1 // Copyright 2014 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 // +build ppc64 ppc64le 6 7 #include "textflag.h" 8 9 // void runtimememclrNoHeapPointers(void*, uintptr) 10 TEXT runtimememclrNoHeapPointers(SB), NOSPLIT|NOFRAME, $0-16 11 MOVD ptr+0(FP), R3 12 MOVD n+8(FP), R4 13 14 // Determine if there are doublewords to clear 15 check: 16 ANDCC $7, R4, R5 // R5: leftover bytes to clear 17 SRAD $3, R4, R6 // R6: double words to clear 18 CMP R6, $0, CR1 // CR1[EQ] set if no double words 19 20 BC 12, 6, nozerolarge // only single bytes 21 MOVD R6, CTR // R6 = number of double words 22 SRADCC $2, R6, R7 // 32 byte chunks? 23 BNE zero32setup 24 25 // Clear double words 26 27 zero8: 28 MOVD R0, 0(R3) // double word 29 ADD $8, R3 30 BC 16, 0, zero8 // dec ctr, br zero8 if ctr not 0 31 BR nozerolarge // handle remainder 32 33 // Prepare to clear 32 bytes at a time. 34 35 zero32setup: 36 DCBTST (R3) // prepare data cache 37 MOVD R7, CTR // number of 32 byte chunks 38 39 zero32: 40 MOVD R0, 0(R3) // clear 4 double words 41 MOVD R0, 8(R3) 42 MOVD R0, 16(R3) 43 MOVD R0, 24(R3) 44 ADD $32, R3 45 BC 16, 0, zero32 // dec ctr, br zero32 if ctr not 0 46 RLDCLCC $61, R4, $3, R6 // remaining doublewords 47 BEQ nozerolarge 48 MOVD R6, CTR // set up the CTR for doublewords 49 BR zero8 50 51 nozerolarge: 52 CMP R5, $0 // any remaining bytes 53 BC 4, 1, LR // ble lr 54 55 zerotail: 56 MOVD R5, CTR // set up to clear tail bytes 57 58 zerotailloop: 59 MOVB R0, 0(R3) // clear single bytes 60 ADD $1, R3 61 BC 16, 0, zerotailloop // dec ctr, br zerotailloop if ctr not 0 62 RET 63
