/* * Copyright (c) 2013 * MIPS Technologies, Inc., California. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the MIPS Technologies, Inc., nor the names of its * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE MIPS TECHNOLOGIES, INC. ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE MIPS TECHNOLOGIES, INC. BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifdef ANDROID_CHANGES # include "machine/asm.h" # include "machine/regdef.h" # define PREFETCH_STORE_HINT PREFETCH_HINT_PREPAREFORSTORE #elif _LIBC # include "machine/asm.h" # include "machine/regdef.h" # define PREFETCH_STORE_HINT PREFETCH_HINT_PREPAREFORSTORE #else # include <regdef.h> # include <sys/asm.h> #endif /* Check to see if the MIPS architecture we are compiling for supports prefetching. */ #if (__mips == 4) || (__mips == 5) || (__mips == 32) || (__mips == 64) # ifndef DISABLE_PREFETCH # define USE_PREFETCH # endif #endif #if defined(_MIPS_SIM) && ((_MIPS_SIM == _ABI64) || (_MIPS_SIM == _ABIN32)) # ifndef DISABLE_DOUBLE # define USE_DOUBLE # endif #endif #ifndef USE_DOUBLE # ifndef DISABLE_DOUBLE_ALIGN # define DOUBLE_ALIGN # endif #endif /* Some asm.h files do not have the L macro definition. */ #ifndef L # if _MIPS_SIM == _ABIO32 # define L(label) $L ## label # else # define L(label) .L ## label # endif #endif /* Some asm.h files do not have the PTR_ADDIU macro definition. */ #ifndef PTR_ADDIU # ifdef USE_DOUBLE # define PTR_ADDIU daddiu # else # define PTR_ADDIU addiu # endif #endif /* New R6 instructions that may not be in asm.h. */ #ifndef PTR_LSA # if _MIPS_SIM == _ABI64 # define PTR_LSA dlsa # else # define PTR_LSA lsa # endif #endif /* Using PREFETCH_HINT_PREPAREFORSTORE instead of PREFETCH_STORE or PREFETCH_STORE_STREAMED offers a large performance advantage but PREPAREFORSTORE has some special restrictions to consider. Prefetch with the 'prepare for store' hint does not copy a memory location into the cache, it just allocates a cache line and zeros it out. This means that if you do not write to the entire cache line before writing it out to memory some data will get zero'ed out when the cache line is written back to memory and data will be lost. There are ifdef'ed sections of this memcpy to make sure that it does not do prefetches on cache lines that are not going to be completely written. This code is only needed and only used when PREFETCH_STORE_HINT is set to PREFETCH_HINT_PREPAREFORSTORE. This code assumes that cache lines are less than MAX_PREFETCH_SIZE bytes and if the cache line is larger it will not work correctly. */ #ifdef USE_PREFETCH # define PREFETCH_HINT_STORE 1 # define PREFETCH_HINT_STORE_STREAMED 5 # define PREFETCH_HINT_STORE_RETAINED 7 # define PREFETCH_HINT_PREPAREFORSTORE 30 /* If we have not picked out what hints to use at this point use the standard load and store prefetch hints. */ # ifndef PREFETCH_STORE_HINT # define PREFETCH_STORE_HINT PREFETCH_HINT_STORE # endif /* We double everything when USE_DOUBLE is true so we do 2 prefetches to get 64 bytes in that case. The assumption is that each individual prefetch brings in 32 bytes. */ # ifdef USE_DOUBLE # define PREFETCH_CHUNK 64 # define PREFETCH_FOR_STORE(chunk, reg) \ pref PREFETCH_STORE_HINT, (chunk)*64(reg); \ pref PREFETCH_STORE_HINT, ((chunk)*64)+32(reg) # else # define PREFETCH_CHUNK 32 # define PREFETCH_FOR_STORE(chunk, reg) \ pref PREFETCH_STORE_HINT, (chunk)*32(reg) # endif /* MAX_PREFETCH_SIZE is the maximum size of a prefetch, it must not be less than PREFETCH_CHUNK, the assumed size of each prefetch. If the real size of a prefetch is greater than MAX_PREFETCH_SIZE and the PREPAREFORSTORE hint is used, the code will not work correctly. If PREPAREFORSTORE is not used than MAX_PREFETCH_SIZE does not matter. */ # define MAX_PREFETCH_SIZE 128 /* PREFETCH_LIMIT is set based on the fact that we never use an offset greater than 5 on a STORE prefetch and that