fpu/softfloat: Pass FloatClass to pickNaN

For each operand, pass a single enumeration instead of a pair of booleans.
The commit also merges multiple different ifdef-selected implementations
of pickNaN into a single function whose body is ifdef-selected.

Tested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2018-05-10 15:21:31 -07:00
parent 247d1f2190
commit 4f251cfd52
2 changed files with 82 additions and 89 deletions

View File

@ -501,10 +501,10 @@ static float32 commonNaNToFloat32(commonNaNT a, float_status *status)
| tie-break rule. | tie-break rule.
*----------------------------------------------------------------------------*/ *----------------------------------------------------------------------------*/
#if defined(TARGET_ARM) static int pickNaN(FloatClass a_cls, FloatClass b_cls,
static int pickNaN(flag aIsQNaN, flag aIsSNaN, flag bIsQNaN, flag bIsSNaN,
flag aIsLargerSignificand) flag aIsLargerSignificand)
{ {
#if defined(TARGET_ARM) || defined(TARGET_MIPS) || defined(TARGET_HPPA)
/* ARM mandated NaN propagation rules (see FPProcessNaNs()), take /* ARM mandated NaN propagation rules (see FPProcessNaNs()), take
* the first of: * the first of:
* 1. A if it is signaling * 1. A if it is signaling
@ -513,20 +513,6 @@ static int pickNaN(flag aIsQNaN, flag aIsSNaN, flag bIsQNaN, flag bIsSNaN,
* 4. B (quiet) * 4. B (quiet)
* A signaling NaN is always quietened before returning it. * A signaling NaN is always quietened before returning it.
*/ */
if (aIsSNaN) {
return 0;
} else if (bIsSNaN) {
return 1;
} else if (aIsQNaN) {
return 0;
} else {
return 1;
}
}
#elif defined(TARGET_MIPS) || defined(TARGET_HPPA)
static int pickNaN(flag aIsQNaN, flag aIsSNaN, flag bIsQNaN, flag bIsSNaN,
flag aIsLargerSignificand)
{
/* According to MIPS specifications, if one of the two operands is /* According to MIPS specifications, if one of the two operands is
* a sNaN, a new qNaN has to be generated. This is done in * a sNaN, a new qNaN has to be generated. This is done in
* floatXX_silence_nan(). For qNaN inputs the specifications * floatXX_silence_nan(). For qNaN inputs the specifications
@ -540,35 +526,21 @@ static int pickNaN(flag aIsQNaN, flag aIsSNaN, flag bIsQNaN, flag bIsSNaN,
* 4. B (quiet) * 4. B (quiet)
* A signaling NaN is always silenced before returning it. * A signaling NaN is always silenced before returning it.
*/ */
if (aIsSNaN) { if (is_snan(a_cls)) {
return 0; return 0;
} else if (bIsSNaN) { } else if (is_snan(b_cls)) {
return 1; return 1;
} else if (aIsQNaN) { } else if (is_qnan(a_cls)) {
return 0; return 0;
} else { } else {
return 1; return 1;
} }
} #elif defined(TARGET_PPC) || defined(TARGET_XTENSA) || defined(TARGET_M68K)
#elif defined(TARGET_PPC) || defined(TARGET_XTENSA)
static int pickNaN(flag aIsQNaN, flag aIsSNaN, flag bIsQNaN, flag bIsSNaN,
flag aIsLargerSignificand)
{
/* PowerPC propagation rules: /* PowerPC propagation rules:
* 1. A if it sNaN or qNaN * 1. A if it sNaN or qNaN
* 2. B if it sNaN or qNaN * 2. B if it sNaN or qNaN
* A signaling NaN is always silenced before returning it. * A signaling NaN is always silenced before returning it.
