newlib/libc/machine/aarch64/asmdefs.h
> > @@ -88,4 +88,18 @@ GNU_PROPERTY (FEATURE_1_AND,
> FEATURE_1_BTI|FEATURE_1_PAC)
> >
> >  #define L(l) .L ## l
> >
> > +#ifdef __ILP32__
> > +  /* Sanitize padding bits of pointer arguments as per aapcs64 */
> > +#define PTR_ARG(n)  mov w##n, w##n
> > +#else
> > +#define PTR_ARG(n)
> > +#endif
> > +
> > +#ifdef __ILP32__
> > +  /* Sanitize padding bits of size arguments as per aapcs64 */
> > +#define SIZE_ARG(n)  mov w##n, w##n
> > +#else
> > +#define SIZE_ARG(n)
> > +#endif
> > +
> >  #endif
> > diff --git a/newlib/libc/machine/aarch64/memchr.S
> b/newlib/libc/machine/aarch64/memchr.S
> > index 074a004cf..a0f305e0f 100644
> > --- a/newlib/libc/machine/aarch64/memchr.S
> > +++ b/newlib/libc/machine/aarch64/memchr.S
> > @@ -50,6 +50,8 @@
> >   */
> >
> >  ENTRY (memchr)
> > +     PTR_ARG (0)
> > +     SIZE_ARG (2)
> >       /* Do not dereference srcin if no bytes to compare.  */
> >       cbz     cntin, L(zero_length)
> >       /*
> > diff --git a/newlib/libc/machine/aarch64/memcmp.S
> b/newlib/libc/machine/aarch64/memcmp.S
> > index 2a9c446bb..18874d321 100644
> > --- a/newlib/libc/machine/aarch64/memcmp.S
> > +++ b/newlib/libc/machine/aarch64/memcmp.S
> > @@ -34,6 +34,10 @@
> >
> >
> >  ENTRY (memcmp)
> > +     PTR_ARG (0)
> > +     PTR_ARG (1)
> > +     SIZE_ARG (2)
> > +
> >       cmp     limit, 16
> >       b.lo    L(less16)
> >       ldp     data1, data3, [src1]
> > diff --git a/newlib/libc/machine/aarch64/memcpy.S
> b/newlib/libc/machine/aarch64/memcpy.S
> > index 252d2452a..248e7843a 100644
> > --- a/newlib/libc/machine/aarch64/memcpy.S
> > +++ b/newlib/libc/machine/aarch64/memcpy.S
> > @@ -58,6 +58,9 @@
> >
> >  ENTRY_ALIAS (memmove)
> >  ENTRY (memcpy)
> > +     PTR_ARG (0)
> > +     PTR_ARG (1)
> > +     SIZE_ARG (2)
> >       add     srcend, src, count
> >       add     dstend, dstin, count
> >       cmp     count, 128
> > diff --git a/newlib/libc/machine/aarch64/memrchr.S
> b/newlib/libc/machine/aarch64/memrchr.S
> > index 2525cf190..ba9915cc3 100644
> > --- a/newlib/libc/machine/aarch64/memrchr.S
> > +++ b/newlib/libc/machine/aarch64/memrchr.S
> > @@ -45,6 +45,7 @@
> >     exactly which byte matched.  */
> >
> >  ENTRY (memrchr)
> > +     PTR_ARG (0)
> >       add     end, srcin, cntin
> >       sub     endm1, end, 1
> >       bic     src, endm1, 15
> > diff --git a/newlib/libc/machine/aarch64/memset.S
> b/newlib/libc/machine/aarch64/memset.S
> > index 5bf4851f3..ca76439a9 100644
> > --- a/newlib/libc/machine/aarch64/memset.S
> > +++ b/newlib/libc/machine/aarch64/memset.S
> > @@ -25,6 +25,9 @@
> >  #define zva_val      x5
> >
> >  ENTRY (memset)
> > +     PTR_ARG (0)
> > +     SIZE_ARG (2)
> > +
> >       dup     v0.16B, valw
> >       add     dstend, dstin, count
> >
> > diff --git a/newlib/libc/machine/aarch64/strchr.S
> b/newlib/libc/machine/aarch64/strchr.S
> > index a4e089b99..500d9aff2 100644
> > --- a/newlib/libc/machine/aarch64/strchr.S
> > +++ b/newlib/libc/machine/aarch64/strchr.S
> > @@ -54,6 +54,7 @@
> >  /* Locals and temporaries.  */
> >
> >  ENTRY (strchr)
> > +     PTR_ARG (0)
> >       /* Magic constant 0xc0300c03 to allow us to identify which lane
> >          matches the requested byte.  Even bits are set if the character
> >          matches, odd bits if either the char is NUL or matches.  */
> > diff --git a/newlib/libc/machine/aarch64/strchrnul.S
> b/newlib/libc/machine/aarch64/strchrnul.S
> > index 4d6093be7..ceaf4dca1 100644
