xref: /freebsd/contrib/llvm-project/compiler-rt/lib/builtins/x86_64/floatundidf.S (revision 7fdf597e96a02165cfe22ff357b857d5fa15ed8a)
1//===-- floatundidf.S - Implement __floatundidf for x86_64 ----------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements __floatundidf for the compiler_rt library.
10//
11//===----------------------------------------------------------------------===//
12
13#include "../assembly.h"
14
15// double __floatundidf(du_int a);
16
17#ifdef __x86_64__
18
19CONST_SECTION
20
21	.balign 16
22twop52:
23	.quad 0x4330000000000000
24
25	.balign 16
26twop84_plus_twop52:
27	.quad 0x4530000000100000
28
29	.balign 16
30twop84:
31	.quad 0x4530000000000000
32
33#define REL_ADDR(_a)	(_a)(%rip)
34
35.text
36.balign 4
37DEFINE_COMPILERRT_FUNCTION(__floatundidf)
38	movd	%edi,							%xmm0 // low 32 bits of a
39	shrq	$32,							%rdi  // high 32 bits of a
40	orq		REL_ADDR(twop84),				%rdi  // 0x1p84 + a_hi (no rounding occurs)
41	orpd	REL_ADDR(twop52),				%xmm0 // 0x1p52 + a_lo (no rounding occurs)
42	movd	%rdi,							%xmm1
43	subsd	REL_ADDR(twop84_plus_twop52),	%xmm1 // a_hi - 0x1p52 (no rounding occurs)
44	addsd	%xmm1,							%xmm0 // a_hi + a_lo   (round happens here)
45	ret
46END_COMPILERRT_FUNCTION(__floatundidf)
47
48#endif // __x86_64__
49
50NO_EXEC_STACK_DIRECTIVE
51
52