kbuild: rust: keep Rust objects out of Clang LTO with inline helpersgrafted

Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit
`objtool` errors such as:

    vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a:
    can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd

The reason is that in such builds, the Clang invocation that compiles
the combined Rust plus helpers bitcode emits LLVM bitcode (again) --
the final code generation happens in the linker's LTO step, which the
`-mllvm` trap options passed to Clang do not reach.

This, in turn, means that unreachable traps are missing, and the
impossible paths do not merely fallthrough to the next symbol, but past
the end of their own section, since LTO builds place each function in
its own section.

Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always
emits machine code directly, with the traps in place.

Assisted-by: LLM
Cc: Gary Guo <gary@garyguo.net>
Cc: Boqun Feng <boqun@kernel.org>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Matthew Maurer <mmaurer@google.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust")
Acked-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

1 files changed, 666 insertions, 0 deletions

diff --git a/arch/microblaze/lib/fastcopy.S b/arch/microblaze/lib/fastcopy.S
new file mode 100644
index 000000000..fdc48bb06
--- /dev/null
+++ b/arch/microblaze/lib/fastcopy.S
@@ -0,0 +1,666 @@
+/*
+ * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
+ * Copyright (C) 2008-2009 PetaLogix
+ * Copyright (C) 2008 Jim Law - Iris LP  All rights reserved.
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License.  See the file COPYING in the main directory of this
+ * archive for more details.
+ *
+ * Written by Jim Law <jlaw@irispower.com>
+ *
+ * intended to replace:
+ *	memcpy in memcpy.c and
+ *	memmove in memmove.c
+ * ... in arch/microblaze/lib
+ *
+ *
+ * assly_fastcopy.S
+ *
+ * Attempt at quicker memcpy and memmove for MicroBlaze
+ *	Input :	Operand1 in Reg r5 - destination address
+ *		Operand2 in Reg r6 - source address
+ *		Operand3 in Reg r7 - number of bytes to transfer
+ *	Output: Result in Reg r3 - starting destinaition address
+ *
+ *
+ * Explanation:
+ *	Perform (possibly unaligned) copy of a block of memory
+ *	between mem locations with size of xfer spec'd in bytes
+ */
+
+#include <linux/linkage.h>
+	.text
+	.globl	memcpy
+	.type  memcpy, @function
+	.ent	memcpy
+
+memcpy:
+fast_memcpy_ascending:
+	/* move d to return register as value of function */
+	addi	r3, r5, 0
+
+	addi	r4, r0, 4	/* n = 4 */
+	cmpu	r4, r4, r7	/* n = c - n  (unsigned) */
+	blti	r4, a_xfer_end	/* if n < 0, less than one word to transfer */
+
+	/* transfer first 0~3 bytes to get aligned dest address */
+	andi	r4, r5, 3		/* n = d & 3 */
+	/* if zero, destination already aligned */
+	beqi	r4, a_dalign_done
