diff --git a/clang/test/Preprocessor/riscv-target-features.c b/clang/test/Preprocessor/riscv-target-features.c
--- a/clang/test/Preprocessor/riscv-target-features.c
+++ b/clang/test/Preprocessor/riscv-target-features.c
@@ -59,6 +59,8 @@
 // CHECK-NOT: __riscv_zvksed {{.*$}}
 // CHECK-NOT: __riscv_zvksh {{.*$}}
 // CHECK-NOT: __riscv_zicond {{.*$}}
+// CHECK-NOT: __riscv_smaia
+// CHECK-NOT: __riscv_ssaia
 
 // RUN: %clang -target riscv32-unknown-linux-gnu -march=rv32i -x c -E -dM %s \
 // RUN: -o - | FileCheck %s
@@ -604,3 +606,15 @@
 // RUN: -march=rv64i_zicond1p0 -x c -E -dM %s \
 // RUN: -o - | FileCheck --check-prefix=CHECK-ZICOND-EXT %s
 // CHECK-ZICOND-EXT: __riscv_zicond  1000000{{$}}
+
+// RUN: %clang -target riscv32 -march=rv32ismaia -x c -E -dM %s \
+// RUN: -o - | FileCheck --check-prefix=CHECK-SMAIA-EXT %s
+// RUN: %clang -target riscv64 -march=rv64ismaia -x c -E -dM %s \
+// RUN: -o - | FileCheck --check-prefix=CHECK-SMAIA-EXT %s
+// CHECK-SMAIA-EXT: __riscv_smaia  1000000{{$}}
+
+// RUN: %clang -target riscv32 -march=rv32issaia -x c -E -dM %s \
+// RUN: -o - | FileCheck --check-prefix=CHECK-SSAIA-EXT %s
+// RUN: %clang -target riscv64 -march=rv64issaia -x c -E -dM %s \
+// RUN: -o - | FileCheck --check-prefix=CHECK-SSAIA-EXT %s
+// CHECK-SSAIA-EXT: __riscv_ssaia  1000000{{$}}
diff --git a/llvm/lib/Support/RISCVISAInfo.cpp b/llvm/lib/Support/RISCVISAInfo.cpp
--- a/llvm/lib/Support/RISCVISAInfo.cpp
+++ b/llvm/lib/Support/RISCVISAInfo.cpp
@@ -116,6 +116,9 @@
     {"svpbmt", RISCVExtensionVersion{1, 0}},
     {"svinval", RISCVExtensionVersion{1, 0}},
 
+    {"smaia", RISCVExtensionVersion{1, 0}},
+    {"ssaia", RISCVExtensionVersion{1, 0}},
+
     // vendor-defined ('X') extensions
     {"xsfvcp", RISCVExtensionVersion{1, 0}},
     {"xtheadba", RISCVExtensionVersion{1, 0}},
diff --git a/llvm/lib/Target/RISCV/RISCVFeatures.td b/llvm/lib/Target/RISCV/RISCVFeatures.td
--- a/llvm/lib/Target/RISCV/RISCVFeatures.td
+++ b/llvm/lib/Target/RISCV/RISCVFeatures.td
@@ -545,6 +545,19 @@
                                 AssemblerPredicate<(all_of FeatureStdExtZicond),
                                 "'Zicond' (Integer Conditional Operations)">;
 
+def FeatureStdExtSmaia
+    : SubtargetFeature<"smaia", "HasStdExtSmaia", "true",
+                       "'Smaia' (Smaia encompasses all added CSRs and all "
+                       "modifications to interrupt response behavior that the "
+                       "AIA specifies for a hart, over all privilege levels.)",
+                       []>;
+
+def FeatureStdExtSsaia
+    : SubtargetFeature<"ssaia", "HasStdExtSsaia", "true",
+                       "'Ssaia' (Ssaia is essentially the same as Smaia except "
+                       "excluding the machine-level CSRs and behavior not "
+                       "directly visible to supervisor level.)", []>;
+
 //===----------------------------------------------------------------------===//
 // Vendor extensions
 //===----------------------------------------------------------------------===//
diff --git a/llvm/lib/Target/RISCV/RISCVSystemOperands.td b/llvm/lib/Target/RISCV/RISCVSystemOperands.td
--- a/llvm/lib/Target/RISCV/RISCVSystemOperands.td
+++ b/llvm/lib/Target/RISCV/RISCVSystemOperands.td
@@ -378,3 +378,51 @@
 //===-----------------------------------------------
 
