/* Optimized memset implementation for PowerPC64/POWER7. Copyright (C) 2010-2017 Free Software Foundation, Inc. Contributed by Luis Machado . This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, see . */ #include /* __ptr_t [r3] memset (__ptr_t s [r3], int c [r4], size_t n [r5])); Returns 's'. */ #ifndef MEMSET # define MEMSET memset #endif .machine power7 EALIGN (MEMSET, 5, 0) CALL_MCOUNT 3 L(_memset): cmpldi cr7,5,31 cmpldi cr6,5,8 mr 10,3 /* Replicate byte to word. */ insrdi 4,4,8,48 insrdi 4,4,16,32 ble cr6,L(small) /* If length <= 8, use short copy code. */ neg 0,3 ble cr7,L(medium) /* If length < 32, use medium copy code. */ andi. 11,10,7 /* Check alignment of SRC. */ insrdi 4,4,32,0 /* Replicate word to double word. */ mr 12,5 beq L(big_aligned) clrldi 0,0,61 mtocrf 0x01,0 subf 5,0,5 /* Get DST aligned to 8 bytes. */ 1: bf 31,2f stb 4,0(10) addi 10,10,1 2: bf 30,4f sth 4,0(10) addi 10,10,2 4: bf 29,L(big_aligned) stw 4,0(10) addi 10,10,4 .align 4 L(big_aligned): cmpldi cr5,5,255 li 0,32 dcbtst 0,10 cmpldi cr6,4,0 srdi 9,5,3 /* Number of full doublewords remaining. */ crand 27,26,21 mtocrf 0x01,9 bt 27,L(huge) /* From this point on, we'll copy 32+ bytes and the value isn't 0 (so we can't use dcbz). */ srdi 8,5,5 clrldi 11,5,61 cmpldi cr6,11,0 cmpldi cr1,9,4 mtctr 8 /* Copy 1~3 doublewords so the main loop starts at a multiple of 32 bytes. */ bf 30,1f std 4,0(10) std 4,8(10) addi 10,10,16 bf 31,L(big_loop) std 4,0(10) addi 10,10,8 mr 12,10 blt cr1,L(tail_bytes) b L(big_loop) .align 4 1: /* Copy 1 doubleword. */ bf 31,L(big_loop) std 4,0(10) addi 10,10,8 /* Main aligned copy loop. Copies 32-bytes at a time and ping-pong through r10 and r12 to avoid AGEN delays. */ .align 4 L(big_loop): addi 12,10,32 std 4,0(10) std 4,8(10) std 4,16(10) std 4,24(10) bdz L(tail_bytes) addi 10,10,64 std 4,0(12) std 4,8(12) std 4,16(12) std 4,24(12) bdnz L(big_loop) mr 12,10 b L(tail_bytes) .align 4 L(tail_bytes): /* Check for tail bytes. */ beqlr cr6 clrldi 0,5,61 mtocrf 0x01,0 /* At this point we have a tail of 0-7 bytes and we know that the destination is doubleword-aligned. */ 4: /* Copy 4 bytes. */ bf 29,2f stw 4,0(12) addi 12,12,4 2: /* Copy 2 bytes. */ bf 30,1f sth 4,0(12) addi 12,12,2 1: /* Copy 1 byte. */ bflr 31 stb 4,0(12) blr /* Special case when value is 0 and we have a long length to deal with. Use dcbz to zero out 128-bytes at a time. Before using dcbz though, we need to get the destination 128-bytes aligned. */ .align 4 L(huge): andi. 11,10,127 neg 0,10 beq L(huge_aligned) clrldi 0,0,57 subf 5,0,5 srdi 0,0,3 mtocrf 0x01,0 /* Get DST aligned to 128 bytes. */ 8: bf 28,4f std 4,0(10) std 4,8(10) std 4,16(10) std 