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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-16 19:25:22 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-16 19:25:22 +0000 |
commit | f6ad4dcef54c5ce997a4bad5a6d86de229015700 (patch) | |
tree | 7cfa4e31ace5c2bd95c72b154d15af494b2bcbef /src/runtime/memclr_riscv64.s | |
parent | Initial commit. (diff) | |
download | golang-1.22-f6ad4dcef54c5ce997a4bad5a6d86de229015700.tar.xz golang-1.22-f6ad4dcef54c5ce997a4bad5a6d86de229015700.zip |
Adding upstream version 1.22.1.upstream/1.22.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/runtime/memclr_riscv64.s')
-rw-r--r-- | src/runtime/memclr_riscv64.s | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/src/runtime/memclr_riscv64.s b/src/runtime/memclr_riscv64.s new file mode 100644 index 0000000..16c511c --- /dev/null +++ b/src/runtime/memclr_riscv64.s @@ -0,0 +1,104 @@ +// Copyright 2016 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +#include "textflag.h" + +// See memclrNoHeapPointers Go doc for important implementation constraints. + +// void runtime·memclrNoHeapPointers(void*, uintptr) +TEXT runtime·memclrNoHeapPointers<ABIInternal>(SB),NOSPLIT,$0-16 + // X10 = ptr + // X11 = n + + // If less than 8 bytes, do single byte zeroing. + MOV $8, X9 + BLT X11, X9, check4 + + // Check alignment + AND $7, X10, X5 + BEQZ X5, aligned + + // Zero one byte at a time until we reach 8 byte alignment. + SUB X5, X9, X5 + SUB X5, X11, X11 +align: + SUB $1, X5 + MOVB ZERO, 0(X10) + ADD $1, X10 + BNEZ X5, align + +aligned: + // X9 already contains $8 + BLT X11, X9, check4 + MOV $16, X9 + BLT X11, X9, zero8 + MOV $32, X9 + BLT X11, X9, zero16 + MOV $64, X9 + BLT X11, X9, zero32 +loop64: + MOV ZERO, 0(X10) + MOV ZERO, 8(X10) + MOV ZERO, 16(X10) + MOV ZERO, 24(X10) + MOV ZERO, 32(X10) + MOV ZERO, 40(X10) + MOV ZERO, 48(X10) + MOV ZERO, 56(X10) + ADD $64, X10 + SUB $64, X11 + BGE X11, X9, loop64 + BEQZ X11, done + +check32: + MOV $32, X9 + BLT X11, X9, check16 +zero32: + MOV ZERO, 0(X10) + MOV ZERO, 8(X10) + MOV ZERO, 16(X10) + MOV ZERO, 24(X10) + ADD $32, X10 + SUB $32, X11 + BEQZ X11, done + +check16: + MOV $16, X9 + BLT X11, X9, check8 +zero16: + MOV ZERO, 0(X10) + MOV ZERO, 8(X10) + ADD $16, X10 + SUB $16, X11 + BEQZ X11, done + +check8: + MOV $8, X9 + BLT X11, X9, check4 +zero8: + MOV ZERO, 0(X10) + ADD $8, X10 + SUB $8, X11 + BEQZ X11, done + +check4: + MOV $4, X9 + BLT X11, X9, loop1 +zero4: + MOVB ZERO, 0(X10) + MOVB ZERO, 1(X10) + MOVB ZERO, 2(X10) + MOVB ZERO, 3(X10) + ADD $4, X10 + SUB $4, X11 + +loop1: + BEQZ X11, done + MOVB ZERO, 0(X10) + ADD $1, X10 + SUB $1, X11 + JMP loop1 + +done: + RET |