--- /dev/null
+/*
+ * Copyright (C) 2006 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/*
+ * memset32.S
+ *
+ */
+
+ .syntax unified
+
+ .text
+ .align
+
+ .global android_memset32
+ .type android_memset32, %function
+ .global android_memset16
+ .type android_memset16, %function
+
+ /*
+ * Optimized memset32 and memset16 for ARM.
+ *
+ * void android_memset16(uint16_t* dst, uint16_t value, size_t size);
+ * void android_memset32(uint32_t* dst, uint32_t value, size_t size);
+ *
+ */
+
+android_memset16:
+ .fnstart
+ cmp r2, #1
+ bxle lr
+
+ /* expand the data to 32 bits */
+ mov r1, r1, lsl #16
+ orr r1, r1, r1, lsr #16
+
+ /* align to 32 bits */
+ tst r0, #2
+ strhne r1, [r0], #2
+ subne r2, r2, #2
+ .fnend
+
+android_memset32:
+ .fnstart
+ .cfi_startproc
+ str lr, [sp, #-4]!
+ .cfi_def_cfa_offset 4
+ .cfi_rel_offset lr, 0
+
+ /* align the destination to a cache-line */
+ mov r12, r1
+ mov lr, r1
+ rsb r3, r0, #0
+ ands r3, r3, #0x1C
+ beq .Laligned32
+ cmp r3, r2
+ andhi r3, r2, #0x1C
+ sub r2, r2, r3
+
+ /* conditionally writes 0 to 7 words (length in r3) */
+ movs r3, r3, lsl #28
+ stmiacs r0!, {r1, lr}
+ stmiacs r0!, {r1, lr}
+ stmiami r0!, {r1, lr}
+ movs r3, r3, lsl #2
+ strcs r1, [r0], #4
+
+.Laligned32:
+ mov r3, r1
+1: subs r2, r2, #32
+ stmiahs r0!, {r1,r3,r12,lr}
+ stmiahs r0!, {r1,r3,r12,lr}
+ bhs 1b
+ add r2, r2, #32
+
+ /* conditionally stores 0 to 30 bytes */
+ movs r2, r2, lsl #28
+ stmiacs r0!, {r1,r3,r12,lr}
+ stmiami r0!, {r1,lr}
+ movs r2, r2, lsl #2
+ strcs r1, [r0], #4
+ strhmi lr, [r0], #2
+
+ ldr lr, [sp], #4
+ .cfi_def_cfa_offset 0
+ .cfi_restore lr
+ bx lr
+ .cfi_endproc
+ .fnend
--- /dev/null
+/* Copyright (c) 2012, Linaro Limited
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+ * Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+ * 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.
+ * Neither the name of the Linaro 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 COPYRIGHT HOLDERS AND CONTRIBUTORS
+ "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 COPYRIGHT
+ HOLDER OR CONTRIBUTORS 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.
+*/
+
+/* Assumptions:
+ *
+ * ARMv8-a, AArch64
+ * Unaligned accesses
+ *
+ */
+
+/* By default we assume that the DC instruction can be used to zero
+ data blocks more efficiently. In some circumstances this might be
+ unsafe, for example in an asymmetric multiprocessor environment with
+ different DC clear lengths (neither the upper nor lower lengths are
+ safe to use). */
+
+#define dst x0
+#define count x2
+#define tmp1 x3
+#define tmp1w w3
+#define tmp2 x4
+#define tmp2w w4
+#define zva_len_x x5
+#define zva_len w5
+#define zva_bits_x x6
+
+#define A_l x1
+#define A_lw w1
+#define tmp3w w9
+
+#define ENTRY(f) \
+ .text; \
+ .globl f; \
+ .align 0; \
+ .type f, %function; \
+ f: \
+ .cfi_startproc \
+
+#define END(f) \
+ .cfi_endproc; \
+ .size f, .-f; \
+
+ENTRY(android_memset16)
+ ands A_lw, A_lw, #0xffff
+ b.eq .Lzero_mem
+ orr A_lw, A_lw, A_lw, lsl #16
+ b .Lexpand_to_64
+END(android_memset16)
+
+ENTRY(android_memset32)
+ cmp A_lw, #0
+ b.eq .Lzero_mem
+.Lexpand_to_64:
+ orr A_l, A_l, A_l, lsl #32
+.Ltail_maybe_long:
