floatdisf.S
1.05 KB
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#include "../assembly.h"
// float __floatdisf(di_int a);
// This routine has some extra memory traffic, loading the 64-bit input via two
// 32-bit loads, then immediately storing it back to the stack via a single 64-bit
// store. This is to avoid a write-small, read-large stall.
// However, if callers of this routine can be safely assumed to store the argument
// via a 64-bt store, this is unnecessary memory traffic, and should be avoided.
// It can be turned off by defining the TRUST_CALLERS_USE_64_BIT_STORES macro.
#ifdef __i386__
.text
.balign 4
DEFINE_COMPILERRT_FUNCTION(__floatdisf)
#ifndef TRUST_CALLERS_USE_64_BIT_STORES
movd 4(%esp), %xmm0
movd 8(%esp), %xmm1
punpckldq %xmm1, %xmm0
movq %xmm0, 4(%esp)
#endif
fildll 4(%esp)
fstps 4(%esp)
flds 4(%esp)
ret
END_COMPILERRT_FUNCTION(__floatdisf)
#endif // __i386__
NO_EXEC_STACK_DIRECTIVE