*/ */
if (aIsSNaN || aIsQNaN) {
return 0;
} else {
return 1;
}
}
#elif defined(TARGET_M68K)
static int pickNaN(flag aIsQNaN, flag aIsSNaN, flag bIsQNaN, flag bIsSNaN,
flag aIsLargerSignificand)
{
/* M68000 FAMILY PROGRAMMER'S REFERENCE MANUAL /* M68000 FAMILY PROGRAMMER'S REFERENCE MANUAL
* 3.4 FLOATING-POINT INSTRUCTION DETAILS * 3.4 FLOATING-POINT INSTRUCTION DETAILS
* If either operand, but not both operands, of an operation is a * If either operand, but not both operands, of an operation is a
@ -583,16 +555,12 @@ static int pickNaN(flag aIsQNaN, flag aIsSNaN, flag bIsQNaN, flag bIsSNaN,
* a nonsignaling NaN. The operation then continues as described in the * a nonsignaling NaN. The operation then continues as described in the
* preceding paragraph for nonsignaling NaNs. * preceding paragraph for nonsignaling NaNs.
*/ */
if (aIsQNaN || aIsSNaN) { /* a is the destination operand */ if (is_nan(a_cls)) {
return 0; /* return the destination operand */ return 0;
} else { } else {
return 1; /* return b */ return 1;
}
} }
#else #else
static int pickNaN(flag aIsQNaN, flag aIsSNaN, flag bIsQNaN, flag bIsSNaN,
flag aIsLargerSignificand)
{
/* This implements x87 NaN propagation rules: /* This implements x87 NaN propagation rules:
* SNaN + QNaN => return the QNaN * SNaN + QNaN => return the QNaN
* two SNaNs => return the one with the larger significand, silenced * two SNaNs => return the one with the larger significand, silenced
@ -603,13 +571,13 @@ static int pickNaN(flag aIsQNaN, flag aIsSNaN, flag bIsQNaN, flag bIsSNaN,
* If we get down to comparing significands and they are the same, * If we get down to comparing significands and they are the same,
* return the NaN with the positive sign bit (if any). * return the NaN with the positive sign bit (if any).
*/ */
if (aIsSNaN) { if (is_snan(a_cls)) {
if (bIsSNaN) { if (is_snan(b_cls)) {
return aIsLargerSignificand ? 0 : 1; return aIsLargerSignificand ? 0 : 1;
} }
return bIsQNaN ? 1 : 0; return is_qnan(b_cls) ? 1 : 0;
} else if (aIsQNaN) { } else if (is_qnan(a_cls)) {
if (bIsSNaN || !bIsQNaN) { if (is_snan(b_cls) || !is_qnan(b_cls)) {
return 0; return 0;
} else { } else {
return aIsLargerSignificand ? 0 : 1; return aIsLargerSignificand ? 0 : 1;
@ -617,8 +585,8 @@ static int pickNaN(flag aIsQNaN, flag aIsSNaN, flag bIsQNaN, flag bIsSNaN,
} else { } else {
return 1; return 1;
} }
}
#endif #endif
}
/*---------------------------------------------------------------------------- /*----------------------------------------------------------------------------
| Select which NaN to propagate for a three-input operation. | Select which NaN to propagate for a three-input operation.
@ -752,18 +720,26 @@ static int pickNaNMulAdd(flag aIsQNaN, flag aIsSNaN, flag bIsQNaN, flag bIsSNaN,
static float32 propagateFloat32NaN(float32 a, float32 b, float_status *status) static float32 propagateFloat32NaN(float32 a, float32 b, float_status *status)
{ {
flag aIsQuietNaN, aIsSignalingNaN, bIsQuietNaN, bIsSignalingNaN;
flag aIsLargerSignificand; flag aIsLargerSignificand;
uint32_t av, bv; uint32_t av, bv;
FloatClass a_cls, b_cls;
/* This is not complete, but is good enough for pickNaN. */
a_cls = (!float32_is_any_nan(a)
? float_class_normal
: float32_is_signaling_nan(a, status)
? float_class_snan
: float_class_qnan);
b_cls = (!float32_is_any_nan(b)
? float_class_normal
: float32_is_signaling_nan(b, status)
? float_class_snan
: float_class_qnan);
aIsQuietNaN = float32_is_quiet_nan(a, status);
