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// +build sse
// +build amd64
// +build !fastmath
/*
Sqrt takes a []float32 and square roots every element in the slice.
*/
#include "textflag.h"
// func Sqrt(a []float64)
TEXT ·Sqrt(SB), NOSPLIT, $0
MOVQ a_data+0(FP), SI
MOVQ SI, CX
MOVQ a_len+8(FP), AX // len(a) into AX - +8, because first 8 is pointer, second 8 is length, third 8 is cap
SUBQ $2, AX
JL remainder
loop:
SQRTPD (SI), X0
MOVUPD X0, (SI)
// we processed 2 elements. Each element is 8 bytes. So jump 16 ahead
ADDQ $16, SI
SUBQ $2, AX
JGE loop
remainder:
ADDQ $2, AX
JE done
remainder1:
MOVSD (SI), X0
SQRTSD X0, X0
MOVSD X0, (SI)
ADDQ $8, SI
DECQ AX
JNE remainder1
done:
RET
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