a single prefetch can never be larger than MAX_PREFETCH_SIZE. We add the extra 32 when USE_DOUBLE is set because we actually do two prefetches in that case, one 32 bytes after the other. */ # ifdef USE_DOUBLE # define PREFETCH_LIMIT (5 * PREFETCH_CHUNK) + 32 + MAX_PREFETCH_SIZE # else # define PREFETCH_LIMIT (5 * PREFETCH_CHUNK) + MAX_PREFETCH_SIZE # endif # if (PREFETCH_STORE_HINT == PREFETCH_HINT_PREPAREFORSTORE) \ && ((PREFETCH_CHUNK * 4) < MAX_PREFETCH_SIZE) /* We cannot handle this because the initial prefetches may fetch bytes that are before the buffer being copied. We start copies with an offset of 4 so avoid this situation when using PREPAREFORSTORE. */ # error "PREFETCH_CHUNK is too large and/or MAX_PREFETCH_SIZE is too small." # endif #else /* USE_PREFETCH not defined */ # define PREFETCH_FOR_STORE(offset, reg) #endif #if __mips_isa_rev > 5 # if (PREFETCH_STORE_HINT == PREFETCH_HINT_PREPAREFORSTORE) # undef PREFETCH_STORE_HINT # define PREFETCH_STORE_HINT PREFETCH_HINT_STORE_STREAMED # endif # define R6_CODE #endif /* Allow the routine to be named something else if desired. */ #ifndef MEMSET_NAME # define MEMSET_NAME memset #endif /* We load/store 64 bits at a time when USE_DOUBLE is true. The C_ prefix stands for CHUNK and is used to avoid macro name conflicts with system header files. */ #ifdef USE_DOUBLE # define C_ST sd # if __MIPSEB # define C_STHI sdl /* high part is left in big-endian */ # else # define C_STHI sdr /* high part is right in little-endian */ # endif #else # define C_ST sw # if __MIPSEB # define C_STHI swl /* high part is left in big-endian */ # else # define C_STHI swr /* high part is right in little-endian */ # endif #endif /* Bookkeeping values for 32 vs. 64 bit mode. */ #ifdef USE_DOUBLE # define NSIZE 8 # define NSIZEMASK 0x3f # define NSIZEDMASK 0x7f #else # define NSIZE 4 # define NSIZEMASK 0x1f # define NSIZEDMASK 0x3f #endif #define UNIT(unit) ((unit)*NSIZE) #define UNITM1(unit) (((unit)*NSIZE)-1) #ifdef ANDROID_CHANGES LEAF(MEMSET_NAME,0) #else LEAF(MEMSET_NAME) #endif .set nomips16 .set noreorder /* If the size is less than 2*NSIZE (8 or 16), go to L(lastb). Regardless of size, copy dst pointer to v0 for the return value. */ slti t2,a2,(2 * NSIZE) bne t2,zero,L(lastb) move v0,a0 /* If memset value is not zero, we copy it to all the bytes in a 32 or 64 bit word. */ beq a1,zero,L(set0) /* If memset value is zero no smear */ PTR_SUBU a3,zero,a0 nop /* smear byte into 32 or 64 bit word */ #if ((__mips == 64) || (__mips == 32)) && (__mips_isa_rev >= 2) # ifdef USE_DOUBLE dins a1, a1, 8, 8 /* Replicate fill byte into half-word. */ dins a1, a1, 16, 16 /* Replicate fill byte into word. */ dins a1, a1, 32, 32 /* Replicate fill byte into dbl word. */ # else ins a1, a1, 8, 8 /* Replicate fill byte into half-word. */ ins a1, a1, 16, 16 /* Replicate fill byte into word. */ # endif #else # ifdef USE_DOUBLE and a1,0xff dsll t2,a1,8 or a1,t2 dsll t2,a1,16 or a1,t2 dsll t2,a1,32 or a1,t2 # else and a1,0xff sll t2,a1,8 or a1,t2 sll t2,a1,16 or a1,t2 # endif #endif /* If the destination address is not aligned do a partial store to get it aligned. If it is already aligned just jump to L(aligned). */ L(set0): #ifndef R6_CODE andi t2,a3,(NSIZE-1) /* word-unaligned address? */ beq t2,zero,L(aligned) /* t2 is the unalignment count */ PTR_SUBU a2,a2,t2 C_STHI a1,0(a0) PTR_ADDU a0,a0,t2 #else /* R6_CODE */ andi t2,a0,(NSIZE-1) lapc t9,L(atable) PTR_LSA t9,t2,t9,2 jrc t9 L(atable): bc L(aligned) # ifdef USE_DOUBLE bc L(lb7) bc L(lb6) bc L(lb5) bc L(lb4) # endif bc L(lb3) bc L(lb2) bc L(lb1) L(lb7): sb a1,6(a0) L(lb6): sb a1,5(a0) L(lb5): sb a1,4(a0) L(lb4): sb a1,3(a0) L(lb3): sb a1,2(a0) L(lb2): sb a1,1(a0) L(lb1): sb a1,0(a0) li t9,NSIZE subu t2,t9,t2 PTR_SUBU a2,a2,t2 PTR_ADDU a0,a0,t2 #endif /* R6_CODE */ L(aligned): /* If USE_DOUBLE is not set we may still want to align the data on a 16 byte boundry instead of