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| Started by | Aleksandar Markovic <aleksandar.markovic@rt-rk.com> |
|---|---|
| First post | 2017-07-21 16:20 +0200 |
| Last post | 2017-07-21 17:10 +0200 |
| Articles | 2 — 2 participants |
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[PATCH v3 06/16] MIPS: math-emu: <MAX|MAXA|MIN|MINA>.<D|S>: Fix cases of both inputs zero Aleksandar Markovic <aleksandar.markovic@rt-rk.com> - 2017-07-21 16:20 +0200
Re: [PATCH v3 06/16] MIPS: math-emu: <MAX|MAXA|MIN|MINA>.<D|S>: Fix cases of both inputs zero James Hogan <james.hogan@imgtec.com> - 2017-07-21 17:10 +0200
| From | Aleksandar Markovic <aleksandar.markovic@rt-rk.com> |
|---|---|
| Date | 2017-07-21 16:20 +0200 |
| Subject | [PATCH v3 06/16] MIPS: math-emu: <MAX|MAXA|MIN|MINA>.<D|S>: Fix cases of both inputs zero |
| Message-ID | <u5GWC-5Tl-31@gated-at.bofh.it> |
From: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Fix the value returned by <MAX|MAXA|MIN|MINA>.<D|S>, if both inputs
are zeros. The right behavior in such cases is stated in instruction
reference manual and is as follows:
fs ft MAX MIN MAXA MINA
---------------------------------------------
0 0 0 0 0 0
0 -0 0 -0 0 -0
-0 0 0 -0 0 -0
-0 -0 -0 -0 -0 -0
The relevant example:
MAX.S fd,fs,ft:
If fs contains +0, and ft contains -0, fd is going to contain 0
(without this patch, it used to contain -0).
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
---
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, 8 insertions(+), 24 deletions(-)
diff --git a/arch/mips/math-emu/dp_fmax.c b/arch/mips/math-emu/dp_fmax.c
index 567fc33..9517572 100644
--- a/arch/mips/math-emu/dp_fmax.c
+++ b/arch/mips/math-emu/dp_fmax.c
@@ -82,9 +82,7 @@ union ieee754dp ieee754dp_fmax(union ieee754dp x, union ieee754dp y)
return ys ? x : y;
case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO):
- if (xs == ys)
- return x;
- return ieee754dp_zero(1);
+ return ieee754dp_zero(xs & ys);
case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
DPDNORMX;
@@ -184,9 +182,7 @@ union ieee754dp ieee754dp_fmaxa(union ieee754dp x, union ieee754dp y)
return y;
case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO):
- if (xs == ys)
- return x;
- return ieee754dp_zero(1);
+ return ieee754dp_zero(xs & ys);
case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
DPDNORMX;
diff --git a/arch/mips/math-emu/dp_fmin.c b/arch/mips/math-emu/dp_fmin.c
index 77f7ca9..7069320 100644
--- a/arch/mips/math-emu/dp_fmin.c
+++ b/arch/mips/math-emu/dp_fmin.c
@@ -82,9 +82,7 @@ union ieee754dp ieee754dp_fmin(union ieee754dp x, union ieee754dp y)
return ys ? y : x;
case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO):
- if (xs == ys)
- return x;
- return ieee754dp_zero(1);
+ return ieee754dp_zero(xs | ys);
case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
DPDNORMX;
@@ -184,9 +182,7 @@ union ieee754dp ieee754dp_fmina(union ieee754dp x, union ieee754dp y)
return y;
case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO):
- if (xs == ys)
- return x;
- return ieee754dp_zero(1);
+ return ieee754dp_zero(xs | ys);
case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
DPDNORMX;
diff --git a/arch/mips/math-emu/sp_fmax.c b/arch/mips/math-emu/sp_fmax.c
index d46e8e4..d72111a 100644
--- a/arch/mips/math-emu/sp_fmax.c
+++ b/arch/mips/math-emu/sp_fmax.c
@@ -82,9 +82,7 @@ union ieee754sp ieee754sp_fmax(union ieee754sp x, union ieee754sp y)
return ys ? x : y;
case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO):
- if (xs == ys)
- return x;
- return ieee754sp_zero(1);
+ return ieee754sp_zero(xs & ys);
case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
SPDNORMX;
@@ -184,9 +182,7 @@ union ieee754sp ieee754sp_fmaxa(union ieee754sp x, union ieee754sp y)
return y;
case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO):
- if (xs == ys)
- return x;
- return ieee754sp_zero(1);
+ return ieee754sp_zero(xs & ys);
case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
SPDNORMX;
diff --git a/arch/mips/math-emu/sp_fmin.c b/arch/mips/math-emu/sp_fmin.c
index b528c4b..61ff9c6 100644
--- a/arch/mips/math-emu/sp_fmin.c
+++ b/arch/mips/math-emu/sp_fmin.c
@@ -82,9 +82,7 @@ union ieee754sp ieee754sp_fmin(union ieee754sp x, union ieee754sp y)
return ys ? y : x;
case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO):
- if (xs == ys)
- return x;
- return ieee754sp_zero(1);
+ return ieee754sp_zero(xs | ys);
case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
SPDNORMX;
@@ -184,9 +182,7 @@ union ieee754sp ieee754sp_fmina(union ieee754sp x, union ieee754sp y)
return y;
case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO):
- if (xs == ys)
- return x;
- return ieee754sp_zero(1);
+ return ieee754sp_zero(xs | ys);
case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
SPDNORMX;
--
2.7.4
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| From | James Hogan <james.hogan@imgtec.com> |
|---|---|
| Date | 2017-07-21 17:10 +0200 |
| Subject | Re: [PATCH v3 06/16] MIPS: math-emu: <MAX|MAXA|MIN|MINA>.<D|S>: Fix cases of both inputs zero |
