From 4f251cfd52c7945ebd6ab0d86518b1a9aa51b10c Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Thu, 10 May 2018 15:21:31 -0700 Subject: [PATCH] fpu/softfloat: Pass FloatClass to pickNaN MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Peter Maydell Signed-off-by: Richard Henderson --- fpu/softfloat-specialize.h | 176 ++++++++++++++++++++++----------------------- fpu/softfloat.c | 3 +- 2 files changed, 86 insertions(+), 93 deletions(-) diff --git a/fpu/softfloat-specialize.h b/fpu/softfloat-specialize.h index d1e06da75b..2695183188 100644 --- a/fpu/softfloat-specialize.h +++ b/fpu/softfloat-specialize.h @@ -501,10 +501,10 @@ static float32 commonNaNToFloat32(commonNaNT a, float_status *status) | tie-break rule. *----------------------------------------------------------------------------*/ -#if defined(TARGET_ARM) -static int pickNaN(flag aIsQNaN, flag aIsSNaN, flag bIsQNaN, flag bIsSNaN, +static int pickNaN(FloatClass a_cls, FloatClass b_cls, flag aIsLargerSignificand) { +#if defined(TARGET_ARM) || defined(TARGET_MIPS) || defined(TARGET_HPPA) /* ARM mandated NaN propagation rules (see FPProcessNaNs()), take * the first of: * 1. A if it is signaling @@ -513,20 +513,6 @@ static int pickNaN(flag aIsQNaN, flag aIsSNaN, flag bIsQNaN, flag bIsSNaN, * 4. B (quiet) * 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 * a sNaN, a new qNaN has to be generated. This is done in * 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) * A signaling NaN is always silenced before returning it. */ - if (aIsSNaN) { + if (is_snan(a_cls)) { return 0; - } else if (bIsSNaN) { + } else if (is_snan(b_cls)) { return 1; - } else if (aIsQNaN) { + } else if (is_qnan(a_cls)) { return 0; } else { return 1; } -} -#elif defined(TARGET_PPC) || defined(TARGET_XTENSA) -static int pickNaN(flag aIsQNaN, flag aIsSNaN, flag bIsQNaN, flag bIsSNaN, - flag aIsLargerSignificand) -{ +#elif defined(TARGET_PPC) || defined(TARGET_XTENSA) || defined(TARGET_M68K) /* PowerPC propagation rules: * 1. A if it sNaN or qNaN * 2. B if it sNaN or qNaN * 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 * 3.4 FLOATING-POINT INSTRUCTION DETAILS * 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 * preceding paragraph for nonsignaling NaNs. */ - if (aIsQNaN || aIsSNaN) { /* a is the destination operand */ - return 0; /* return the destination operand */ + if (is_nan(a_cls)) { + return 0; } else { - return 1; /* return b */ + return 1; } -} #else -static int pickNaN(flag aIsQNaN, flag aIsSNaN, flag bIsQNaN, flag bIsSNaN, - flag aIsLargerSignificand) -{ /* This implements x87 NaN propagation rules: * SNaN + QNaN => return the QNaN * 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, * return the NaN with the positive sign bit (if any). */ - if (aIsSNaN) { - if (bIsSNaN) { + if (is_snan(a_cls)) { + if (is_snan(b_cls)) { return aIsLargerSignificand ? 0 : 1; } - return bIsQNaN ? 1 : 0; - } else if (aIsQNaN) { - if (bIsSNaN || !bIsQNaN) { + return is_qnan(b_cls) ? 1 : 0; + } else if (is_qnan(a_cls)) { + if (is_snan(b_cls) || !is_qnan(b_cls)) { return 0; } else { return aIsLargerSignificand ? 0 : 1; @@ -617,8 +585,8 @@ static int pickNaN(flag aIsQNaN, flag aIsSNaN, flag bIsQNaN, flag bIsSNaN, } else { return 1; } -} #endif +} /*---------------------------------------------------------------------------- | 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) { - flag aIsQuietNaN, aIsSignalingNaN, bIsQuietNaN, bIsSignalingNaN; flag aIsLargerSignificand; 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); bv = float32_val(b); - if (aIsSignalingNaN | bIsSignalingNaN) { + if (is_snan(a_cls) || is_snan(b_cls)) { 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; } - if (pickNaN(aIsQuietNaN, aIsSignalingNaN, bIsQuietNaN, bIsSignalingNaN, - aIsLargerSignificand)) { - if (bIsSignalingNaN) { + if (pickNaN(a_cls, b_cls, aIsLargerSignificand)) { + if (is_snan(b_cls)) { return float32_silence_nan(b, status); } return