| // Copyright ©2016 The Gonum Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| // +build !noasm,!gccgo,!safe |
| |
| #include "textflag.h" |
| |
| // func Div(dst, s []float64) |
| TEXT ·Div(SB), NOSPLIT, $0 |
| MOVQ dst_base+0(FP), DI // DI = &dst |
| MOVQ dst_len+8(FP), CX // CX = len(dst) |
| MOVQ s_base+24(FP), SI // SI = &s |
| CMPQ s_len+32(FP), CX // CX = max( CX, len(s) ) |
| CMOVQLE s_len+32(FP), CX |
| CMPQ CX, $0 // if CX == 0 { return } |
| JE div_end |
| XORQ AX, AX // i = 0 |
| MOVQ SI, BX |
| ANDQ $15, BX // BX = &s & 15 |
| JZ div_no_trim // if BX == 0 { goto div_no_trim } |
| |
| // Align on 16-bit boundary |
| MOVSD (DI)(AX*8), X0 // X0 = dst[i] |
| DIVSD (SI)(AX*8), X0 // X0 /= s[i] |
| MOVSD X0, (DI)(AX*8) // dst[i] = X0 |
| INCQ AX // ++i |
| DECQ CX // --CX |
| JZ div_end // if CX == 0 { return } |
| |
| div_no_trim: |
| MOVQ CX, BX |
| ANDQ $7, BX // BX = len(dst) % 8 |
| SHRQ $3, CX // CX = floor( len(dst) / 8 ) |
| JZ div_tail_start // if CX == 0 { goto div_tail_start } |
| |
| div_loop: // Loop unrolled 8x do { |
| MOVUPS (DI)(AX*8), X0 // X0 = dst[i:i+1] |
| MOVUPS 16(DI)(AX*8), X1 |
| MOVUPS 32(DI)(AX*8), X2 |
| MOVUPS 48(DI)(AX*8), X3 |
| DIVPD (SI)(AX*8), X0 // X0 /= s[i:i+1] |
| DIVPD 16(SI)(AX*8), X1 |
| DIVPD 32(SI)(AX*8), X2 |
| DIVPD 48(SI)(AX*8), X3 |
| MOVUPS X0, (DI)(AX*8) // dst[i] = X0 |
| MOVUPS X1, 16(DI)(AX*8) |
| MOVUPS X2, 32(DI)(AX*8) |
| MOVUPS X3, 48(DI)(AX*8) |
| ADDQ $8, AX // i += 8 |
| LOOP div_loop // } while --CX > 0 |
| CMPQ BX, $0 // if BX == 0 { return } |
| JE div_end |
| |
| div_tail_start: // Reset loop registers |
| MOVQ BX, CX // Loop counter: CX = BX |
| |
| div_tail: // do { |
| MOVSD (DI)(AX*8), X0 // X0 = dst[i] |
| DIVSD (SI)(AX*8), X0 // X0 /= s[i] |
| MOVSD X0, (DI)(AX*8) // dst[i] = X0 |
| INCQ AX // ++i |
| LOOP div_tail // } while --CX > 0 |
| |
| div_end: |
| RET |
| |
