Index: llvm/trunk/lib/Target/AArch64/AArch64SystemOperands.td
===================================================================
--- llvm/trunk/lib/Target/AArch64/AArch64SystemOperands.td
+++ llvm/trunk/lib/Target/AArch64/AArch64SystemOperands.td
@@ -576,6 +576,12 @@
 def : ROSysReg<"ICH_EISR_EL2",       0b11, 0b100, 0b1100, 0b1011, 0b011>;
 def : ROSysReg<"ICH_ELRSR_EL2",      0b11, 0b100, 0b1100, 0b1011, 0b101>;
 
+// SVE control registers
+//                                   Op0   Op1    CRn     CRm     Op2
+let Requires = [{ {AArch64::FeatureSVE} }] in {
+def : ROSysReg<"ID_AA64ZFR0_EL1",    0b11, 0b000, 0b0000, 0b0100, 0b100>;
+}
+
 // v8.1a "Limited Ordering Regions" extension-specific system register
 //                         Op0    Op1     CRn     CRm    Op2
 let Requires = [{ {AArch64::HasV8_1aOps} }] in
@@ -1311,6 +1317,15 @@
 
 } // HasV8_4aOps
 
+// SVE control registers
+//                                 Op0   Op1    CRn     CRm     Op2
+let Requires = [{ {AArch64::FeatureSVE} }] in {
+def : RWSysReg<"ZCR_EL1",          0b11, 0b000, 0b0001, 0b0010, 0b000>;
+def : RWSysReg<"ZCR_EL2",          0b11, 0b100, 0b0001, 0b0010, 0b000>;
+def : RWSysReg<"ZCR_EL3",          0b11, 0b110, 0b0001, 0b0010, 0b000>;
+def : RWSysReg<"ZCR_EL12",         0b11, 0b101, 0b0001, 0b0010, 0b000>;
+}
+
 // Cyclone specific system registers
 //                                 Op0    Op1     CRn     CRm    Op2
 let Requires = [{ {AArch64::ProcCyclone} }] in
Index: llvm/trunk/test/MC/AArch64/SVE/system-regs-diagnostics.s
===================================================================
--- llvm/trunk/test/MC/AArch64/SVE/system-regs-diagnostics.s
+++ llvm/trunk/test/MC/AArch64/SVE/system-regs-diagnostics.s
@@ -0,0 +1,51 @@
+// RUN: not llvm-mc -triple aarch64 -mattr=+sve -show-encoding < %s 2>&1 | FileCheck %s --check-prefix=CHECK-SVE
+// RUN: not llvm-mc -triple aarch64 -show-encoding < %s 2>&1 | FileCheck %s --check-prefix=CHECK-NOSVE
+
+
+// --------------------------------------------------------------------------//
+// ID_AA64ZFR0_EL1 is read-only
+
+msr ID_AA64ZFR0_EL1, x3
+// CHECK-SVE: error: expected writable system register or pstate
+// CHECK-SVE-NEXT:         msr ID_AA64ZFR0_EL1, x3
+
+
+// --------------------------------------------------------------------------//
+// Check that the other SVE registers are only readable/writable when
+// the +sve attribute is set.
+
+mrs x3, ID_AA64ZFR0_EL1
+// CHECK-NOSVE: error: expected readable system register
+// CHECK-NOSVE: mrs x3, ID_AA64ZFR0_EL1
+
+mrs x3, ZCR_EL1
+// CHECK-NOSVE: error: expected readable system register
+// CHECK-NOSVE-NEXT: mrs x3, ZCR_EL1
+
+mrs x3, ZCR_EL2
+// CHECK-NOSVE: error: expected readable system register
+// CHECK-NOSVE-NEXT: mrs x3, ZCR_EL2
+
+mrs x3, ZCR_EL3
+// CHECK-NOSVE: error: expected readable system register
+// CHECK-NOSVE-NEXT: mrs x3, ZCR_EL3
+
+mrs x3, ZCR_EL12
+// CHECK-NOSVE: error: expected readable system register
+// CHECK-NOSVE-NEXT: mrs x3, ZCR_EL12
+
+msr ZCR_EL1, x3
+// CHECK-NOSVE: error: expected writable system register or pstate
