softfloat: Implement run-time-configurable meaning of signaling NaN bit

This patch modifies SoftFloat library so that it can be configured in
run-time in relation to the meaning of signaling NaN bit, while, at the
same time, strictly preserving its behavior on all existing platforms.

Background:

In floating-point calculations, there is a need for denoting undefined or
unrepresentable values. This is achieved by defining certain floating-point
numerical values to be NaNs (which stands for "not a number"). For additional
reasons, virtually all modern floating-point unit implementations use two
kinds of NaNs: quiet and signaling. The binary representations of these two
kinds of NaNs, as a rule, differ only in one bit (that bit is, traditionally,
the first bit of mantissa).

Up to 2008, standards for floating-point did not specify all details about
binary representation of NaNs. More specifically, the meaning of the bit
that is used for distinguishing between signaling and quiet NaNs was not
strictly prescribed. (IEEE 754-2008 was the first floating-point standard
that defined that meaning clearly, see [1], p. 35) As a result, different
platforms took different approaches, and that presented considerable
challenge for multi-platform emulators like QEMU.

Mips platform represents the most complex case among QEMU-supported
platforms regarding signaling NaN bit. Up to the Release 6 of Mips
architecture, "1" in signaling NaN bit denoted signaling NaN, which is
opposite to IEEE 754-2008 standard. From Release 6 on, Mips architecture
adopted IEEE standard prescription, and "0" denotes signaling NaN. On top of
that, Mips architecture for SIMD (also known as MSA, or vector instructions)
also specifies signaling bit in accordance to IEEE standard. MSA unit can be
implemented with both pre-Release 6 and Release 6 main processor units.

QEMU uses SoftFloat library to implement various floating-point-related
instructions on all platforms. The current QEMU implementation allows for
defining meaning of signaling NaN bit during build time, and is implemented
via preprocessor macro called SNAN_BIT_IS_ONE.

On the other hand, the change in this patch enables SoftFloat library to be
configured in run-time. This configuration is meant to occur during CPU
initialization, at the moment when it is definitely known what desired
behavior for particular CPU (or any additional FPUs) is.

The change is implemented so that it is consistent with existing
implementation of similar cases. This means that structure float_status is
used for passing the information about desired signaling NaN bit on each
invocation of SoftFloat functions. The additional field in float_status is
called snan_bit_is_one, which supersedes macro SNAN_BIT_IS_ONE.

IMPORTANT:

This change is not meant to create any change in emulator behavior or
functionality on any platform. It just provides the means for SoftFloat
library to be used in a more flexible way - in other words, it will just
prepare SoftFloat library for usage related to Mips platform and its
specifics regarding signaling bit meaning, which is done in some of
subsequent patches from this series.

Further break down of changes:

  1) Added field snan_bit_is_one to the structure float_status, and
     correspondent setter function set_snan_bit_is_one().

  2) Constants <float16|float32|float64|floatx80|float128>_default_nan
     (used both internally and externally) converted to functions
     <float16|float32|float64|floatx80|float128>_default_nan(float_status*).
     This is necessary since they are dependent on signaling bit meaning.
     At the same time, for the sake of code cleanup and simplicity, constants
     <floatx80|float128>_default_nan_<low|high> (used only internally within
     SoftFloat library) are removed, as not needed.

  3) Added a float_status* argument to SoftFloat library functions
     XXX_is_quiet_nan(XXX a_), XXX_is_signaling_nan(XXX a_),
     XXX_maybe_silence_nan(XXX a_). This argument must be present in
     order to enable correct invocation of new version of functions
     XXX_default_nan(). (XXX is <float16|float32|float64|floatx80|float128>
     here)

  4) Updated code for all platforms to reflect changes in SoftFloat library.
     This change is twofolds: it includes modifications of SoftFloat library
     functions invocations, and an addition of invocation of function
     set_snan_bit_is_one() during CPU initialization, with arguments that
     are appropriate for each particular platform. It was established that
     all platforms zero their main CPU data structures, so snan_bit_is_one(0)
     in appropriate places is not added, as it is not needed.

[1] "IEEE Standard for Floating-Point Arithmetic",
    IEEE Computer Society, August 29, 2008.

