Re: [PATCH v3 05/16] MIPS: math-emu: <MAX|MAXA|MIN|MINA>.<D|S>: Fix quiet NaN propagation

From: James Hogan
Date: Fri Jul 21 2017 - 10:47:08 EST

Next message: Quentin Schulz: "[PATCH 1/2] staging: net: wireless: add ESP8089 WiFi driver"
Previous message: Masami Hiramatsu: "[PATCH] [BUGFIX] kprobes/x86: Release insn_slot in failure path"
In reply to: Aleksandar Markovic: "[PATCH v3 05/16] MIPS: math-emu: <MAX|MAXA|MIN|MINA>.<D|S>: Fix quiet NaN propagation"
Next in thread: Aleksandar Markovic: "[PATCH v3 06/16] MIPS: math-emu: <MAX|MAXA|MIN|MINA>.<D|S>: Fix cases of both inputs zero"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

On Fri, Jul 21, 2017 at 04:09:03PM +0200, Aleksandar Markovic wrote:
> From: Aleksandar Markovic <aleksandar.markovic@xxxxxxxxxx>
>
> Fix the value returned by <MAX|MAXA|MIN|MINA>.<D|S>, if both inputs
> are quiet NaNs. The specifications of <MAX|MAXA|MIN|MINA>.<D|S> state
> that the returned value in such cases should be the quiet NaN
> contained in register fs.
>
> The relevant example:
>
> MAX.S fd,fs,ft:
> If fs contains qNaN1, and ft contains qNaN2, fd is going to contain
> qNaN1 (without this patch, it used to contain qNaN2).
>

Consider adding:

Fixes: a79f5f9ba508 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e2f ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")

> Signed-off-by: Miodrag Dinic <miodrag.dinic@xxxxxxxxxx>
> Signed-off-by: Goran Ferenc <goran.ferenc@xxxxxxxxxx>
> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@xxxxxxxxxx>

Consider adding:

Cc: <stable@xxxxxxxxxxxxxxx> # 4.3+

> ---
> arch/mips/math-emu/dp_fmax.c | 8 ++++++--
> arch/mips/math-emu/dp_fmin.c | 8 ++++++--
> arch/mips/math-emu/sp_fmax.c | 8 ++++++--
> arch/mips/math-emu/sp_fmin.c | 8 ++++++--
> 4 files changed, 24 insertions(+), 8 deletions(-)
>
> diff --git a/arch/mips/math-emu/dp_fmax.c b/arch/mips/math-emu/dp_fmax.c
> index fd71b8d..567fc33 100644
> --- a/arch/mips/math-emu/dp_fmax.c
> +++ b/arch/mips/math-emu/dp_fmax.c
> @@ -47,6 +47,9 @@ union ieee754dp ieee754dp_fmax(union ieee754dp x, union ieee754dp y)
> case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_INF):
> return ieee754dp_nanxcpt(x);
>
> + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
> + return x;

couldn't the above...

> +
> /* numbers are preferred to NaNs */
> case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_QNAN):
> case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_QNAN):
> @@ -54,7 +57,6 @@ union ieee754dp ieee754dp_fmax(union ieee754dp x, union ieee754dp y)

... go somewhere around here and fall through to the existing return x
case?

and same below of course.

