[Qemu-devel] [PATCH] softfloat: fix floatx80_is_{quiet, signaling}_nan()

[Aurelien Jarno <aurelien@aurel32.net>]

floatx80_is_{quiet,signaling}_nan() functions are incorrectly detecting
the type of NaN, depending on SNAN_BIT_IS_ONE, one of the two is
returning the correct value, and the other true for any kind of NaN.

This patch fixes that by applying the same kind of comparison as for
other float formats, but taking into account the explicit bit.

Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
---
 fpu/softfloat-specialize.h |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/fpu/softfloat-specialize.h b/fpu/softfloat-specialize.h
index f293f24..50e56b4 100644
--- a/fpu/softfloat-specialize.h
+++ b/fpu/softfloat-specialize.h
@@ -482,7 +482,8 @@ int floatx80_is_quiet_nan( floatx80 a )
         && (bits64) ( aLow<<1 )
         && ( a.low == aLow );
 #else
-    return ( ( a.high & 0x7FFF ) == 0x7FFF ) && (bits64) ( a.low<<1 );
+    return ( ( a.high & 0x7FFF ) == 0x7FFF )
+        && (LIT64( 0x8000000000000000 ) >= ((bits64) ( a.low<<1 )));
 #endif
 }
 
@@ -494,7 +495,8 @@ int floatx80_is_quiet_nan( floatx80 a )
 int floatx80_is_signaling_nan( floatx80 a )
 {
 #if SNAN_BIT_IS_ONE
-    return ( ( a.high & 0x7FFF ) == 0x7FFF ) && (bits64) ( a.low<<1 );
+    return ( ( a.high & 0x7FFF ) == 0x7FFF )
+        && (LIT64( 0x8000000000000000 ) >= ((bits64) ( a.low<<1 )));
 #else
     bits64 aLow;
 
-- 
1.7.2.3