 def SEED : SysReg<"seed", 0x015>;
+
+//===-----------------------------------------------
+// Advanced Interrupt Architecture
+//===-----------------------------------------------
+
+// Machine-level CSRs
+def : SysReg<"miselect", 0x350>;
+def : SysReg<"mireg", 0x351>;
+def : SysReg<"mtopei", 0x35C>;
+def : SysReg<"mtopi", 0xFB0>;
+def : SysReg<"mvien", 0x308>;
+def : SysReg<"mvip", 0x309>;
+let isRV32Only = 1 in {
+def : SysReg<"midelegh", 0x313>;
+def : SysReg<"mieh", 0x314>;
+def : SysReg<"mvienh", 0x318>;
+def : SysReg<"mviph", 0x319>;
+def : SysReg<"miph", 0x354>;
+} // isRV32Only
+
+// Supervisor-level CSRs
+def : SysReg<"siselect", 0x150>;
+def : SysReg<"sireg", 0x151>;
+def : SysReg<"stopei", 0x15C>;
+def : SysReg<"stopi", 0xDB0>;
+let isRV32Only = 1 in {
+def : SysReg<"sieh", 0x114>;
+def : SysReg<"siph", 0x154>;
+} // isRV32Only
+
+// Hypervisor and VS CSRs
+def : SysReg<"hvien", 0x608>;
+def : SysReg<"hvictl", 0x609>;
+def : SysReg<"hviprio1", 0x646>;
+def : SysReg<"hviprio2", 0x647>;
+def : SysReg<"vsiselect", 0x250>;
+def : SysReg<"vsireg", 0x251>;
+def : SysReg<"vstopei", 0x25C>;
+def : SysReg<"vstopi", 0xEB0>;
+let isRV32Only = 1 in {
+def : SysReg<"hidelegh", 0x613>;
+def : SysReg<"hvienh", 0x618>;
+def : SysReg<"hviph", 0x655>;
+def : SysReg<"hviprio1h", 0x656>;
+def : SysReg<"hviprio2h", 0x657>;
+def : SysReg<"vsieh", 0x214>;
+def : SysReg<"vsiph", 0x254>;
+} // isRV32Only
diff --git a/llvm/test/CodeGen/RISCV/attributes.ll b/llvm/test/CodeGen/RISCV/attributes.ll
--- a/llvm/test/CodeGen/RISCV/attributes.ll
+++ b/llvm/test/CodeGen/RISCV/attributes.ll
@@ -65,6 +65,8 @@
 ; RUN: llc -mtriple=riscv32 -mattr=+zve32x -mattr=+experimental-zvksed %s -o - | FileCheck --check-prefix=RV32ZVKSED %s
 ; RUN: llc -mtriple=riscv32 -mattr=+zve32x -mattr=+experimental-zvksh %s -o - | FileCheck --check-prefix=RV32ZVKSH %s
 ; RUN: llc -mtriple=riscv32 -mattr=+experimental-zicond %s -o - | FileCheck --check-prefix=RV32ZICOND %s
+; RUN: llc -mtriple=riscv32 -mattr=+smaia %s -o - | FileCheck --check-prefixes=CHECK,RV32SMAIA %s
+; RUN: llc -mtriple=riscv32 -mattr=+ssaia %s -o - | FileCheck --check-prefixes=CHECK,RV32SSAIA %s
 