Signed-off-by: Thomas Schwinge <thomas@codesourcery.com>
Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Tested-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Reviewed-by: Leon Alrae <leon.alrae@imgtec.com>
Tested-by: Leon Alrae <leon.alrae@imgtec.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[leon.alrae@imgtec.com:
 * cherry-picked 2 chunks from patch #2 to fix compilation warnings]
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>

1 files changed, 75 insertions, 97 deletions

diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 166c48e434..9b1eccff24 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -2105,7 +2105,7 @@ static float32 subFloat32Sigs(float32 a, float32 b, flag zSign,
             return propagateFloat32NaN(a, b, status);
         }
         float_raise(float_flag_invalid, status);
-        return float32_default_nan;
+        return float32_default_nan(status);
     }
     if ( aExp == 0 ) {
         aExp = 1;
@@ -2234,7 +2234,7 @@ float32 float32_mul(float32 a, float32 b, float_status *status)
         }
         if ( ( bExp | bSig ) == 0 ) {
             float_raise(float_flag_invalid, status);
-            return float32_default_nan;
+            return float32_default_nan(status);
         }
         return packFloat32( zSign, 0xFF, 0 );
     }
@@ -2244,7 +2244,7 @@ float32 float32_mul(float32 a, float32 b, float_status *status)
         }
         if ( ( aExp | aSig ) == 0 ) {
             float_raise(float_flag_invalid, status);
-            return float32_default_nan;
+            return float32_default_nan(status);
         }
         return packFloat32( zSign, 0xFF, 0 );
     }
@@ -2299,7 +2299,7 @@ float32 float32_div(float32 a, float32 b, float_status *status)
                 return propagateFloat32NaN(a, b, status);
             }
             float_raise(float_flag_invalid, status);
-            return float32_default_nan;
+            return float32_default_nan(status);
         }
         return packFloat32( zSign, 0xFF, 0 );
     }
@@ -2313,7 +2313,7 @@ float32 float32_div(float32 a, float32 b, float_status *status)
         if ( bSig == 0 ) {
             if ( ( aExp | aSig ) == 0 ) {
                 float_raise(float_flag_invalid, status);
-                return float32_default_nan;
+                return float32_default_nan(status);
             }
             float_raise(float_flag_divbyzero, status);
             return packFloat32( zSign, 0xFF, 0 );
@@ -2367,7 +2367,7 @@ float32 float32_rem(float32 a, float32 b, float_status *status)
             return propagateFloat32NaN(a, b, status);
         }
         float_raise(float_flag_invalid, status);
-        return float32_default_nan;
+        return float32_default_nan(status);
     }
     if ( bExp == 0xFF ) {
         if (bSig) {
@@ -2378,7 +2378,7 @@ float32 float32_rem(float32 a, float32 b, float_status *status)
     if ( bExp == 0 ) {
         if ( bSig == 0 ) {
             float_raise(float_flag_invalid, status);
-            return float32_default_nan;
+            return float32_default_nan(status);
         }
         normalizeFloat32Subnormal( bSig, &bExp, &bSig );
     }
@@ -2493,7 +2493,7 @@ float32 float32_muladd(float32 a, float32 b, float32 c, int flags,
 
     if (infzero) {
         float_raise(float_flag_invalid, status);
-        return float32_default_nan;
+        return float32_default_nan(status);
     }
 
