1
0
mirror of https://github.com/golang/go synced 2024-10-02 04:18:33 -06:00
go/src/math/hypot_386.s
Brad Fitzpatrick 519474451a all: make copyright headers consistent with one space after period
This is a subset of https://golang.org/cl/20022 with only the copyright
header lines, so the next CL will be smaller and more reviewable.

Go policy has been single space after periods in comments for some time.

The copyright header template at:

    https://golang.org/doc/contribute.html#copyright

also uses a single space.

Make them all consistent.

Change-Id: Icc26c6b8495c3820da6b171ca96a74701b4a01b0
Reviewed-on: https://go-review.googlesource.com/20111
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-01 23:34:33 +00:00

60 lines
1.8 KiB
ArmAsm

// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
#include "textflag.h"
// func Hypot(p, q float64) float64
TEXT ·Hypot(SB),NOSPLIT,$0
// test bits for not-finite
MOVL p_hi+4(FP), AX // high word p
ANDL $0x7ff00000, AX
CMPL AX, $0x7ff00000
JEQ not_finite
MOVL q_hi+12(FP), AX // high word q
ANDL $0x7ff00000, AX
CMPL AX, $0x7ff00000
JEQ not_finite
FMOVD p+0(FP), F0 // F0=p
FABS // F0=|p|
FMOVD q+8(FP), F0 // F0=q, F1=|p|
FABS // F0=|q|, F1=|p|
FUCOMI F0, F1 // compare F0 to F1
JCC 2(PC) // jump if F0 >= F1
FXCHD F0, F1 // F0=|p| (larger), F1=|q| (smaller)
FTST // compare F0 to 0
FSTSW AX
ANDW $0x4000, AX
JNE 10(PC) // jump if F0 = 0
FXCHD F0, F1 // F0=q (smaller), F1=p (larger)
FDIVD F1, F0 // F0=q(=q/p), F1=p
FMULD F0, F0 // F0=q*q, F1=p
FLD1 // F0=1, F1=q*q, F2=p
FADDDP F0, F1 // F0=1+q*q, F1=p
FSQRT // F0=sqrt(1+q*q), F1=p
FMULDP F0, F1 // F0=p*sqrt(1+q*q)
FMOVDP F0, ret+16(FP)
RET
FMOVDP F0, F1 // F0=0
FMOVDP F0, ret+16(FP)
RET
not_finite:
// test bits for -Inf or +Inf
MOVL p_hi+4(FP), AX // high word p
ORL p_lo+0(FP), AX // low word p
ANDL $0x7fffffff, AX
CMPL AX, $0x7ff00000
JEQ is_inf
MOVL q_hi+12(FP), AX // high word q
ORL q_lo+8(FP), AX // low word q
ANDL $0x7fffffff, AX
CMPL AX, $0x7ff00000
JEQ is_inf
MOVL $0x7ff80000, ret_hi+20(FP) // return NaN = 0x7FF8000000000001
MOVL $0x00000001, ret_lo+16(FP)
RET
is_inf:
MOVL AX, ret_hi+20(FP) // return +Inf = 0x7FF0000000000000
MOVL $0x00000000, ret_lo+16(FP)
RET