196 lines
8.1 KiB
C++
Executable File
196 lines
8.1 KiB
C++
Executable File
/*============================================================================
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This C source fragment is part of the SoftFloat IEC/IEEE Floating-point
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Arithmetic Package, Release 2b.
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Written by John R. Hauser. This work was made possible in part by the
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International Computer Science Institute, located at Suite 600, 1947 Center
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Street, Berkeley, California 94704. Funding was partially provided by the
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National Science Foundation under grant MIP-9311980. The original version
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of this code was written as part of a project to build a fixed-point vector
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processor in collaboration with the University of California at Berkeley,
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overseen by Profs. Nelson Morgan and John Wawrzynek. More information
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is available through the Web page `http://www.cs.berkeley.edu/~jhauser/
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arithmetic/SoftFloat.html'.
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THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE. Although reasonable effort has
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been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT WILL AT TIMES
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RESULT IN INCORRECT BEHAVIOR. USE OF THIS SOFTWARE IS RESTRICTED TO PERSONS
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AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ALL LOSSES,
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COSTS, OR OTHER PROBLEMS THEY INCUR DUE TO THE SOFTWARE, AND WHO FURTHERMORE
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EFFECTIVELY INDEMNIFY JOHN HAUSER AND THE INTERNATIONAL COMPUTER SCIENCE
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INSTITUTE (possibly via similar legal warning) AGAINST ALL LOSSES, COSTS, OR
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OTHER PROBLEMS INCURRED BY THEIR CUSTOMERS AND CLIENTS DUE TO THE SOFTWARE.
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Derivative works are acceptable, even for commercial purposes, so long as
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(1) the source code for the derivative work includes prominent notice that
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the work is derivative, and (2) the source code includes prominent notice with
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these four paragraphs for those parts of this code that are retained.
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=============================================================================*/
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#define FLOAT128
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/*============================================================================
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* Adapted for Bochs (x86 achitecture simulator) by
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* Stanislav Shwartsman (stl at fidonet.org.il)
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* ==========================================================================*/
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#include "softfloat.h"
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#include "softfloat-specialize.h"
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/*----------------------------------------------------------------------------
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| Takes two single-precision floating-point values `a' and `b', one of which
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| is a NaN, and returns the appropriate NaN result. If either `a' or `b' is a
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| signaling NaN, the invalid exception is raised.
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*----------------------------------------------------------------------------*/
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float32 propagateFloat32NaN(float32 a, float32 b, float_status_t &status)
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{
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int aIsNaN, aIsSignalingNaN, bIsNaN, bIsSignalingNaN;
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aIsNaN = float32_is_nan(a);
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aIsSignalingNaN = float32_is_signaling_nan(a);
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bIsNaN = float32_is_nan(b);
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bIsSignalingNaN = float32_is_signaling_nan(b);
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a |= 0x00400000;
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b |= 0x00400000;
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if (aIsSignalingNaN | bIsSignalingNaN) float_raise(status, float_flag_invalid);
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if (get_float_nan_handling_mode(status) == float_larger_significand_nan) {
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if (aIsSignalingNaN) {
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if (bIsSignalingNaN) goto returnLargerSignificand;
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return bIsNaN ? b : a;
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}
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else if (aIsNaN) {
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if (bIsSignalingNaN | ! bIsNaN) return a;
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returnLargerSignificand:
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if ((Bit32u) (a<<1) < (Bit32u) (b<<1)) return b;
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if ((Bit32u) (b<<1) < (Bit32u) (a<<1)) return a;
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return (a < b) ? a : b;
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}
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else {
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return b;
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}
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} else {
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return (aIsSignalingNaN | aIsNaN) ? a : b;
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}
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}
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/*----------------------------------------------------------------------------
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| Takes two double-precision floating-point values `a' and `b', one of which
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| is a NaN, and returns the appropriate NaN result. If either `a' or `b' is a
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| signaling NaN, the invalid exception is raised.