     if (flags & float_muladd_negate_c) {
@@ -2514,7 +2514,7 @@ float32 float32_muladd(float32 a, float32 b, float32 c, int flags,
         if (pInf && (pSign ^ cSign)) {
             /* addition of opposite-signed infinities => InvalidOperation */
             float_raise(float_flag_invalid, status);
-            return float32_default_nan;
+            return float32_default_nan(status);
         }
         /* Otherwise generate an infinity of the same sign */
         return packFloat32(cSign ^ signflip, 0xff, 0);
@@ -2690,12 +2690,12 @@ float32 float32_sqrt(float32 a, float_status *status)
         }
         if ( ! aSign ) return a;
         float_raise(float_flag_invalid, status);
-        return float32_default_nan;
+        return float32_default_nan(status);
     }
     if ( aSign ) {
         if ( ( aExp | aSig ) == 0 ) return a;
         float_raise(float_flag_invalid, status);
-        return float32_default_nan;
+        return float32_default_nan(status);
     }
     if ( aExp == 0 ) {
         if ( aSig == 0 ) return float32_zero;
@@ -2828,7 +2828,7 @@ float32 float32_log2(float32 a, float_status *status)
     }
     if ( aSign ) {
         float_raise(float_flag_invalid, status);
-        return float32_default_nan;
+        return float32_default_nan(status);
     }
     if ( aExp == 0xFF ) {
         if (aSig) {
@@ -2974,7 +2974,8 @@ int float32_eq_quiet(float32 a, float32 b, float_status *status)
     if (    ( ( extractFloat32Exp( a ) == 0xFF ) && extractFloat32Frac( a ) )
          || ( ( extractFloat32Exp( b ) == 0xFF ) && extractFloat32Frac( b ) )
        ) {
-        if ( float32_is_signaling_nan( a ) || float32_is_signaling_nan( b ) ) {
+        if (float32_is_signaling_nan(a, status)
+         || float32_is_signaling_nan(b, status)) {
             float_raise(float_flag_invalid, status);
         }
         return 0;
@@ -3000,7 +3001,8 @@ int float32_le_quiet(float32 a, float32 b, float_status *status)
     if (    ( ( extractFloat32Exp( a ) == 0xFF ) && extractFloat32Frac( a ) )
          || ( ( extractFloat32Exp( b ) == 0xFF ) && extractFloat32Frac( b ) )
        ) {
-        if ( float32_is_signaling_nan( a ) || float32_is_signaling_nan( b ) ) {
+        if (float32_is_signaling_nan(a, status)
+         || float32_is_signaling_nan(b, status)) {
             float_raise(float_flag_invalid, status);
         }
         return 0;
@@ -3031,7 +3033,8 @@ int float32_lt_quiet(float32 a, float32 b, float_status *status)
     if (    ( ( extractFloat32Exp( a ) == 0xFF ) && extractFloat32Frac( a ) )
          || ( ( extractFloat32Exp( b ) == 0xFF ) && extractFloat32Frac( b ) )
        ) {
-        if ( float32_is_signaling_nan( a ) || float32_is_signaling_nan( b ) ) {
+        if (float32_is_signaling_nan(a, status)
+         || float32_is_signaling_nan(b, status)) {
             float_raise(float_flag_invalid, status);
         }
         return 0;
@@ -3060,7 +3063,8 @@ int float32_unordered_quiet(float32 a, float32 b, float_status *status)
     if (    ( ( extractFloat32Exp( a ) == 0xFF ) && extractFloat32Frac( a ) )
          || ( ( extractFloat32Exp( b ) == 0xFF ) && extractFloat32Frac( b ) )
        ) {
-        if ( float32_is_signaling_nan( a ) || float32_is_signaling_nan( b ) ) {
+        if (float32_is_signaling_nan(a, status)
+         || float32_is_signaling_nan(b, status)) {
             float_raise(float_flag_invalid, status);
         }
         return 1;
@@ -3896,7 +3900,7 @@ static float64 subFloat64Sigs(float64 a, float64 b, flag zSign,
             return propagateFloat64NaN(a, b, status);
         }
         float_raise(float_flag_invalid, status);
-        return float64_default_nan;
+        return float64_default_nan(status);
     }
     if ( aExp == 0 ) {
         aExp = 1;
@@ -4023,7 +4027,7 @@ float64 float64_mul(float64 a, float64 b, float_status *status)
         }
         if ( ( bExp | bSig ) == 0 ) {
             float_raise(float_flag_invalid, status);
-            return float64_default_nan;
+            return float64_default_nan(status);
         }
         return packFloat64( zSign, 0x7FF, 0 );
     }
@@ -4033,7 +4037,7 @@ float64 float64_mul(float64 a, float64 b, float_status *status)
         }
         if ( ( aExp | aSig ) == 0 ) {
             float_raise(float_flag_invalid, status);
-            return float64_default_nan;
+            return float64_default_nan(status);
         }
         return packFloat64( zSign, 0x7FF, 0 );
     }
@@ -4090,7 +4094,7 @@ float64 float64_div(float64 a, float64 b, float_status *status)
                 return propagateFloat64NaN(a, b, status);
             }
             float_raise(float_flag_invalid, status);
-            return float64_default_nan;
+            return float64_default_nan(status);
         }
         return packFloat64( zSign, 0x7FF, 0 );
     }
@@ -4104,7 +4108,7 @@ float64 float64_div(float64 a, float64 b, float_status *status)
         if ( bSig == 0 ) {
             if ( ( aExp | aSig ) == 0 ) {
                 float_raise(float_flag_invalid, status);
-                return float64_default_nan;
+                return float64_default_nan(status);
             }
             float_raise(float_flag_divbyzero, status);
             return packFloat64( zSign, 0x7FF, 0 );
@@ -4162,7 +4166,7 @@ float64 float64_rem(float64 a, float64 b, float_status *status)
             return propagateFloat64NaN(a, b, status);
         }
         float_raise(float_flag_invalid, status);
-        return float64_default_nan;
+        return float64_default_nan(status);
     }
     if ( bExp == 0x7FF ) {
         if (bSig) {
@@ -4173,7 +4177,7 @@ float64 float64_rem(float64 a, float64 b, float_status *status)
     if ( bExp == 0 ) {
         if ( bSig == 0 ) {
             float_raise(float_flag_invalid, status);
-            return float64_default_nan;
+            return float64_default_nan(status);
         }
         normalizeFloat64Subnormal( bSig, &bExp, &bSig );
     }
@@ -4275,7 +4279,7 @@ float64 float64_muladd(float64 a, float64 b, float64 c, int flags,
 