aIsSignalingNaN = float32_is_signaling_nan(a, status);
bIsQuietNaN = float32_is_quiet_nan(b, status);
bIsSignalingNaN = float32_is_signaling_nan(b, status);
av = float32_val(a); av = float32_val(a);
bv = float32_val(b); bv = float32_val(b);
if (aIsSignalingNaN | bIsSignalingNaN) { if (is_snan(a_cls) || is_snan(b_cls)) {
float_raise(float_flag_invalid, status); float_raise(float_flag_invalid, status);
} }
@ -779,14 +755,13 @@ static float32 propagateFloat32NaN(float32 a, float32 b, float_status *status)
aIsLargerSignificand = (av < bv) ? 1 : 0; aIsLargerSignificand = (av < bv) ? 1 : 0;
} }
if (pickNaN(aIsQuietNaN, aIsSignalingNaN, bIsQuietNaN, bIsSignalingNaN, if (pickNaN(a_cls, b_cls, aIsLargerSignificand)) {
aIsLargerSignificand)) { if (is_snan(b_cls)) {
if (bIsSignalingNaN) {
return float32_silence_nan(b, status); return float32_silence_nan(b, status);
} }
return b; return b;
} else { } else {
if (aIsSignalingNaN) { if (is_snan(a_cls)) {
return float32_silence_nan(a, status); return float32_silence_nan(a, status);
} }
return a; return a;
@ -908,18 +883,26 @@ static float64 commonNaNToFloat64(commonNaNT a, float_status *status)
static float64 propagateFloat64NaN(float64 a, float64 b, float_status *status) static float64 propagateFloat64NaN(float64 a, float64 b, float_status *status)
{ {
flag aIsQuietNaN, aIsSignalingNaN, bIsQuietNaN, bIsSignalingNaN;
flag aIsLargerSignificand; flag aIsLargerSignificand;
uint64_t av, bv; uint64_t av, bv;
FloatClass a_cls, b_cls;
/* This is not complete, but is good enough for pickNaN. */
a_cls = (!float64_is_any_nan(a)
? float_class_normal
: float64_is_signaling_nan(a, status)
? float_class_snan
: float_class_qnan);
b_cls = (!float64_is_any_nan(b)
? float_class_normal
: float64_is_signaling_nan(b, status)
? float_class_snan
: float_class_qnan);
aIsQuietNaN = float64_is_quiet_nan(a, status);
aIsSignalingNaN = float64_is_signaling_nan(a, status);
bIsQuietNaN = float64_is_quiet_nan(b, status);
bIsSignalingNaN = float64_is_signaling_nan(b, status);
av = float64_val(a); av = float64_val(a);
bv = float64_val(b); bv = float64_val(b);
if (aIsSignalingNaN | bIsSignalingNaN) { if (is_snan(a_cls) || is_snan(b_cls)) {
float_raise(float_flag_invalid, status); float_raise(float_flag_invalid, status);
} }
@ -935,14 +918,13 @@ static float64 propagateFloat64NaN(float64 a, float64 b, float_status *status)
aIsLargerSignificand = (av < bv) ? 1 : 0; aIsLargerSignificand = (av < bv) ? 1 : 0;
} }
if (pickNaN(aIsQuietNaN, aIsSignalingNaN, bIsQuietNaN, bIsSignalingNaN, if (pickNaN(a_cls, b_cls, aIsLargerSignificand)) {
aIsLargerSignificand)) { if (is_snan(b_cls)) {
if (bIsSignalingNaN) {
return float64_silence_nan(b, status); return float64_silence_nan(b, status);
} }
return b; return b;
} else { } else {
if (aIsSignalingNaN) { if (is_snan(a_cls)) {
return float64_silence_nan(a, status); return float64_silence_nan(a, status);
} }
return a; return a;
@ -1075,15 +1057,22 @@ static floatx80 commonNaNToFloatx80(commonNaNT a, float_status *status)
floatx80 propagateFloatx80NaN(floatx80 a, floatx80 b, float_status *status) floatx80 propagateFloatx80NaN(floatx80 a, floatx80 b, float_status *status)
{ {
flag aIsQuietNaN, aIsSignalingNaN, bIsQuietNaN, bIsSignalingNaN;
flag aIsLargerSignificand; flag aIsLargerSignificand;
FloatClass a_cls, b_cls;
aIsQuietNaN = floatx80_is_quiet_nan(a, status); /* This is not complete, but is good enough for pickNaN. */