> > --- a/newlib/libc/machine/aarch64/strchrnul.S
> > +++ b/newlib/libc/machine/aarch64/strchrnul.S
> > @@ -50,6 +50,7 @@
> >  /* Locals and temporaries.  */
> >
> >  ENTRY (strchrnul)
> > +     PTR_ARG (0)
> >       /* Magic constant 0x40100401 to allow us to identify which lane
> >          matches the termination condition.  */
> >       mov     wtmp2, #0x0401
> > diff --git a/newlib/libc/machine/aarch64/strcmp.S
> b/newlib/libc/machine/aarch64/strcmp.S
> > index 1d85da432..691a1760e 100644
> > --- a/newlib/libc/machine/aarch64/strcmp.S
> > +++ b/newlib/libc/machine/aarch64/strcmp.S
> > @@ -54,6 +54,8 @@
> >
> >
> >  ENTRY (strcmp)
> > +     PTR_ARG (0)
> > +     PTR_ARG (1)
> >       sub     off2, src2, src1
> >       mov     zeroones, REP8_01
> >       and     tmp, src1, 7
> > diff --git a/newlib/libc/machine/aarch64/strcpy.S
> b/newlib/libc/machine/aarch64/strcpy.S
> > index 1f5f70792..57c46f390 100644
> > --- a/newlib/libc/machine/aarch64/strcpy.S
> > +++ b/newlib/libc/machine/aarch64/strcpy.S
> > @@ -55,6 +55,8 @@
> >     exactly which byte matched.  */
> >
> >  ENTRY (STRCPY)
> > +     PTR_ARG (0)
> > +     PTR_ARG (1)
> >       bic     src, srcin, 15
> >       ld1     {vdata.16b}, [src]
> >       cmeq    vhas_nul.16b, vdata.16b, 0
> > diff --git a/newlib/libc/machine/aarch64/strlen.S
> b/newlib/libc/machine/aarch64/strlen.S
> > index a3345a3ab..68a6f357c 100644
> > --- a/newlib/libc/machine/aarch64/strlen.S
> > +++ b/newlib/libc/machine/aarch64/strlen.S
> > @@ -78,6 +78,7 @@
> >     character, return the length, if not, continue in the main loop.  */
> >
> >  ENTRY (strlen)
> > +     PTR_ARG (0)
> >       and     tmp1, srcin, MIN_PAGE_SIZE - 1
> >       cmp     tmp1, MIN_PAGE_SIZE - 32
> >       b.hi    L(page_cross)
> > diff --git a/newlib/libc/machine/aarch64/strncmp.S
> b/newlib/libc/machine/aarch64/strncmp.S
> > index 6b1994ef5..373695503 100644
> > --- a/newlib/libc/machine/aarch64/strncmp.S
> > +++ b/newlib/libc/machine/aarch64/strncmp.S
> > @@ -58,6 +58,9 @@
> >  #endif
> >
> >  ENTRY (strncmp)
> > +     PTR_ARG (0)
> > +     PTR_ARG (1)
> > +     SIZE_ARG (2)
> >       cbz     limit, L(ret0)
> >       eor     tmp1, src1, src2
> >       mov     zeroones, #REP8_01
> > diff --git a/newlib/libc/machine/aarch64/strnlen.S
> b/newlib/libc/machine/aarch64/strnlen.S
> > index dc9fcb2fd..091002e0b 100644
> > --- a/newlib/libc/machine/aarch64/strnlen.S
> > +++ b/newlib/libc/machine/aarch64/strnlen.S
> > @@ -39,6 +39,8 @@
> >     identifies the first zero byte.  */
> >
> >  ENTRY (strnlen)
> > +     PTR_ARG (0)
> > +     SIZE_ARG (1)
> >       bic     src, srcin, 15
> >       cbz     cntin, L(nomatch)
> >       ld1     {vdata.16b}, [src]
> > diff --git a/newlib/libc/machine/aarch64/strrchr.S
> b/newlib/libc/machine/aarch64/strrchr.S
> > index 67013e39d..b0574228b 100644
> > --- a/newlib/libc/machine/aarch64/strrchr.S
> > +++ b/newlib/libc/machine/aarch64/strrchr.S
> > @@ -58,6 +58,7 @@
> >     identify exactly which byte is causing the termination, and why.  */
> >
> >  ENTRY (strrchr)
> > +     PTR_ARG (0)
> >       /* Magic constant 0x40100401 to allow us to identify which lane
> >          matches the requested byte.  Magic constant 0x80200802 used
> >          similarly for NUL termination.  */
> > --
> > 2.50.1.vfs.0.0
> >
>
>
>
Joel Sherrill July 24, 2025, 5:41 p.m. UTC | #3 
This is not quite right. This warning appears a LOT -- >4000 times linking
tests for one RTEMS BSP.