     if (infzero) {
         float_raise(float_flag_invalid, status);
-        return float64_default_nan;
+        return float64_default_nan(status);
     }
 
     if (flags & float_muladd_negate_c) {
@@ -4296,7 +4300,7 @@ float64 float64_muladd(float64 a, float64 b, float64 c, int flags,
         if (pInf && (pSign ^ cSign)) {
             /* addition of opposite-signed infinities => InvalidOperation */
             float_raise(float_flag_invalid, status);
-            return float64_default_nan;
+            return float64_default_nan(status);
         }
         /* Otherwise generate an infinity of the same sign */
         return packFloat64(cSign ^ signflip, 0x7ff, 0);
@@ -4494,12 +4498,12 @@ float64 float64_sqrt(float64 a, float_status *status)
         }
         if ( ! aSign ) return a;
         float_raise(float_flag_invalid, status);
-        return float64_default_nan;
+        return float64_default_nan(status);
     }
     if ( aSign ) {
         if ( ( aExp | aSig ) == 0 ) return a;
         float_raise(float_flag_invalid, status);
-        return float64_default_nan;
+        return float64_default_nan(status);
     }
     if ( aExp == 0 ) {
         if ( aSig == 0 ) return float64_zero;
@@ -4547,7 +4551,7 @@ float64 float64_log2(float64 a, float_status *status)
     }
     if ( aSign ) {
         float_raise(float_flag_invalid, status);
-        return float64_default_nan;
+        return float64_default_nan(status);
     }
     if ( aExp == 0x7FF ) {
         if (aSig) {
@@ -4694,7 +4698,8 @@ int float64_eq_quiet(float64 a, float64 b, float_status *status)
     if (    ( ( extractFloat64Exp( a ) == 0x7FF ) && extractFloat64Frac( a ) )
          || ( ( extractFloat64Exp( b ) == 0x7FF ) && extractFloat64Frac( b ) )
        ) {
-        if ( float64_is_signaling_nan( a ) || float64_is_signaling_nan( b ) ) {
+        if (float64_is_signaling_nan(a, status)
+         || float64_is_signaling_nan(b, status)) {
             float_raise(float_flag_invalid, status);
         }
         return 0;
@@ -4722,7 +4727,8 @@ int float64_le_quiet(float64 a, float64 b, float_status *status)
     if (    ( ( extractFloat64Exp( a ) == 0x7FF ) && extractFloat64Frac( a ) )
          || ( ( extractFloat64Exp( b ) == 0x7FF ) && extractFloat64Frac( b ) )
        ) {
-        if ( float64_is_signaling_nan( a ) || float64_is_signaling_nan( b ) ) {
+        if (float64_is_signaling_nan(a, status)
+         || float64_is_signaling_nan(b, status)) {
             float_raise(float_flag_invalid, status);
         }
         return 0;
@@ -4753,7 +4759,8 @@ int float64_lt_quiet(float64 a, float64 b, float_status *status)
     if (    ( ( extractFloat64Exp( a ) == 0x7FF ) && extractFloat64Frac( a ) )
          || ( ( extractFloat64Exp( b ) == 0x7FF ) && extractFloat64Frac( b ) )
        ) {
-        if ( float64_is_signaling_nan( a ) || float64_is_signaling_nan( b ) ) {
+        if (float64_is_signaling_nan(a, status)
+         || float64_is_signaling_nan(b, status)) {
             float_raise(float_flag_invalid, status);
         }
         return 0;
@@ -4782,7 +4789,8 @@ int float64_unordered_quiet(float64 a, float64 b, float_status *status)
     if (    ( ( extractFloat64Exp( a ) == 0x7FF ) && extractFloat64Frac( a ) )
          || ( ( extractFloat64Exp( b ) == 0x7FF ) && extractFloat64Frac( b ) )
        ) {
-        if ( float64_is_signaling_nan( a ) || float64_is_signaling_nan( b ) ) {
+        if (float64_is_signaling_nan(a, status)
+         || float64_is_signaling_nan(b, status)) {
             float_raise(float_flag_invalid, status);
         }
         return 1;
@@ -5207,7 +5215,6 @@ static floatx80 subFloatx80Sigs(floatx80 a, floatx80 b, flag zSign,
     int32_t aExp, bExp, zExp;
     uint64_t aSig, bSig, zSig0, zSig1;
     int32_t expDiff;
-    floatx80 z;
 
