MIPS: Fix abs.[sd] and neg.[sd] emulation for NaN operands

This patch ensures that the sign bit is always updated for NaN operands.

Signed-off-by: Chris Dearman <chris@mips.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

2 files changed, 7 insertions, 17 deletions

diff --git a/arch/mips/math-emu/dp_simple.c b/arch/mips/math-emu/dp_simple.c
index 1c555e6c6a9f..d9ae1dbabda7 100644
--- a/arch/mips/math-emu/dp_simple.c
+++ b/arch/mips/math-emu/dp_simple.c
@@ -62,8 +62,6 @@ ieee754dp ieee754dp_neg(ieee754dp x)
                 return ieee754dp_nanxcpt(y, "neg");
         }
 
-        if (ieee754dp_isnan(x)) /* but not infinity */
-                return ieee754dp_nanxcpt(x, "neg", x);
         return x;
 }
 
@@ -76,15 +74,12 @@ ieee754dp ieee754dp_abs(ieee754dp x)
         CLEARCX;
         FLUSHXDP;
 
+        /* Clear sign ALWAYS, irrespective of NaN */
+        DPSIGN(x) = 0;
+
         if (xc == IEEE754_CLASS_SNAN) {
-                SETCX(IEEE754_INVALID_OPERATION);
-                return ieee754dp_nanxcpt(ieee754dp_indef(), "neg");
+                return ieee754dp_nanxcpt(ieee754dp_indef(), "abs");
         }
 
-        if (ieee754dp_isnan(x)) /* but not infinity */
-                return ieee754dp_nanxcpt(x, "abs", x);
-
-        /* quick fix up */
-        DPSIGN(x) = 0;
         return x;
 }
diff --git a/arch/mips/math-emu/sp_simple.c b/arch/mips/math-emu/sp_simple.c
index 770f0f4677cd..3175477d36f6 100644
--- a/arch/mips/math-emu/sp_simple.c
+++ b/arch/mips/math-emu/sp_simple.c
@@ -62,8 +62,6 @@ ieee754sp ieee754sp_neg(ieee754sp x)
                 return ieee754sp_nanxcpt(y, "neg");
         }
 
-        if (ieee754sp_isnan(x)) /* but not infinity */
-                return ieee754sp_nanxcpt(x, "neg", x);
         return x;
 }
 
@@ -76,15 +74,12 @@ ieee754sp ieee754sp_abs(ieee754sp x)
         CLEARCX;
         FLUSHXSP;
 
+        /* Clear sign ALWAYS, irrespective of NaN */
+        SPSIGN(x) = 0;
+
         if (xc == IEEE754_CLASS_SNAN) {
-                SETCX(IEEE754_INVALID_OPERATION);
                 return ieee754sp_nanxcpt(ieee754sp_indef(), "abs");
         }
 
-        if (ieee754sp_isnan(x)) /* but not infinity */
-                return ieee754sp_nanxcpt(x, "abs", x);
-
-        /* quick fix up */
-        SPSIGN(x) = 0;
         return x;
 }