+// CHECK-NOSVE-NEXT: msr ZCR_EL1, x3
+
+msr ZCR_EL2, x3
+// CHECK-NOSVE: error: expected writable system register or pstate
+// CHECK-NOSVE-NEXT: msr ZCR_EL2, x3
+
+msr ZCR_EL3, x3
+// CHECK-NOSVE: error: expected writable system register or pstate
+// CHECK-NOSVE-NEXT: msr ZCR_EL3, x3
+
+msr ZCR_EL12, x3
+// CHECK-NOSVE: error: expected writable system register or pstate
+// CHECK-NOSVE-NEXT: msr ZCR_EL12, x3
Index: llvm/trunk/test/MC/AArch64/SVE/system-regs.s
===================================================================
--- llvm/trunk/test/MC/AArch64/SVE/system-regs.s
+++ llvm/trunk/test/MC/AArch64/SVE/system-regs.s
@@ -0,0 +1,62 @@
+// RUN: llvm-mc -triple=aarch64 -show-encoding -mattr=+sve < %s \
+// RUN:        | FileCheck %s --check-prefixes=CHECK-ENCODING,CHECK-INST
+// RUN: not llvm-mc -triple=aarch64 -show-encoding < %s 2>&1 \
+// RUN:        | FileCheck %s --check-prefix=CHECK-ERROR
+// RUN: llvm-mc -triple=aarch64 -filetype=obj -mattr=+sve < %s \
+// RUN:        | llvm-objdump -d -mattr=+sve - | FileCheck %s --check-prefix=CHECK-INST
+// RUN: llvm-mc -triple=aarch64 -filetype=obj -mattr=+sve < %s \
+// RUN:        | llvm-objdump -d - | FileCheck %s --check-prefix=CHECK-UNKNOWN
+
+mrs x3, ID_AA64ZFR0_EL1
+// CHECK-INST: mrs x3, ID_AA64ZFR0_EL1
+// CHECK-ENCODING: [0x83,0x04,0x38,0xd5]
+// CHECK-ERROR: expected readable system register
+// CHECK-UNKNOWN: 83 04 38 d5   mrs   x3, S3_0_C0_C4_4
+
+mrs x3, ZCR_EL1
+// CHECK-INST: mrs x3, ZCR_EL1
+// CHECK-ENCODING: [0x03,0x12,0x38,0xd5]
+// CHECK-ERROR: expected readable system register
+// CHECK-UNKNOWN: 03 12 38 d5   mrs   x3, S3_0_C1_C2_0
+
+mrs x3, ZCR_EL2
+// CHECK-INST: mrs x3, ZCR_EL2
+// CHECK-ENCODING: [0x03,0x12,0x3c,0xd5]
+// CHECK-ERROR: expected readable system register
+// CHECK-UNKNOWN: 03 12 3c d5   mrs   x3, S3_4_C1_C2_0
+
+mrs x3, ZCR_EL3
+// CHECK-INST: mrs x3, ZCR_EL3
+// CHECK-ENCODING: [0x03,0x12,0x3e,0xd5]
+// CHECK-ERROR: expected readable system register
+// CHECK-UNKNOWN: 03 12 3e d5   mrs   x3, S3_6_C1_C2_0
+
+mrs x3, ZCR_EL12
+// CHECK-INST: mrs x3, ZCR_EL12
+// CHECK-ENCODING: [0x03,0x12,0x3d,0xd5]
+// CHECK-ERROR: expected readable system register
+// CHECK-UNKNOWN: 03 12 3d d5   mrs   x3, S3_5_C1_C2_0
+
+msr ZCR_EL1, x3
+// CHECK-INST: msr ZCR_EL1, x3
+// CHECK-ENCODING: [0x03,0x12,0x18,0xd5]
+// CHECK-ERROR: expected writable system register or pstate
+// CHECK-UNKNOWN: 03 12 18 d5   msr   S3_0_C1_C2_0, x3
+
+msr ZCR_EL2, x3
+// CHECK-INST: msr ZCR_EL2, x3
+// CHECK-ENCODING: [0x03,0x12,0x1c,0xd5]
+// CHECK-ERROR: expected writable system register or pstate
+// CHECK-UNKNOWN: 03 12 1c d5   msr   S3_4_C1_C2_0, x3
+
+msr ZCR_EL3, x3
+// CHECK-INST: msr ZCR_EL3, x3
+// CHECK-ENCODING: [0x03,0x12,0x1e,0xd5]
+// CHECK-ERROR: expected writable system register or pstate
+// CHECK-UNKNOWN: 03 12 1e d5   msr   S3_6_C1_C2_0, x3
+
+msr ZCR_EL12, x3
+// CHECK-INST: msr ZCR_EL12, x3
+// CHECK-ENCODING: [0x03,0x12,0x1d,0xd5]
+// CHECK-ERROR: expected writable system register or pstate
+// CHECK-UNKNOWN: 03 12 1d d5   msr   S3_5_C1_C2_0, x3