+	/* n = 4 - n (yields 3, 2, 1 transfers for 1, 2, 3 addr offset) */
+	rsubi	r4, r4, 4
+	rsub	r7, r4, r7		/* c = c - n adjust c */
+
+a_xfer_first_loop:
+	/* if no bytes left to transfer, transfer the bulk */
+	beqi	r4, a_dalign_done
+	lbui	r11, r6, 0		/* h = *s */
+	sbi	r11, r5, 0		/* *d = h */
+	addi	r6, r6, 1		/* s++ */
+	addi	r5, r5, 1		/* d++ */
+	brid	a_xfer_first_loop	/* loop */
+	addi	r4, r4, -1		/* n-- (IN DELAY SLOT) */
+
+a_dalign_done:
+	addi	r4, r0, 32		/* n = 32 */
+	cmpu	r4, r4, r7		/* n = c - n  (unsigned) */
+	/* if n < 0, less than one block to transfer */
+	blti	r4, a_block_done
+
+a_block_xfer:
+	andi	r4, r7, 0xffffffe0	/* n = c & ~31 */
+	rsub	r7, r4, r7		/* c = c - n */
+
+	andi	r9, r6, 3		/* t1 = s & 3 */
+	/* if temp != 0, unaligned transfers needed */
+	bnei	r9, a_block_unaligned
+
+a_block_aligned:
+	lwi	r9, r6, 0		/* t1 = *(s + 0) */
+	lwi	r10, r6, 4		/* t2 = *(s + 4) */
+	lwi	r11, r6, 8		/* t3 = *(s + 8) */
+	lwi	r12, r6, 12		/* t4 = *(s + 12) */
+	swi	r9, r5, 0		/* *(d + 0) = t1 */
+	swi	r10, r5, 4		/* *(d + 4) = t2 */
+	swi	r11, r5, 8		/* *(d + 8) = t3 */
+	swi	r12, r5, 12		/* *(d + 12) = t4 */
+	lwi	r9, r6, 16		/* t1 = *(s + 16) */
+	lwi	r10, r6, 20		/* t2 = *(s + 20) */
+	lwi	r11, r6, 24		/* t3 = *(s + 24) */
+	lwi	r12, r6, 28		/* t4 = *(s + 28) */
+	swi	r9, r5, 16		/* *(d + 16) = t1 */
+	swi	r10, r5, 20		/* *(d + 20) = t2 */
+	swi	r11, r5, 24		/* *(d + 24) = t3 */
+	swi	r12, r5, 28		/* *(d + 28) = t4 */
+	addi	r6, r6, 32		/* s = s + 32 */
+	addi	r4, r4, -32		/* n = n - 32 */
+	bneid	r4, a_block_aligned	/* while (n) loop */
+	addi	r5, r5, 32		/* d = d + 32 (IN DELAY SLOT) */
+	bri	a_block_done
+
+a_block_unaligned:
+	andi	r8, r6, 0xfffffffc	/* as = s & ~3 */
+	add	r6, r6, r4		/* s = s + n */
+	lwi	r11, r8, 0		/* h = *(as + 0) */
+
+	addi	r9, r9, -1
+	beqi	r9, a_block_u1		/* t1 was 1 => 1 byte offset */
+	addi	r9, r9, -1
+	beqi	r9, a_block_u2		/* t1 was 2 => 2 byte offset */
+
+a_block_u3:
+	bslli	r11, r11, 24	/* h = h << 24 */
+a_bu3_loop:
+	lwi	r12, r8, 4	/* v = *(as + 4) */
+	bsrli	r9, r12, 8	/* t1 = v >> 8 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 0	/* *(d + 0) = t1 */
+	bslli	r11, r12, 24	/* h = v << 24 */
+	lwi	r12, r8, 8	/* v = *(as + 8) */
+	bsrli	r9, r12, 8	/* t1 = v >> 8 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 4	/* *(d + 4) = t1 */
+	bslli	r11, r12, 24	/* h = v << 24 */
+	lwi	r12, r8, 12	/* v = *(as + 12) */
+	bsrli	r9, r12, 8	/* t1 = v >> 8 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 8	/* *(d + 8) = t1 */
+	bslli	r11, r12, 24	/* h = v << 24 */
+	lwi	r12, r8, 16	/* v = *(as + 16) */
+	bsrli	r9, r12, 8	/* t1 = v >> 8 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 12	/* *(d + 12) = t1 */
+	bslli	r11, r12, 24	/* h = v << 24 */
+	lwi	r12, r8, 20	/* v = *(as + 20) */
+	bsrli	r9, r12, 8	/* t1 = v >> 8 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 16	/* *(d + 16) = t1 */
