/* * Copyright (c) 2009 * 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. */ /************************************************************************ * * memset.S, version "64h" with 1 cache line horizon for "pref 30" and 14 nops * Version: "043009" * ************************************************************************/ /************************************************************************ * Include files ************************************************************************/ #include /* * This routine could be optimized for MIPS64. The current code only * uses MIPS32 instructions. */ #if defined(__MIPSEB__) # define SWHI swl /* high part is left in big-endian */ # define SWLO swr /* low part is right in big-endian */ #endif #if defined(__MIPSEL__) # define SWHI swr /* high part is right in little-endian */ # define SWLO swl /* low part is left in little-endian */ #endif #if !(defined(XGPROF) || defined(XPROF)) #undef SETUP_GP #define SETUP_GP #endif #ifdef NDEBUG #define DBG # #else #define DBG #endif /* * void _memset16(uint16_t* dst, uint16_t value, size_t size); */ LEAF(_memset16,0) .set noreorder DBG /* Check parameters */ DBG andi t0,a0,1 # a0 must be halfword aligned DBG tne t0,zero DBG andi t2,a2,1 # a2 must be even DBG tne t2,zero #ifdef FIXARGS # ensure count is even #if (__mips==32) && (__mips_isa_rev>=2) ins a2,zero,0,1 #else ori a2,1 xori a2,1 #endif #endif #if (__mips==32) && (__mips_isa_rev>=2) ins a1,a1,16,16 #else andi a1,0xffff sll t3,a1,16 or a1,t3 #endif beqz a2,.Ldone andi t1,a0,2 beqz t1,.Lalignok addu t0,a0,a2 # t0 is the "past the end" address sh a1,0(a0) # store one halfword to get aligned addu a0,2 subu a2,2 .Lalignok: slti t1,a2,4 # .Laligned for 4 or more bytes beqz t1,.Laligned sne t1,a2,2 # one more halfword? bnez t1,.Ldone nop sh a1,0(a0) .Ldone: j ra nop .set reorder END(_memset16) /* * void _memset32(uint32_t* dst, uint32_t value, size_t size); */ LEAF(_memset32,0) .set noreorder DBG /* Check parameters */ DBG andi t0,a0,3 # a0 must be word aligned DBG tne t0,zero DBG andi t2,a2,3 # a2 must be a multiple of 4 bytes DBG tne t2,zero #ifdef FIXARGS # ensure count is a multiple of 4 #if (__mips==32) && (__mips_isa_rev>=2) ins $a2,$0,0,2 #else ori a2,3 xori a2,3 #endif #endif bnez a2,.Laligned # any work to do? addu t0,a0,a2 # t0 is the "past the end" address j ra nop .set reorder END(_memset32) LEAF(memset,0) .set noreorder .set noat addu t0,a0,a2 # t0 is the "past the end" address slti AT,a2,4 # is a2 less than 4? bne AT,zero,.Llast4 # if yes, go to last4 move v0,a0 # memset returns the dst pointer beq a1,zero,.Lset0 subu v1,zero,a0 # smear byte into 32 bit word #if (__mips==32) && (__mips_isa_rev>=2) ins a1, a1, 8, 8 # Replicate fill byte into half-word. ins a1, a1, 16, 16 # Replicate fill byte into word. #else and a1,0xff sll AT,a1,8 or a1,AT sll AT,a1,16 or a1,AT #endif .Lset0: andi v1,v1,0x3 # word-unaligned address? beq v1,zero,.Laligned # v1 is the unalignment count subu a2,a2,v1 SWHI a1,0(a0) addu a0,a0,v1 # Here we have the "word-aligned" a0 (until the "last4") .Laligned: andi t8,a2,0x3f # any 64-byte chunks? # t8 is the byte count past 64-byte chunks beq a2,t8,.Lchk8w # when a2==t8, no 64-byte chunks # There will be at most 1 