From: Jeff Johnston <jjohnstn@redhat.com>
To: Sebastian Huber <sebastian.huber@embedded-brains.de>
Cc: Newlib <newlib@sourceware.org>
Subject: Re: [PATCH] powerpc/setjmp: Add 64-bit support
Date: Fri, 23 Sep 2022 14:04:02 -0400 [thread overview]
Message-ID: <CAOox84tmW03+JtS66Rdx_c=X5SF1=dW3eXV-zzA+qMfMpwzODQ@mail.gmail.com> (raw)
In-Reply-To: <20220923113713.103017-1-sebastian.huber@embedded-brains.de>
[-- Attachment #1: Type: text/plain, Size: 6908 bytes --]
Hi Sebastian,
Just a couple of questions/issues:
1. How did you arrive at 70 doubles and 43 doubles length values?
2. It appears that __SPE__ is not accounted for in setjmp.h
-- Jeff J.
On Fri, Sep 23, 2022 at 7:37 AM Sebastian Huber <
sebastian.huber@embedded-brains.de> wrote:
> Use 64-bit store/load instructions to save/restore the general-purpose
> registers.
> ---
> newlib/libc/include/machine/setjmp.h | 8 +++
> newlib/libc/machine/powerpc/setjmp.S | 79 ++++++++++++++++++++++++----
> 2 files changed, 78 insertions(+), 9 deletions(-)
>
> diff --git a/newlib/libc/include/machine/setjmp.h
> b/newlib/libc/include/machine/setjmp.h
> index 0bb53238b..53878a03d 100644
> --- a/newlib/libc/include/machine/setjmp.h
> +++ b/newlib/libc/include/machine/setjmp.h
> @@ -173,11 +173,19 @@ _BEGIN_STD_C
> #endif
>
> #ifdef __PPC__
> +#ifdef __powerpc64__
> +#ifdef __ALTIVEC__
> +#define _JBLEN 70
> +#else
> +#define _JBLEN 43
> +#endif
> +#else
> #ifdef __ALTIVEC__
> #define _JBLEN 64
> #else
> #define _JBLEN 32
> #endif
> +#endif
> #define _JBTYPE double
> #endif
>
> diff --git a/newlib/libc/machine/powerpc/setjmp.S
> b/newlib/libc/machine/powerpc/setjmp.S
> index f4ccd1bb5..f1f8ac28f 100644
> --- a/newlib/libc/machine/powerpc/setjmp.S
> +++ b/newlib/libc/machine/powerpc/setjmp.S
> @@ -1,6 +1,7 @@
> /* This is a simple version of setjmp and longjmp for the PowerPC.
> Ian Lance Taylor, Cygnus Support, 9 Feb 1994.
> - Modified by Jeff Johnston, Red Hat Inc. 2 Oct 2001. */
> + Modified by Jeff Johnston, Red Hat Inc. 2 Oct 2001.
> + Modified by Sebastian Huber, embedded brains GmbH. 22 Sep 2022. */
>
> #include "ppc-asm.h"
>
> @@ -40,6 +41,31 @@ FUNC_START(setjmp)
> stored. Note that we are not adding 168 because the next
> store instruction uses an offset of 4. */
> addi 3,3,164
> +#elif __powerpc64__
> + /* In the first store, add 16 to r3 so that the subsequent
> floating
> + point stores are aligned on an 8 byte boundary and the Altivec
> + stores are aligned on a 16 byte boundary. */
> + stdu 1,16(3) # offset 16
> + stdu 2,8(3) # offset 24
> + stdu 13,8(3) # offset 32
> + stdu 14,8(3) # offset 40
> + stdu 15,8(3) # offset 48
> + stdu 16,8(3) # offset 56
> + stdu 17,8(3) # offset 64
> + stdu 18,8(3) # offset 72
> + stdu 19,8(3) # offset 80
> + stdu 20,8(3) # offset 88
> + stdu 21,8(3) # offset 96
> + stdu 22,8(3) # offset 104
> + stdu 23,8(3) # offset 112
> + stdu 24,8(3) # offset 120
> + stdu 25,8(3) # offset 128
> + stdu 26,8(3) # offset 136
> + stdu 27,8(3) # offset 144
> + stdu 28,8(3) # offset 152
> + stdu 29,8(3) # offset 160
> + stdu 30,8(3) # offset 168
> + stdu 31,8(3) # offset 176
> #else
> stw 1,0(3) # offset 0
> stwu 2,4(3) # offset 4
> @@ -64,10 +90,15 @@ FUNC_START(setjmp)
> stwu 31,4(3) # offset 80
> #endif
>
> - /* From this point on until the end of this function, add 84
> - to the offset shown if __SPE__. This difference comes from
> - the fact that we save 21 64-bit registers instead of 21
> - 32-bit registers above. */
> + /* If __SPE__, then add 84 to the offset shown from this point on
> until
> + the end of this function. This difference comes from the fact
> that
> + we save 21 64-bit registers instead of 21 32-bit registers
> above.