+	bslli	r11, r12, 24	/* h = v << 24 */
+	lwi	r12, r8, 24	/* v = *(as + 24) */
+	bsrli	r9, r12, 8	/* t1 = v >> 8 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 20	/* *(d + 20) = t1 */
+	bslli	r11, r12, 24	/* h = v << 24 */
+	lwi	r12, r8, 28	/* v = *(as + 28) */
+	bsrli	r9, r12, 8	/* t1 = v >> 8 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 24	/* *(d + 24) = t1 */
+	bslli	r11, r12, 24	/* h = v << 24 */
+	lwi	r12, r8, 32	/* v = *(as + 32) */
+	bsrli	r9, r12, 8	/* t1 = v >> 8 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 28	/* *(d + 28) = t1 */
+	bslli	r11, r12, 24	/* h = v << 24 */
+	addi	r8, r8, 32	/* as = as + 32 */
+	addi	r4, r4, -32	/* n = n - 32 */
+	bneid	r4, a_bu3_loop	/* while (n) loop */
+	addi	r5, r5, 32	/* d = d + 32 (IN DELAY SLOT) */
+	bri	a_block_done
+
+a_block_u1:
+	bslli	r11, r11, 8	/* h = h << 8 */
+a_bu1_loop:
+	lwi	r12, r8, 4	/* v = *(as + 4) */
+	bsrli	r9, r12, 24	/* t1 = v >> 24 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 0	/* *(d + 0) = t1 */
+	bslli	r11, r12, 8	/* h = v << 8 */
+	lwi	r12, r8, 8	/* v = *(as + 8) */
+	bsrli	r9, r12, 24	/* t1 = v >> 24 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 4	/* *(d + 4) = t1 */
+	bslli	r11, r12, 8	/* h = v << 8 */
+	lwi	r12, r8, 12	/* v = *(as + 12) */
+	bsrli	r9, r12, 24	/* t1 = v >> 24 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 8	/* *(d + 8) = t1 */
+	bslli	r11, r12, 8	/* h = v << 8 */
+	lwi	r12, r8, 16	/* v = *(as + 16) */
+	bsrli	r9, r12, 24	/* t1 = v >> 24 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 12	/* *(d + 12) = t1 */
+	bslli	r11, r12, 8	/* h = v << 8 */
+	lwi	r12, r8, 20	/* v = *(as + 20) */
+	bsrli	r9, r12, 24	/* t1 = v >> 24 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 16	/* *(d + 16) = t1 */
+	bslli	r11, r12, 8	/* h = v << 8 */
+	lwi	r12, r8, 24	/* v = *(as + 24) */
+	bsrli	r9, r12, 24	/* t1 = v >> 24 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 20	/* *(d + 20) = t1 */
+	bslli	r11, r12, 8	/* h = v << 8 */
+	lwi	r12, r8, 28	/* v = *(as + 28) */
+	bsrli	r9, r12, 24	/* t1 = v >> 24 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 24	/* *(d + 24) = t1 */
+	bslli	r11, r12, 8	/* h = v << 8 */
+	lwi	r12, r8, 32	/* v = *(as + 32) */
+	bsrli	r9, r12, 24	/* t1 = v >> 24 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 28	/* *(d + 28) = t1 */
+	bslli	r11, r12, 8	/* h = v << 8 */
+	addi	r8, r8, 32	/* as = as + 32 */
+	addi	r4, r4, -32	/* n = n - 32 */
+	bneid	r4, a_bu1_loop	/* while (n) loop */
+	addi	r5, r5, 32	/* d = d + 32 (IN DELAY SLOT) */
+	bri	a_block_done
+
+a_block_u2:
+	bslli	r11, r11, 16	/* h = h << 16 */
+a_bu2_loop:
+	lwi	r12, r8, 4	/* v = *(as + 4) */
+	bsrli	r9, r12, 16	/* t1 = v >> 16 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 0	/* *(d + 0) = t1 */
+	bslli	r11, r12, 16	/* h = v << 16 */
+	lwi	r12, r8, 8	/* v = *(as + 8) */
