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authorAleksandar Markovic <aleksandar.markovic@imgtec.com>2017-07-27 19:08:49 +0300
committerRalf Baechle <ralf@linux-mips.org>2017-08-29 16:21:55 +0300
commit15560a58bfd4ff82cdd16b2270d4ef9b06d2cc4d (patch)
treeda8ea65ca2db73f2007aacf86e35e0702a0364f6 /arch/mips/math-emu
parente78bf0dc4789bdea1453595ae89e8db65918e22e (diff)
downloadlinux-15560a58bfd4ff82cdd16b2270d4ef9b06d2cc4d.tar.xz
MIPS: math-emu: <MAX|MAXA|MIN|MINA>.<D|S>: Fix cases of both inputs zero
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 Prior to this patch, some of the above cases were yielding correct results. However, for the sake of code consistency, all such cases are rewritten in this patch. A relevant example: MAX.S fd,fs,ft: If fs contains +0.0, and ft contains -0.0, fd is going to contain +0.0 (without this patch, it used to contain -0.0). 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@imgtec.com> Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: Bo Hu <bohu@google.com> Cc: Douglas Leung <douglas.leung@imgtec.com> Cc: Jin Qian <jinqian@google.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Petar Jovanovic <petar.jovanovic@imgtec.com> Cc: Raghu Gandham <raghu.gandham@imgtec.com> Cc: <stable@vger.kernel.org> # 4.3+ Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/16881/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/math-emu')
-rw-r--r--arch/mips/math-emu/dp_fmax.c8
-rw-r--r--arch/mips/math-emu/dp_fmin.c8
-rw-r--r--arch/mips/math-emu/sp_fmax.c8
-rw-r--r--arch/mips/math-emu/sp_fmin.c8
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 41bd6ed852b9..31f091a7819b 100644
--- a/arch/mips/math-emu/dp_fmax.c
+++ b/arch/mips/math-emu/dp_fmax.c
@@ -92,9 +92,7 @@ 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;
@@ -204,9 +202,7 @@ 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 53fb8c904e32..e607d55208ad 100644
--- a/arch/mips/math-emu/dp_fmin.c
+++ b/arch/mips/math-emu/dp_fmin.c
@@ -92,9 +92,7 @@ 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;
@@ -204,9 +202,7 @@ 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 d0d73c3226dc..3ca5b204e9d0 100644
--- a/arch/mips/math-emu/sp_fmax.c
+++ b/arch/mips/math-emu/sp_fmax.c
@@ -92,9 +92,7 @@ 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;
@@ -204,9 +202,7 @@ 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 011692e326af..c982647df39a 100644
--- a/arch/mips/math-emu/sp_fmin.c
+++ b/arch/mips/math-emu/sp_fmin.c
@@ -92,9 +92,7 @@ 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;
@@ -204,9 +202,7 @@ 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;