mirror of https://gitee.com/openkylin/qemu.git
fpu/softfloat: re-factor int/uint to float
These are considerably simpler as the lower order integers can just use the higher order conversion function. As the decomposed fractional part is a full 64 bit rounding and inexact handling comes from the pack functions. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Alex Bennée
parent
ab52f973a5
commit
c02e1fb80b
322
fpu/softfloat.c
322
fpu/softfloat.c
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@ -1500,6 +1500,169 @@ FLOAT_TO_UINT(64, 64)
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#undef FLOAT_TO_UINT
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/*
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* Integer to float conversions
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*
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* Returns the result of converting the two's complement integer `a'
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* to the floating-point format. The conversion is performed according
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* to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
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*/
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static FloatParts int_to_float(int64_t a, float_status *status)
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{
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FloatParts r;
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if (a == 0) {
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r.cls = float_class_zero;
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r.sign = false;
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} else if (a == (1ULL << 63)) {
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r.cls = float_class_normal;
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r.sign = true;
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r.frac = DECOMPOSED_IMPLICIT_BIT;
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r.exp = 63;
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} else {
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uint64_t f;
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if (a < 0) {
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f = -a;
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r.sign = true;
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} else {
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f = a;
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r.sign = false;
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}
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int shift = clz64(f) - 1;
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r.cls = float_class_normal;
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r.exp = (DECOMPOSED_BINARY_POINT - shift);
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r.frac = f << shift;
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}
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return r;
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}
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float16 int64_to_float16(int64_t a, float_status *status)
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{
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FloatParts pa = int_to_float(a, status);
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return float16_round_pack_canonical(pa, status);
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}
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float16 int32_to_float16(int32_t a, float_status *status)
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{
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return int64_to_float16(a, status);
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}
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float16 int16_to_float16(int16_t a, float_status *status)
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{
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return int64_to_float16(a, status);
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}
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float32 int64_to_float32(int64_t a, float_status *status)
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{
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FloatParts pa = int_to_float(a, status);
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return float32_round_pack_canonical(pa, status);
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}
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float32 int32_to_float32(int32_t a, float_status *status)
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{
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return int64_to_float32(a, status);
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}
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float32 int16_to_float32(int16_t a, float_status *status)
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{
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return int64_to_float32(a, status);
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}
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float64 int64_to_float64(int64_t a, float_status *status)
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{
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FloatParts pa = int_to_float(a, status);
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return float64_round_pack_canonical(pa, status);
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}
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float64 int32_to_float64(int32_t a, float_status *status)
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{
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return int64_to_float64(a, status);
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}
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float64 int16_to_float64(int16_t a, float_status *status)
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{
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return int64_to_float64(a, status);
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}
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/*
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* Unsigned Integer to float conversions
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*
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* Returns the result of converting the unsigned integer `a' to the
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* floating-point format. The conversion is performed according to the
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* IEC/IEEE Standard for Binary Floating-Point Arithmetic.
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*/
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static FloatParts uint_to_float(uint64_t a, float_status *status)
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{
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FloatParts r = { .sign = false};
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if (a == 0) {
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r.cls = float_class_zero;
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} else {
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int spare_bits = clz64(a) - 1;
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r.cls = float_class_normal;
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r.exp = DECOMPOSED_BINARY_POINT - spare_bits;
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if (spare_bits < 0) {
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shift64RightJamming(a, -spare_bits, &a);
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r.frac = a;
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} else {
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r.frac = a << spare_bits;
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}
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}
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return r;
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}
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float16 uint64_to_float16(uint64_t a, float_status *status)
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{
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FloatParts pa = uint_to_float(a, status);
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return float16_round_pack_canonical(pa, status);
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}
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float16 uint32_to_float16(uint32_t a, float_status *status)
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{
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return uint64_to_float16(a, status);
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}
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float16 uint16_to_float16(uint16_t a, float_status *status)
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{
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return uint64_to_float16(a, status);
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}
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float32 uint64_to_float32(uint64_t a, float_status *status)
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{
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FloatParts pa = uint_to_float(a, status);
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return float32_round_pack_canonical(pa, status);
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}
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float32 uint32_to_float32(uint32_t a, float_status *status)
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{
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return uint64_to_float32(a, status);
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}
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float32 uint16_to_float32(uint16_t a, float_status *status)
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{
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return uint64_to_float32(a, status);
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}
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float64 uint64_to_float64(uint64_t a, float_status *status)
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{
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FloatParts pa = uint_to_float(a, status);
