1 //===-- lib/comparesf2.c - Single-precision comparisons -----------*- C -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the following soft-fp_t comparison routines:
12 // __eqsf2 __gesf2 __unordsf2
17 // The semantics of the routines grouped in each column are identical, so there
18 // is a single implementation for each, and wrappers to provide the other names.
20 // The main routines behave as follows:
22 // __lesf2(a,b) returns -1 if a < b
25 // 1 if either a or b is NaN
27 // __gesf2(a,b) returns -1 if a < b
30 // -1 if either a or b is NaN
32 // __unordsf2(a,b) returns 0 if both a and b are numbers
33 // 1 if either a or b is NaN
35 // Note that __lesf2( ) and __gesf2( ) are identical except in their handling of
38 //===----------------------------------------------------------------------===//
40 #define SINGLE_PRECISION
50 enum LE_RESULT
__lesf2(fp_t a
, fp_t b
) {
52 const srep_t aInt
= toRep(a
);
53 const srep_t bInt
= toRep(b
);
54 const rep_t aAbs
= aInt
& absMask
;
55 const rep_t bAbs
= bInt
& absMask
;
57 // If either a or b is NaN, they are unordered.
58 if (aAbs
> infRep
|| bAbs
> infRep
) return LE_UNORDERED
;
60 // If a and b are both zeros, they are equal.
61 if ((aAbs
| bAbs
) == 0) return LE_EQUAL
;
63 // If at least one of a and b is positive, we get the same result comparing
64 // a and b as signed integers as we would with a fp_ting-point compare.
65 if ((aInt
& bInt
) >= 0) {
66 if (aInt
< bInt
) return LE_LESS
;
67 else if (aInt
== bInt
) return LE_EQUAL
;
68 else return LE_GREATER
;
71 // Otherwise, both are negative, so we need to flip the sense of the
72 // comparison to get the correct result. (This assumes a twos- or ones-
73 // complement integer representation; if integers are represented in a
74 // sign-magnitude representation, then this flip is incorrect).
76 if (aInt
> bInt
) return LE_LESS
;
77 else if (aInt
== bInt
) return LE_EQUAL
;
78 else return LE_GREATER
;
86 GE_UNORDERED
= -1 // Note: different from LE_UNORDERED
89 enum GE_RESULT
__gesf2(fp_t a
, fp_t b
) {
91 const srep_t aInt
= toRep(a
);
92 const srep_t bInt
= toRep(b
);
93 const rep_t aAbs
= aInt
& absMask
;
94 const rep_t bAbs
= bInt
& absMask
;
96 if (aAbs
> infRep
|| bAbs
> infRep
) return GE_UNORDERED
;
97 if ((aAbs
| bAbs
) == 0) return GE_EQUAL
;
98 if ((aInt
& bInt
) >= 0) {
99 if (aInt
< bInt
) return GE_LESS
;
100 else if (aInt
== bInt
) return GE_EQUAL
;
101 else return GE_GREATER
;
103 if (aInt
> bInt
) return GE_LESS
;
104 else if (aInt
== bInt
) return GE_EQUAL
;
105 else return GE_GREATER
;
109 int __unordsf2(fp_t a
, fp_t b
) {
110 const rep_t aAbs
= toRep(a
) & absMask
;
111 const rep_t bAbs
= toRep(b
) & absMask
;
112 return aAbs
> infRep
|| bAbs
> infRep
;
115 // The following are alternative names for the preceeding routines.
117 enum LE_RESULT
__eqsf2(fp_t a
, fp_t b
) {
118 return __lesf2(a
, b
);
121 enum LE_RESULT
__ltsf2(fp_t a
, fp_t b
) {
122 return __lesf2(a
, b
);
125 enum LE_RESULT
__nesf2(fp_t a
, fp_t b
) {
126 return __lesf2(a
, b
);
129 enum GE_RESULT
__gtsf2(fp_t a
, fp_t b
) {
130 return __gesf2(a
, b
);