+	bsrli	r9, r12, 16	/* t1 = v >> 16 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 4	/* *(d + 4) = t1 */
+	bslli	r11, r12, 16	/* h = v << 16 */
+	lwi	r12, r8, 12	/* v = *(as + 12) */
+	bsrli	r9, r12, 16	/* t1 = v >> 16 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 8	/* *(d + 8) = t1 */
+	bslli	r11, r12, 16	/* h = v << 16 */
+	lwi	r12, r8, 16	/* v = *(as + 16) */
+	bsrli	r9, r12, 16	/* t1 = v >> 16 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 12	/* *(d + 12) = t1 */
+	bslli	r11, r12, 16	/* h = v << 16 */
+	lwi	r12, r8, 20	/* v = *(as + 20) */
+	bsrli	r9, r12, 16	/* t1 = v >> 16 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 16	/* *(d + 16) = t1 */
+	bslli	r11, r12, 16	/* h = v << 16 */
+	lwi	r12, r8, 24	/* v = *(as + 24) */
+	bsrli	r9, r12, 16	/* t1 = v >> 16 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 20	/* *(d + 20) = t1 */
+	bslli	r11, r12, 16	/* h = v << 16 */
+	lwi	r12, r8, 28	/* v = *(as + 28) */
+	bsrli	r9, r12, 16	/* t1 = v >> 16 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 24	/* *(d + 24) = t1 */
+	bslli	r11, r12, 16	/* h = v << 16 */
+	lwi	r12, r8, 32	/* v = *(as + 32) */
+	bsrli	r9, r12, 16	/* t1 = v >> 16 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 28	/* *(d + 28) = t1 */
+	bslli	r11, r12, 16	/* h = v << 16 */
+	addi	r8, r8, 32	/* as = as + 32 */
+	addi	r4, r4, -32	/* n = n - 32 */
+	bneid	r4, a_bu2_loop	/* while (n) loop */
+	addi	r5, r5, 32	/* d = d + 32 (IN DELAY SLOT) */
+
+a_block_done:
+	addi	r4, r0, 4	/* n = 4 */
+	cmpu	r4, r4, r7	/* n = c - n  (unsigned) */
+	blti	r4, a_xfer_end	/* if n < 0, less than one word to transfer */
+
+a_word_xfer:
+	andi	r4, r7, 0xfffffffc	/* n = c & ~3 */
+	addi	r10, r0, 0		/* offset = 0 */
+
+	andi	r9, r6, 3		/* t1 = s & 3 */
+	/* if temp != 0, unaligned transfers needed */
+	bnei	r9, a_word_unaligned
+
+a_word_aligned:
+	lw	r9, r6, r10		/* t1 = *(s+offset) */
+	sw	r9, r5, r10		/* *(d+offset) = t1 */
+	addi	r4, r4,-4		/* n-- */
+	bneid	r4, a_word_aligned	/* loop */
+	addi	r10, r10, 4		/* offset++ (IN DELAY SLOT) */
+
+	bri	a_word_done
+
+a_word_unaligned:
+	andi	r8, r6, 0xfffffffc	/* as = s & ~3 */
+	lwi	r11, r8, 0		/* h = *(as + 0) */
+	addi	r8, r8, 4		/* as = as + 4 */
+
+	addi	r9, r9, -1
+	beqi	r9, a_word_u1		/* t1 was 1 => 1 byte offset */
+	addi	r9, r9, -1
+	beqi	r9, a_word_u2		/* t1 was 2 => 2 byte offset */
+
+a_word_u3:
+	bslli	r11, r11, 24	/* h = h << 24 */
+a_wu3_loop:
+	lw	r12, r8, r10	/* v = *(as + offset) */
+	bsrli	r9, r12, 8	/* t1 = v >> 8 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	sw	r9, r5, r10	/* *(d + offset) = t1 */
+	bslli	r11, r12, 24	/* h = v << 24 */
+	addi	r4, r4,-4	/* n = n - 4 */
+	bneid	r4, a_wu3_loop	/* while (n) loop */
+	addi	r10, r10, 4	/* offset = ofset + 4 (IN DELAY SLOT) */
+
+	bri	a_word_done
+
+a_word_u1:
+	bslli	r11, r11, 8	/* h = h << 8 */
