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Diffstat (limited to 'lib/x86_64/floatundixf.s')
-rw-r--r-- | lib/x86_64/floatundixf.s | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/lib/x86_64/floatundixf.s b/lib/x86_64/floatundixf.s new file mode 100644 index 00000000..0764da49 --- /dev/null +++ b/lib/x86_64/floatundixf.s @@ -0,0 +1,60 @@ +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. + +// long double __floatundixf(du_int a); + +#ifdef __x86_64__ + +.const +.align 4 +twop64: .quad 0x43f0000000000000 + +#define REL_ADDR(_a) (_a)(%rip) + +.text +.align 4 +.globl ___floatundixf +___floatundixf: + movq %rdi, -8(%rsp) + fildq -8(%rsp) + test %rdi, %rdi + js 1f + ret +1: faddl REL_ADDR(twop64) + ret + +#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 +.align 4 +twop52: .quad 0x4330000000000000 +twop84_plus_twop52_neg: + .quad 0xc530000000100000 +twop84: .quad 0x4530000000000000 + +#define REL_ADDR(_a) (_a)(%rip) + +.text +.align 4 +.globl ___floatundixf +___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 + +#endif // __x86_64__ + +*/
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