diff --git a/compiler-rt/cmake/builtin-config-ix.cmake b/compiler-rt/cmake/builtin-config-ix.cmake
--- a/compiler-rt/cmake/builtin-config-ix.cmake
+++ b/compiler-rt/cmake/builtin-config-ix.cmake
@@ -28,6 +28,12 @@
 asm(\"cas w0, w1, [x2]\");
 ")
 
+builtin_check_c_compiler_source(COMPILER_RT_HAS_ASM_SME
+"
+asm(\".arch armv9-a+sme\");
+asm(\"smstart\");
+")
+
 set(ARM64 aarch64)
 set(ARM32 arm armhf armv4t armv5te armv6 armv6m armv7m armv7em armv7 armv7s armv7k armv8m.base armv8m.main armv8.1m.main)
 set(AVR avr)
diff --git a/compiler-rt/lib/builtins/CMakeLists.txt b/compiler-rt/lib/builtins/CMakeLists.txt
--- a/compiler-rt/lib/builtins/CMakeLists.txt
+++ b/compiler-rt/lib/builtins/CMakeLists.txt
@@ -556,6 +556,7 @@
   ${GENERIC_SOURCES}
   cpu_model.c
   aarch64/fp_mode.c
+  aarch64/sme-abi.S
 )
 
 # Generate outline atomics helpers from lse.S base
@@ -781,6 +782,7 @@
   endif()
 
   append_list_if(COMPILER_RT_HAS_ASM_LSE HAS_ASM_LSE BUILTIN_DEFS)
+  append_list_if(COMPILER_RT_HAS_ASM_SME HAS_ASM_SME BUILTIN_DEFS)
 