+a_wu1_loop:
+	lw	r12, r8, r10	/* v = *(as + offset) */
+	bsrli	r9, r12, 24	/* t1 = v >> 24 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	sw	r9, r5, r10	/* *(d + offset) = t1 */
+	bslli	r11, r12, 8	/* h = v << 8 */
+	addi	r4, r4,-4	/* n = n - 4 */
+	bneid	r4, a_wu1_loop	/* while (n) loop */
+	addi	r10, r10, 4	/* offset = ofset + 4 (IN DELAY SLOT) */
+
+	bri	a_word_done
+
+a_word_u2:
+	bslli	r11, r11, 16	/* h = h << 16 */
+a_wu2_loop:
+	lw	r12, r8, r10	/* v = *(as + offset) */
+	bsrli	r9, r12, 16	/* t1 = v >> 16 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	sw	r9, r5, r10	/* *(d + offset) = t1 */
+	bslli	r11, r12, 16	/* h = v << 16 */
+	addi	r4, r4,-4	/* n = n - 4 */
+	bneid	r4, a_wu2_loop	/* while (n) loop */
+	addi	r10, r10, 4	/* offset = ofset + 4 (IN DELAY SLOT) */
+
+a_word_done:
+	add	r5, r5, r10	/* d = d + offset */
+	add	r6, r6, r10	/* s = s + offset */
+	rsub	r7, r10, r7	/* c = c - offset */
+
+a_xfer_end:
+a_xfer_end_loop:
+	beqi	r7, a_done		/* while (c) */
+	lbui	r9, r6, 0		/* t1 = *s */
+	addi	r6, r6, 1		/* s++ */
+	sbi	r9, r5, 0		/* *d = t1 */
+	addi	r7, r7, -1		/* c-- */
+	brid	a_xfer_end_loop		/* loop */
+	addi	r5, r5, 1		/* d++ (IN DELAY SLOT) */
+
+a_done:
+	rtsd	r15, 8
+	nop
+
+.size  memcpy, . - memcpy
+.end memcpy
+/*----------------------------------------------------------------------------*/
+	.globl	memmove
+	.type  memmove, @function
+	.ent	memmove
+
+memmove:
+	cmpu	r4, r5, r6	/* n = s - d */
+	bgei	r4,fast_memcpy_ascending
+
+fast_memcpy_descending:
+	/* move d to return register as value of function */
+	addi	r3, r5, 0
+
+	add	r5, r5, r7	/* d = d + c */
+	add	r6, r6, r7	/* s = s + c */
+
+	addi	r4, r0, 4	/* n = 4 */
+	cmpu	r4, r4, r7	/* n = c - n  (unsigned) */
+	blti	r4,d_xfer_end	/* if n < 0, less than one word to transfer */
+
+	/* transfer first 0~3 bytes to get aligned dest address */
+	andi	r4, r5, 3		/* n = d & 3 */
+	/* if zero, destination already aligned */
+	beqi	r4,d_dalign_done
+	rsub	r7, r4, r7		/* c = c - n adjust c */
+
+d_xfer_first_loop:
+	/* if no bytes left to transfer, transfer the bulk */
+	beqi	r4,d_dalign_done
+	addi	r6, r6, -1		/* s-- */
+	addi	r5, r5, -1		/* d-- */
+	lbui	r11, r6, 0		/* h = *s */
+	sbi	r11, r5, 0		/* *d = h */
+	brid	d_xfer_first_loop	/* loop */
+	addi	r4, r4, -1		/* n-- (IN DELAY SLOT) */
+
+d_dalign_done:
+	addi	r4, r0, 32	/* n = 32 */
+	cmpu	r4, r4, r7	/* n = c - n  (unsigned) */
+	/* if n < 0, less than one block to transfer */
+	blti	r4, d_block_done
+
+d_block_xfer:
+	andi	r4, r7, 0xffffffe0	/* n = c & ~31 */
+	rsub	r7, r4, r7		/* c = c - n */
+
+	andi	r9, r6, 3		/* t1 = s & 3 */
+	/* if temp != 0, unaligned transfers needed */
+	bnei	r9, d_block_unaligned
+
+d_block_aligned:
+	addi	r6, r6, -32		/* s = s - 32 */
+	addi	r5, r5, -32		/* d = d - 32 */
+	lwi	r9, r6, 28		/* t1 = *(s + 28) */
+	lwi	r10, r6, 24		/* t2 = *(s + 24) */