+ cmp count, #64
+ b.ge .Lnot_short
+.Ltail_maybe_tiny:
+ cmp count, #15
+ b.le .Ltail15tiny
+.Ltail63:
+ ands tmp1, count, #0x30
+ b.eq .Ltail15
+ add dst, dst, tmp1
+ cmp tmp1w, #0x20
+ b.eq 1f
+ b.lt 2f
+ stp A_l, A_l, [dst, #-48]
+1:
+ stp A_l, A_l, [dst, #-32]
+2:
+ stp A_l, A_l, [dst, #-16]
+
+.Ltail15:
+ and count, count, #15
+ add dst, dst, count
+ stp A_l, A_l, [dst, #-16] /* Repeat some/all of last store. */
+ ret
+
+.Ltail15tiny:
+ /* Set up to 15 bytes. Does not assume earlier memory
+ being set. */
+ tbz count, #3, 1f
+ str A_l, [dst], #8
+1:
+ tbz count, #2, 1f
+ str A_lw, [dst], #4
+1:
+ tbz count, #1, 1f
+ strh A_lw, [dst], #2
+1:
+ ret
+
+ /* Critical loop. Start at a new cache line boundary. Assuming
+ * 64 bytes per line, this ensures the entire loop is in one line. */
+ .p2align 6
+.Lnot_short:
+ neg tmp2, dst
+ ands tmp2, tmp2, #15
+ b.eq 2f
+ /* Bring DST to 128-bit (16-byte) alignment. We know that there's
+ * more than that to set, so we simply store 16 bytes and advance by
+ * the amount required to reach alignment. */
+ sub count, count, tmp2
+ stp A_l, A_l, [dst]
+ add dst, dst, tmp2
+ /* There may be less than 63 bytes to go now. */
+ cmp count, #63
+ b.le .Ltail63
+2:
+ sub dst, dst, #16 /* Pre-bias. */
+ sub count, count, #64
+1:
+ stp A_l, A_l, [dst, #16]
+ stp A_l, A_l, [dst, #32]
+ stp A_l, A_l, [dst, #48]
+ stp A_l, A_l, [dst, #64]!
+ subs count, count, #64
+ b.ge 1b
+ tst count, #0x3f
+ add dst, dst, #16
+ b.ne .Ltail63
+ ret
+
+ /* For zeroing memory, check to see if we can use the ZVA feature to
+ * zero entire 'cache' lines. */
+.Lzero_mem:
+ mov A_l, #0
+ cmp count, #63
+ b.le .Ltail_maybe_tiny
+ neg tmp2, dst
+ ands tmp2, tmp2, #15
+ b.eq 1f
+ sub count, count, tmp2
+ stp A_l, A_l, [dst]
+ add dst, dst, tmp2
+ cmp count, #63
+ b.le .Ltail63
+1:
+ /* For zeroing small amounts of memory, it's not worth setting up
+ * the line-clear code. */
+ cmp count, #128
+ b.lt .Lnot_short
+ mrs tmp1, dczid_el0
+ tbnz tmp1, #4, .Lnot_short
+ mov tmp3w, #4
+ and zva_len, tmp1w, #15 /* Safety: other bits reserved. */
+ lsl zva_len, tmp3w, zva_len
+
+.Lzero_by_line:
+ /* Compute how far we need to go to become suitably aligned. We're
+ * already at quad-word alignment. */
+ cmp count, zva_len_x
+ b.lt .Lnot_short /* Not enough to reach alignment. */
+ sub zva_bits_x, zva_len_x, #1
+ neg tmp2, dst
+ ands tmp2, tmp2, zva_bits_x
+ b.eq 1f /* Already aligned. */
+ /* Not aligned, check that there's enough to copy after alignment. */
+ sub tmp1, count, tmp2
+ cmp tmp1, #64
+ ccmp tmp1, zva_len_x, #8, ge /* NZCV=0b1000 */
+ b.lt .Lnot_short
+ /* We know that there's at least 64 bytes to zero and that it's safe
+ * to overrun by 64 bytes. */
+ mov count, tmp1
+2:
+ stp A_l, A_l, [dst]
+ stp A_l, A_l, [dst, #16]
+ stp A_l, A_l, [dst, #32]
+ subs tmp2, tmp2, #64
+ stp A_l, A_l, [dst, #48]
+ add dst, dst, #64
+ b.ge 2b
+ /* We've overrun a bit, so adjust dst downwards. */
+ add dst, dst, tmp2
+1:
+ sub count, count, zva_len_x
+3:
+ dc zva, dst
+ add dst, dst, zva_len_x
+ subs count, count, zva_len_x
+ b.ge 3b
+ ands count, count, zva_bits_x
+ b.ne .Ltail_maybe_long
+ ret
+END(android_memset32)