1 //===-- lib/floatunsisf.c - uint -> single-precision conversion ---*- 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 unsigned integer to single-precision conversion for the
11 // compiler-rt library in the IEEE-754 default round-to-nearest, ties-to-even
14 //===----------------------------------------------------------------------===//
16 #define SINGLE_PRECISION
21 ARM_EABI_FNALIAS(ui2f
, floatunsisf
)
23 fp_t
__floatunsisf(unsigned int a
) {
25 const int aWidth
= sizeof a
* CHAR_BIT
;
27 // Handle zero as a special case to protect clz
28 if (a
== 0) return fromRep(0);
30 // Exponent of (fp_t)a is the width of abs(a).
31 const int exponent
= (aWidth
- 1) - __builtin_clz(a
);
34 // Shift a into the significand field, rounding if it is a right-shift
35 if (exponent
<= significandBits
) {
36 const int shift
= significandBits
- exponent
;
37 result
= (rep_t
)a
<< shift
^ implicitBit
;
39 const int shift
= exponent
- significandBits
;
40 result
= (rep_t
)a
>> shift
^ implicitBit
;
41 rep_t round
= (rep_t
)a
<< (typeWidth
- shift
);
42 if (round
> signBit
) result
++;
43 if (round
== signBit
) result
+= result
& 1;
46 // Insert the exponent
47 result
+= (rep_t
)(exponent
+ exponentBias
) << significandBits
;
48 return fromRep(result
);