/home/joel/rtems-work/tools/next-gcc15/bin/../lib/gcc/aarch64-rtems7/15.1.0/../../../../aarch64-rtems7/bin/ld:
warning:
/home/joel/rtems-work/tools/next-gcc15/bin/../lib/gcc/aarch64-rtems7/15.1.0/../../../../aarch64-rtems7/lib/ilp32/nooa/a53/fix835769/fix843419/libc.a(libc_a-memcmp.o):
corrupt GNU_PROPERTY_TYPE (5) size: 0x10

The original patch had changes to the definition of GNU_PROPERTY() which
are not reverted by your current patch.

FWIW I am in the process of updating the RTEMS "next" tools to GCC 15
and tracking this issue as
https://gitlab.rtems.org/rtems/tools/rtems-source-builder/-/issues/115. The
RSB builds
RTEMS tool chains from source and sometimes we attach patches to issues to
make
them available before they show up upstream. When this works out of the box
from
newlib git, I will close that issue and just change the recipe to use a
hash with the fix.

Anyway, I turned this around quicker than I thought so if you get another
one, I
can try it this afternoon.

--joel

--joel


On Thu, Jul 24, 2025 at 9:41 AM Joel Sherrill <joel.sherrill@gmail.com>
wrote:

> Yes. I will test. It may be tomorrow before results pop out.
>
> Also ip32 is still in GCC 15. It is not the usual --enable-obsolete as the
> nios2
> requires in gcc 14. You needed to add   -Wno-error=deprecated to the
> target
> CFLAGS. Different but works fine.
>
> Thanks.
>
> --joel
>
> On Thu, Jul 24, 2025 at 6:07 AM Corinna Vinschen <vinschen@redhat.com>
> wrote:
>
>> Joel, can you please test?
>>
>>
>> Thanks,
>> Corinna
>>
>>
>> On Jul 24 11:04, Radek Barton via Newlib wrote:
>> > Hello.
>> >
>> > As discussed at
>> https://sourceware.org/pipermail/newlib/2025/022045.html, sending a
>> patch reverting removal of AArch64 ILP32 ABI support.
>> >
>> > Radek
>> >
>> > ---
>> > >From 0b67661adf790719d91f1ee8be3a737316dfc4d6 Mon Sep 17 00:00:00 2001
>> > From: =?UTF-8?q?Radek=20Barto=C5=88?= <radek.barton@microsoft.com>
>> > Date: Thu, 24 Jul 2025 12:36:02 +0200
>> > Subject: [PATCH] newlib: libc: return back support for AArch64 ILP32
>> > MIME-Version: 1.0
>> > Content-Type: text/plain; charset=UTF-8
>> > Content-Transfer-Encoding: 8bit
>> >
>> > This patch is returning back support for AArch64 ILP32 ABI that was
>> > removed in de479a54e22e8fcb6262639a8e67fe8b00a27c37 commit but is needed
>> > to ensure source code compatibility with GCC 14.
>> >
>> > The change in newlib/libc/machine/aarch64/asmdefs.h makes it
>> > out-of-the-sync with the current upstream implementation in
>> > https://github.com/ARM-software/optimized-routines repository.
>> >
>> > Signed-off-by: Radek Bartoň <radek.barton@microsoft.com>
>> > ---
