From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-1.5 required=5.0 tests=DKIM_INVALID,DKIM_SIGNED, FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_LOW, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 1988 invoked from network); 7 Jun 2023 10:08:57 -0000 Received: from second.openwall.net (193.110.157.125) by inbox.vuxu.org with ESMTPUTF8; 7 Jun 2023 10:08:57 -0000 Received: (qmail 27787 invoked by uid 550); 7 Jun 2023 10:08:18 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Reply-To: musl@lists.openwall.com Received: (qmail 26601 invoked from network); 7 Jun 2023 10:08:17 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id:MIME-Version; bh=kz3w8 0qJvobAzILS7zuCjQiWuKtD36bhikde95hGckA=; b=QS8kLQcFfln3Kdj9Iahea u489yjLAKlzYqxNFhZhH05dWDFrc4KZT/mMUZnhXbEvdWZrbrt78z6xz2D6kfH7P 1dSegiV4OwE4Vd5LBox9bfw2TP+dRMkbgdyn/Xg7yErOiwbY0QG4L2dt5Hp62TJC V3nDkLFRatUjvCDcRXXSMY= From: zhangfei To: dalias@libc.org, musl@lists.openwall.com Cc: zhangfei Date: Wed, 7 Jun 2023 18:07:10 +0800 Message-Id: <20230607100710.4286-4-zhang_fei_0403@163.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230607100710.4286-1-zhang_fei_0403@163.com> References: <20230607100710.4286-1-zhang_fei_0403@163.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID:_____wBXhbbPVoBki6btBg--.27251S5 X-Coremail-Antispam: 1Uf129KBjvJXoW3Jr18CrWDAw4xJrWfCF17KFg_yoW3uFWkpF 43Kr98tF9FqrnY9r4aq3WYy398ZayfAry3Grsrt34F9rW5WFy5Z3W3tFWYvFyDKr4xWrs3 ZF1jqF13Xr15JFDanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07j4iifUUUUU= X-Originating-IP: [180.111.101.91] X-CM-SenderInfo: x2kd0w5bihxsiquqjqqrwthudrp/1tbiMhuHl1WB4CtvxgAAsP Subject: [musl] [PATCH 3/3] RISC-V: Optimize memmove From: zhangfei This code is based on linux/arch/riscv/lib/memcpy.S. Removed macro definition to support RISCV64. Signed-off-by: Zhang Fei --- src/string/riscv64/memmove.S | 315 +++++++++++++++++++++++++++++++++++ 1 file changed, 315 insertions(+) create mode 100644 src/string/riscv64/memmove.S diff --git a/src/string/riscv64/memmove.S b/src/string/riscv64/memmove.S new file mode 100644 index 0000000..41b84e3 --- /dev/null +++ b/src/string/riscv64/memmove.S @@ -0,0 +1,315 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2022 Michael T. Kloos + */ + +#define SZREG 8 +#define REG_S sd +#define REG_L ld + +.global memmove +.type memmove,@function +memmove: + /* + * Returns + * a0 - dest + * + * Parameters + * a0 - Inclusive first byte of dest + * a1 - Inclusive first byte of src + * a2 - Length of copy n + * + * Because the return matches the parameter register a0, + * we will not clobber or modify that register. + * + * Note: This currently only works on little-endian. + * To port to big-endian, reverse the direction of shifts + * in the 2 misaligned fixup copy loops. + */ + + /* Return if nothing to do */ + beq a0, a1, return_from_memmove + beqz a2, return_from_memmove + + /* + * Register Uses + * Forward Copy: a1 - Index counter of src + * Reverse Copy: a4 - Index counter of src + * Forward Copy: t3 - Index counter of dest + * Reverse Copy: t4 - Index counter of dest + * Both Copy Modes: t5 - Inclusive first multibyte/aligned of dest + * Both Copy Modes: t6 - Non-Inclusive last multibyte/aligned of dest + * Both Copy Modes: t0 - Link / Temporary for load-store + * Both Copy Modes: t1 - Temporary for load-store + * Both Copy Modes: t2 - Temporary for load-store + * Both