lib/builtins/x86_64/floatundixf.S

// 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"

// xf_float __floatundixf(du_int a);

#ifdef __x86_64__

CONST_SECTION

	.balign 16
twop64:
	.quad 0x43f0000000000000

#define REL_ADDR(_a)	(_a)(%rip)

	.text

	.balign 4
DEFINE_COMPILERRT_FUNCTION(__floatundixf)
	movq	%rdi,	 -8(%rsp)
	fildq	-8(%rsp)
	test	%rdi,		%rdi
	js		1f
	ret
1:	faddl	REL_ADDR(twop64)
	ret
END_COMPILERRT_FUNCTION(__floatundixf)

#endif // __x86_64__


/* Branch-free implementation is ever so slightly slower, but more beautiful.
   It is likely superior for inlining, so I kept it around for future reference.

#ifdef __x86_64__

CONST_SECTION

	.balign 4
twop52:
	.quad 0x4330000000000000
twop84_plus_twop52_neg:
	.quad 0xc530000000100000
twop84:
	.quad 0x4530000000000000

#define REL_ADDR(_a)	(_a)(%rip)

.text
.balign 4
DEFINE_COMPILERRT_FUNCTION(__floatundixf)
	movl	%edi,				%esi			// low 32 bits of input
	shrq	$32,				%rdi			// hi 32 bits of input
	orq		REL_ADDR(twop84),	%rdi			// 2^84 + hi (as a double)
	orq		REL_ADDR(twop52),	%rsi			// 2^52 + lo (as a double)
	movq	%rdi,			 -8(%rsp)
	movq	%rsi,			-16(%rsp)
	fldl	REL_ADDR(twop84_plus_twop52_neg)
	faddl	-8(%rsp)	// hi - 2^52 (as double extended, no rounding occurs)
	faddl	-16(%rsp)	// hi + lo (as double extended)
	ret
END_COMPILERRT_FUNCTION(__floatundixf)

#endif // __x86_64__

*/

NO_EXEC_STACK_DIRECTIVE