     aSig = extractFloatx80Frac( a );
     aExp = extractFloatx80Exp( a );
@@ -5221,9 +5228,7 @@ static floatx80 subFloatx80Sigs(floatx80 a, floatx80 b, flag zSign,
             return propagateFloatx80NaN(a, b, status);
         }
         float_raise(float_flag_invalid, status);
-        z.low = floatx80_default_nan_low;
-        z.high = floatx80_default_nan_high;
-        return z;
+        return floatx80_default_nan(status);
     }
     if ( aExp == 0 ) {
         aExp = 1;
@@ -5317,7 +5322,6 @@ floatx80 floatx80_mul(floatx80 a, floatx80 b, float_status *status)
     flag aSign, bSign, zSign;
     int32_t aExp, bExp, zExp;
     uint64_t aSig, bSig, zSig0, zSig1;
-    floatx80 z;
 
     aSig = extractFloatx80Frac( a );
     aExp = extractFloatx80Exp( a );
@@ -5341,9 +5345,7 @@ floatx80 floatx80_mul(floatx80 a, floatx80 b, float_status *status)
         if ( ( aExp | aSig ) == 0 ) {
  invalid:
             float_raise(float_flag_invalid, status);
-            z.low = floatx80_default_nan_low;
-            z.high = floatx80_default_nan_high;
-            return z;
+            return floatx80_default_nan(status);
         }
         return packFloatx80( zSign, 0x7FFF, LIT64( 0x8000000000000000 ) );
     }
@@ -5377,7 +5379,6 @@ floatx80 floatx80_div(floatx80 a, floatx80 b, float_status *status)
     int32_t aExp, bExp, zExp;
     uint64_t aSig, bSig, zSig0, zSig1;
     uint64_t rem0, rem1, rem2, term0, term1, term2;
-    floatx80 z;
 
     aSig = extractFloatx80Frac( a );
     aExp = extractFloatx80Exp( a );
@@ -5409,9 +5410,7 @@ floatx80 floatx80_div(floatx80 a, floatx80 b, float_status *status)
             if ( ( aExp | aSig ) == 0 ) {
  invalid:
                 float_raise(float_flag_invalid, status);
-                z.low = floatx80_default_nan_low;
-                z.high = floatx80_default_nan_high;
-                return z;
+                return floatx80_default_nan(status);
             }
             float_raise(float_flag_divbyzero, status);
             return packFloatx80( zSign, 0x7FFF, LIT64( 0x8000000000000000 ) );
@@ -5461,7 +5460,6 @@ floatx80 floatx80_rem(floatx80 a, floatx80 b, float_status *status)
     int32_t aExp, bExp, expDiff;
     uint64_t aSig0, aSig1, bSig;
     uint64_t q, term0, term1, alternateASig0, alternateASig1;
-    floatx80 z;
 
     aSig0 = extractFloatx80Frac( a );
     aExp = extractFloatx80Exp( a );
@@ -5485,9 +5483,7 @@ floatx80 floatx80_rem(floatx80 a, floatx80 b, float_status *status)
         if ( bSig == 0 ) {
  invalid:
             float_raise(float_flag_invalid, status);
-            z.low = floatx80_default_nan_low;
-            z.high = floatx80_default_nan_high;
-            return z;
+            return floatx80_default_nan(status);
         }
         normalizeFloatx80Subnormal( bSig, &bExp, &bSig );
     }
@@ -5559,7 +5555,6 @@ floatx80 floatx80_sqrt(floatx80 a, float_status *status)
     int32_t aExp, zExp;
     uint64_t aSig0, aSig1, zSig0, zSig1, doubleZSig0;
     uint64_t rem0, rem1, rem2, rem3, term0, term1, term2, term3;
-    floatx80 z;
 