Copy Modes: a5 - dest to src alignment offset + * Both Copy Modes: a6 - Shift ammount + * Both Copy Modes: a7 - Inverse Shift ammount + * Both Copy Modes: a2 - Alternate breakpoint for unrolled loops + */ + + /* + * Solve for some register values now. + * Byte copy does not need t5 or t6. + */ + mv t3, a0 + add t4, a0, a2 + add a4, a1, a2 + + /* + * Byte copy if copying less than (2 * SZREG) bytes. This can + * cause problems with the bulk copy implementation and is + * small enough not to bother. + */ + andi t0, a2, -(2 * SZREG) + beqz t0, byte_copy + + /* + * Now solve for t5 and t6. + */ + andi t5, t3, -SZREG + andi t6, t4, -SZREG + /* + * If dest(Register t3) rounded down to the nearest naturally + * aligned SZREG address, does not equal dest, then add SZREG + * to find the low-bound of SZREG alignment in the dest memory + * region. Note that this could overshoot the dest memory + * region if n is less than SZREG. This is one reason why + * we always byte copy if n is less than SZREG. + * Otherwise, dest is already naturally aligned to SZREG. + */ + beq t5, t3, 1f + addi t5, t5, SZREG + 1: + + /* + * If the dest and src are co-aligned to SZREG, then there is + * no need for the full rigmarole of a full misaligned fixup copy. + * Instead, do a simpler co-aligned copy. + */ + xor t0, a0, a1 + andi t1, t0, (SZREG - 1) + beqz t1, coaligned_copy + /* Fall through to misaligned fixup copy */ + +misaligned_fixup_copy: + bltu a1, a0, misaligned_fixup_copy_reverse + +misaligned_fixup_copy_forward: + jal t0, byte_copy_until_aligned_forward + + andi a5, a1, (SZREG - 1) /* Find the alignment offset of src (a1) */ + slli a6, a5, 3 /* Multiply by 8 to convert that to bits to shift */ + sub a5, a1, t3 /* Find the difference between src and dest */ + andi a1, a1, -SZREG /* Align the src pointer */ + addi a2, t6, SZREG /* The other breakpoint for the unrolled loop*/ + + /* + * Compute The Inverse Shift + * a7 = XLEN - a6 = XLEN + -a6 + * 2s complement negation to find the negative: -a6 = ~a6 + 1 + * Add that to XLEN. XLEN = SZREG * 8. + */ + not a7, a6 + addi a7, a7, (SZREG * 8 + 1) + + /* + * Fix Misalignment Copy Loop - Forward + * load_val0 = load_ptr[0]; + * do { + * load_val1 = load_ptr[1]; + * store_ptr += 2; + * store_ptr[0 - 2] = (load_val0 >> {a6}) | (load_val1 << {a7}); + * + * if (store_ptr == {a2}) + * break; + * + * load_val0 = load_ptr[2]; + * load_ptr += 2; + * store_ptr[1 - 2] = (load_val1 >> {a6}) | (load_val0 << {a7}); + * + * } while (store_ptr != store_ptr_end); + * store_ptr = store_ptr_end; + */ + + REG_L t0, (0 * SZREG)(a1) + 1: + REG_L t1, (1 * SZREG)(a1) + addi t3, t3, (2 * SZREG) + srl t0, t0, a6 + sll t2, t1, a7 + or t2, t0, t2 + REG_S t2, ((0 * SZREG) - (2 * SZREG))(t3) + + beq t3, a2, 2f + + REG_L t0, (2 * SZREG)(a1) + addi a1, a1, (2 * SZREG) + srl t1, t1, a6 + sll t2, t0, a7 + or t2, t1, t2 + REG_S t2, ((1 * SZREG) - (2 * SZREG))(t3) + + bne t3, t6, 1b + 2: + mv t3, t6 /* Fix the dest pointer in case the loop was broken */ + + add a1, t3, a5 /* Restore the src pointer */ + j byte_copy_forward /* Copy any remaining bytes */ + +misaligned_fixup_copy_reverse: + jal t0, byte_copy_until_aligned_reverse + + andi a5, a4, (SZREG - 1) /* Find the alignment offset of src (a4) */ + slli a6, a5, 3 /* Multiply by 8 to convert that to bits to shift */ + sub a5, a4, t4 /* Find the difference between src and dest */ + andi a4, a4, -SZREG /* Align the src pointer */ + addi a2, t5, -SZREG /* The other breakpoint for the unrolled loop*/ + + /* + * Compute The Inverse Shift + * a7 = XLEN - a6 = XLEN + -a6 + * 2s complement negation to find the negative: -a6 = ~a6 + 1 + * Add that to XLEN. XLEN = SZREG * 8. + */ + not a7, a6 + addi a7, a7, (SZREG * 8 + 1) + + /* + * Fix Misalignment Copy Loop - Reverse + * load_val1 = load_ptr[0]; + * do { + * load_val0 = load_ptr[-1]; + * store_ptr -= 2; + * store_ptr[1] = (load_val0 >> {a6}) | (load_val1 << {a7}); + * + * if (store_ptr == {a2}) + * break; + * + * load_val1 = load_ptr[-2]; + * load_ptr -= 2; + * store_ptr[0] = (load_val1 >> {a6}) | (load_val0 << {a7}); + * + * } while (store_ptr != store_ptr_end); + * store_ptr = store_ptr_end; + */ + + REG_L t1, ( 0 * SZREG)(a4) + 1: + REG_L t0, (-1 * SZREG)(a4) + addi t4, t4, (-2 * SZREG) + sll t1, t1, a7 + srl t2, t0, a6 + or t2, t1, t2 + REG_S t2, ( 1 * SZREG)(t4) + + beq t4, a2, 2f + + REG_L t1, (-2 * SZREG)(a4) + addi a4, a4, (-2 * SZREG) + sll t0, t0, a7 + srl t2, t1, a6 + or t2, t0, t2 + REG_S t2, ( 0 * SZREG)(t4) + + bne t4, t5, 1b + 2: + mv t4, t5 /* Fix the dest pointer in case the loop was broken */ + + add a4, t4, a5 /* Restore the src pointer */ + j byte_copy_reverse /* Copy any remaining bytes */ + +/* + * Simple copy loops for SZREG co-aligned memory locations. + * These also make calls to do byte copies for any unaligned + * data at their terminations. + */ +coaligned_copy: + bltu a1, a0, coaligned_copy_reverse + +coaligned_copy_forward: + jal t0, byte_copy_until_aligned_forward + + 1: + REG_L t1, ( 0 * SZREG)(a1) + addi a1, a1, SZREG + addi t3, t3, SZREG + REG_S t1, (-1 * SZREG)(t3) + bne t3, t6, 1b + + j byte_copy_forward /* Copy any remaining bytes */ + +coaligned_copy_reverse: + jal t0, byte_copy_until_aligned_reverse + + 1: + REG_L t1, (-1 * SZREG)(a4) + addi a4, a4, -SZREG + addi t4, t4, -SZREG + REG_S t1, ( 0 * SZREG)(t4) + bne t4, t5, 1b + + j byte_copy_reverse /* Copy any remaining bytes */ + +/* + * These are basically sub-functions within the function. They + * are used to byte copy until the dest pointer is in alignment. + * At which point, a bulk copy method can be used by the + * calling code. These work on the same registers as the bulk + * copy loops. Therefore, the register values can be picked + * up from where they were left and we avoid code duplication + * without any overhead except the call in and return jumps. + */ +byte_copy_until_aligned_forward: + beq t3, t5, 2f + 1: + lb t1, 0(a1) + addi a1, a1, 1 + addi t3, t3, 1 + sb t1, -1(t3) + bne t3, t5, 1b + 2: + jalr zero, 0x0(t0) /* Return to multibyte copy loop */ + +byte_copy_until_aligned_reverse: + beq t4, t6, 2f + 1: + lb t1, -1(a4) + addi a4, a4, -1 + addi t4, t4, -1 + sb t1, 0(t4) + bne t4, t6, 1b + 2: + jalr zero, 0x0(t0) /* Return to multibyte copy loop */ + +/* + * Simple byte copy loops. + * These will byte copy until they reach the end of data to copy. + * At that point, they will call to return from memmove. + */ +byte_copy: + bltu a1, a0, byte_copy_reverse + +byte_copy_forward: + beq t3, t4, 2f + 1: + lb t1, 0(a1) + addi a1, a1, 1 + addi t3, t3, 1 + sb t1, -1(t3) + bne t3, t4, 1b + 2: + ret + +byte_copy_reverse: + beq t4, t3, 2f + 1: + lb t1, -1(a4) + addi a4, a4, -1 + addi t4, t4, -1 + sb t1, 0(t4) + bne t4, t3, 1b + 2: + +return_from_memmove: + ret -- 2.34.1