>> >  newlib/libc/machine/aarch64/asmdefs.h   | 14 ++++++++++++++
>> >  newlib/libc/machine/aarch64/memchr.S    |  2 ++
>> >  newlib/libc/machine/aarch64/memcmp.S    |  4 ++++
>> >  newlib/libc/machine/aarch64/memcpy.S    |  3 +++
>> >  newlib/libc/machine/aarch64/memrchr.S   |  1 +
>> >  newlib/libc/machine/aarch64/memset.S    |  3 +++
>> >  newlib/libc/machine/aarch64/strchr.S    |  1 +
>> >  newlib/libc/machine/aarch64/strchrnul.S |  1 +
>> >  newlib/libc/machine/aarch64/strcmp.S    |  2 ++
>> >  newlib/libc/machine/aarch64/strcpy.S    |  2 ++
>> >  newlib/libc/machine/aarch64/strlen.S    |  1 +
>> >  newlib/libc/machine/aarch64/strncmp.S   |  3 +++
>> >  newlib/libc/machine/aarch64/strnlen.S   |  2 ++
>> >  newlib/libc/machine/aarch64/strrchr.S   |  1 +
>> >  14 files changed, 40 insertions(+)
>> >
>> > diff --git a/newlib/libc/machine/aarch64/asmdefs.h
>> b/newlib/libc/machine/aarch64/asmdefs.h
>> > index 6c99fa704..cf156a5a8 100644
>> > --- a/newlib/libc/machine/aarch64/asmdefs.h
>> > +++ b/newlib/libc/machine/aarch64/asmdefs.h
>> > @@ -88,4 +88,18 @@ GNU_PROPERTY (FEATURE_1_AND,
>> FEATURE_1_BTI|FEATURE_1_PAC)
>> >
>> >  #define L(l) .L ## l
>> >
>> > +#ifdef __ILP32__
>> > +  /* Sanitize padding bits of pointer arguments as per aapcs64 */
>> > +#define PTR_ARG(n)  mov w##n, w##n
>> > +#else
>> > +#define PTR_ARG(n)
>> > +#endif
>> > +
>> > +#ifdef __ILP32__
>> > +  /* Sanitize padding bits of size arguments as per aapcs64 */
>> > +#define SIZE_ARG(n)  mov w##n, w##n
>> > +#else
>> > +#define SIZE_ARG(n)
>> > +#endif
>> > +
>> >  #endif
>> > diff --git a/newlib/libc/machine/aarch64/memchr.S
>> b/newlib/libc/machine/aarch64/memchr.S
>> > index 074a004cf..a0f305e0f 100644
>> > --- a/newlib/libc/machine/aarch64/memchr.S
>> > +++ b/newlib/libc/machine/aarch64/memchr.S
>> > @@ -50,6 +50,8 @@
>> >   */
>> >
>> >  ENTRY (memchr)
>> > +     PTR_ARG (0)
>> > +     SIZE_ARG (2)
>> >       /* Do not dereference srcin if no bytes to compare.  */
>> >       cbz     cntin, L(zero_length)
>> >       /*
>> > diff --git a/newlib/libc/machine/aarch64/memcmp.S
>> b/newlib/libc/machine/aarch64/memcmp.S
>> > index 2a9c446bb..18874d321 100644
>> > --- a/newlib/libc/machine/aarch64/memcmp.S
>> > +++ b/newlib/libc/machine/aarch64/memcmp.S
>> > @@ -34,6 +34,10 @@
>> >
>> >
>> >  ENTRY (memcmp)
>> > +     PTR_ARG (0)
>> > +     PTR_ARG (1)
>> > +     SIZE_ARG (2)
>> > +
>> >       cmp     limit, 16
>> >       b.lo    L(less16)
>> >       ldp     data1, data3, [src1]
>> > diff --git a/newlib/libc/machine/aarch64/memcpy.S
>> b/newlib/libc/machine/aarch64/memcpy.S
>> > index 252d2452a..248e7843a 100644
>> > --- a/newlib/libc/machine/aarch64/memcpy.S