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return float64_round_pack_canonical(pa, status);
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}
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float64 uint32_to_float64(uint32_t a, float_status *status)
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{
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return uint64_to_float64(a, status);
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}
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float64 uint16_to_float64(uint16_t a, float_status *status)
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{
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return uint64_to_float64(a, status);
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}
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/*----------------------------------------------------------------------------
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| Takes a 64-bit fixed-point value `absZ' with binary point between bits 6
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| and 7, and returns the properly rounded 32-bit integer corresponding to the
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@ -2591,43 +2754,6 @@ static float128 normalizeRoundAndPackFloat128(flag zSign, int32_t zExp,
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}
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/*----------------------------------------------------------------------------
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| Returns the result of converting the 32-bit two's complement integer `a'
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| to the single-precision floating-point format. The conversion is performed
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| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
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*----------------------------------------------------------------------------*/
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float32 int32_to_float32(int32_t a, float_status *status)
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{
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flag zSign;
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if ( a == 0 ) return float32_zero;
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if ( a == (int32_t) 0x80000000 ) return packFloat32( 1, 0x9E, 0 );
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zSign = ( a < 0 );
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return normalizeRoundAndPackFloat32(zSign, 0x9C, zSign ? -a : a, status);
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}
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/*----------------------------------------------------------------------------
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| Returns the result of converting the 32-bit two's complement integer `a'
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| to the double-precision floating-point format. The conversion is performed
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| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
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*----------------------------------------------------------------------------*/
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float64 int32_to_float64(int32_t a, float_status *status)
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{
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flag zSign;
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uint32_t absA;
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int8_t shiftCount;
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uint64_t zSig;
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if ( a == 0 ) return float64_zero;
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zSign = ( a < 0 );
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absA = zSign ? - a : a;
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shiftCount = countLeadingZeros32( absA ) + 21;
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zSig = absA;
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return packFloat64( zSign, 0x432 - shiftCount, zSig<<shiftCount );
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}
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/*----------------------------------------------------------------------------
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| Returns the result of converting the 32-bit two's complement integer `a'
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@ -2674,56 +2800,6 @@ float128 int32_to_float128(int32_t a, float_status *status)
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}
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/*----------------------------------------------------------------------------
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| Returns the result of converting the 64-bit two's complement integer `a'
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| to the single-precision floating-point format. The conversion is performed
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| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
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*----------------------------------------------------------------------------*/
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float32 int64_to_float32(int64_t a, float_status *status)
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{
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flag zSign;
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uint64_t absA;
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int8_t shiftCount;
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if ( a == 0 ) return float32_zero;
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zSign = ( a < 0 );
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absA = zSign ? - a : a;
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shiftCount = countLeadingZeros64( absA ) - 40;
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if ( 0 <= shiftCount ) {
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return packFloat32( zSign, 0x95 - shiftCount, absA<<shiftCount );
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}
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else {
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shiftCount += 7;
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if ( shiftCount < 0 ) {
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shift64RightJamming( absA, - shiftCount, &absA );
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}
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else {
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absA <<= shiftCount;
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}
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return roundAndPackFloat32(zSign, 0x9C - shiftCount, absA, status);
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}
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}
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/*----------------------------------------------------------------------------
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| Returns the result of converting the 64-bit two's complement integer `a'
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| to the double-precision floating-point format. The conversion is performed
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| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
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*----------------------------------------------------------------------------*/
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float64 int64_to_float64(int64_t a, float_status *status)
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{
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flag zSign;
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if ( a == 0 ) return float64_zero;
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if ( a == (int64_t) LIT64( 0x8000000000000000 ) ) {
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return packFloat64( 1, 0x43E, 0 );
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}
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zSign = ( a < 0 );
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return normalizeRoundAndPackFloat64(zSign, 0x43C, zSign ? -a : a, status);
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}
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/*----------------------------------------------------------------------------
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| Returns the result of converting the 64-bit two's complement integer `a'
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| to the extended double-precision floating-point format. The conversion
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@ -2778,65 +2854,6 @@ float128 int64_to_float128(int64_t a, float_status *status)
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}
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/*----------------------------------------------------------------------------
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| Returns the result of converting the 64-bit unsigned integer `a'
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| to the single-precision floating-point format. The conversion is performed
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| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
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*----------------------------------------------------------------------------*/
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float32 uint64_to_float32(uint64_t a, float_status *status)
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{
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int shiftcount;
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if (a == 0) {
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return float32_zero;
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}
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/* Determine (left) shift needed to put first set bit into bit posn 23
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* (since packFloat32() expects the binary point between bits 23 and 22);
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* this is the fast case for smallish numbers.
