floatdixf.S revision 2d1fdb26e458c4ddc04155c1d421bced3ba90cd0 
1// This file is dual licensed under the MIT and the University of Illinois Open
2// Source Licenses. See LICENSE.TXT for details.
3
4#include "../assembly.h"
5
6// float __floatdixf(di_int a);
7
8#ifdef __i386__
9
10// This routine has some extra memory traffic, loading the 64-bit input via two
11// 32-bit loads, then immediately storing it back to the stack via a single 64-bit
12// store.  This is to avoid a write-small, read-large stall.
13// However, if callers of this routine can be safely assumed to store the argument
14// via a 64-bt store, this is unnecessary memory traffic, and should be avoided.
15// It can be turned off by defining the TRUST_CALLERS_USE_64_BIT_STORES macro.
16
17.text
18.balign 4
19DEFINE_COMPILERRT_FUNCTION(__floatdixf)
20#ifndef TRUST_CALLERS_USE_64_BIT_STORES
21	movd		4(%esp),	%xmm0
22	movd		8(%esp),	%xmm1
23	punpckldq	%xmm1,		%xmm0
24	movq		%xmm0,		4(%esp)
25#endif
26	fildll		4(%esp)
27	ret
28END_COMPILERRT_FUNCTION(__floatdixf)
29
30#endif // __i386__
31