>> > +++ b/newlib/libc/machine/aarch64/memcpy.S
>> > @@ -58,6 +58,9 @@
>> >
>> >  ENTRY_ALIAS (memmove)
>> >  ENTRY (memcpy)
>> > +     PTR_ARG (0)
>> > +     PTR_ARG (1)
>> > +     SIZE_ARG (2)
>> >       add     srcend, src, count
>> >       add     dstend, dstin, count
>> >       cmp     count, 128
>> > diff --git a/newlib/libc/machine/aarch64/memrchr.S
>> b/newlib/libc/machine/aarch64/memrchr.S
>> > index 2525cf190..ba9915cc3 100644
>> > --- a/newlib/libc/machine/aarch64/memrchr.S
>> > +++ b/newlib/libc/machine/aarch64/memrchr.S
>> > @@ -45,6 +45,7 @@
>> >     exactly which byte matched.  */
>> >
>> >  ENTRY (memrchr)
>> > +     PTR_ARG (0)
>> >       add     end, srcin, cntin
>> >       sub     endm1, end, 1
>> >       bic     src, endm1, 15
>> > diff --git a/newlib/libc/machine/aarch64/memset.S
>> b/newlib/libc/machine/aarch64/memset.S
>> > index 5bf4851f3..ca76439a9 100644
>> > --- a/newlib/libc/machine/aarch64/memset.S
>> > +++ b/newlib/libc/machine/aarch64/memset.S
>> > @@ -25,6 +25,9 @@
>> >  #define zva_val      x5
>> >
>> >  ENTRY (memset)
>> > +     PTR_ARG (0)
>> > +     SIZE_ARG (2)
>> > +
>> >       dup     v0.16B, valw
>> >       add     dstend, dstin, count
>> >
>> > diff --git a/newlib/libc/machine/aarch64/strchr.S
>> b/newlib/libc/machine/aarch64/strchr.S
>> > index a4e089b99..500d9aff2 100644
>> > --- a/newlib/libc/machine/aarch64/strchr.S
>> > +++ b/newlib/libc/machine/aarch64/strchr.S
>> > @@ -54,6 +54,7 @@
>> >  /* Locals and temporaries.  */
>> >
>> >  ENTRY (strchr)
>> > +     PTR_ARG (0)
>> >       /* Magic constant 0xc0300c03 to allow us to identify which lane
>> >          matches the requested byte.  Even bits are set if the character
>> >          matches, odd bits if either the char is NUL or matches.  */
>> > diff --git a/newlib/libc/machine/aarch64/strchrnul.S
>> b/newlib/libc/machine/aarch64/strchrnul.S
>> > index 4d6093be7..ceaf4dca1 100644
>> > --- a/newlib/libc/machine/aarch64/strchrnul.S
>> > +++ b/newlib/libc/machine/aarch64/strchrnul.S
>> > @@ -50,6 +50,7 @@
>> >  /* Locals and temporaries.  */
>> >
>> >  ENTRY (strchrnul)
>> > +     PTR_ARG (0)
>> >       /* Magic constant 0x40100401 to allow us to identify which lane
>> >          matches the termination condition.  */
>> >       mov     wtmp2, #0x0401
>> > diff --git a/newlib/libc/machine/aarch64/strcmp.S
>> b/newlib/libc/machine/aarch64/strcmp.S
>> > index 1d85da432..691a1760e 100644
>> > --- a/newlib/libc/machine/aarch64/strcmp.S
>> > +++ b/newlib/libc/machine/aarch64/strcmp.S
>> > @@ -54,6 +54,8 @@
>> >
>> >
>> >  ENTRY (strcmp)
>> > +     PTR_ARG (0)
>> > +     PTR_ARG (1)
>> >       sub     off2, src2, src1
