floatundidf.S
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//===-- floatundidf.S - Implement __floatundidf for x86_64 ----------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This file implements __floatundidf for the compiler_rt library.
//
//===----------------------------------------------------------------------===//
#include "../assembly.h"
// double __floatundidf(du_int a);
#ifdef __x86_64__
CONST_SECTION
.balign 16
twop52:
.quad 0x4330000000000000
.balign 16
twop84_plus_twop52:
.quad 0x4530000000100000
.balign 16
twop84:
.quad 0x4530000000000000
#define REL_ADDR(_a) (_a)(%rip)
.text
.balign 4
DEFINE_COMPILERRT_FUNCTION(__floatundidf)
movd %edi, %xmm0 // low 32 bits of a
shrq $32, %rdi // high 32 bits of a
orq REL_ADDR(twop84), %rdi // 0x1p84 + a_hi (no rounding occurs)
orpd REL_ADDR(twop52), %xmm0 // 0x1p52 + a_lo (no rounding occurs)
movd %rdi, %xmm1
subsd REL_ADDR(twop84_plus_twop52), %xmm1 // a_hi - 0x1p52 (no rounding occurs)
addsd %xmm1, %xmm0 // a_hi + a_lo (round happens here)
ret
END_COMPILERRT_FUNCTION(__floatundidf)
#endif // __x86_64__
NO_EXEC_STACK_DIRECTIVE