an 8 byte boundry to maximize the opportunity of proAptiv chips to do memory bonding (combining two sequential 4 byte stores into one 8 byte store). We know there are at least 4 bytes left to store or we would have jumped to L(lastb) earlier in the code. */ #ifdef DOUBLE_ALIGN andi t2,a3,4 beq t2,zero,L(double_aligned) PTR_SUBU a2,a2,t2 sw a1,0(a0) PTR_ADDU a0,a0,t2 L(double_aligned): #endif /* Now the destination is aligned to (word or double word) aligned address Set a2 to count how many bytes we have to copy after all the 64/128 byte chunks are copied and a3 to the dest pointer after all the 64/128 byte chunks have been copied. We will loop, incrementing a0 until it equals a3. */ andi t8,a2,NSIZEDMASK /* any whole 64-byte/128-byte chunks? */ beq a2,t8,L(chkw) /* if a2==t8, no 64-byte/128-byte chunks */ PTR_SUBU a3,a2,t8 /* subtract from a2 the reminder */ PTR_ADDU a3,a0,a3 /* Now a3 is the final dst after loop */ /* When in the loop we may prefetch with the 'prepare to store' hint, in this case the a0+x should not be past the "t0-32" address. This means: for x=128 the last "safe" a0 address is "t0-160". Alternatively, for x=64 the last "safe" a0 address is "t0-96" In the current version we will use "prefetch hint,128(a0)", so "t0-160" is the limit. */ #if defined(USE_PREFETCH) \ && (PREFETCH_STORE_HINT == PREFETCH_HINT_PREPAREFORSTORE) PTR_ADDU t0,a0,a2 /* t0 is the "past the end" address */ PTR_SUBU t9,t0,PREFETCH_LIMIT /* t9 is the "last safe pref" address */ #endif #if defined(USE_PREFETCH) \ && (PREFETCH_STORE_HINT != PREFETCH_HINT_PREPAREFORSTORE) PREFETCH_FOR_STORE (1, a0) PREFETCH_FOR_STORE (2, a0) PREFETCH_FOR_STORE (3, a0) #endif L(loop16w): #if defined(USE_PREFETCH) \ && (PREFETCH_STORE_HINT == PREFETCH_HINT_PREPAREFORSTORE) sltu v1,t9,a0 /* If a0 > t9 don't use next prefetch */ bgtz v1,L(skip_pref) nop #endif #ifndef R6_CODE PREFETCH_FOR_STORE (4, a0) PREFETCH_FOR_STORE (5, a0) #else PREFETCH_FOR_STORE (2, a0) #endif L(skip_pref): C_ST a1,UNIT(0)(a0) C_ST a1,UNIT(1)(a0) C_ST a1,UNIT(2)(a0) C_ST a1,UNIT(3)(a0) C_ST a1,UNIT(4)(a0) C_ST a1,UNIT(5)(a0) C_ST a1,UNIT(6)(a0) C_ST a1,UNIT(7)(a0) C_ST a1,UNIT(8)(a0) C_ST a1,UNIT(9)(a0) C_ST a1,UNIT(10)(a0) C_ST a1,UNIT(11)(a0) C_ST a1,UNIT(12)(a0) C_ST a1,UNIT(13)(a0) C_ST a1,UNIT(14)(a0) C_ST a1,UNIT(15)(a0) PTR_ADDIU a0,a0,UNIT(16) /* adding 64/128 to dest */ bne a0,a3,L(loop16w) nop move a2,t8 /* Here we have dest word-aligned but less than 64-bytes or 128 bytes to go. Check for a 32(64) byte chunk and copy if if there is one. Otherwise jump down to L(chk1w) to handle the tail end of the copy. */ L(chkw): andi t8,a2,NSIZEMASK /* is there a 32-byte/64-byte chunk. */ /* the t8 is the reminder count past 32-bytes */ beq a2,t8,L(chk1w)/* when a2==t8, no 32-byte chunk */ nop C_ST a1,UNIT(0)(a0) C_ST a1,UNIT(1)(a0) C_ST a1,UNIT(2)(a0) C_ST a1,UNIT(3)(a0) C_ST a1,UNIT(4)(a0) C_ST a1,UNIT(5)(a0) C_ST a1,UNIT(6)(a0) C_ST a1,UNIT(7)(a0) PTR_ADDIU a0,a0,UNIT(8) /* Here we have less than 32(64) bytes to set. Set up for a loop to copy one word (or double word) at a time. Set a2 to count how many bytes we have to copy after all the word (or double word) chunks are copied and a3 to the dest pointer after all the (d)word chunks have been copied. We will loop, incrementing a0 until a0 equals a3. */ L(chk1w): andi a2,t8,(NSIZE-1) /* a2 is the reminder past one (d)word chunks */ beq a2,t8,L(lastb) PTR_SUBU a3,t8,a2 /* a3 is count of bytes in one (d)word chunks */ PTR_ADDU a3,a0,a3 /* a3 is the dst address after loop */ /* copying in words (4-byte or 8 byte chunks) */ L(wordCopy_loop): PTR_ADDIU a0,a0,UNIT(1) bne a0,a3,L(wordCopy_loop) C_ST a1,UNIT(-1)(a0) /* Copy the last 8 (or 16) bytes */ L(lastb): blez a2,L(leave) PTR_ADDU a3,a0,a2 /* a3 is the last dst address */ L(lastbloop): PTR_ADDIU a0,a0,1 bne a0,a3,L(lastbloop) sb a1,-1(a0) L(leave): j ra nop .set at .set reorder END(MEMSET_NAME)