   foreach (arch ${BUILTIN_SUPPORTED_ARCH})
     if (CAN_TARGET_${arch})
diff --git a/compiler-rt/lib/builtins/aarch64/sme-abi.S b/compiler-rt/lib/builtins/aarch64/sme-abi.S
new file mode 100644
--- /dev/null
+++ b/compiler-rt/lib/builtins/aarch64/sme-abi.S
@@ -0,0 +1,175 @@
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+#include "assembly.h"
+
+#ifdef __aarch64__
+
+#ifdef HAS_ASM_SME
+#define ARCH armv9-a+sme
+#define SMSTOP_SM smstop sm
+#define SMSTOP_ZA smstop za
+#define REG_TPIDR2_EL0 TPIDR2_EL0
+#define REG_SVCR SVCR
+#define RDSVL_X15_1 rdsvl x15,#1
+#define RDSVL_X14_1 rdsvl x14,#1
+#define LDR_ZA_W12_0_X16 ldr za[w12,0],[x16]
+#define STR_ZA_W12_0_X16 str za[w12,0],[x16]
+#else
+#define ARCH armv8-a
+#define SMSTOP_SM .inst 0xd503427f
+#define SMSTOP_ZA .inst 0xd503447f
+#define REG_TPIDR2_EL0 S3_3_C13_C0_5
+#define REG_SVCR S3_3_C4_C2_2
+#define RDSVL_X15_1 .inst 0x04bf582f
+#define RDSVL_X14_1 .inst 0x04bf582e
+#define LDR_ZA_W12_0_X16 .inst 0xe1000200
+#define STR_ZA_W12_0_X16 .inst 0xe1200200
+#endif
+
+.arch ARCH
+
+// Utility function which calls a system's abort() routine.
+// Because the function is streaming-compatible it should disable
+// streaming-SVE mode before calling abort(). Note that there is no
+// need to preserve any state before the call, because the function
+// does not return.
+DEFINE_COMPILERRT_PRIVATE_FUNCTION(do_abort)
+	.variant_pcs	do_abort
+	bl	__arm_sme_state
+	and	x19, x0, #0x1
+	tbnz	x19, #0, 1f
+	b	2f
+1:
+	SMSTOP_SM
+2:
+	bl	abort
+END_COMPILERRT_FUNCTION(do_abort)
+
+DEFINE_COMPILERRT_OUTLINE_FUNCTION_UNMANGLED(__arm_sme_state)
+	.variant_pcs	__arm_sme_state
+	mrs	x16, CPTR_EL3
+	tbnz	w16, #12, 2f
+	mov	x0, xzr
+	mrs	x16, CPTR_EL3
+	tbz	w16, #12, 3f
+1:
+	mrs	x1, REG_TPIDR2_EL0
+	orr	x0, x0, #0x4000000000000000
+	ret
+2:
+	mov	x0, #-9223372036854775808
+	mrs	x16, REG_SVCR
+	bfxil	x0, x16, #0, #2
+	mrs	x16, CPTR_EL3
+	tbnz	w16, #12, 1b
+3:
+	mov	x1, xzr
+	ret
+END_COMPILERRT_OUTLINE_FUNCTION(__arm_sme_state)
+
+DEFINE_COMPILERRT_OUTLINE_FUNCTION_UNMANGLED(__arm_tpidr2_restore)
+	.variant_pcs	__arm_tpidr2_restore
+	stp	x29, x30, [sp, #-32]!
+	str	x12, [sp, #16]
+	mrs	x14, REG_TPIDR2_EL0
+	cbnz	x14, 3f
+	ldrh	w14, [x0, #10]
+	cbnz	w14, 3f
+	ldr	w14, [x0, #12]
+	cbnz	w14, 3f
+	RDSVL_X14_1
+	ldrh	w15, [x0, #8]
+	cbz	x15, 2f
+	mov	x12, xzr
+	ldr	x16, [x0]
+1:
+	LDR_ZA_W12_0_X16
+	add	x16, x16, x14
+	add	x12, x12, #1
+	cmp	x15, x12
+	b.ne	1b
+2:
+	ldr	x12, [sp, #16]
+	ldp	x29, x30, [sp], #32
+	ret
+3:
+	bl	SYMBOL_NAME(do_abort)
+END_COMPILERRT_OUTLINE_FUNCTION(__arm_tpidr2_restore)
+
+DEFINE_COMPILERRT_OUTLINE_FUNCTION_UNMANGLED(__arm_tpidr2_save)
+	.variant_pcs	__arm_tpidr2_save
+	stp	x29, x30, [sp, #-32]!
+	str	x12, [sp, #16]
+	mov	x29, sp
+	mrs	x14, CPTR_EL3
+	tbz	w14, #12, 2f
+	mrs	x16, REG_TPIDR2_EL0
+	cbz	x16, 2f
+	ldrh	w14, [x16, #10]
+	cbnz	w14, 3f
+	ldr	w14, [x16, #12]
+	cbnz	w14, 3f
+	ldr	x14, [x16]
+	cbz	x14, 2f
+	RDSVL_X14_1
+	ldrh	w15, [x16, #8]
+	cbz	x15, 2f
+	mov	x12, xzr
+	ldr	x16, [x16]
+1:
+	STR_ZA_W12_0_X16
+	add	x16, x16, x14
+	add	x12, x12, #1
+	cmp	x15, x12
+	b.ne	1b
+2:
+	ldr	x12, [sp, #16]
+	ldp	x29, x30, [sp], #32
+	ret
+3:
+	bl	SYMBOL_NAME(do_abort)
+END_COMPILERRT_OUTLINE_FUNCTION(__arm_tpidr2_save)
+
+DEFINE_COMPILERRT_OUTLINE_FUNCTION_UNMANGLED(__arm_za_disable)
+	.variant_pcs	__arm_za_disable
+	stp	x29, x30, [sp, #-32]!
+	str	x12, [sp, #16]
+	mov	x29, sp
+	mrs	x14, CPTR_EL3
+	tbz	w14, #12, 3f
+	mrs	x14, CPTR_EL3
+	tbz	w14, #12, 2f
+	mrs	x16, REG_TPIDR2_EL0
+	cbz	x16, 2f
+	ldrh	w14, [x16, #10]
+	cbnz	w14, 4f
+	ldr	w14, [x16, #12]
+	cbnz	w14, 4f
+	ldr	x14, [x16]
+	cbz	x14, 2f
+	RDSVL_X14_1
+	ldrh	w15, [x16, #8]
+	cbz	x15, 2f
+	mov	x12, xzr
+	ldr	x16, [x16]
+1:
+	STR_ZA_W12_0_X16
+	add	x16, x16, x14
+	add	x12, x12, #1
+	cmp	x15, x12
+	b.ne	1b
+2:
+	mov	x14, xzr
+	msr	REG_TPIDR2_EL0, x14
+	SMSTOP_ZA
+3:
+	ldr	x12, [sp, #16]
+	ldp	x29, x30, [sp], #32
+	ret
+4:
+	bl	SYMBOL_NAME(do_abort)
+END_COMPILERRT_OUTLINE_FUNCTION(__arm_za_disable)
+
+#endif // __aarch64__