>> >       mov     zeroones, REP8_01
>> >       and     tmp, src1, 7
>> > diff --git a/newlib/libc/machine/aarch64/strcpy.S
>> b/newlib/libc/machine/aarch64/strcpy.S
>> > index 1f5f70792..57c46f390 100644
>> > --- a/newlib/libc/machine/aarch64/strcpy.S
>> > +++ b/newlib/libc/machine/aarch64/strcpy.S
>> > @@ -55,6 +55,8 @@
>> >     exactly which byte matched.  */
>> >
>> >  ENTRY (STRCPY)
>> > +     PTR_ARG (0)
>> > +     PTR_ARG (1)
>> >       bic     src, srcin, 15
>> >       ld1     {vdata.16b}, [src]
>> >       cmeq    vhas_nul.16b, vdata.16b, 0
>> > diff --git a/newlib/libc/machine/aarch64/strlen.S
>> b/newlib/libc/machine/aarch64/strlen.S
>> > index a3345a3ab..68a6f357c 100644
>> > --- a/newlib/libc/machine/aarch64/strlen.S
>> > +++ b/newlib/libc/machine/aarch64/strlen.S
>> > @@ -78,6 +78,7 @@
>> >     character, return the length, if not, continue in the main loop.  */
>> >
>> >  ENTRY (strlen)
>> > +     PTR_ARG (0)
>> >       and     tmp1, srcin, MIN_PAGE_SIZE - 1
>> >       cmp     tmp1, MIN_PAGE_SIZE - 32
>> >       b.hi    L(page_cross)
>> > diff --git a/newlib/libc/machine/aarch64/strncmp.S
>> b/newlib/libc/machine/aarch64/strncmp.S
>> > index 6b1994ef5..373695503 100644
>> > --- a/newlib/libc/machine/aarch64/strncmp.S
>> > +++ b/newlib/libc/machine/aarch64/strncmp.S
>> > @@ -58,6 +58,9 @@
>> >  #endif
>> >
>> >  ENTRY (strncmp)
>> > +     PTR_ARG (0)
>> > +     PTR_ARG (1)
>> > +     SIZE_ARG (2)
>> >       cbz     limit, L(ret0)
>> >       eor     tmp1, src1, src2
>> >       mov     zeroones, #REP8_01
>> > diff --git a/newlib/libc/machine/aarch64/strnlen.S
>> b/newlib/libc/machine/aarch64/strnlen.S
>> > index dc9fcb2fd..091002e0b 100644
>> > --- a/newlib/libc/machine/aarch64/strnlen.S
>> > +++ b/newlib/libc/machine/aarch64/strnlen.S
>> > @@ -39,6 +39,8 @@
>> >     identifies the first zero byte.  */
>> >
>> >  ENTRY (strnlen)
>> > +     PTR_ARG (0)
>> > +     SIZE_ARG (1)
>> >       bic     src, srcin, 15
>> >       cbz     cntin, L(nomatch)
>> >       ld1     {vdata.16b}, [src]
>> > diff --git a/newlib/libc/machine/aarch64/strrchr.S
>> b/newlib/libc/machine/aarch64/strrchr.S
>> > index 67013e39d..b0574228b 100644
>> > --- a/newlib/libc/machine/aarch64/strrchr.S
>> > +++ b/newlib/libc/machine/aarch64/strrchr.S
>> > @@ -58,6 +58,7 @@
>> >     identify exactly which byte is causing the termination, and why.  */
>> >
>> >  ENTRY (strrchr)
>> > +     PTR_ARG (0)
>> >       /* Magic constant 0x40100401 to allow us to identify which lane
>> >          matches the requested byte.  Magic constant 0x80200802 used
>> >          similarly for NUL termination.  */
>> > --
>> > 2.50.1.vfs.0.0
>> >
>>
>>
>>
diff mbox series