b; } else { - if (aIsSignalingNaN) { + if (is_snan(a_cls)) { return float32_silence_nan(a, status); } return a; @@ -908,18 +883,26 @@ static float64 commonNaNToFloat64(commonNaNT a, float_status *status) static float64 propagateFloat64NaN(float64 a, float64 b, float_status *status) { - flag aIsQuietNaN, aIsSignalingNaN, bIsQuietNaN, bIsSignalingNaN; flag aIsLargerSignificand; 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); bv = float64_val(b); - if (aIsSignalingNaN | bIsSignalingNaN) { + if (is_snan(a_cls) || is_snan(b_cls)) { 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; } - if (pickNaN(aIsQuietNaN, aIsSignalingNaN, bIsQuietNaN, bIsSignalingNaN, - aIsLargerSignificand)) { - if (bIsSignalingNaN) { + if (pickNaN(a_cls, b_cls, aIsLargerSignificand)) { + if (is_snan(b_cls)) { return float64_silence_nan(b, status); } return b; } else { - if (aIsSignalingNaN) { + if (is_snan(a_cls)) { return float64_silence_nan(a, status); } return a; @@ -1075,15 +1057,22 @@ static floatx80 commonNaNToFloatx80(commonNaNT a, float_status *status) floatx80 propagateFloatx80NaN(floatx80 a, floatx80 b, float_status *status) { - flag aIsQuietNaN, aIsSignalingNaN, bIsQuietNaN, bIsSignalingNaN; flag aIsLargerSignificand; - - aIsQuietNaN = floatx80_is_quiet_nan(a, status); - aIsSignalingNaN = floatx80_is_signaling_nan(a, status); - bIsQuietNaN = floatx80_is_quiet_nan(b, status); - bIsSignalingNaN = floatx80_is_signaling_nan(b, status); - - if (aIsSignalingNaN | bIsSignalingNaN) { + FloatClass a_cls, b_cls; + + /* This is not complete, but is good enough for pickNaN. */ + a_cls = (!floatx80_is_any_nan(a) + ? float_class_normal + : 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 (is_snan(a_cls) || is_snan(b_cls)) { 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; } - if (pickNaN(aIsQuietNaN, aIsSignalingNaN, bIsQuietNaN, bIsSignalingNaN, - aIsLargerSignificand)) { - if (bIsSignalingNaN) { + if (pickNaN(a_cls, b_cls, aIsLargerSignificand)) { + if (is_snan(b_cls)) { return floatx80_silence_nan(b, status); } return b; } else { - if (aIsSignalingNaN) { + if (is_snan(a_cls)) { return floatx80_silence_nan(a, status); } return a; @@ -1217,15 +1205,22 @@ static float128 commonNaNToFloat128(commonNaNT a, float_status *status) static float128 propagateFloat128NaN(float128 a, float128 b, float_status *status) { - flag aIsQuietNaN, aIsSignalingNaN, bIsQuietNaN, bIsSignalingNaN; flag aIsLargerSignificand; - - aIsQuietNaN = float128_is_quiet_nan(a, status); - aIsSignalingNaN = float128_is_signaling_nan(a, status); - bIsQuietNaN = float128_is_quiet_nan(b, status); - bIsSignalingNaN = float128_is_signaling_nan(b, status); - - if (aIsSignalingNaN | bIsSignalingNaN) { + FloatClass a_cls, b_cls; + + /* This is not complete, but is good enough for pickNaN. */ + a_cls = (!float128_is_any_nan(a) + ? float_class_normal + : 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 (is_snan(a_cls) || is_snan(b_cls)) { float_raise(float_flag_invalid, status); } @@ -1241,14 +1236,13 @@ static float128 propagateFloat128NaN(float128 a, float128 b, aIsLargerSignificand = (a.high < b.high) ? 1 : 0; } - if (pickNaN(aIsQuietNaN, aIsSignalingNaN, bIsQuietNaN, bIsSignalingNaN, - aIsLargerSignificand)) { - if (bIsSignalingNaN) { + if (pickNaN(a_cls, b_cls, aIsLargerSignificand)) { + if (is_snan(b_cls)) { return float128_silence_nan(b, status); } return b; } else { - if (aIsSignalingNaN) { + if (is_snan(a_cls)) { return float128_silence_nan(a, status); } return a; diff --git a/fpu/softfloat.c b/fpu/softfloat.c index ea252e0c84..55954385ff 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -580,8 +580,7 @@ static FloatParts pick_nan(FloatParts a, FloatParts b, float_status *s) if (s->default_nan_mode) { return parts_default_nan(s); } else { - if (pickNaN(is_qnan(a.cls), is_snan(a.cls), - is_qnan(b.cls), is_snan(b.cls), + if (pickNaN(a.cls, b.cls, a.frac > b.frac || (a.frac == b.frac && a.sign < b.sign))) { a = b; -- 2.11.0