> +
> + If __powerpc64__, then add 96 to the offset shown from this
> point on until
> + the end of this function. This difference comes from the fact
> that
> + we save 21 64-bit registers instead of 21 32-bit registers
> above and
> + we take alignement requirements of floating point and Altivec
> stores
> + into account. */
> mflr 4
> stwu 4,4(3) # offset 84
> mfcr 4
> @@ -188,6 +219,31 @@ FUNC_START(longjmp)
> loaded. Note that we are not adding 168 because the next
> load instruction uses an offset of 4. */
> addi 3,3,164
> +#elif __powerpc64__
> + /* In the first load, add 16 to r3 so that the subsequent floating
> + point loades are aligned on an 8 byte boundary and the Altivec
> + loads are aligned on a 16 byte boundary. */
> + ldu 1,16(3) # offset 16
> + ldu 2,8(3) # offset 24
> + ldu 13,8(3) # offset 32
> + ldu 14,8(3) # offset 40
> + ldu 15,8(3) # offset 48
> + ldu 16,8(3) # offset 56
> + ldu 17,8(3) # offset 64
> + ldu 18,8(3) # offset 72
> + ldu 19,8(3) # offset 80
> + ldu 20,8(3) # offset 88
> + ldu 21,8(3) # offset 96
> + ldu 22,8(3) # offset 104
> + ldu 23,8(3) # offset 112
> + ldu 24,8(3) # offset 120
> + ldu 25,8(3) # offset 128
> + ldu 26,8(3) # offset 136
> + ldu 27,8(3) # offset 144
> + ldu 28,8(3) # offset 152
> + ldu 29,8(3) # offset 160
> + ldu 30,8(3) # offset 168
> + ldu 31,8(3) # offset 176
> #else
> lwz 1,0(3) # offset 0
> lwzu 2,4(3) # offset 4
> @@ -211,10 +267,15 @@ FUNC_START(longjmp)
> lwzu 30,4(3) # offset 76
> lwzu 31,4(3) # offset 80
> #endif
> - /* From this point on until the end of this function, add 84
> - to the offset shown if __SPE__. This difference comes from
> - the fact that we restore 21 64-bit registers instead of 21
> - 32-bit registers above. */
> + /* If __SPE__, then add 84 to the offset shown from this point on
> until
> + the end of this function. This difference comes from the fact
> that
> + we restore 21 64-bit registers instead of 21 32-bit registers
> above.
> +
> + If __powerpc64__, then add 96 to the offset shown from this
> point on until
> + the end of this function. This difference comes from the fact
> that
> + we restore 21 64-bit registers instead of 21 32-bit registers
> above and
> + we take alignement requirements of floating point and Altivec
> loads
> + into account. */
> lwzu 5,4(3) # offset 84
> mtlr 5
> lwzu 5,4(3) # offset 88
> --
> 2.35.3
>
>
next prev parent reply other threads:[~2022-09-23 18:04 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-23 11:37 Sebastian Huber
2022-09-23 18:04 ` Jeff Johnston [this message]
2022-09-23 19:02 ` Sebastian Huber
2022-09-23 19:29 ` Jeff Johnston
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