[Qemu-devel] [PATCH 4/6] softfloat: use float{32, 64, x80, 128}_maybe_silence_nan()

[Aurelien Jarno]

Use float{32,64,x80,128}_maybe_silence_nan() instead of toggling the
sNaN bit manually. This allow per target implementation of sNaN to qNaN
conversion.

Signed-off-by: Aurelien Jarno <aurel...@aurel32.net>
---
 fpu/softfloat-specialize.h |   55 +++++++++++++------------------------------
 1 files changed, 17 insertions(+), 38 deletions(-)

diff --git a/fpu/softfloat-specialize.h b/fpu/softfloat-specialize.h
index 49e3cc2..4deb165 100644
--- a/fpu/softfloat-specialize.h
+++ b/fpu/softfloat-specialize.h
@@ -228,7 +228,7 @@ static int pickNaN(flag aIsQNaN, flag aIsSNaN, flag 
bIsQNaN, flag bIsSNaN,
 static float32 propagateFloat32NaN( float32 a, float32 b STATUS_PARAM)
 {
     flag aIsNaN, aIsSignalingNaN, bIsNaN, bIsSignalingNaN, 
aIsLargerSignificand;
-    bits32 av, bv, res;
+    bits32 av, bv;
 
     if ( STATUS(default_nan_mode) )
         return float32_default_nan;
@@ -237,15 +237,11 @@ static float32 propagateFloat32NaN( float32 a, float32 b 
STATUS_PARAM)
     aIsSignalingNaN = float32_is_signaling_nan( a );
     bIsNaN = float32_is_quiet_nan( b );
     bIsSignalingNaN = float32_is_signaling_nan( b );
+    a = float32_maybe_silence_nan(a);
+    b = float32_maybe_silence_nan(b);
     av = float32_val(a);
     bv = float32_val(b);
-#if SNAN_BIT_IS_ONE
-    av &= ~0x00400000;
-    bv &= ~0x00400000;
-#else
-    av |= 0x00400000;
-    bv |= 0x00400000;
-#endif
+
     if ( aIsSignalingNaN | bIsSignalingNaN ) float_raise( float_flag_invalid 
STATUS_VAR);
 
     if ((bits32)(av<<1) < (bits32)(bv<<1)) {
@@ -258,12 +254,10 @@ static float32 propagateFloat32NaN( float32 a, float32 b 
STATUS_PARAM)
 
     if (pickNaN(aIsNaN, aIsSignalingNaN, bIsNaN, bIsSignalingNaN,
                 aIsLargerSignificand)) {
-        res = bv;
+        return b;
     } else {
-        res = av;
+        return a;
     }
-
-    return make_float32(res);
 }
 
 /*----------------------------------------------------------------------------
@@ -376,7 +370,7 @@ static float64 commonNaNToFloat64( commonNaNT a )
 static float64 propagateFloat64NaN( float64 a, float64 b STATUS_PARAM)
 {
     flag aIsNaN, aIsSignalingNaN, bIsNaN, bIsSignalingNaN, 
aIsLargerSignificand;
-    bits64 av, bv, res;
+    bits64 av, bv;
 
     if ( STATUS(default_nan_mode) )
         return float64_default_nan;
@@ -385,15 +379,10 @@ static float64 propagateFloat64NaN( float64 a, float64 b 
STATUS_PARAM)
     aIsSignalingNaN = float64_is_signaling_nan( a );
     bIsNaN = float64_is_quiet_nan( b );
     bIsSignalingNaN = float64_is_signaling_nan( b );
+    a = float64_maybe_silence_nan(a);
+    b = float64_maybe_silence_nan(b);
     av = float64_val(a);
     bv = float64_val(b);
-#if SNAN_BIT_IS_ONE
-    av &= ~LIT64( 0x0008000000000000 );
-    bv &= ~LIT64( 0x0008000000000000 );
-#else
-    av |= LIT64( 0x0008000000000000 );
-    bv |= LIT64( 0x0008000000000000 );
-#endif
     if ( aIsSignalingNaN | bIsSignalingNaN ) float_raise( float_flag_invalid 
STATUS_VAR);
 
     if ((bits64)(av<<1) < (bits64)(bv<<1)) {
@@ -406,12 +395,10 @@ static float64 propagateFloat64NaN( float64 a, float64 b 
STATUS_PARAM)
 
     if (pickNaN(aIsNaN, aIsSignalingNaN, bIsNaN, bIsSignalingNaN,
                 aIsLargerSignificand)) {
-        res = bv;
+        return b;
     } else {
-        res = av;
+        return a;
     }
-
-    return make_float64(res);
 }
 
 #ifdef FLOATX80
@@ -542,13 +529,9 @@ static floatx80 propagateFloatx80NaN( floatx80 a, floatx80 
b STATUS_PARAM)
     aIsSignalingNaN = floatx80_is_signaling_nan( a );
     bIsNaN = floatx80_is_quiet_nan( b );
     bIsSignalingNaN = floatx80_is_signaling_nan( b );
-#if SNAN_BIT_IS_ONE
-    a.low &= ~LIT64( 0xC000000000000000 );
-    b.low &= ~LIT64( 0xC000000000000000 );
-#else
-    a.low |= LIT64( 0xC000000000000000 );
-    b.low |= LIT64( 0xC000000000000000 );
-#endif
+    a = floatx80_maybe_silence_nan(a);
+    a = floatx80_maybe_silence_nan(b);
+
     if ( aIsSignalingNaN | bIsSignalingNaN ) float_raise( float_flag_invalid 
STATUS_VAR);
 
     if (a.low < b.low) {
@@ -688,13 +671,9 @@ static float128 propagateFloat128NaN( float128 a, float128 
b STATUS_PARAM)
     aIsSignalingNaN = float128_is_signaling_nan( a );
     bIsNaN = float128_is_quiet_nan( b );
     bIsSignalingNaN = float128_is_signaling_nan( b );
-#if SNAN_BIT_IS_ONE
-    a.high &= ~LIT64( 0x0000800000000000 );
-    b.high &= ~LIT64( 0x0000800000000000 );
-#else
-    a.high |= LIT64( 0x0000800000000000 );
-    b.high |= LIT64( 0x0000800000000000 );
-#endif
+    a = float128_maybe_silence_nan(a);
+    b = float128_maybe_silence_nan(b);
+
     if ( aIsSignalingNaN | bIsSignalingNaN ) float_raise( float_flag_invalid 
STATUS_VAR);
 
     if (lt128(a.high<<1, a.low, b.high<<1, b.low)) {
-- 
1.7.2.3