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93e46f8773
Implement memset family IFUNC selectors in C. All internal calls within libc.so can use IFUNC on x86-64 since unlike x86, x86-64 supports PC-relative addressing to access the GOT entry so that it can call via PLT without using an extra register. For libc.a, we can't use IFUNC for functions which are called before IFUNC has been initialized. Use IFUNC internally reduces the icache footprint since libc.so and other codes in the process use the same implementations. This patch uses IFUNC for memset functions within libc. 2017-06-07 H.J. Lu <hongjiu.lu@intel.com> Erich Elsen <eriche@google.com> * sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add memset-sse2-unaligned-erms, and memset_chk-nonshared. * sysdeps/x86_64/multiarch/ifunc-impl-list.c (__libc_ifunc_impl_list): Add test for __memset_chk_erms. Update comments. * sysdeps/x86_64/multiarch/ifunc-memset.h: New file. * sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S: Likewise. * sysdeps/x86_64/multiarch/memset.c: Likewise. * sysdeps/x86_64/multiarch/memset_chk-nonshared.S: Likewise. * sysdeps/x86_64/multiarch/memset_chk.c: Likewise. * sysdeps/x86_64/multiarch/memset.S: Removed. * sysdeps/x86_64/multiarch/memset_chk.S: Likewise. * sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S (__memset_chk_erms): New function.
269 lines
6.7 KiB
ArmAsm
269 lines
6.7 KiB
ArmAsm
/* memset/bzero with unaligned store and rep stosb
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Copyright (C) 2016-2017 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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/* memset is implemented as:
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1. Use overlapping store to avoid branch.
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2. If size is less than VEC, use integer register stores.
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3. If size is from VEC_SIZE to 2 * VEC_SIZE, use 2 VEC stores.
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4. If size is from 2 * VEC_SIZE to 4 * VEC_SIZE, use 4 VEC stores.
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5. If size is more to 4 * VEC_SIZE, align to 4 * VEC_SIZE with
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4 VEC stores and store 4 * VEC at a time until done. */
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#include <sysdep.h>
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#ifndef MEMSET_CHK_SYMBOL
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# define MEMSET_CHK_SYMBOL(p,s) MEMSET_SYMBOL(p, s)
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#endif
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#ifndef WMEMSET_CHK_SYMBOL
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# define WMEMSET_CHK_SYMBOL(p,s) WMEMSET_SYMBOL(p, s)
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#endif
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#ifndef VZEROUPPER
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# if VEC_SIZE > 16
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# define VZEROUPPER vzeroupper
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# else
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# define VZEROUPPER
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# endif
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#endif
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#ifndef VZEROUPPER_SHORT_RETURN
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# if VEC_SIZE > 16
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# define VZEROUPPER_SHORT_RETURN vzeroupper
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# else
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# define VZEROUPPER_SHORT_RETURN rep
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# endif
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#endif
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#ifndef MOVQ
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# if VEC_SIZE > 16
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# define MOVQ vmovq
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# else
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# define MOVQ movq
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# endif
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#endif
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/* Threshold to use Enhanced REP STOSB. Since there is overhead to set
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up REP STOSB operation, REP STOSB isn't faster on short data. The
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memset micro benchmark in glibc shows that 2KB is the approximate
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value above which REP STOSB becomes faster on processors with
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Enhanced REP STOSB. Since the stored value is fixed, larger register
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size has minimal impact on threshold. */
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#ifndef REP_STOSB_THRESHOLD
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# define REP_STOSB_THRESHOLD 2048
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#endif
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#ifndef SECTION
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# error SECTION is not defined!
