floatundidf.S revision 214152
1//===-- floatundidf.S - Implement __floatundidf for x86_64 ----------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements __floatundidf for the compiler_rt library. 11// 12//===----------------------------------------------------------------------===// 13 14#include "../assembly.h" 15 16// double __floatundidf(du_int a); 17 18#ifdef __x86_64__ 19 20#ifndef __ELF__ 21.const 22#endif 23.align 4 24twop52: .quad 0x4330000000000000 25twop84_plus_twop52: 26 .quad 0x4530000000100000 27twop84: .quad 0x4530000000000000 28 29#define REL_ADDR(_a) (_a)(%rip) 30 31.text 32.align 4 33DEFINE_COMPILERRT_FUNCTION(__floatundidf) 34 movd %edi, %xmm0 // low 32 bits of a 35 shrq $32, %rdi // high 32 bits of a 36 orq REL_ADDR(twop84), %rdi // 0x1p84 + a_hi (no rounding occurs) 37 orpd REL_ADDR(twop52), %xmm0 // 0x1p52 + a_lo (no rounding occurs) 38 movd %rdi, %xmm1 39 subsd REL_ADDR(twop84_plus_twop52), %xmm1 // a_hi - 0x1p52 (no rounding occurs) 40 addsd %xmm1, %xmm0 // a_hi + a_lo (round happens here) 41 ret 42 43#endif // __x86_64__ 44