Otherwise:
Reviewed-by: James Hogan <james.hogan@xxxxxxxxxx>

Cheers
James

> case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_QNAN):
> return x;
>
> - case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
> case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_ZERO):
> case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_NORM):
> case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_DNORM):
> @@ -147,6 +149,9 @@ union ieee754dp ieee754dp_fmaxa(union ieee754dp x, union ieee754dp y)
> case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_INF):
> return ieee754dp_nanxcpt(x);
>
> + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
> + return x;
> +
> /* numbers are preferred to NaNs */
> case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_QNAN):
> case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_QNAN):
> @@ -154,7 +159,6 @@ union ieee754dp ieee754dp_fmaxa(union ieee754dp x, union ieee754dp y)
> case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_QNAN):
> return x;
>
> - case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
> case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_ZERO):
> case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_NORM):
> case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_DNORM):
> diff --git a/arch/mips/math-emu/dp_fmin.c b/arch/mips/math-emu/dp_fmin.c
> index c1072b0..77f7ca9 100644
> --- a/arch/mips/math-emu/dp_fmin.c
> +++ b/arch/mips/math-emu/dp_fmin.c
> @@ -47,6 +47,9 @@ union ieee754dp ieee754dp_fmin(union ieee754dp x, union ieee754dp y)
> case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_INF):
> return ieee754dp_nanxcpt(x);
>
> + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
> + return x;
> +
> /* numbers are preferred to NaNs */
> case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_QNAN):
> case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_QNAN):
> @@ -54,7 +57,6 @@ union ieee754dp ieee754dp_fmin(union ieee754dp x, union ieee754dp y)
> case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_QNAN):
> return x;
>
> - case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
> case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_ZERO):
> case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_NORM):
> case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_DNORM):
> @@ -147,6 +149,9 @@ union ieee754dp ieee754dp_fmina(union ieee754dp x, union ieee754dp y)
> case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_INF):
> return ieee754dp_nanxcpt(x);
>
> + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
> + return x;
> +
> /* numbers are preferred to NaNs */
> case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_QNAN):
> case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_QNAN):
> @@ -154,7 +159,6 @@ union ieee754dp ieee754dp_fmina(union ieee754dp x, union ieee754dp y)
> case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_QNAN):
> return x;
>
> - case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
> case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_ZERO):
> case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_NORM):
> case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_DNORM):
> diff --git a/arch/mips/math-emu/sp_fmax.c b/arch/mips/math-emu/sp_fmax.c
> index 4d00084..d46e8e4 100644
> --- a/arch/mips/math-emu/sp_fmax.c
> +++ b/arch/mips/math-emu/sp_fmax.c
> @@ -47,6 +47,9 @@ union ieee754sp ieee754sp_fmax(union ieee754sp x, union ieee754sp y)
> case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_INF):
> return ieee754sp_nanxcpt(x);
>
> + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
> + return x;
> +
> /* numbers are preferred to NaNs */
> case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_QNAN):
> case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_QNAN):
> @@ -54,7 +57,6 @@ union ieee754sp ieee754sp_fmax(union ieee754sp x, union ieee754sp y)
> case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_QNAN):
> return x;
>
> - case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
> case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_ZERO):
> case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_NORM):
> case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_DNORM):
> @@ -147,6 +149,9 @@ union ieee754sp ieee754sp_fmaxa(union ieee754sp x, union ieee754sp y)
> case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_INF):
> return ieee754sp_nanxcpt(x);
>
> + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
> + return x;
> +
> /* numbers are preferred to NaNs */
> case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_QNAN):
> case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_QNAN):
> @@ -154,7 +159,6 @@ union ieee754sp ieee754sp_fmaxa(union ieee754sp x, union ieee754sp y)
> case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_QNAN):
> return x;
>
> - case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
> case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_ZERO):
> case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_NORM):
> case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_DNORM):
> diff --git a/arch/mips/math-emu/sp_fmin.c b/arch/mips/math-emu/sp_fmin.c
> index 4eb1bb9..b528c4b 100644
> --- a/arch/mips/math-emu/sp_fmin.c
> +++ b/arch/mips/math-emu/sp_fmin.c
> @@ -47,6 +47,9 @@ union ieee754sp ieee754sp_fmin(union ieee754sp x, union ieee754sp y)
> case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_INF):
> return ieee754sp_nanxcpt(x);
>
> + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
> + return x;
> +
> /* numbers are preferred to NaNs */
> case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_QNAN):
> case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_QNAN):
> @@ -54,7 +57,6 @@ union ieee754sp ieee754sp_fmin(union ieee754sp x, union ieee754sp y)
> case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_QNAN):
> return x;
>
> - case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
> case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_ZERO):
> case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_NORM):
> case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_DNORM):
> @@ -147,6 +149,9 @@ union ieee754sp ieee754sp_fmina(union ieee754sp x, union ieee754sp y)
> case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_INF):
> return ieee754sp_nanxcpt(x);
>
> + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
> + return x;
> +
> /* numbers are preferred to NaNs */
> case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_QNAN):
> case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_QNAN):
> @@ -154,7 +159,6 @@ union ieee754sp ieee754sp_fmina(union ieee754sp x, union ieee754sp y)
> case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_QNAN):
> return x;
>
> - case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
> case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_ZERO):
> case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_NORM):
> case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_DNORM):
> --
> 2.7.4
>

Attachment: signature.asc
Description: Digital signature

Next message: Quentin Schulz: "[PATCH 1/2] staging: net: wireless: add ESP8089 WiFi driver"
Previous message: Masami Hiramatsu: "[PATCH] [BUGFIX] kprobes/x86: Release insn_slot in failure path"
In reply to: Aleksandar Markovic: "[PATCH v3 05/16] MIPS: math-emu: <MAX|MAXA|MIN|MINA>.<D|S>: Fix quiet NaN propagation"
Next in thread: Aleksandar Markovic: "[PATCH v3 06/16] MIPS: math-emu: <MAX|MAXA|MIN|MINA>.<D|S>: Fix cases of both inputs zero"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]