+	lwi	r11, r6, 20		/* t3 = *(s + 20) */
+	lwi	r12, r6, 16		/* t4 = *(s + 16) */
+	swi	r9, r5, 28		/* *(d + 28) = t1 */
+	swi	r10, r5, 24		/* *(d + 24) = t2 */
+	swi	r11, r5, 20		/* *(d + 20) = t3 */
+	swi	r12, r5, 16		/* *(d + 16) = t4 */
+	lwi	r9, r6, 12		/* t1 = *(s + 12) */
+	lwi	r10, r6, 8		/* t2 = *(s + 8) */
+	lwi	r11, r6, 4		/* t3 = *(s + 4) */
+	lwi	r12, r6, 0		/* t4 = *(s + 0) */
+	swi	r9, r5, 12		/* *(d + 12) = t1 */
+	swi	r10, r5, 8		/* *(d + 8) = t2 */
+	swi	r11, r5, 4		/* *(d + 4) = t3 */
+	addi	r4, r4, -32		/* n = n - 32 */
+	bneid	r4, d_block_aligned	/* while (n) loop */
+	swi	r12, r5, 0		/* *(d + 0) = t4 (IN DELAY SLOT) */
+	bri	d_block_done
+
+d_block_unaligned:
+	andi	r8, r6, 0xfffffffc	/* as = s & ~3 */
+	rsub	r6, r4, r6		/* s = s - n */
+	lwi	r11, r8, 0		/* h = *(as + 0) */
+
+	addi	r9, r9, -1
+	beqi	r9,d_block_u1		/* t1 was 1 => 1 byte offset */
+	addi	r9, r9, -1
+	beqi	r9,d_block_u2		/* t1 was 2 => 2 byte offset */
+
+d_block_u3:
+	bsrli	r11, r11, 8	/* h = h >> 8 */
+d_bu3_loop:
+	addi	r8, r8, -32	/* as = as - 32 */
+	addi	r5, r5, -32	/* d = d - 32 */
+	lwi	r12, r8, 28	/* v = *(as + 28) */
+	bslli	r9, r12, 24	/* t1 = v << 24 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 28	/* *(d + 28) = t1 */
+	bsrli	r11, r12, 8	/* h = v >> 8 */
+	lwi	r12, r8, 24	/* v = *(as + 24) */
+	bslli	r9, r12, 24	/* t1 = v << 24 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 24	/* *(d + 24) = t1 */
+	bsrli	r11, r12, 8	/* h = v >> 8 */
+	lwi	r12, r8, 20	/* v = *(as + 20) */
+	bslli	r9, r12, 24	/* t1 = v << 24 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 20	/* *(d + 20) = t1 */
+	bsrli	r11, r12, 8	/* h = v >> 8 */
+	lwi	r12, r8, 16	/* v = *(as + 16) */
+	bslli	r9, r12, 24	/* t1 = v << 24 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 16	/* *(d + 16) = t1 */
+	bsrli	r11, r12, 8	/* h = v >> 8 */
+	lwi	r12, r8, 12	/* v = *(as + 12) */
+	bslli	r9, r12, 24	/* t1 = v << 24 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 12	/* *(d + 112) = t1 */
+	bsrli	r11, r12, 8	/* h = v >> 8 */
+	lwi	r12, r8, 8	/* v = *(as + 8) */
+	bslli	r9, r12, 24	/* t1 = v << 24 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 8	/* *(d + 8) = t1 */
+	bsrli	r11, r12, 8	/* h = v >> 8 */
+	lwi	r12, r8, 4	/* v = *(as + 4) */
+	bslli	r9, r12, 24	/* t1 = v << 24 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 4	/* *(d + 4) = t1 */
+	bsrli	r11, r12, 8	/* h = v >> 8 */
+	lwi	r12, r8, 0	/* v = *(as + 0) */
+	bslli	r9, r12, 24	/* t1 = v << 24 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 0	/* *(d + 0) = t1 */
+	addi	r4, r4, -32	/* n = n - 32 */
+	bneid	r4, d_bu3_loop	/* while (n) loop */
+	bsrli	r11, r12, 8	/* h = v >> 8 (IN DELAY SLOT) */
+	bri	d_block_done
+
+d_block_u1:
+	bsrli	r11, r11, 24	/* h = h >> 24 */
+d_bu1_loop:
+	addi	r8, r8, -32	/* as = as - 32 */
+	addi	r5, r5, -32	/* d = d - 32 */
