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https://sourceware.org/git/glibc.git
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5e8c5bb1ac
Since the new SSE2/AVX2 memsets are faster than the previous ones, we can remove the previous SSE2/AVX2 memsets and replace them with the new ones. This reduces the size of libc.so by about 900 bytes. No change in IFUNC selection if SSE2 and AVX2 memsets weren't used before. If SSE2 or AVX2 memset was used, the new SSE2 or AVX2 memset optimized with Enhanced REP STOSB will be used for processors with ERMS. The new AVX512 memset will be used for processors with AVX512 which prefer vzeroupper. [BZ #19881] * sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S: Folded into ... * sysdeps/x86_64/memset.S: This. (__bzero): Removed. (__memset_tail): Likewise. (__memset_chk): Likewise. (memset): Likewise. (MEMSET_CHK_SYMBOL): New. Define only if MEMSET_SYMBOL isn't defined. (MEMSET_SYMBOL): Define only if MEMSET_SYMBOL isn't defined. * sysdeps/x86_64/multiarch/memset-avx2.S: Removed. (__memset_zero_constant_len_parameter): Check SHARED instead of PIC. * sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Remove memset-avx2 and memset-sse2-unaligned-erms. * sysdeps/x86_64/multiarch/ifunc-impl-list.c (__libc_ifunc_impl_list): Remove __memset_chk_sse2, __memset_chk_avx2, __memset_sse2 and __memset_avx2_unaligned. * sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S (__bzero): Enabled. * sysdeps/x86_64/multiarch/memset.S (memset): Replace __memset_sse2 and __memset_avx2 with __memset_sse2_unaligned and __memset_avx2_unaligned. Use __memset_sse2_unaligned_erms or __memset_avx2_unaligned_erms if processor has ERMS. Support __memset_avx512_unaligned_erms and __memset_avx512_unaligned. (memset): Removed. (__memset_chk): Likewise. (MEMSET_SYMBOL): New. (libc_hidden_builtin_def): Replace __memset_sse2 with __memset_sse2_unaligned. * sysdeps/x86_64/multiarch/memset_chk.S (__memset_chk): Replace __memset_chk_sse2 and __memset_chk_avx2 with __memset_chk_sse2_unaligned and __memset_chk_avx2_unaligned_erms. Use __memset_chk_sse2_unaligned_erms or __memset_chk_avx2_unaligned_erms if processor has ERMS. Support __memset_chk_avx512_unaligned_erms and __memset_chk_avx512_unaligned.
244 lines
6.1 KiB
ArmAsm
244 lines
6.1 KiB
ArmAsm
/* memset/bzero with unaligned store and rep stosb
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Copyright (C) 2016 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 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 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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L(memset_entry):
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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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/* 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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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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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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