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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 13:54:38 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 13:54:38 +0000
commit8c1ab65c0f548d20b7f177bdb736daaf603340e1 (patch)
treedf55b7e75bf43f2bf500845b105afe3ac3a5157e /libc-top-half/musl/src/string/aarch64/memset.S
parentInitial commit. (diff)
downloadwasi-libc-upstream/0.0_git20221206.8b7148f.tar.xz
wasi-libc-upstream/0.0_git20221206.8b7148f.zip
Adding upstream version 0.0~git20221206.8b7148f.upstream/0.0_git20221206.8b7148f
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'libc-top-half/musl/src/string/aarch64/memset.S')
-rw-r--r--libc-top-half/musl/src/string/aarch64/memset.S115
1 files changed, 115 insertions, 0 deletions
diff --git a/libc-top-half/musl/src/string/aarch64/memset.S b/libc-top-half/musl/src/string/aarch64/memset.S
new file mode 100644
index 0000000..f0d29b7
--- /dev/null
+++ b/libc-top-half/musl/src/string/aarch64/memset.S
@@ -0,0 +1,115 @@
+/*
+ * memset - fill memory with a constant byte
+ *
+ * Copyright (c) 2012-2020, Arm Limited.
+ * SPDX-License-Identifier: MIT
+ */
+
+/* Assumptions:
+ *
+ * ARMv8-a, AArch64, Advanced SIMD, unaligned accesses.
+ *
+ */
+
+#define dstin x0
+#define val x1
+#define valw w1
+#define count x2
+#define dst x3
+#define dstend x4
+#define zva_val x5
+
+.global memset
+.type memset,%function
+memset:
+
+ dup v0.16B, valw
+ add dstend, dstin, count
+
+ cmp count, 96
+ b.hi .Lset_long
+ cmp count, 16
+ b.hs .Lset_medium
+ mov val, v0.D[0]
+
+ /* Set 0..15 bytes. */
+ tbz count, 3, 1f
+ str val, [dstin]
+ str val, [dstend, -8]
+ ret
+ nop
+1: tbz count, 2, 2f
+ str valw, [dstin]
+ str valw, [dstend, -4]
+ ret
+2: cbz count, 3f
+ strb valw, [dstin]
+ tbz count, 1, 3f
+ strh valw, [dstend, -2]
+3: ret
+
+ /* Set 17..96 bytes. */
+.Lset_medium:
+ str q0, [dstin]
+ tbnz count, 6, .Lset96
+ str q0, [dstend, -16]
+ tbz count, 5, 1f
+ str q0, [dstin, 16]
+ str q0, [dstend, -32]
+1: ret
+
+ .p2align 4
+ /* Set 64..96 bytes. Write 64 bytes from the start and
+ 32 bytes from the end. */
+.Lset96:
+ str q0, [dstin, 16]
+ stp q0, q0, [dstin, 32]
+ stp q0, q0, [dstend, -32]
+ ret
+
+ .p2align 4
+.Lset_long:
+ and valw, valw, 255
+ bic dst, dstin, 15
+ str q0, [dstin]
+ cmp count, 160
+ ccmp valw, 0, 0, hs
+ b.ne .Lno_zva
+
+#ifndef SKIP_ZVA_CHECK
+ mrs zva_val, dczid_el0
+ and zva_val, zva_val, 31
+ cmp zva_val, 4 /* ZVA size is 64 bytes. */
+ b.ne .Lno_zva
+#endif
+ str q0, [dst, 16]
+ stp q0, q0, [dst, 32]
+ bic dst, dst, 63
+ sub count, dstend, dst /* Count is now 64 too large. */
+ sub count, count, 128 /* Adjust count and bias for loop. */
+
+ .p2align 4
+.Lzva_loop:
+ add dst, dst, 64
+ dc zva, dst
+ subs count, count, 64
+ b.hi .Lzva_loop
+ stp q0, q0, [dstend, -64]
+ stp q0, q0, [dstend, -32]
+ ret
+
+.Lno_zva:
+ sub count, dstend, dst /* Count is 16 too large. */
+ sub dst, dst, 16 /* Dst is biased by -32. */
+ sub count, count, 64 + 16 /* Adjust count and bias for loop. */
+.Lno_zva_loop:
+ stp q0, q0, [dst, 32]
+ stp q0, q0, [dst, 64]!
+ subs count, count, 64
+ b.hi .Lno_zva_loop
+ stp q0, q0, [dstend, -64]
+ stp q0, q0, [dstend, -32]
+ ret
+
+.size memset,.-memset
+