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#endif
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.section SECTION(.text),"ax",@progbits
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#if VEC_SIZE == 16 && IS_IN (libc)
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ENTRY (__bzero)
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movq %rdi, %rax /* Set return value. */
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movq %rsi, %rdx /* Set n. */
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pxor %xmm0, %xmm0
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jmp L(entry_from_bzero)
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END (__bzero)
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weak_alias (__bzero, bzero)
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#endif
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#if IS_IN (libc)
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# if defined SHARED
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ENTRY_CHK (WMEMSET_CHK_SYMBOL (__wmemset_chk, unaligned))
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cmpq %rdx, %rcx
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jb HIDDEN_JUMPTARGET (__chk_fail)
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END_CHK (WMEMSET_CHK_SYMBOL (__wmemset_chk, unaligned))
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# endif
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ENTRY (WMEMSET_SYMBOL (__wmemset, unaligned))
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shlq $2, %rdx
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WMEMSET_VDUP_TO_VEC0_AND_SET_RETURN (%esi, %rdi)
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jmp L(entry_from_bzero)
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END (WMEMSET_SYMBOL (__wmemset, unaligned))
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#endif
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#if defined SHARED && IS_IN (libc)
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ENTRY_CHK (MEMSET_CHK_SYMBOL (__memset_chk, unaligned))
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cmpq %rdx, %rcx
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jb HIDDEN_JUMPTARGET (__chk_fail)
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END_CHK (MEMSET_CHK_SYMBOL (__memset_chk, unaligned))
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#endif
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ENTRY (MEMSET_SYMBOL (__memset, unaligned))
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MEMSET_VDUP_TO_VEC0_AND_SET_RETURN (%esi, %rdi)
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L(entry_from_bzero):
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cmpq $VEC_SIZE, %rdx
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jb L(less_vec)
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cmpq $(VEC_SIZE * 2), %rdx
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ja L(more_2x_vec)
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/* From VEC and to 2 * VEC. No branch when size == VEC_SIZE. */
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VMOVU %VEC(0), -VEC_SIZE(%rdi,%rdx)
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VMOVU %VEC(0), (%rdi)
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VZEROUPPER
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ret
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#if defined USE_MULTIARCH && IS_IN (libc)
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END (MEMSET_SYMBOL (__memset, unaligned))
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# if VEC_SIZE == 16
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ENTRY (__memset_chk_erms)
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cmpq %rdx, %rcx
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jb HIDDEN_JUMPTARGET (__chk_fail)
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END (__memset_chk_erms)
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/* Only used to measure performance of REP STOSB. */
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ENTRY (__memset_erms)
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# else
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/* Provide a symbol to debugger. */
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ENTRY (MEMSET_SYMBOL (__memset, erms))
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# endif
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L(stosb):
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/* Issue vzeroupper before rep stosb. */
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VZEROUPPER
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movq %rdx, %rcx
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movzbl %sil, %eax
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movq %rdi, %rdx
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rep stosb
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movq %rdx, %rax
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ret
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# if VEC_SIZE == 16
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END (__memset_erms)
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# else
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END (MEMSET_SYMBOL (__memset, erms))
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# endif
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# if defined SHARED && IS_IN (libc)
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ENTRY_CHK (MEMSET_CHK_SYMBOL (__memset_chk, unaligned_erms))
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cmpq %rdx, %rcx
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jb HIDDEN_JUMPTARGET (__chk_fail)
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END_CHK (MEMSET_CHK_SYMBOL (__memset_chk, unaligned_erms))
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# endif
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ENTRY (MEMSET_SYMBOL (__memset, unaligned_erms))
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MEMSET_VDUP_TO_VEC0_AND_SET_RETURN (%esi, %rdi)
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cmpq $VEC_SIZE, %rdx
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jb L(less_vec)
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cmpq $(VEC_SIZE * 2), %rdx
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ja L(stosb_more_2x_vec)
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/* From VEC and to 2 * VEC. No branch when size == VEC_SIZE. */
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VMOVU %VEC(0), -VEC_SIZE(%rdi,%rdx)
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VMOVU %VEC(0), (%rdi)
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VZEROUPPER
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ret
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L(stosb_more_2x_vec):
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cmpq $REP_STOSB_THRESHOLD, %rdx
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ja L(stosb)