+	lwi	r12, r8, 28	/* v = *(as + 28) */
+	bslli	r9, r12, 8	/* t1 = v << 8 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 28	/* *(d + 28) = t1 */
+	bsrli	r11, r12, 24	/* h = v >> 24 */
+	lwi	r12, r8, 24	/* v = *(as + 24) */
+	bslli	r9, r12, 8	/* t1 = v << 8 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 24	/* *(d + 24) = t1 */
+	bsrli	r11, r12, 24	/* h = v >> 24 */
+	lwi	r12, r8, 20	/* v = *(as + 20) */
+	bslli	r9, r12, 8	/* t1 = v << 8 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 20	/* *(d + 20) = t1 */
+	bsrli	r11, r12, 24	/* h = v >> 24 */
+	lwi	r12, r8, 16	/* v = *(as + 16) */
+	bslli	r9, r12, 8	/* t1 = v << 8 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 16	/* *(d + 16) = t1 */
+	bsrli	r11, r12, 24	/* h = v >> 24 */
+	lwi	r12, r8, 12	/* v = *(as + 12) */
+	bslli	r9, r12, 8	/* t1 = v << 8 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 12	/* *(d + 112) = t1 */
+	bsrli	r11, r12, 24	/* h = v >> 24 */
+	lwi	r12, r8, 8	/* v = *(as + 8) */
+	bslli	r9, r12, 8	/* t1 = v << 8 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 8	/* *(d + 8) = t1 */
+	bsrli	r11, r12, 24	/* h = v >> 24 */
+	lwi	r12, r8, 4	/* v = *(as + 4) */
+	bslli	r9, r12, 8	/* t1 = v << 8 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 4	/* *(d + 4) = t1 */
+	bsrli	r11, r12, 24	/* h = v >> 24 */
+	lwi	r12, r8, 0	/* v = *(as + 0) */
+	bslli	r9, r12, 8	/* t1 = v << 8 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 0	/* *(d + 0) = t1 */
+	addi	r4, r4, -32	/* n = n - 32 */
+	bneid	r4, d_bu1_loop	/* while (n) loop */
+	bsrli	r11, r12, 24	/* h = v >> 24 (IN DELAY SLOT) */
+	bri	d_block_done
+
+d_block_u2:
+	bsrli	r11, r11, 16	/* h = h >> 16 */
+d_bu2_loop:
+	addi	r8, r8, -32	/* as = as - 32 */
+	addi	r5, r5, -32	/* d = d - 32 */
+	lwi	r12, r8, 28	/* v = *(as + 28) */
+	bslli	r9, r12, 16	/* t1 = v << 16 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 28	/* *(d + 28) = t1 */
+	bsrli	r11, r12, 16	/* h = v >> 16 */
+	lwi	r12, r8, 24	/* v = *(as + 24) */
+	bslli	r9, r12, 16	/* t1 = v << 16 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 24	/* *(d + 24) = t1 */
+	bsrli	r11, r12, 16	/* h = v >> 16 */
+	lwi	r12, r8, 20	/* v = *(as + 20) */
+	bslli	r9, r12, 16	/* t1 = v << 16 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 20	/* *(d + 20) = t1 */
+	bsrli	r11, r12, 16	/* h = v >> 16 */
+	lwi	r12, r8, 16	/* v = *(as + 16) */
+	bslli	r9, r12, 16	/* t1 = v << 16 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 16	/* *(d + 16) = t1 */
+	bsrli	r11, r12, 16	/* h = v >> 16 */
+	lwi	r12, r8, 12	/* v = *(as + 12) */
+	bslli	r9, r12, 16	/* t1 = v << 16 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 12	/* *(d + 112) = t1 */
+	bsrli	r11, r12, 16	/* h = v >> 16 */
+	lwi	r12, r8, 8	/* v = *(as + 8) */
+	bslli	r9, r12, 16	/* t1 = v << 16 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 8	/* *(d + 8) = t1 */
