xref: /freebsd/contrib/llvm-project/compiler-rt/lib/builtins/i386/floatdisf.S (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
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// float __floatdisf(di_int a);
8
9// This routine has some extra memory traffic, loading the 64-bit input via two
10// 32-bit loads, then immediately storing it back to the stack via a single 64-bit
11// store.  This is to avoid a write-small, read-large stall.
12// However, if callers of this routine can be safely assumed to store the argument
13// via a 64-bt store, this is unnecessary memory traffic, and should be avoided.
14// It can be turned off by defining the TRUST_CALLERS_USE_64_BIT_STORES macro.
15
16#ifdef __i386__
17
18.text
19.balign 4
20DEFINE_COMPILERRT_FUNCTION(__floatdisf)
21#ifndef TRUST_CALLERS_USE_64_BIT_STORES
22	movd		4(%esp),	%xmm0
23	movd		8(%esp),	%xmm1
24	punpckldq	%xmm1,		%xmm0
25	movq		%xmm0,		4(%esp)
26#endif
27	fildll		4(%esp)
28	fstps		4(%esp)
29	flds		4(%esp)
30	ret
31END_COMPILERRT_FUNCTION(__floatdisf)
32
33#endif // __i386__
34
35NO_EXEC_STACK_DIRECTIVE
36
37