 ; RUN: llc -mtriple=riscv64 %s -o - | FileCheck %s
 ; RUN: llc -mtriple=riscv64 -mattr=+m %s -o - | FileCheck --check-prefixes=CHECK,RV64M %s
@@ -137,6 +139,8 @@
 ; RUN: llc -mtriple=riscv64 -mattr=+zve32x -mattr=+experimental-zvksed %s -o - | FileCheck --check-prefix=RV64ZVKSED %s
 ; RUN: llc -mtriple=riscv64 -mattr=+zve32x -mattr=+experimental-zvksh %s -o - | FileCheck --check-prefix=RV64ZVKSH %s
 ; RUN: llc -mtriple=riscv64 -mattr=+experimental-zicond %s -o - | FileCheck --check-prefix=RV64ZICOND %s
+; RUN: llc -mtriple=riscv64 -mattr=+smaia %s -o - | FileCheck --check-prefixes=CHECK,RV64SMAIA %s
+; RUN: llc -mtriple=riscv64 -mattr=+ssaia %s -o - | FileCheck --check-prefixes=CHECK,RV64SSAIA %s
 
 ; CHECK: .attribute 4, 16
 
@@ -204,6 +208,8 @@
 ; RV32ZVKSED: .attribute 5, "rv32i2p1_zicsr2p0_zve32x1p0_zvksed0p3_zvl32b1p0"
 ; RV32ZVKSH: .attribute 5, "rv32i2p1_zicsr2p0_zve32x1p0_zvksh0p3_zvl32b1p0"
 ; RV32ZICOND: .attribute 5, "rv32i2p1_zicond1p0"
+; RV32SMAIA: .attribute 5, "rv32i2p1_smaia1p0"
+; RV32SSAIA: .attribute 5, "rv32i2p1_ssaia1p0"
 
 ; RV64M: .attribute 5, "rv64i2p1_m2p0"
 ; RV64ZMMUL: .attribute 5, "rv64i2p1_zmmul1p0"
@@ -275,6 +281,8 @@
 ; RV64ZVKSED: .attribute 5, "rv64i2p1_zicsr2p0_zve32x1p0_zvksed0p3_zvl32b1p0"
 ; RV64ZVKSH: .attribute 5, "rv64i2p1_zicsr2p0_zve32x1p0_zvksh0p3_zvl32b1p0"
 ; RV64ZICOND: .attribute 5, "rv64i2p1_zicond1p0"
+; RV64SMAIA: .attribute 5, "rv64i2p1_smaia1p0"
+; RV64SSAIA: .attribute 5, "rv64i2p1_ssaia1p0"
 
 define i32 @addi(i32 %a) {
   %1 = add i32 %a, 1
diff --git a/llvm/test/MC/RISCV/attribute-arch.s b/llvm/test/MC/RISCV/attribute-arch.s
--- a/llvm/test/MC/RISCV/attribute-arch.s
+++ b/llvm/test/MC/RISCV/attribute-arch.s
@@ -239,3 +239,9 @@
 
