diff options
Diffstat (limited to 'sysdeps/powerpc/powerpc64/le/power10/memcmp.S')
| -rw-r--r-- | sysdeps/powerpc/powerpc64/le/power10/memcmp.S | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/sysdeps/powerpc/powerpc64/le/power10/memcmp.S b/sysdeps/powerpc/powerpc64/le/power10/memcmp.S new file mode 100644 index 0000000000..52f244e7e7 --- /dev/null +++ b/sysdeps/powerpc/powerpc64/le/power10/memcmp.S @@ -0,0 +1,179 @@ +/* Optimized memcmp implementation for POWER10. + Copyright (C) 2021 Free Software Foundation, Inc. + 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 + <https://www.gnu.org/licenses/>. */ + +#include <sysdep.h> + +/* TODO: Replace macros by the actual instructions when minimum binutils becomes + >= 2.35. This is used to keep compatibility with older versions. */ +#define VEXTRACTBM(rt,vrb) \ + .long(((4)<<(32-6)) \ + | ((rt)<<(32-11)) \ + | ((8)<<(32-16)) \ + | ((vrb)<<(32-21)) \ + | 1602) + +#define LXVP(xtp,dq,ra) \ + .long(((6)<<(32-6)) \ + | ((((xtp)-32)>>1)<<(32-10)) \ + | ((1)<<(32-11)) \ + | ((ra)<<(32-16)) \ + | dq) + +/* Compare 32 bytes. */ +#define COMPARE_32(vr1,vr2,offset,tail_1,tail_2)\ + LXVP(32+vr1,offset,r3); \ + LXVP(32+vr2,offset,r4); \ + vcmpneb. v5,vr1+1,vr2+1; \ + bne cr6,L(tail_2); \ + vcmpneb. v4,vr1,vr2; \ + bne cr6,L(tail_1); \ + +#define TAIL(v_res,s1,s2) \ + vctzlsbb r7,v_res; \ + vextubrx r8,r7,s1; \ + vextubrx r9,r7,s2; \ + subf r3,r9,r8; \ + blr; \ + +/* int [r3] memcmp (const char *s1 [r3], const char *s2 [r4], + size_t size [r5]) */ + +#ifndef MEMCMP +# define MEMCMP memcmp +#endif + .machine power9 +ENTRY_TOCLESS (MEMCMP, 4) + CALL_MCOUNT 3 + + cmpldi cr6,r5,64 + bgt cr6,L(loop_head) + +/* Compare 64 bytes. This section is used for lengths <= 64 and for the last + bytes for larger lengths. */ +L(last_compare): + li r8,16 + + sldi r9,r5,56 + sldi r8,r8,56 + addi r6,r3,16 + addi r7,r4,16 + + /* Align up to 16 bytes. */ + lxvl 32+v0,r3,r9 + lxvl 32+v2,r4,r9 + + /* The sub. and vcmpneb. results are concatenated by the crnand in order + to do a single branch. It's doing a NOT(CR0.GT AND CR6.EQ) then + loading to CR0.LT. That means r9 is not bigger than 0 and v4 is not + all equal to 0. */ + sub. r9,r9,r8 + vcmpneb. v4,v0,v2 + crnand 4*cr0+lt,4*cr0+gt,4*cr6+eq + bt 4*cr0+lt,L(tail1) + + addi r3,r3,32 + addi r4,r4,32 + + lxvl 32+v1,r6,r9 + lxvl 32+v3,r7,r9 + sub. r9,r9,r8 + vcmpneb. v5,v1,v3 + crnand 4*cr0+lt,4*cr0+gt,4*cr6+eq + bt 4*cr0+lt,L(tail2) + + addi r6,r3,16 + addi r7,r4,16 + + lxvl 32+v6,r3,r9 + lxvl 32+v8,r4,r9 + sub. r9,r9,r8 + vcmpneb. v4,v6,v8 + crnand 4*cr0+lt,4*cr0+gt,4*cr6+eq + bt 4*cr0+lt,L(tail3) + + lxvl 32+v7,r6,r9 + lxvl 32+v9,r7,r9 + vcmpneb. v5,v7,v9 + bne cr6,L(tail4) + +L(finish): + /* The contents are equal. */ + li r3,0 + blr + +L(loop_head): + /* Calculate how many loops to run. */ + srdi. r8,r5,7 + beq L(loop_tail) + mtctr r8 + +/* Main loop. Compares 128 bytes each loop. */ + .p2align 5 +L(loop_128): + COMPARE_32(v0,v2,0,tail1,tail2) + COMPARE_32(v6,v8,32,tail3,tail4) + COMPARE_32(v10,v12,64,tail5,tail6) + COMPARE_32(v14,v16,96,tail7,tail8) + + addi r3,r3,128 + addi r4,r4,128 + bdnz L(loop_128) + + /* Account loop comparisons. */ + clrldi. r5,r5,57 + beq L(finish) + +/* Compares 64 bytes if length is still bigger than 64 bytes. */ + .p2align 5 +L(loop_tail): + cmpldi r5,64 + ble L(last_compare) + COMPARE_32(v0,v2,0,tail1,tail2) + COMPARE_32(v6,v8,32,tail3,tail4) + addi r3,r3,64 + addi r4,r4,64 + subi r5,r5,64 + b L(last_compare) + +L(tail1): + TAIL(v4,v0,v2) + +L(tail2): + TAIL(v5,v1,v3) + +L(tail3): + TAIL(v4,v6,v8) + +L(tail4): + TAIL(v5,v7,v9) + +L(tail5): + TAIL(v4,v10,v12) + +L(tail6): + TAIL(v5,v11,v13) + +L(tail7): + TAIL(v4,v14,v16) + +L(tail8): + TAIL(v5,v15,v17) + +END (MEMCMP) +libc_hidden_builtin_def (memcmp) +weak_alias (memcmp, bcmp) |