fpu/softfloat: Use float*_silence_nan in propagateFloat*NaN

We have already checked the arguments for SNaN;
we don't need to do it again.

Backports commit 4885312f47c0b3607e36d0568db3d717a79e51a3 from qemu
This commit is contained in:
Richard Henderson 2018-05-19 23:27:32 -04:00 committed by Lioncash
parent 4c8b31e7fe
commit 2eb50e8117
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@ -498,7 +498,7 @@ static float32 commonNaNToFloat32(commonNaNT a, float_status *status)
| The routine is passed various bits of information about the
| two NaNs and should return 0 to select NaN a and 1 for NaN b.
| Note that signalling NaNs are always squashed to quiet NaNs
| by the caller, by calling floatXX_maybe_silence_nan() before
| by the caller, by calling floatXX_silence_nan() before
| returning them.
|
| aIsLargerSignificand is only valid if both a and b are NaNs
@ -536,7 +536,7 @@ static int pickNaN(flag aIsQNaN, flag aIsSNaN, flag bIsQNaN, flag bIsSNaN,
{
/* According to MIPS specifications, if one of the two operands is
* a sNaN, a new qNaN has to be generated. This is done in
* floatXX_maybe_silence_nan(). For qNaN inputs the specifications
* floatXX_silence_nan(). For qNaN inputs the specifications
* says: "When possible, this QNaN result is one of the operand QNaN
* values." In practice it seems that most implementations choose
* the first operand if both operands are qNaN. In short this gives
@ -788,9 +788,15 @@ static float32 propagateFloat32NaN(float32 a, float32 b, float_status *status)
if (pickNaN(aIsQuietNaN, aIsSignalingNaN, bIsQuietNaN, bIsSignalingNaN,
aIsLargerSignificand)) {
return float32_maybe_silence_nan(b, status);
if (bIsSignalingNaN) {
return float32_silence_nan(b, status);
}
return b;
} else {
return float32_maybe_silence_nan(a, status);
if (aIsSignalingNaN) {
return float32_silence_nan(a, status);
}
return a;
}
}
@ -950,9 +956,15 @@ static float64 propagateFloat64NaN(float64 a, float64 b, float_status *status)
if (pickNaN(aIsQuietNaN, aIsSignalingNaN, bIsQuietNaN, bIsSignalingNaN,
aIsLargerSignificand)) {
return float64_maybe_silence_nan(b, status);
if (bIsSignalingNaN) {
return float64_silence_nan(b, status);
}
return b;
} else {
return float64_maybe_silence_nan(a, status);
if (aIsSignalingNaN) {
return float64_silence_nan(a, status);
}
return a;
}
}
@ -1121,9 +1133,15 @@ floatx80 propagateFloatx80NaN(floatx80 a, floatx80 b, float_status *status)
if (pickNaN(aIsQuietNaN, aIsSignalingNaN, bIsQuietNaN, bIsSignalingNaN,
aIsLargerSignificand)) {
return floatx80_maybe_silence_nan(b, status);
if (bIsSignalingNaN) {
return floatx80_silence_nan(b, status);
}
return b;
} else {
return floatx80_maybe_silence_nan(a, status);
if (aIsSignalingNaN) {
return floatx80_silence_nan(a, status);
}
return a;
}
}
@ -1270,8 +1288,14 @@ static float128 propagateFloat128NaN(float128 a, float128 b,
if (pickNaN(aIsQuietNaN, aIsSignalingNaN, bIsQuietNaN, bIsSignalingNaN,
aIsLargerSignificand)) {
return float128_maybe_silence_nan(b, status);
if (bIsSignalingNaN) {
return float128_silence_nan(b, status);
}
return b;
} else {
return float128_maybe_silence_nan(a, status);
if (aIsSignalingNaN) {
return float128_silence_nan(a, status);
}
return a;
}
}