softfloat: pass float_status pointer to pickNaN

Pass float_status structure pointer to the pickNaN so that
machine-specific settings are available to NaN selection code.
Add use_first_nan property to float_status and use it in Xtensa-specific
pickNaN.

Backports commit 913602e3ffe6bf50b869a14028a55cb267645ba3
This commit is contained in:
Max Filippov 2021-02-26 12:15:59 -05:00 committed by Lioncash
parent db780eff66
commit fee4c62fe4
4 changed files with 31 additions and 7 deletions

View file

@ -380,7 +380,7 @@ static float32 commonNaNToFloat32(commonNaNT a, float_status *status)
*----------------------------------------------------------------------------*/
static int pickNaN(FloatClass a_cls, FloatClass b_cls,
bool aIsLargerSignificand)
bool aIsLargerSignificand, float_status *status)
{
#if defined(TARGET_ARM) || defined(TARGET_MIPS) || defined(TARGET_HPPA)
/* ARM mandated NaN propagation rules (see FPProcessNaNs()), take
@ -413,7 +413,7 @@ static int pickNaN(FloatClass a_cls, FloatClass b_cls,
} else {
return 1;
}
#elif defined(TARGET_PPC) || defined(TARGET_XTENSA) || defined(TARGET_M68K)
#elif defined(TARGET_PPC) || defined(TARGET_M68K)
/* PowerPC propagation rules:
* 1. A if it sNaN or qNaN
* 2. B if it sNaN or qNaN
@ -438,6 +438,24 @@ static int pickNaN(FloatClass a_cls, FloatClass b_cls,
} else {
return 1;
}
#elif defined(TARGET_XTENSA)
/*
* Xtensa has two NaN propagation modes.
* Which one is active is controlled by float_status::use_first_nan.
*/
if (status->use_first_nan) {
if (is_nan(a_cls)) {
return 0;
} else {
return 1;
}
} else {
if (is_nan(b_cls)) {
return 1;
} else {
return 0;
}
}
#else
/* This implements x87 NaN propagation rules:
* SNaN + QNaN => return the QNaN
@ -617,7 +635,7 @@ static float32 propagateFloat32NaN(float32 a, float32 b, float_status *status)
aIsLargerSignificand = (av < bv) ? 1 : 0;
}
if (pickNaN(a_cls, b_cls, aIsLargerSignificand)) {
if (pickNaN(a_cls, b_cls, aIsLargerSignificand, status)) {
if (is_snan(b_cls)) {
return float32_silence_nan(b, status);
}
@ -755,7 +773,7 @@ static float64 propagateFloat64NaN(float64 a, float64 b, float_status *status)
aIsLargerSignificand = (av < bv) ? 1 : 0;
}
if (pickNaN(a_cls, b_cls, aIsLargerSignificand)) {
if (pickNaN(a_cls, b_cls, aIsLargerSignificand, status)) {
if (is_snan(b_cls)) {
return float64_silence_nan(b, status);
}
@ -919,7 +937,7 @@ floatx80 propagateFloatx80NaN(floatx80 a, floatx80 b, float_status *status)
aIsLargerSignificand = (a.high < b.high) ? 1 : 0;
}
if (pickNaN(a_cls, b_cls, aIsLargerSignificand)) {
if (pickNaN(a_cls, b_cls, aIsLargerSignificand, status)) {
if (is_snan(b_cls)) {
return floatx80_silence_nan(b, status);
}
@ -1067,7 +1085,7 @@ static float128 propagateFloat128NaN(float128 a, float128 b,
aIsLargerSignificand = (a.high < b.high) ? 1 : 0;
}
if (pickNaN(a_cls, b_cls, aIsLargerSignificand)) {
if (pickNaN(a_cls, b_cls, aIsLargerSignificand, status)) {
if (is_snan(b_cls)) {
return float128_silence_nan(b, status);
}

View file

@ -882,7 +882,7 @@ static FloatParts pick_nan(FloatParts a, FloatParts b, float_status *s)
} else {
if (pickNaN(a.cls, b.cls,
a.frac > b.frac ||
(a.frac == b.frac && a.sign < b.sign))) {
(a.frac == b.frac && a.sign < b.sign), s)) {
a = b;
}
if (is_snan(a.cls)) {

View file

@ -95,6 +95,11 @@ static inline void set_snan_bit_is_one(bool val, float_status *status)
status->snan_bit_is_one = val;
}
static inline void set_use_first_nan(bool val, float_status *status)
{
status->use_first_nan = val;
}
static inline void set_no_signaling_nans(bool val, float_status *status)
{
status->no_signaling_nans = val;

View file

@ -171,6 +171,7 @@ typedef struct float_status {
* softfloat-specialize.inc.c)
*/
bool snan_bit_is_one;
bool use_first_nan;
bool no_signaling_nans;
} float_status;