4,24(10) std 4,32(10) std 4,40(10) std 4,48(10) std 4,56(10) addi 10,10,64 .align 4 4: bf 29,2f std 4,0(10) std 4,8(10) std 4,16(10) std 4,24(10) addi 10,10,32 .align 4 2: bf 30,1f std 4,0(10) std 4,8(10) addi 10,10,16 .align 4 1: bf 31,L(huge_aligned) std 4,0(10) addi 10,10,8 L(huge_aligned): srdi 8,5,7 clrldi 11,5,57 cmpldi cr6,11,0 mtctr 8 .align 4 L(huge_loop): dcbz 0,10 addi 10,10,128 bdnz L(huge_loop) /* Check how many bytes are still left. */ beqlr cr6 subf 9,3,10 subf 5,9,12 srdi 8,5,3 cmpldi cr6,8,0 mtocrf 0x01,8 /* We have a tail o 1~127 bytes. Copy up to 15 doublewords for speed. We'll handle the resulting tail bytes later. */ beq cr6,L(tail) 8: bf 28,4f std 4,0(10) std 4,8(10) std 4,16(10) std 4,24(10) std 4,32(10) std 4,40(10) std 4,48(10) std 4,56(10) addi 10,10,64 .align 4 4: bf 29,2f std 4,0(10) std 4,8(10) std 4,16(10) std 4,24(10) addi 10,10,32 .align 4 2: bf 30,1f std 4,0(10) std 4,8(10) addi 10,10,16 .align 4 1: bf 31,L(tail) std 4,0(10) addi 10,10,8 /* Handle the rest of the tail bytes here. */ L(tail): mtocrf 0x01,5 .align 4 4: bf 29,2f stw 4,0(10) addi 10,10,4 .align 4 2: bf 30,1f sth 4,0(10) addi 10,10,2 .align 4 1: bflr 31 stb 4,0(10) blr /* Expanded tree to copy tail bytes without increments. */ .align 4 L(copy_tail): bf 29,L(FXX) stw 4,0(10) bf 30,L(TFX) sth 4,4(10) bflr 31 stb 4,6(10) blr .align 4 L(FXX): bf 30,L(FFX) sth 4,0(10) bflr 31 stb 4,2(10) blr .align 4 L(TFX): bflr 31 stb 4,4(10) blr .align 4 L(FFX): bflr 31 stb 4,0(10) blr /* Handle copies of 9~31 bytes. */ .align 4 L(medium): /* At least 9 bytes to go. */ andi. 11,10,3 clrldi 0,0,62 beq L(medium_aligned) /* Force 4-bytes alignment for DST. */ mtocrf 0x01,0 subf 5,0,5 1: /* Copy 1 byte. */ bf 31,2f stb 4,0(10) addi 10,10,1 2: /* Copy 2 bytes. */ bf 30,L(medium_aligned) sth 4,0(10) addi 10,10,2 .align 4 L(medium_aligned): /* At least 6 bytes to go, and DST is word-aligned. */ cmpldi cr1,5,16 mtocrf 0x01,5 blt cr1,8f /* Copy 16 bytes. */ stw 4,0(10) stw 4,4(10) stw 4,8(10) stw 4,12(10) addi 10,10,16 8: /* Copy 8 bytes. */ bf 28,4f stw 4,0(10) stw 4,4(10) addi 10,10,8 4: /* Copy 4 bytes. */ bf 29,2f stw 4,0(10) addi 10,10,4 2: /* Copy 2-3 bytes. */ bf 30,1f sth 4,0(10) addi 10,10,2 1: /* Copy 1 byte. */ bflr 31 stb 4,0(10) blr /* Handles copies of 0~8 bytes. */ .align 4 L(small): mtocrf 0x01,5 bne cr6,L(copy_tail) stw 4,0(10) stw 4,4(10) blr END_GEN_TB (MEMSET,TB_TOCLESS) libc_hidden_builtin_def (memset) /* Copied from bzero.S to prevent the linker from inserting a stub between bzero and memset. */ ENTRY (__bzero) CALL_MCOUNT 3 mr r5,r4 li r4,0 b L(_memset) END (__bzero) #ifndef __bzero weak_alias (__bzero, bzero) #endif