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*----------------------------------------------------------------------------*/
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float64 propagateFloat64NaN(float64 a, float64 b, float_status_t &status)
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{
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int aIsNaN, aIsSignalingNaN, bIsNaN, bIsSignalingNaN;
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aIsNaN = float64_is_nan(a);
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aIsSignalingNaN = float64_is_signaling_nan(a);
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bIsNaN = float64_is_nan(b);
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bIsSignalingNaN = float64_is_signaling_nan(b);
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a |= BX_CONST64(0x0008000000000000);
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b |= BX_CONST64(0x0008000000000000);
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if (aIsSignalingNaN | bIsSignalingNaN) float_raise(status, float_flag_invalid);
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if (get_float_nan_handling_mode(status) == float_larger_significand_nan) {
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if (aIsSignalingNaN) {
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if (bIsSignalingNaN) goto returnLargerSignificand;
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return bIsNaN ? b : a;
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}
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else if (aIsNaN) {
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if (bIsSignalingNaN | ! bIsNaN) return a;
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returnLargerSignificand:
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if ((Bit64u) (a<<1) < (Bit64u) (b<<1)) return b;
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if ((Bit64u) (b<<1) < (Bit64u) (a<<1)) return a;
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return (a < b) ? a : b;
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}
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else {
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return b;
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}
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} else {
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return (aIsSignalingNaN | aIsNaN) ? a : b;
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}
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}
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#ifdef FLOATX80
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/*----------------------------------------------------------------------------
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| Takes two extended double-precision floating-point values `a' and `b', one
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| of which is a NaN, and returns the appropriate NaN result. If either `a' or
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| `b' is a signaling NaN, the invalid exception is raised.
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*----------------------------------------------------------------------------*/
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floatx80 propagateFloatx80NaN(floatx80 a, floatx80 b, float_status_t &status)
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{
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int aIsNaN, aIsSignalingNaN, bIsNaN, bIsSignalingNaN;
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aIsNaN = floatx80_is_nan(a);
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aIsSignalingNaN = floatx80_is_signaling_nan(a);
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bIsNaN = floatx80_is_nan(b);
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bIsSignalingNaN = floatx80_is_signaling_nan(b);
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a.fraction |= BX_CONST64(0xC000000000000000);
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b.fraction |= BX_CONST64(0xC000000000000000);
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if (aIsSignalingNaN | bIsSignalingNaN) float_raise(status, float_flag_invalid);
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if (aIsSignalingNaN) {
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if (bIsSignalingNaN) goto returnLargerSignificand;
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return bIsNaN ? b : a;
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}
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else if (aIsNaN) {
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if (bIsSignalingNaN | ! bIsNaN) return a;
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returnLargerSignificand:
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if (a.fraction < b.fraction) return b;
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if (b.fraction < a.fraction) return a;
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return (a.exp < b.exp) ? a : b;
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}
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else {
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return b;
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}
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}
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/*----------------------------------------------------------------------------
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| The pattern for a default generated extended double-precision NaN.
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*----------------------------------------------------------------------------*/
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const floatx80 floatx80_default_nan =
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packFloatx80(0, floatx80_default_nan_exp, floatx80_default_nan_fraction);
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#endif /* FLOATX80 */
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#ifdef FLOAT128
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/*----------------------------------------------------------------------------
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| Takes two quadruple-precision floating-point values `a' and `b', one of
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| which is a NaN, and returns the appropriate NaN result. If either `a' or
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| `b' is a signaling NaN, the invalid exception is raised.
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*----------------------------------------------------------------------------*/
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float128 propagateFloat128NaN(float128 a, float128 b, float_status_t &status)
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{
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int aIsNaN, aIsSignalingNaN, bIsNaN, bIsSignalingNaN;
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aIsNaN = float128_is_nan(a);
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aIsSignalingNaN = float128_is_signaling_nan(a);
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bIsNaN = float128_is_nan(b);
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bIsSignalingNaN = float128_is_signaling_nan(b);
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a.hi |= BX_CONST64(0x0000800000000000);
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b.hi |= BX_CONST64(0x0000800000000000);
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if (aIsSignalingNaN | bIsSignalingNaN) float_raise(status, float_flag_invalid);
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if (aIsSignalingNaN) {
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if (bIsSignalingNaN) goto returnLargerSignificand;
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return bIsNaN ? b : a;
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}
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else if (aIsNaN) {
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if (bIsSignalingNaN | !bIsNaN) return a;
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returnLargerSignificand:
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if (lt128(a.hi<<1, a.lo, b.hi<<1, b.lo)) return b;
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if (lt128(b.hi<<1, b.lo, a.hi<<1, a.lo)) return a;
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return (a.hi < b.hi) ? a : b;
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}
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else {
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return b;
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}
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}
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/*----------------------------------------------------------------------------
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| The pattern for a default generated quadruple-precision NaN.
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*----------------------------------------------------------------------------*/
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const float128 float128_default_nan =
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packFloat128(float128_default_nan_hi, float128_default_nan_lo);
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#endif /* FLOAT128 */
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