Implement default-NaN mode.

Signed-off-by: Paul Brook <paul@codesourcery.com>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6106 c046a42c-6fe2-441c-8c8c-71466251a162

diff --git a/fpu/softfloat-specialize.h b/fpu/softfloat-specialize.h
index 166b913..d279210 100644 (file)
--- a/fpu/softfloat-specialize.h
+++ b/fpu/softfloat-specialize.h
@@ -144,6 +144,9 @@ static float32 propagateFloat32NaN( float32 a, float32 b STATUS_PARAM)
     flag aIsNaN, aIsSignalingNaN, bIsNaN, bIsSignalingNaN;
     bits32 av, bv, res;
 
+    if ( STATUS(default_nan_mode) )
+        return float32_default_nan;
+
     aIsNaN = float32_is_nan( a );
     aIsSignalingNaN = float32_is_signaling_nan( a );
     bIsNaN = float32_is_nan( b );
@@ -276,6 +279,9 @@ static float64 propagateFloat64NaN( float64 a, float64 b STATUS_PARAM)
     flag aIsNaN, aIsSignalingNaN, bIsNaN, bIsSignalingNaN;
     bits64 av, bv, res;
 
+    if ( STATUS(default_nan_mode) )
+        return float64_default_nan;
+
     aIsNaN = float64_is_nan( a );
     aIsSignalingNaN = float64_is_signaling_nan( a );
     bIsNaN = float64_is_nan( b );
@@ -412,6 +418,12 @@ static floatx80 propagateFloatx80NaN( floatx80 a, floatx80 b STATUS_PARAM)
 {
     flag aIsNaN, aIsSignalingNaN, bIsNaN, bIsSignalingNaN;
 
+    if ( STATUS(default_nan_mode) ) {
+        a.low = floatx80_default_nan_low;
+        a.high = floatx80_default_nan_high;
+        return a;
+    }
+
     aIsNaN = floatx80_is_nan( a );
     aIsSignalingNaN = floatx80_is_signaling_nan( a );
     bIsNaN = floatx80_is_nan( b );
@@ -532,6 +544,12 @@ static float128 propagateFloat128NaN( float128 a, float128 b STATUS_PARAM)
 {
     flag aIsNaN, aIsSignalingNaN, bIsNaN, bIsSignalingNaN;
 
+    if ( STATUS(default_nan_mode) ) {
+        a.low = float128_default_nan_low;
+        a.high = float128_default_nan_high;
+        return a;
+    }
+
     aIsNaN = float128_is_nan( a );
     aIsSignalingNaN = float128_is_signaling_nan( a );
     bIsNaN = float128_is_nan( b );

diff --git a/fpu/softfloat.h b/fpu/softfloat.h
index 9061f03..6cd4fac 100644 (file)
--- a/fpu/softfloat.h
+++ b/fpu/softfloat.h
@@ -190,10 +190,15 @@ typedef struct float_status {
 #ifdef FLOATX80
     signed char floatx80_rounding_precision;
 #endif
+    flag default_nan_mode;
 } float_status;
 
 void set_float_rounding_mode(int val STATUS_PARAM);
 void set_float_exception_flags(int val STATUS_PARAM);
+INLINE void set_default_nan_mode(flag val STATUS_PARAM)
+{
+    STATUS(default_nan_mode) = val;
+}
 INLINE int get_float_exception_flags(float_status *status)
 {
     return STATUS(float_exception_flags);

diff --git a/target-arm/helper.c b/target-arm/helper.c
index 14f19a9..79163b8 100644 (file)
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -2334,6 +2334,8 @@ void HELPER(vfp_set_fpscr)(CPUState *env, uint32_t val)
         }
         set_float_rounding_mode(i, &env->vfp.fp_status);
     }
+    if (changed & (1 << 25))
+        set_default_nan_mode((val & (1 << 25)) != 0, &env->vfp.fp_status);
 
     i = vfp_exceptbits_to_host((val >> 8) & 0x1f);
     set_float_exception_flags(i, &env->vfp.fp_status);