     aSig0 = extractFloatx80Frac( a );
     aExp = extractFloatx80Exp( a );
@@ -5575,9 +5570,7 @@ floatx80 floatx80_sqrt(floatx80 a, float_status *status)
         if ( ( aExp | aSig0 ) == 0 ) return a;
  invalid:
         float_raise(float_flag_invalid, status);
-        z.low = floatx80_default_nan_low;
-        z.high = floatx80_default_nan_high;
-        return z;
+        return floatx80_default_nan(status);
     }
     if ( aExp == 0 ) {
         if ( aSig0 == 0 ) return packFloatx80( 0, 0, 0 );
@@ -5745,8 +5738,8 @@ int floatx80_eq_quiet(floatx80 a, floatx80 b, float_status *status)
          || (    ( extractFloatx80Exp( b ) == 0x7FFF )
               && (uint64_t) ( extractFloatx80Frac( b )<<1 ) )
        ) {
-        if (    floatx80_is_signaling_nan( a )
-             || floatx80_is_signaling_nan( b ) ) {
+        if (floatx80_is_signaling_nan(a, status)
+         || floatx80_is_signaling_nan(b, status)) {
             float_raise(float_flag_invalid, status);
         }
         return 0;
@@ -5776,8 +5769,8 @@ int floatx80_le_quiet(floatx80 a, floatx80 b, float_status *status)
          || (    ( extractFloatx80Exp( b ) == 0x7FFF )
               && (uint64_t) ( extractFloatx80Frac( b )<<1 ) )
        ) {
-        if (    floatx80_is_signaling_nan( a )
-             || floatx80_is_signaling_nan( b ) ) {
+        if (floatx80_is_signaling_nan(a, status)
+         || floatx80_is_signaling_nan(b, status)) {
             float_raise(float_flag_invalid, status);
         }
         return 0;
@@ -5812,8 +5805,8 @@ int floatx80_lt_quiet(floatx80 a, floatx80 b, float_status *status)
          || (    ( extractFloatx80Exp( b ) == 0x7FFF )
               && (uint64_t) ( extractFloatx80Frac( b )<<1 ) )
        ) {
-        if (    floatx80_is_signaling_nan( a )
-             || floatx80_is_signaling_nan( b ) ) {
+        if (floatx80_is_signaling_nan(a, status)
+         || floatx80_is_signaling_nan(b, status)) {
             float_raise(float_flag_invalid, status);
         }
         return 0;
@@ -5845,8 +5838,8 @@ int floatx80_unordered_quiet(floatx80 a, floatx80 b, float_status *status)
          || (    ( extractFloatx80Exp( b ) == 0x7FFF )
               && (uint64_t) ( extractFloatx80Frac( b )<<1 ) )
        ) {
-        if (    floatx80_is_signaling_nan( a )
-             || floatx80_is_signaling_nan( b ) ) {
+        if (floatx80_is_signaling_nan(a, status)
+         || floatx80_is_signaling_nan(b, status)) {
             float_raise(float_flag_invalid, status);
         }
         return 1;
@@ -6385,7 +6378,6 @@ static float128 subFloat128Sigs(float128 a, float128 b, flag zSign,
     int32_t aExp, bExp, zExp;
     uint64_t aSig0, aSig1, bSig0, bSig1, zSig0, zSig1;
     int32_t expDiff;
-    float128 z;
 
     aSig1 = extractFloat128Frac1( a );
     aSig0 = extractFloat128Frac0( a );
@@ -6403,9 +6395,7 @@ static float128 subFloat128Sigs(float128 a, float128 b, flag zSign,
             return propagateFloat128NaN(a, b, status);
         }
         float_raise(float_flag_invalid, status);
-        z.low = float128_default_nan_low;
-        z.high = float128_default_nan_high;
-        return z;
+        return float128_default_nan(status);
     }
     if ( aExp == 0 ) {
         aExp = 1;
@@ -6515,7 +6505,6 @@ float128 float128_mul(float128 a, float128 b, float_status *status)
     flag aSign, bSign, zSign;
     int32_t aExp, bExp, zExp;
     uint64_t aSig0, aSig1, bSig0, bSig1, zSig0, zSig1, zSig2, zSig3;
-    float128 z;
 