 .attribute arch, "rv32izicond1p0"
 # CHECK: attribute      5, "rv32i2p1_zicond1p0"
+
+.attribute arch, "rv32i_smaia"
+# CHECK: attribute      5, "rv32i2p1_smaia1p0"
+
+.attribute arch, "rv32i_ssaia"
+# CHECK: attribute      5, "rv32i2p1_ssaia1p0"
diff --git a/llvm/test/MC/RISCV/hypervisor-csr-names.s b/llvm/test/MC/RISCV/hypervisor-csr-names.s
--- a/llvm/test/MC/RISCV/hypervisor-csr-names.s
+++ b/llvm/test/MC/RISCV/hypervisor-csr-names.s
@@ -447,3 +447,119 @@
 csrrs t1, hstateen3, zero
 # uimm12
 csrrs t2, 0x60F, zero
+
+#########################################
+# Advanced Interrupt Architecture (Smaia and Ssaia)
+#########################################
+
+# hvien
+# name
+# CHECK-INST: csrrs t1, hvien, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x80,0x60]
+# CHECK-INST-ALIAS: csrr t1, hvien
+# uimm12
+# CHECK-INST: csrrs t2, hvien, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x80,0x60]
+# CHECK-INST-ALIAS: csrr t2, hvien
+# name
+csrrs t1, hvien, zero
+# uimm12
+csrrs t2, 0x608, zero
+
+# hvictl
+# name
+# CHECK-INST: csrrs t1, hvictl, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x90,0x60]
+# CHECK-INST-ALIAS: csrr t1, hvictl
+# uimm12
+# CHECK-INST: csrrs t2, hvictl, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x90,0x60]
+# CHECK-INST-ALIAS: csrr t2, hvictl
+# name
+csrrs t1, hvictl, zero
+# uimm12
+csrrs t2, 0x609, zero
+
+# hviprio1
+# name
+# CHECK-INST: csrrs t1, hviprio1, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x60,0x64]
+# CHECK-INST-ALIAS: csrr t1, hviprio1
+# uimm12
+# CHECK-INST: csrrs t2, hviprio1, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x60,0x64]
+# CHECK-INST-ALIAS: csrr t2, hviprio1
+# name
+csrrs t1, hviprio1, zero
+# uimm12
+csrrs t2, 0x646, zero
+
+# hviprio2
+# name
+# CHECK-INST: csrrs t1, hviprio2, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x70,0x64]
+# CHECK-INST-ALIAS: csrr t1, hviprio2
+# uimm12
+# CHECK-INST: csrrs t2, hviprio2, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x70,0x64]
+# CHECK-INST-ALIAS: csrr t2, hviprio2
+# name
+csrrs t1, hviprio2, zero
+# uimm12
+csrrs t2, 0x647, zero
+
+# vsiselect
+# name
+# CHECK-INST: csrrs t1, vsiselect, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x00,0x25]
+# CHECK-INST-ALIAS: csrr t1, vsiselect
+# uimm12
+# CHECK-INST: csrrs t2, vsiselect, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x00,0x25]
+# CHECK-INST-ALIAS: csrr t2, vsiselect
+# name
+csrrs t1, vsiselect, zero
+# uimm12
+csrrs t2, 0x250, zero
+
+# vsireg
+# name
+# CHECK-INST: csrrs t1, vsireg, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x10,0x25]
+# CHECK-INST-ALIAS: csrr t1, vsireg
+# uimm12
+# CHECK-INST: csrrs t2, vsireg, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x10,0x25]
+# CHECK-INST-ALIAS: csrr t2, vsireg
+# name
+csrrs t1, vsireg, zero
+# uimm12
+csrrs t2, 0x251, zero
+
+# vstopei
+# name
+# CHECK-INST: csrrs t1, vstopei, zero
+# CHECK-ENC: encoding: [0x73,0x23,0xc0,0x25]
+# CHECK-INST-ALIAS: csrr t1, vstopei
+# uimm12
+# CHECK-INST: csrrs t2, vstopei, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0xc0,0x25]
+# CHECK-INST-ALIAS: csrr t2, vstopei
+# name
+csrrs t1, vstopei, zero
+# uimm12
+csrrs t2, 0x25C, zero
+
+# vstopi
+# name
+# CHECK-INST: csrrs t1, vstopi, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x00,0xeb]
+# CHECK-INST-ALIAS: csrr t1, vstopi
+# uimm12
+# CHECK-INST: csrrs t2, vstopi, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x00,0xeb]
+# CHECK-INST-ALIAS: csrr t2, vstopi
+# name
+csrrs t1, vstopi, zero
+# uimm12
+csrrs t2, 0xEB0, zero
diff --git a/llvm/test/MC/RISCV/machine-csr-names.s b/llvm/test/MC/RISCV/machine-csr-names.s
--- a/llvm/test/MC/RISCV/machine-csr-names.s