aIsSignalingNaN = floatx80_is_signaling_nan(a, status); a_cls = (!floatx80_is_any_nan(a)
bIsQuietNaN = floatx80_is_quiet_nan(b, status); ? float_class_normal
bIsSignalingNaN = floatx80_is_signaling_nan(b, status); : floatx80_is_signaling_nan(a, status)
? float_class_snan
: float_class_qnan);
b_cls = (!floatx80_is_any_nan(b)
? float_class_normal
: floatx80_is_signaling_nan(b, status)
? float_class_snan
: float_class_qnan);
if (aIsSignalingNaN | bIsSignalingNaN) { if (is_snan(a_cls) || is_snan(b_cls)) {
float_raise(float_flag_invalid, status); float_raise(float_flag_invalid, status);
} }
@ -1099,14 +1088,13 @@ floatx80 propagateFloatx80NaN(floatx80 a, floatx80 b, float_status *status)
aIsLargerSignificand = (a.high < b.high) ? 1 : 0; aIsLargerSignificand = (a.high < b.high) ? 1 : 0;
} }
if (pickNaN(aIsQuietNaN, aIsSignalingNaN, bIsQuietNaN, bIsSignalingNaN, if (pickNaN(a_cls, b_cls, aIsLargerSignificand)) {
aIsLargerSignificand)) { if (is_snan(b_cls)) {
if (bIsSignalingNaN) {
return floatx80_silence_nan(b, status); return floatx80_silence_nan(b, status);
} }
return b; return b;
} else { } else {
if (aIsSignalingNaN) { if (is_snan(a_cls)) {
return floatx80_silence_nan(a, status); return floatx80_silence_nan(a, status);
} }
return a; return a;
@ -1217,15 +1205,22 @@ static float128 commonNaNToFloat128(commonNaNT a, float_status *status)
static float128 propagateFloat128NaN(float128 a, float128 b, static float128 propagateFloat128NaN(float128 a, float128 b,
float_status *status) float_status *status)
{ {
flag aIsQuietNaN, aIsSignalingNaN, bIsQuietNaN, bIsSignalingNaN;
flag aIsLargerSignificand; flag aIsLargerSignificand;
FloatClass a_cls, b_cls;
aIsQuietNaN = float128_is_quiet_nan(a, status); /* This is not complete, but is good enough for pickNaN. */
aIsSignalingNaN = float128_is_signaling_nan(a, status); a_cls = (!float128_is_any_nan(a)
bIsQuietNaN = float128_is_quiet_nan(b, status); ? float_class_normal
bIsSignalingNaN = float128_is_signaling_nan(b, status); : float128_is_signaling_nan(a, status)
? float_class_snan
: float_class_qnan);
b_cls = (!float128_is_any_nan(b)
? float_class_normal
: float128_is_signaling_nan(b, status)
? float_class_snan
: float_class_qnan);
if (aIsSignalingNaN | bIsSignalingNaN) { if (is_snan(a_cls) || is_snan(b_cls)) {
float_raise(float_flag_invalid, status); float_raise(float_flag_invalid, status);
} }
@ -1241,14 +1236,13 @@ static float128 propagateFloat128NaN(float128 a, float128 b,
aIsLargerSignificand = (a.high < b.high) ? 1 : 0; aIsLargerSignificand = (a.high < b.high) ? 1 : 0;
} }
if (pickNaN(aIsQuietNaN, aIsSignalingNaN, bIsQuietNaN, bIsSignalingNaN, if (pickNaN(a_cls, b_cls, aIsLargerSignificand)) {
aIsLargerSignificand)) { if (is_snan(b_cls)) {
if (bIsSignalingNaN) {
return float128_silence_nan(b, status); return float128_silence_nan(b, status);
} }
return b; return b;
} else { } else {
if (aIsSignalingNaN) { if (is_snan(a_cls)) {
return float128_silence_nan(a, status); return float128_silence_nan(a, status);
} }
return a; return a;

View File

@ -580,8 +580,7 @@ static FloatParts pick_nan(FloatParts a, FloatParts b, float_status *s)
if (s->default_nan_mode) { if (s->default_nan_mode) {
return parts_default_nan(s); return parts_default_nan(s);
} else { } else {
if (pickNaN(is_qnan(a.cls), is_snan(a.cls), if (pickNaN(a.cls, b.cls,
is_qnan(b.cls), is_snan(b.cls),
a.frac > b.frac || a.frac > b.frac ||
(a.frac == b.frac && a.sign < b.sign))) { (a.frac == b.frac && a.sign < b.sign))) {
a = b; a = b;