diff options
Diffstat (limited to 'libc/string/bfin/memset.S')
-rw-r--r-- | libc/string/bfin/memset.S | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/libc/string/bfin/memset.S b/libc/string/bfin/memset.S new file mode 100644 index 000000000..bd8eb4b6a --- /dev/null +++ b/libc/string/bfin/memset.S @@ -0,0 +1,86 @@ +/* memset.S + * Copyright (C) 2003, 2005, 2006 Analog Devices Inc., All Rights Reserved. + * + * This file is subject to the terms and conditions of the GNU Library General + * Public License. See the file "COPYING.LIB" in the main directory of this + * archive for more details. + * + * Non-LGPL License also available as part of VisualDSP++ + * http://www.analog.com/processors/resources/crosscore/visualDspDevSoftware.html + */ + +/* void *memset(void *s, int c, size_t n); + * R0 = address (s) (leave unchanged to form result) + * R1 = filler byte (c) + * R2 = count (n) + * + * Note: Favours word aligned data. + */ + +.text + +.align 2 + +.global _memset +.type _memset, STT_FUNC +_memset: + P0 = R0 ; // P0 = address + P2 = R2 ; // P2 = count + R3 = R0 + R2; // end + CC = R2 <= 7(IU); + IF CC JUMP too_small; + R1 = R1.B (Z); // R1 = fill char + R2 = 3; + R2 = R0 & R2; // addr bottom two bits + CC = R2 == 0; // AZ set if zero. + IF !CC JUMP force_align ; // Jump if addr not aligned. + +aligned: + P1 = P2 >> 2; // count = n/4 + R2 = R1 << 8; // create quad filler + R2.L = R2.L + R1.L(NS); + R2.H = R2.L + R1.H(NS); + P2 = R3; + + LSETUP (quad_loop , quad_loop) LC0=P1; +quad_loop: + [P0++] = R2; + + CC = P0 == P2; + IF !CC JUMP bytes_left; + RTS; + +bytes_left: + R2 = R3; // end point + R3 = P0; // current position + R2 = R2 - R3; // bytes left + P2 = R2; + +too_small: + CC = P2 == 0; //Check zero count + IF CC JUMP finished; // Unusual + +bytes: LSETUP (byte_loop , byte_loop) LC0=P2; +byte_loop: B[P0++] = R1; + +finished: + RTS; + +force_align: + CC = BITTST (R0, 0 ); // odd byte + R0 = 4; + R0 = R0 - R2; + P1 = R0; + R0 = P0; // Recover return address + IF !CC JUMP skip1; + B[P0++] = R1; +skip1: + CC = R2 <= 2; // 2 bytes + P2 -= P1; // reduce count + IF !CC JUMP aligned; + B[P0++] = R1; + B[P0++] = R1; + JUMP aligned; +.size _memset,.-_memset + +libc_hidden_def (memset) |