32-byte chunk then subu a3,a2,t8 # subtract from a2 the reminder # Here a3 counts bytes in 16w chunks addu a3,a0,a3 # Now a3 is the final dst after 64-byte chunks # Find out, if there are any 64-byte chunks after which will be still at least # 96 bytes left. The value "96" is calculated as needed buffer for # "pref 30,64(a0)" prefetch, which can be used as "pref 30,0(a0)" after # incrementing "a0" by 64. # For "a2" below 160 there will be no such "pref 30 safe" 64-byte chunk. # sltiu v1,a2,160 bgtz v1,.Lloop16w_nopref30 # skip "pref 30,0(a0)" subu t7,a2,96 # subtract "pref 30 unsafe" region # below we have at least 1 64-byte chunk which is "pref 30 safe" andi t6,t7,0x3f # t6 is past "64-byte safe chunks" reminder subu t5,t7,t6 # subtract from t7 the reminder # Here t5 counts bytes in 16w "safe" chunks addu t4,a0,t5 # Now t4 is the dst after 64-byte "safe" chunks # Don't use "pref 30,0(a0)" for a0 in a "middle" of a cache line # pref 30,0(a0) # Here we are in the region, where it is safe to use "pref 30,64(a0)" .Lloop16w: addiu a0,a0,64 pref 30,-32(a0) # continue setting up the dest, addr 64-32 sw a1,-64(a0) sw a1,-60(a0) sw a1,-56(a0) sw a1,-52(a0) sw a1,-48(a0) sw a1,-44(a0) sw a1,-40(a0) sw a1,-36(a0) nop nop # the extra nop instructions help to balance nop # cycles needed for "store" + "fill" + "evict" nop # For 64byte store there are needed 8 fill nop # and 8 evict cycles, i.e. at least 32 instr. nop nop pref 30,0(a0) # continue setting up the dest, addr 64-0 sw a1,-32(a0) sw a1,-28(a0) sw a1,-24(a0) sw a1,-20(a0) sw a1,-16(a0) sw a1,-12(a0) sw a1,-8(a0) sw a1,-4(a0) nop nop nop nop # NOTE: adding 14 nop-s instead of 12 nop-s nop # gives better results for "fast" memory nop bne a0,t4,.Lloop16w nop beq a0,a3,.Lchk8w # maybe no more 64-byte chunks? nop # this "delayed slot" is useless ... .Lloop16w_nopref30: # there could be up to 3 "64-byte nopref30" chunks addiu a0,a0,64 sw a1,-64(a0) sw a1,-60(a0) sw a1,-56(a0) sw a1,-52(a0) sw a1,-48(a0) sw a1,-44(a0) sw a1,-40(a0) sw a1,-36(a0) sw a1,-32(a0) sw a1,-28(a0) sw a1,-24(a0) sw a1,-20(a0) sw a1,-16(a0) sw a1,-12(a0) sw a1,-8(a0) bne a0,a3,.Lloop16w_nopref30 sw a1,-4(a0) .Lchk8w: # t8 here is the byte count past 64-byte chunks andi t7,t8,0x1f # is there a 32-byte chunk? # the t7 is the reminder count past 32-bytes beq t8,t7,.Lchk1w # when t8==t7, no 32-byte chunk move a2,t7 sw a1,0(a0) sw a1,4(a0) sw a1,8(a0) sw a1,12(a0) sw a1,16(a0) sw a1,20(a0) sw a1,24(a0) sw a1,28(a0) addiu a0,a0,32 .Lchk1w: andi t8,a2,0x3 # now t8 is the reminder past 1w chunks beq a2,t8,.Llast4aligned subu a3,a2,t8 # a3 is the count of bytes in 1w chunks addu a3,a0,a3 # now a3 is the dst address past the 1w chunks # copying in words (4-byte chunks) .LwordCopy_loop: addiu a0,a0,4 bne a0,a3,.LwordCopy_loop sw a1,-4(a0) # store last 0-3 bytes # this will repeat the last store if the memset finishes on a word boundary .Llast4aligned: j ra SWLO a1,-1(t0) .Llast4: beq a0,t0,.Llast4e .Llast4l: addiu a0,a0,1 bne a0,t0,.Llast4l sb a1,-1(a0) .Llast4e: j ra nop .set at .set reorder END(memset) /************************************************************************ * Implementation : Static functions ************************************************************************/