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*/
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shiftcount = countLeadingZeros64(a) - 40;
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if (shiftcount >= 0) {
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return packFloat32(0, 0x95 - shiftcount, a << shiftcount);
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}
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/* Otherwise we need to do a round-and-pack. roundAndPackFloat32()
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* expects the binary point between bits 30 and 29, hence the + 7.
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*/
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shiftcount += 7;
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if (shiftcount < 0) {
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shift64RightJamming(a, -shiftcount, &a);
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} else {
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a <<= shiftcount;
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}
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return roundAndPackFloat32(0, 0x9c - shiftcount, a, status);
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}
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/*----------------------------------------------------------------------------
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| Returns the result of converting the 64-bit unsigned integer `a'
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| to the double-precision floating-point format. The conversion is performed
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| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
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*----------------------------------------------------------------------------*/
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float64 uint64_to_float64(uint64_t a, float_status *status)
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{
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int exp = 0x43C;
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int shiftcount;
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if (a == 0) {
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return float64_zero;
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}
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shiftcount = countLeadingZeros64(a) - 1;
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if (shiftcount < 0) {
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shift64RightJamming(a, -shiftcount, &a);
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} else {
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a <<= shiftcount;
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}
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return roundAndPackFloat64(0, exp - shiftcount, a, status);
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}
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/*----------------------------------------------------------------------------
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| Returns the result of converting the 64-bit unsigned integer `a'
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| to the quadruple-precision floating-point format. The conversion is performed
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@ -6714,19 +6731,6 @@ int float128_unordered_quiet(float128 a, float128 b, float_status *status)
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return 0;
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}
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/* misc functions */
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float32 uint32_to_float32(uint32_t a, float_status *status)
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{
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return int64_to_float32(a, status);
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}
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float64 uint32_to_float64(uint32_t a, float_status *status)
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{
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return int64_to_float64(a, status);
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}
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#define COMPARE(s, nan_exp) \
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static inline int float ## s ## _compare_internal(float ## s a, float ## s b,\
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int is_quiet, float_status *status) \
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@ -190,9 +190,13 @@ enum {
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/*----------------------------------------------------------------------------
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| Software IEC/IEEE integer-to-floating-point conversion routines.
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*----------------------------------------------------------------------------*/
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float32 int16_to_float32(int16_t, float_status *status);
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float32 int32_to_float32(int32_t, float_status *status);
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float64 int16_to_float64(int16_t, float_status *status);
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float64 int32_to_float64(int32_t, float_status *status);
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float32 uint16_to_float32(uint16_t, float_status *status);
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float32 uint32_to_float32(uint32_t, float_status *status);
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float64 uint16_to_float64(uint16_t, float_status *status);
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float64 uint32_to_float64(uint32_t, float_status *status);
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floatx80 int32_to_floatx80(int32_t, float_status *status);
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float128 int32_to_float128(int32_t, float_status *status);
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@ -204,27 +208,6 @@ float32 uint64_to_float32(uint64_t, float_status *status);
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float64 uint64_to_float64(uint64_t, float_status *status);
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float128 uint64_to_float128(uint64_t, float_status *status);
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/* We provide the int16 versions for symmetry of API with float-to-int */
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static inline float32 int16_to_float32(int16_t v, float_status *status)
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{
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return int32_to_float32(v, status);
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}
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static inline float32 uint16_to_float32(uint16_t v, float_status *status)
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{
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return uint32_to_float32(v, status);
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}
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static inline float64 int16_to_float64(int16_t v, float_status *status)
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{
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return int32_to_float64(v, status);
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}
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static inline float64 uint16_to_float64(uint16_t v, float_status *status)
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{
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return uint32_to_float64(v, status);
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}
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/*----------------------------------------------------------------------------
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| Software half-precision conversion routines.
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*----------------------------------------------------------------------------*/
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@ -245,6 +228,11 @@ uint64_t float16_to_uint64(float16 a, float_status *status);
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int64_t float16_to_int64_round_to_zero(float16, float_status *status);
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uint64_t float16_to_uint64_round_to_zero(float16 a, float_status *status);
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float16 int16_to_float16(int16_t a, float_status *status);
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float16 int32_to_float16(int32_t a, float_status *status);
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float16 int64_to_float16(int64_t a, float_status *status);
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float16 uint16_to_float16(uint16_t a, float_status *status);
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float16 uint32_to_float16(uint32_t a, float_status *status);
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float16 uint64_to_float16(uint64_t a, float_status *status);
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/*----------------------------------------------------------------------------
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| Software half-precision operations.
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