     aSig1 = extractFloat128Frac1( a );
     aSig0 = extractFloat128Frac0( a );
@@ -6541,9 +6530,7 @@ float128 float128_mul(float128 a, float128 b, float_status *status)
         if ( ( aExp | aSig0 | aSig1 ) == 0 ) {
  invalid:
             float_raise(float_flag_invalid, status);
-            z.low = float128_default_nan_low;
-            z.high = float128_default_nan_high;
-            return z;
+            return float128_default_nan(status);
         }
         return packFloat128( zSign, 0x7FFF, 0, 0 );
     }
@@ -6582,7 +6569,6 @@ float128 float128_div(float128 a, float128 b, float_status *status)
     int32_t aExp, bExp, zExp;
     uint64_t aSig0, aSig1, bSig0, bSig1, zSig0, zSig1, zSig2;
     uint64_t rem0, rem1, rem2, rem3, term0, term1, term2, term3;
-    float128 z;
 
     aSig1 = extractFloat128Frac1( a );
     aSig0 = extractFloat128Frac0( a );
@@ -6616,9 +6602,7 @@ float128 float128_div(float128 a, float128 b, float_status *status)
             if ( ( aExp | aSig0 | aSig1 ) == 0 ) {
  invalid:
                 float_raise(float_flag_invalid, status);
-                z.low = float128_default_nan_low;
-                z.high = float128_default_nan_high;
-                return z;
+                return float128_default_nan(status);
             }
             float_raise(float_flag_divbyzero, status);
             return packFloat128( zSign, 0x7FFF, 0, 0 );
@@ -6673,7 +6657,6 @@ float128 float128_rem(float128 a, float128 b, float_status *status)
     uint64_t aSig0, aSig1, bSig0, bSig1, q, term0, term1, term2;
     uint64_t allZero, alternateASig0, alternateASig1, sigMean1;
     int64_t sigMean0;
-    float128 z;
 
     aSig1 = extractFloat128Frac1( a );
     aSig0 = extractFloat128Frac0( a );
@@ -6699,9 +6682,7 @@ float128 float128_rem(float128 a, float128 b, float_status *status)
         if ( ( bSig0 | bSig1 ) == 0 ) {
  invalid:
             float_raise(float_flag_invalid, status);
-            z.low = float128_default_nan_low;
-            z.high = float128_default_nan_high;
-            return z;
+            return float128_default_nan(status);
         }
         normalizeFloat128Subnormal( bSig0, bSig1, &bExp, &bSig0, &bSig1 );
     }
@@ -6782,7 +6763,6 @@ float128 float128_sqrt(float128 a, float_status *status)
     int32_t aExp, zExp;
     uint64_t aSig0, aSig1, zSig0, zSig1, zSig2, doubleZSig0;
     uint64_t rem0, rem1, rem2, rem3, term0, term1, term2, term3;
-    float128 z;
 