+	bsrli	r11, r12, 16	/* h = v >> 16 */
+	lwi	r12, r8, 4	/* v = *(as + 4) */
+	bslli	r9, r12, 16	/* t1 = v << 16 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 4	/* *(d + 4) = t1 */
+	bsrli	r11, r12, 16	/* h = v >> 16 */
+	lwi	r12, r8, 0	/* v = *(as + 0) */
+	bslli	r9, r12, 16	/* t1 = v << 16 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	swi	r9, r5, 0	/* *(d + 0) = t1 */
+	addi	r4, r4, -32	/* n = n - 32 */
+	bneid	r4, d_bu2_loop	/* while (n) loop */
+	bsrli	r11, r12, 16	/* h = v >> 16 (IN DELAY SLOT) */
+
+d_block_done:
+	addi	r4, r0, 4	/* n = 4 */
+	cmpu	r4, r4, r7	/* n = c - n  (unsigned) */
+	blti	r4,d_xfer_end	/* if n < 0, less than one word to transfer */
+
+d_word_xfer:
+	andi	r4, r7, 0xfffffffc	/* n = c & ~3 */
+	rsub	r5, r4, r5		/* d = d - n */
+	rsub	r6, r4, r6		/* s = s - n */
+	rsub	r7, r4, r7		/* c = c - n */
+
+	andi	r9, r6, 3		/* t1 = s & 3 */
+	/* if temp != 0, unaligned transfers needed */
+	bnei	r9, d_word_unaligned
+
+d_word_aligned:
+	addi	r4, r4,-4		/* n-- */
+	lw	r9, r6, r4		/* t1 = *(s+n) */
+	bneid	r4, d_word_aligned	/* loop */
+	sw	r9, r5, r4		/* *(d+n) = t1 (IN DELAY SLOT) */
+
+	bri	d_word_done
+
+d_word_unaligned:
+	andi	r8, r6, 0xfffffffc	/* as = s & ~3 */
+	lw	r11, r8, r4		/* h = *(as + n) */
+
+	addi	r9, r9, -1
+	beqi	r9,d_word_u1		/* t1 was 1 => 1 byte offset */
+	addi	r9, r9, -1
+	beqi	r9,d_word_u2		/* t1 was 2 => 2 byte offset */
+
+d_word_u3:
+	bsrli	r11, r11, 8	/* h = h >> 8 */
+d_wu3_loop:
+	addi	r4, r4,-4	/* n = n - 4 */
+	lw	r12, r8, r4	/* v = *(as + n) */
+	bslli	r9, r12, 24	/* t1 = v << 24 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	sw	r9, r5, r4	/* *(d + n) = t1 */
+	bneid	r4, d_wu3_loop	/* while (n) loop */
+	bsrli	r11, r12, 8	/* h = v >> 8 (IN DELAY SLOT) */
+
+	bri	d_word_done
+
+d_word_u1:
+	bsrli	r11, r11, 24	/* h = h >> 24 */
+d_wu1_loop:
+	addi	r4, r4,-4	/* n = n - 4 */
+	lw	r12, r8, r4	/* v = *(as + n) */
+	bslli	r9, r12, 8	/* t1 = v << 8 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	sw	r9, r5, r4	/* *(d + n) = t1 */
+	bneid	r4, d_wu1_loop	/* while (n) loop */
+	bsrli	r11, r12, 24	/* h = v >> 24 (IN DELAY SLOT) */
+
+	bri	d_word_done
+
+d_word_u2:
+	bsrli	r11, r11, 16	/* h = h >> 16 */
+d_wu2_loop:
+	addi	r4, r4,-4	/* n = n - 4 */
+	lw	r12, r8, r4	/* v = *(as + n) */
+	bslli	r9, r12, 16	/* t1 = v << 16 */
+	or	r9, r11, r9	/* t1 = h | t1 */
+	sw	r9, r5, r4	/* *(d + n) = t1 */
+	bneid	r4, d_wu2_loop	/* while (n) loop */
+	bsrli	r11, r12, 16	/* h = v >> 16 (IN DELAY SLOT) */
+
+d_word_done:
+
+d_xfer_end:
+d_xfer_end_loop:
+	beqi	r7, a_done		/* while (c) */
+	addi	r6, r6, -1		/* s-- */
+	lbui	r9, r6, 0		/* t1 = *s */
+	addi	r5, r5, -1		/* d-- */
+	sbi	r9, r5, 0		/* *d = t1 */
+	brid	d_xfer_end_loop		/* loop */
+	addi	r7, r7, -1		/* c-- (IN DELAY SLOT) */
+
+d_done:
+	rtsd	r15, 8
+	nop
+
+.size  memmove, . - memmove
+.end memmove