commit cea2be444380fc1bf665cd023ed84be7e0872d28
author Nigel Stephens <nigel@mips.com> Mon Oct 12 14:57:18 2009 -0700
committer Ralf Baechle <ralf@linux-mips.org> Mon Nov 02 12:00:05 2009 +0100
tree 9e477926a9c67f143a7d44ad89a2cdf2a37dc041
parent a074f0e89faa8989bdbd6110785d2aafe7df5285

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>

arch/mips/math-emu/dp_simple.c

diff --git a/arch/mips/math-emu/dp_simple.c b/arch/mips/math-emu/dp_simple.c
index 1c555e6..d9ae1db 100644
--- a/arch/mips/math-emu/dp_simple.c
+++ b/arch/mips/math-emu/dp_simple.c
@@ -62,8 +62,6 @@
 		return ieee754dp_nanxcpt(y, "neg");
 	}
 
-	if (ieee754dp_isnan(x))	/* but not infinity */
-		return ieee754dp_nanxcpt(x, "neg", x);
 	return x;
 }
 
@@ -76,15 +74,12 @@
 	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;
 }

arch/mips/math-emu/sp_simple.c

diff --git a/arch/mips/math-emu/sp_simple.c b/arch/mips/math-emu/sp_simple.c
index 770f0f4..3175477 100644
--- a/arch/mips/math-emu/sp_simple.c
+++ b/arch/mips/math-emu/sp_simple.c
@@ -62,8 +62,6 @@
 		return ieee754sp_nanxcpt(y, "neg");
 	}
 
-	if (ieee754sp_isnan(x))	/* but not infinity */
-		return ieee754sp_nanxcpt(x, "neg", x);
 	return x;
 }
 
@@ -76,15 +74,12 @@
 	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;
 }