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#endif
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L(more_2x_vec):
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cmpq $(VEC_SIZE * 4), %rdx
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ja L(loop_start)
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VMOVU %VEC(0), (%rdi)
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VMOVU %VEC(0), VEC_SIZE(%rdi)
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VMOVU %VEC(0), -VEC_SIZE(%rdi,%rdx)
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VMOVU %VEC(0), -(VEC_SIZE * 2)(%rdi,%rdx)
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L(return):
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VZEROUPPER
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ret
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L(loop_start):
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leaq (VEC_SIZE * 4)(%rdi), %rcx
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VMOVU %VEC(0), (%rdi)
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andq $-(VEC_SIZE * 4), %rcx
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VMOVU %VEC(0), -VEC_SIZE(%rdi,%rdx)
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VMOVU %VEC(0), VEC_SIZE(%rdi)
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VMOVU %VEC(0), -(VEC_SIZE * 2)(%rdi,%rdx)
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VMOVU %VEC(0), (VEC_SIZE * 2)(%rdi)
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VMOVU %VEC(0), -(VEC_SIZE * 3)(%rdi,%rdx)
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VMOVU %VEC(0), (VEC_SIZE * 3)(%rdi)
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VMOVU %VEC(0), -(VEC_SIZE * 4)(%rdi,%rdx)
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addq %rdi, %rdx
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andq $-(VEC_SIZE * 4), %rdx
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cmpq %rdx, %rcx
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je L(return)
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L(loop):
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VMOVA %VEC(0), (%rcx)
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VMOVA %VEC(0), VEC_SIZE(%rcx)
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VMOVA %VEC(0), (VEC_SIZE * 2)(%rcx)
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VMOVA %VEC(0), (VEC_SIZE * 3)(%rcx)
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addq $(VEC_SIZE * 4), %rcx
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cmpq %rcx, %rdx
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jne L(loop)
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VZEROUPPER_SHORT_RETURN
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ret
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L(less_vec):
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/* Less than 1 VEC. */
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# if VEC_SIZE != 16 && VEC_SIZE != 32 && VEC_SIZE != 64
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# error Unsupported VEC_SIZE!
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# endif
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# if VEC_SIZE > 32
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cmpb $32, %dl
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jae L(between_32_63)
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# endif
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# if VEC_SIZE > 16
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cmpb $16, %dl
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jae L(between_16_31)
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# endif
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MOVQ %xmm0, %rcx
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cmpb $8, %dl
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jae L(between_8_15)
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cmpb $4, %dl
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jae L(between_4_7)
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cmpb $1, %dl
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ja L(between_2_3)
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jb 1f
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movb %cl, (%rdi)
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1:
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VZEROUPPER
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ret
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# if VEC_SIZE > 32
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/* From 32 to 63. No branch when size == 32. */
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L(between_32_63):
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vmovdqu %ymm0, -32(%rdi,%rdx)
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vmovdqu %ymm0, (%rdi)
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VZEROUPPER
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ret
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# endif
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# if VEC_SIZE > 16
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/* From 16 to 31. No branch when size == 16. */
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L(between_16_31):
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vmovdqu %xmm0, -16(%rdi,%rdx)
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vmovdqu %xmm0, (%rdi)
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VZEROUPPER
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ret
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# endif
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/* From 8 to 15. No branch when size == 8. */
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L(between_8_15):
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movq %rcx, -8(%rdi,%rdx)
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movq %rcx, (%rdi)
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VZEROUPPER
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ret
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L(between_4_7):
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/* From 4 to 7. No branch when size == 4. */
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movl %ecx, -4(%rdi,%rdx)
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movl %ecx, (%rdi)
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VZEROUPPER
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ret
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L(between_2_3):
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/* From 2 to 3. No branch when size == 2. */
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movw %cx, -2(%rdi,%rdx)
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movw %cx, (%rdi)
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VZEROUPPER
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ret
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END (MEMSET_SYMBOL (__memset, unaligned_erms))
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