Patch

diff --git a/newlib/libc/machine/aarch64/asmdefs.h b/newlib/libc/machine/aarch64/asmdefs.h
index 6c99fa704..cf156a5a8 100644
--- a/newlib/libc/machine/aarch64/asmdefs.h
+++ b/newlib/libc/machine/aarch64/asmdefs.h
@@ -88,4 +88,18 @@  GNU_PROPERTY (FEATURE_1_AND, FEATURE_1_BTI|FEATURE_1_PAC)
 
 #define L(l) .L ## l
 
+#ifdef __ILP32__
+  /* Sanitize padding bits of pointer arguments as per aapcs64 */
+#define PTR_ARG(n)  mov w##n, w##n
+#else
+#define PTR_ARG(n)
+#endif
+
+#ifdef __ILP32__
+  /* Sanitize padding bits of size arguments as per aapcs64 */
+#define SIZE_ARG(n)  mov w##n, w##n
+#else
+#define SIZE_ARG(n)
+#endif
+
 #endif
diff --git a/newlib/libc/machine/aarch64/memchr.S b/newlib/libc/machine/aarch64/memchr.S
index 074a004cf..a0f305e0f 100644
--- a/newlib/libc/machine/aarch64/memchr.S
+++ b/newlib/libc/machine/aarch64/memchr.S
@@ -50,6 +50,8 @@ 
  */
 
 ENTRY (memchr)
+	PTR_ARG (0)
+	SIZE_ARG (2)
 	/* Do not dereference srcin if no bytes to compare.  */
 	cbz	cntin, L(zero_length)
 	/*
diff --git a/newlib/libc/machine/aarch64/memcmp.S b/newlib/libc/machine/aarch64/memcmp.S
index 2a9c446bb..18874d321 100644
--- a/newlib/libc/machine/aarch64/memcmp.S
+++ b/newlib/libc/machine/aarch64/memcmp.S
@@ -34,6 +34,10 @@ 
 
 
 ENTRY (memcmp)
+	PTR_ARG (0)
+	PTR_ARG (1)
+	SIZE_ARG (2)
+
 	cmp	limit, 16
 	b.lo	L(less16)
 	ldp	data1, data3, [src1]
diff --git a/newlib/libc/machine/aarch64/memcpy.S b/newlib/libc/machine/aarch64/memcpy.S
index 252d2452a..248e7843a 100644
--- a/newlib/libc/machine/aarch64/memcpy.S
+++ b/newlib/libc/machine/aarch64/memcpy.S
@@ -58,6 +58,9 @@ 
 
 ENTRY_ALIAS (memmove)
 ENTRY (memcpy)
+	PTR_ARG (0)
+	PTR_ARG (1)
+	SIZE_ARG (2)
 	add	srcend, src, count
 	add	dstend, dstin, count
 	cmp	count, 128
diff --git a/newlib/libc/machine/aarch64/memrchr.S b/newlib/libc/machine/aarch64/memrchr.S
index 2525cf190..ba9915cc3 100644
--- a/newlib/libc/machine/aarch64/memrchr.S
+++ b/newlib/libc/machine/aarch64/memrchr.S
@@ -45,6 +45,7 @@ 
    exactly which byte matched.  */
 
 ENTRY (memrchr)
+	PTR_ARG (0)
 	add	end, srcin, cntin
 	sub	endm1, end, 1
 	bic	src, endm1, 15
diff --git a/newlib/libc/machine/aarch64/memset.S b/newlib/libc/machine/aarch64/memset.S
index 5bf4851f3..ca76439a9 100644
--- a/newlib/libc/machine/aarch64/memset.S
+++ b/newlib/libc/machine/aarch64/memset.S
@@ -25,6 +25,9 @@ 
 #define zva_val	x5
 
 ENTRY (memset)
+	PTR_ARG (0)
+	SIZE_ARG (2)
+
 	dup	v0.16B, valw
 	add	dstend, dstin, count
 
diff --git a/newlib/libc/machine/aarch64/strchr.S b/newlib/libc/machine/aarch64/strchr.S
index a4e089b99..500d9aff2 100644
--- a/newlib/libc/machine/aarch64/strchr.S
+++ b/newlib/libc/machine/aarch64/strchr.S
@@ -54,6 +54,7 @@ 
 /* Locals and temporaries.  */
 
 ENTRY (strchr)
+	PTR_ARG (0)
 	/* Magic constant 0xc0300c03 to allow us to identify which lane
 	   matches the requested byte.  Even bits are set if the character
 	   matches, odd bits if either the char is NUL or matches.  */
diff --git a/newlib/libc/machine/aarch64/strchrnul.S b/newlib/libc/machine/aarch64/strchrnul.S
index 4d6093be7..ceaf4dca1 100644
--- a/newlib/libc/machine/aarch64/strchrnul.S
+++ b/newlib/libc/machine/aarch64/strchrnul.S
@@ -50,6 +50,7 @@ 
 /* Locals and temporaries.  */
 
