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 24 twop52: .quad 0x4330000000000000 25 twop84_plus_twop52: 26 .quad 0x4530000000100000 27 twop84: .quad 0x4530000000000000 28 29 #define REL_ADDR(_a) (_a)(%rip) 30 31 .text 32 .align 4 33 DEFINE_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