xref: /freebsd/contrib/llvm-project/compiler-rt/lib/builtins/i386/floatdidf.S (revision cd0d51baaa4509a1db83251a601d34404d20c990)
1// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
2// See https://llvm.org/LICENSE.txt for license information.
3// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
4
5#include "../assembly.h"
6
7// double __floatundidf(du_int a);
8
9#ifdef __i386__
10
11CONST_SECTION
12
13	.balign 16
14twop52:
15	.quad 0x4330000000000000
16
17	.balign 16
18twop32:
19	.quad 0x41f0000000000000
20
21#define REL_ADDR(_a)	(_a)-0b(%eax)
22
23.text
24.balign 4
25DEFINE_COMPILERRT_FUNCTION(__floatdidf)
26	cvtsi2sd	8(%esp),			%xmm1
27	movss		4(%esp),			%xmm0 // low 32 bits of a
28	calll		0f
290:	popl		%eax
30	mulsd		REL_ADDR(twop32),	%xmm1 // a_hi as a double (without rounding)
31	movsd		REL_ADDR(twop52),	%xmm2 // 0x1.0p52
32	subsd		%xmm2,				%xmm1 // a_hi - 0x1p52 (no rounding occurs)
33	orpd		%xmm2,				%xmm0 // 0x1p52 + a_lo (no rounding occurs)
34	addsd		%xmm1,				%xmm0 // a_hi + a_lo   (round happens here)
35	movsd		%xmm0,			   4(%esp)
36	fldl	   4(%esp)
37	ret
38END_COMPILERRT_FUNCTION(__floatdidf)
39
40#endif // __i386__
41
42NO_EXEC_STACK_DIRECTIVE
43
44