Text file src/pkg/math/dim_amd64.s
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 #define NegInf 0xFFF0000000000000
10
11 // func ·Max(x, y float64) float64
12 TEXT ·Max(SB),NOSPLIT,$0
13 // +Inf special cases
14 MOVQ $PosInf, AX
15 MOVQ x+0(FP), R8
16 CMPQ AX, R8
17 JEQ isPosInf
18 MOVQ y+8(FP), R9
19 CMPQ AX, R9
20 JEQ isPosInf
21 // NaN special cases
22 MOVQ $~(1<<63), DX // bit mask
23 MOVQ $PosInf, AX
24 MOVQ R8, BX
25 ANDQ DX, BX // x = |x|
26 CMPQ AX, BX
27 JLT isMaxNaN
28 MOVQ R9, CX
29 ANDQ DX, CX // y = |y|
30 CMPQ AX, CX
31 JLT isMaxNaN
32 // ±0 special cases
33 ORQ CX, BX
34 JEQ isMaxZero
35
36 MOVQ R8, X0
37 MOVQ R9, X1
38 MAXSD X1, X0
39 MOVSD X0, ret+16(FP)
40 RET
41 isMaxNaN: // return NaN
42 MOVQ $NaN, AX
43 isPosInf: // return +Inf
44 MOVQ AX, ret+16(FP)
45 RET
46 isMaxZero:
47 MOVQ $(1<<63), AX // -0.0
48 CMPQ AX, R8
49 JEQ +3(PC)
50 MOVQ R8, ret+16(FP) // return 0
51 RET
52 MOVQ R9, ret+16(FP) // return other 0
53 RET
54
55 // func Min(x, y float64) float64
56 TEXT ·Min(SB),NOSPLIT,$0
57 // -Inf special cases
58 MOVQ $NegInf, AX
59 MOVQ x+0(FP), R8
60 CMPQ AX, R8
61 JEQ isNegInf
62 MOVQ y+8(FP), R9
63 CMPQ AX, R9
64 JEQ isNegInf
65 // NaN special cases
66 MOVQ $~(1<<63), DX
67 MOVQ $PosInf, AX
68 MOVQ R8, BX
69 ANDQ DX, BX // x = |x|
70 CMPQ AX, BX
71 JLT isMinNaN
72 MOVQ R9, CX
73 ANDQ DX, CX // y = |y|
74 CMPQ AX, CX
75 JLT isMinNaN
76 // ±0 special cases
77 ORQ CX, BX
78 JEQ isMinZero
79
80 MOVQ R8, X0
81 MOVQ R9, X1
82 MINSD X1, X0
83 MOVSD X0, ret+16(FP)
84 RET
85 isMinNaN: // return NaN
86 MOVQ $NaN, AX
87 isNegInf: // return -Inf
88 MOVQ AX, ret+16(FP)
89 RET
90 isMinZero:
91 MOVQ $(1<<63), AX // -0.0
92 CMPQ AX, R8
93 JEQ +3(PC)
94 MOVQ R9, ret+16(FP) // return other 0
95 RET
96 MOVQ R8, ret+16(FP) // return -0
97 RET
98
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