     aSig1 = extractFloat128Frac1( a );
     aSig0 = extractFloat128Frac0( a );
@@ -6799,9 +6779,7 @@ float128 float128_sqrt(float128 a, float_status *status)
         if ( ( aExp | aSig0 | aSig1 ) == 0 ) return a;
  invalid:
         float_raise(float_flag_invalid, status);
-        z.low = float128_default_nan_low;
-        z.high = float128_default_nan_high;
-        return z;
+        return float128_default_nan(status);
     }
     if ( aExp == 0 ) {
         if ( ( aSig0 | aSig1 ) == 0 ) return packFloat128( 0, 0, 0, 0 );
@@ -6969,8 +6947,8 @@ int float128_eq_quiet(float128 a, float128 b, float_status *status)
          || (    ( extractFloat128Exp( b ) == 0x7FFF )
               && ( extractFloat128Frac0( b ) | extractFloat128Frac1( b ) ) )
        ) {
-        if (    float128_is_signaling_nan( a )
-             || float128_is_signaling_nan( b ) ) {
+        if (float128_is_signaling_nan(a, status)
+         || float128_is_signaling_nan(b, status)) {
             float_raise(float_flag_invalid, status);
         }
         return 0;
@@ -7000,8 +6978,8 @@ int float128_le_quiet(float128 a, float128 b, float_status *status)
          || (    ( extractFloat128Exp( b ) == 0x7FFF )
               && ( extractFloat128Frac0( b ) | extractFloat128Frac1( b ) ) )
        ) {
-        if (    float128_is_signaling_nan( a )
-             || float128_is_signaling_nan( b ) ) {
+        if (float128_is_signaling_nan(a, status)
+         || float128_is_signaling_nan(b, status)) {
             float_raise(float_flag_invalid, status);
         }
         return 0;
@@ -7036,8 +7014,8 @@ int float128_lt_quiet(float128 a, float128 b, float_status *status)
          || (    ( extractFloat128Exp( b ) == 0x7FFF )
               && ( extractFloat128Frac0( b ) | extractFloat128Frac1( b ) ) )
        ) {
-        if (    float128_is_signaling_nan( a )
-             || float128_is_signaling_nan( b ) ) {
+        if (float128_is_signaling_nan(a, status)
+         || float128_is_signaling_nan(b, status)) {
             float_raise(float_flag_invalid, status);
         }
         return 0;
@@ -7070,8 +7048,8 @@ int float128_unordered_quiet(float128 a, float128 b, float_status *status)
          || (    ( extractFloat128Exp( b ) == 0x7FFF )
               && ( extractFloat128Frac0( b ) | extractFloat128Frac1( b ) ) )
        ) {
-        if (    float128_is_signaling_nan( a )
-             || float128_is_signaling_nan( b ) ) {
+        if (float128_is_signaling_nan(a, status)
+         || float128_is_signaling_nan(b, status)) {
             float_raise(float_flag_invalid, status);
         }
         return 1;
@@ -7351,8 +7329,8 @@ static inline int float ## s ## _compare_internal(float ## s a, float ## s b,\
         ( ( extractFloat ## s ## Exp( b ) == nan_exp ) &&                    \
           extractFloat ## s ## Frac( b ) )) {                                \
         if (!is_quiet ||                                                     \
-            float ## s ## _is_signaling_nan( a ) ||                          \
-            float ## s ## _is_signaling_nan( b ) ) {                         \
+            float ## s ## _is_signaling_nan(a, status) ||                  \
+            float ## s ## _is_signaling_nan(b, status)) {                 \
             float_raise(float_flag_invalid, status);                         \
         }                                                                    \
         return float_relation_unordered;                                     \
@@ -7401,8 +7379,8 @@ static inline int floatx80_compare_internal(floatx80 a, floatx80 b,
         ( ( extractFloatx80Exp( b ) == 0x7fff ) &&
           ( extractFloatx80Frac( b )<<1 ) )) {
         if (!is_quiet ||
-            floatx80_is_signaling_nan( a ) ||
-            floatx80_is_signaling_nan( b ) ) {
+            floatx80_is_signaling_nan(a, status) ||
+            floatx80_is_signaling_nan(b, status)) {
             float_raise(float_flag_invalid, status);
         }
         return float_relation_unordered;
@@ -7447,8 +7425,8 @@ static inline int float128_compare_internal(float128 a, float128 b,
         ( ( extractFloat128Exp( b ) == 0x7fff ) &&
           ( extractFloat128Frac0( b ) | extractFloat128Frac1( b ) ) )) {
         if (!is_quiet ||
-            float128_is_signaling_nan( a ) ||
-            float128_is_signaling_nan( b ) ) {
+            float128_is_signaling_nan(a, status) ||
+            float128_is_signaling_nan(b, status)) {
             float_raise(float_flag_invalid, status);
         }
         return float_relation_unordered;
@@ -7508,11 +7486,11 @@ static inline float ## s float ## s ## _minmax(float ## s a, float ## s b,     \
     if (float ## s ## _is_any_nan(a) ||                                 \
         float ## s ## _is_any_nan(b)) {                                 \
         if (isieee) {                                                   \
-            if (float ## s ## _is_quiet_nan(a) &&                       \
+            if (float ## s ## _is_quiet_nan(a, status) &&               \
                 !float ## s ##_is_any_nan(b)) {                         \
                 return b;                                               \
-            } else if (float ## s ## _is_quiet_nan(b) &&                \
-                       !float ## s ## _is_any_nan(a)) {                 \
+            } else if (float ## s ## _is_quiet_nan(b, status) &&        \
+                       !float ## s ## _is_any_nan(a)) {                \
                 return a;                                               \
             }                                                           \
         }                                                               \