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// Copyright 2014 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.
// +build ppc64 ppc64le
#include "textflag.h"
// func memclrNoHeapPointers(ptr unsafe.Pointer, n uintptr)
TEXT runtime·memclrNoHeapPointers(SB), NOSPLIT|NOFRAME, $0-16
MOVD ptr+0(FP), R3
MOVD n+8(FP), R4
// Determine if there are doublewords to clear
check:
ANDCC $7, R4, R5 // R5: leftover bytes to clear
SRAD $3, R4, R6 // R6: double words to clear
CMP R6, $0, CR1 // CR1[EQ] set if no double words
BC 12, 6, nozerolarge // only single bytes
MOVD R6, CTR // R6 = number of double words
SRADCC $2, R6, R7 // 32 byte chunks?
BNE zero32setup
// Clear double words
zero8:
MOVD R0, 0(R3) // double word
ADD $8, R3
BC 16, 0, zero8 // dec ctr, br zero8 if ctr not 0
BR nozerolarge // handle remainder
// Prepare to clear 32 bytes at a time.
zero32setup:
DCBTST (R3) // prepare data cache
MOVD R7, CTR // number of 32 byte chunks
zero32:
MOVD R0, 0(R3) // clear 4 double words
MOVD R0, 8(R3)
MOVD R0, 16(R3)
MOVD R0, 24(R3)
ADD $32, R3
BC 16, 0, zero32 // dec ctr, br zero32 if ctr not 0
RLDCLCC $61, R4, $3, R6 // remaining doublewords
BEQ nozerolarge
MOVD R6, CTR // set up the CTR for doublewords
BR zero8
nozerolarge:
CMP R5, $0 // any remaining bytes
BC 4, 1, LR // ble lr
zerotail:
MOVD R5, CTR // set up to clear tail bytes
zerotailloop:
MOVB R0, 0(R3) // clear single bytes
ADD $1, R3
BC 16, 0, zerotailloop // dec ctr, br zerotailloop if ctr not 0
RET