 ENTRY (strchrnul)
+	PTR_ARG (0)
 	/* Magic constant 0x40100401 to allow us to identify which lane
 	   matches the termination condition.  */
 	mov	wtmp2, #0x0401
diff --git a/newlib/libc/machine/aarch64/strcmp.S b/newlib/libc/machine/aarch64/strcmp.S
index 1d85da432..691a1760e 100644
--- a/newlib/libc/machine/aarch64/strcmp.S
+++ b/newlib/libc/machine/aarch64/strcmp.S
@@ -54,6 +54,8 @@ 
 
 
 ENTRY (strcmp)
+	PTR_ARG (0)
+	PTR_ARG (1)
 	sub	off2, src2, src1
 	mov	zeroones, REP8_01
 	and	tmp, src1, 7
diff --git a/newlib/libc/machine/aarch64/strcpy.S b/newlib/libc/machine/aarch64/strcpy.S
index 1f5f70792..57c46f390 100644
--- a/newlib/libc/machine/aarch64/strcpy.S
+++ b/newlib/libc/machine/aarch64/strcpy.S
@@ -55,6 +55,8 @@ 
    exactly which byte matched.  */
 
 ENTRY (STRCPY)
+	PTR_ARG (0)
+	PTR_ARG (1)
 	bic	src, srcin, 15
 	ld1	{vdata.16b}, [src]
 	cmeq	vhas_nul.16b, vdata.16b, 0
diff --git a/newlib/libc/machine/aarch64/strlen.S b/newlib/libc/machine/aarch64/strlen.S
index a3345a3ab..68a6f357c 100644
--- a/newlib/libc/machine/aarch64/strlen.S
+++ b/newlib/libc/machine/aarch64/strlen.S
@@ -78,6 +78,7 @@ 
    character, return the length, if not, continue in the main loop.  */
 
 ENTRY (strlen)
+	PTR_ARG (0)
 	and	tmp1, srcin, MIN_PAGE_SIZE - 1
 	cmp	tmp1, MIN_PAGE_SIZE - 32
 	b.hi	L(page_cross)
diff --git a/newlib/libc/machine/aarch64/strncmp.S b/newlib/libc/machine/aarch64/strncmp.S
index 6b1994ef5..373695503 100644
--- a/newlib/libc/machine/aarch64/strncmp.S
+++ b/newlib/libc/machine/aarch64/strncmp.S
@@ -58,6 +58,9 @@ 
 #endif
 
 ENTRY (strncmp)
+	PTR_ARG (0)
+	PTR_ARG (1)
+	SIZE_ARG (2)
 	cbz	limit, L(ret0)
 	eor	tmp1, src1, src2
 	mov	zeroones, #REP8_01
diff --git a/newlib/libc/machine/aarch64/strnlen.S b/newlib/libc/machine/aarch64/strnlen.S
index dc9fcb2fd..091002e0b 100644
--- a/newlib/libc/machine/aarch64/strnlen.S
+++ b/newlib/libc/machine/aarch64/strnlen.S
@@ -39,6 +39,8 @@ 
    identifies the first zero byte.  */
 
 ENTRY (strnlen)
+	PTR_ARG (0)
+	SIZE_ARG (1)
 	bic	src, srcin, 15
 	cbz	cntin, L(nomatch)
 	ld1	{vdata.16b}, [src]
diff --git a/newlib/libc/machine/aarch64/strrchr.S b/newlib/libc/machine/aarch64/strrchr.S
index 67013e39d..b0574228b 100644
--- a/newlib/libc/machine/aarch64/strrchr.S
+++ b/newlib/libc/machine/aarch64/strrchr.S
@@ -58,6 +58,7 @@ 
    identify exactly which byte is causing the termination, and why.  */
 
 ENTRY (strrchr)
+	PTR_ARG (0)
 	/* Magic constant 0x40100401 to allow us to identify which lane
 	   matches the requested byte.  Magic constant 0x80200802 used
 	   similarly for NUL termination.  */