| Message-ID | <u5HIZ-6p6-7@gated-at.bofh.it> |
| In reply to | #1693733 |
[Multipart message — attachments visible in raw view] — view raw
On Fri, Jul 21, 2017 at 04:09:04PM +0200, Aleksandar Markovic wrote: > From: Aleksandar Markovic <aleksandar.markovic@imgtec.com> > > Fix the value returned by <MAX|MAXA|MIN|MINA>.<D|S>, if both inputs > are zeros. The right behavior in such cases is stated in instruction > reference manual and is as follows: > > fs ft MAX MIN MAXA MINA > --------------------------------------------- > 0 0 0 0 0 0 > 0 -0 0 -0 0 -0 > -0 0 0 -0 0 -0 > -0 -0 -0 -0 -0 -0 To be fair I think the min behaviour was already technically correct. When the values matched it returned that value, and when they didn't match it returned -0, so max could have just been fixed to return ieee754*p_zero(0), but its fine IMO to rewrite both like you have. > > The relevant example: > > MAX.S fd,fs,ft: > If fs contains +0, and ft contains -0, fd is going to contain 0 > (without this patch, it used to contain -0). > Consider Fixes and Cc stable as with other patch > Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com> > Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com> > Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Otherwise Reviewed-by: James Hogan <james.hogan@imgtec.com> Cheers James > --- > 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, 8 insertions(+), 24 deletions(-) > > diff --git a/arch/mips/math-emu/dp_fmax.c b/arch/mips/math-emu/dp_fmax.c > index 567fc33..9517572 100644 > --- a/arch/mips/math-emu/dp_fmax.c > +++ b/arch/mips/math-emu/dp_fmax.c > @@ -82,9 +82,7 @@ union ieee754dp ieee754dp_fmax(union ieee754dp x, union ieee754dp y) > return ys ? x : y; > > case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO): > - if (xs == ys) > - return x; > - return ieee754dp_zero(1); > + return ieee754dp_zero(xs & ys); > > case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM): > DPDNORMX; > @@ -184,9 +182,7 @@ union ieee754dp ieee754dp_fmaxa(union ieee754dp x, union ieee754dp y) > return y; > > case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO): > - if (xs == ys) > - return x; > - return ieee754dp_zero(1); > + return ieee754dp_zero(xs & ys); > > case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM): > DPDNORMX; > diff --git a/arch/mips/math-emu/dp_fmin.c b/arch/mips/math-emu/dp_fmin.c > index 77f7ca9..7069320 100644 > --- a/arch/mips/math-emu/dp_fmin.c > +++ b/arch/mips/math-emu/dp_fmin.c > @@ -82,9 +82,7 @@ union ieee754dp ieee754dp_fmin(union ieee754dp x, union ieee754dp y) > return ys ? y : x; > > case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO): > - if (xs == ys) > - return x; > - return ieee754dp_zero(1); > + return ieee754dp_zero(xs | ys); > > case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM): > DPDNORMX; > @@ -184,9 +182,7 @@ union ieee754dp ieee754dp_fmina(union ieee754dp x, union ieee754dp y) > return y; > > case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO): > - if (xs == ys) > - return x; > - return ieee754dp_zero(1); > + return ieee754dp_zero(xs | ys); > > case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM): > DPDNORMX; > diff --git a/arch/mips/math-emu/sp_fmax.c b/arch/mips/math-emu/sp_fmax.c > index d46e8e4..d72111a 100644 > --- a/arch/mips/math-emu/sp_fmax.c > +++ b/arch/mips/math-emu/sp_fmax.c > @@ -82,9 +82,7 @@ union ieee754sp ieee754sp_fmax(union ieee754sp x, union ieee754sp y) > return ys ? x : y; > > case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO): > - if (xs == ys) > - return x; > - return ieee754sp_zero(1); > + return ieee754sp_zero(xs & ys); > > case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM): > SPDNORMX; > @@ -184,9 +182,7 @@ union ieee754sp ieee754sp_fmaxa(union ieee754sp x, union ieee754sp y) > return y; > > case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO): > - if (xs == ys) > - return x; > - return ieee754sp_zero(1); > + return ieee754sp_zero(xs & ys); > > case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM): > SPDNORMX; > diff --git a/arch/mips/math-emu/sp_fmin.c b/arch/mips/math-emu/sp_fmin.c > index b528c4b..61ff9c6 100644 > --- a/arch/mips/math-emu/sp_fmin.c > +++ b/arch/mips/math-emu/sp_fmin.c > @@ -82,9 +82,7 @@ union ieee754sp ieee754sp_fmin(union ieee754sp x, union ieee754sp y) > return ys ? y : x; > > case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO): > - if (xs == ys) > - return x; > - return ieee754sp_zero(1); > + return ieee754sp_zero(xs | ys); > > case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM): > SPDNORMX; > @@ -184,9 +182,7 @@ union ieee754sp ieee754sp_fmina(union ieee754sp x, union ieee754sp y) > return y; > > case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO): > - if (xs == ys) > - return x; > - return ieee754sp_zero(1); > + return ieee754sp_zero(xs | ys); > > case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM): > SPDNORMX; > -- > 2.7.4 >
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