1 // Copyright 2010 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 #include "textflag.h" 6 7 #define PosInf 0x7FF0000000000000 8 #define NaN 0x7FF8000000000001 9 10 // func Hypot(p, q float64) float64 11 TEXT Hypot(SB),NOSPLIT,$0 12 // test bits for special cases 13 MOVQ p+0(FP), BX 14 MOVQ $~(1<<63), AX 15 ANDQ AX, BX // p = |p| 16 MOVQ q+8(FP), CX 17 ANDQ AX, CX // q = |q| 18 MOVQ $PosInf, AX 19 CMPQ AX, BX 20 JLE isInfOrNaN 21 CMPQ AX, CX 22 JLE isInfOrNaN 23 // hypot = max * sqrt(1 + (min/max)**2) 24 MOVQ BX, X0 25 MOVQ CX, X1 26 ORQ CX, BX 27 JEQ isZero 28 MOVAPD X0, X2 29 MAXSD X1, X0 30 MINSD X2, X1 31 DIVSD X0, X1 32 MULSD X1, X1 33 ADDSD $1.0, X1 34 SQRTSD X1, X1 35 MULSD X1, X0 36 MOVSD X0, ret+16(FP) 37 RET 38 isInfOrNaN: 39 CMPQ AX, BX 40 JEQ isInf 41 CMPQ AX, CX 42 JEQ isInf 43 MOVQ $NaN, AX 44 MOVQ AX, ret+16(FP) // return NaN 45 RET 46 isInf: 47 MOVQ AX, ret+16(FP) // return +Inf 48 RET 49 isZero: 50 MOVQ $0, AX 51 MOVQ AX, ret+16(FP) // return 0 52 RET 53