+++ b/llvm/test/MC/RISCV/machine-csr-names.s
@@ -2410,3 +2410,91 @@
 csrrs t1, mstateen3, zero
 # uimm12
 csrrs t2, 0x30F, zero
+
+#########################################
+# Advanced Interrupt Architecture (Smaia and Ssaia)
+#########################################
+
+# miselect
+# name
+# CHECK-INST: csrrs t1, miselect, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x00,0x35]
+# CHECK-INST-ALIAS: csrr t1, miselect
+# uimm12
+# CHECK-INST: csrrs t2, miselect, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x00,0x35]
+# CHECK-INST-ALIAS: csrr t2, miselect
+# name
+csrrs t1, miselect, zero
+# uimm12
+csrrs t2, 0x350, zero
+
+# mireg
+# name
+# CHECK-INST: csrrs t1, mireg, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x10,0x35]
+# CHECK-INST-ALIAS: csrr t1, mireg
+# uimm12
+# CHECK-INST: csrrs t2, mireg, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x10,0x35]
+# CHECK-INST-ALIAS: csrr t2, mireg
+# name
+csrrs t1, mireg, zero
+# uimm12
+csrrs t2, 0x351, zero
+
+# mtopei
+# name
+# CHECK-INST: csrrs t1, mtopei, zero
+# CHECK-ENC: encoding: [0x73,0x23,0xc0,0x35]
+# CHECK-INST-ALIAS: csrr t1, mtopei
+# uimm12
+# CHECK-INST: csrrs t2, mtopei, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0xc0,0x35]
+# CHECK-INST-ALIAS: csrr t2, mtopei
+# name
+csrrs t1, mtopei, zero
+# uimm12
+csrrs t2, 0x35C, zero
+
+# mtopi
+# name
+# CHECK-INST: csrrs t1, mtopi, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x00,0xfb]
+# CHECK-INST-ALIAS: csrr t1, mtopi
+# uimm12
+# CHECK-INST: csrrs t2, mtopi, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x00,0xfb]
+# CHECK-INST-ALIAS: csrr t2, mtopi
+# name
+csrrs t1, mtopi, zero
+# uimm12
+csrrs t2, 0xFB0, zero
+
+# mvien
+# name
+# CHECK-INST: csrrs t1, mvien, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x80,0x30]
+# CHECK-INST-ALIAS: csrr t1, mvien
+# uimm12
+# CHECK-INST: csrrs t2, mvien, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x80,0x30]
+# CHECK-INST-ALIAS: csrr t2, mvien
+# name
+csrrs t1, mvien, zero
+# uimm12
+csrrs t2, 0x308, zero
+
+# mvip
+# name
+# CHECK-INST: csrrs t1, mvip, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x90,0x30]
+# CHECK-INST-ALIAS: csrr t1, mvip
+# uimm12
+# CHECK-INST: csrrs t2, mvip, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x90,0x30]
+# CHECK-INST-ALIAS: csrr t2, mvip
+# name
+csrrs t1, mvip, zero
+# uimm12
+csrrs t2, 0x309, zero
diff --git a/llvm/test/MC/RISCV/rv32-hypervisor-csr-names.s b/llvm/test/MC/RISCV/rv32-hypervisor-csr-names.s
--- a/llvm/test/MC/RISCV/rv32-hypervisor-csr-names.s
+++ b/llvm/test/MC/RISCV/rv32-hypervisor-csr-names.s
@@ -117,3 +117,105 @@
 csrrs t1, hstateen3h, zero
 # uimm12
 csrrs t2, 0x61F, zero
+
+#########################################
+# Advanced Interrupt Architecture (Smaia and Ssaia)
+#########################################
+
+# hidelegh
+# name
+# CHECK-INST: csrrs t1, hidelegh, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x30,0x61]
+# CHECK-INST-ALIAS: csrr t1, hidelegh
+# uimm12
+# CHECK-INST: csrrs t2, hidelegh, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x30,0x61]
+# CHECK-INST-ALIAS: csrr t2, hidelegh
+# name
+csrrs t1, hidelegh, zero
+# uimm12
+csrrs t2, 0x613, zero
+
+# hvienh
+# name
+# CHECK-INST: csrrs t1, hvienh, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x80,0x61]
+# CHECK-INST-ALIAS: csrr t1, hvienh
+# uimm12
+# CHECK-INST: csrrs t2, hvienh, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x80,0x61]
+# CHECK-INST-ALIAS: csrr t2, hvienh
+# name
+csrrs t1, hvienh, zero
+# uimm12
+csrrs t2, 0x618, zero
+
+# hviph
+# name
+# CHECK-INST: csrrs t1, hviph, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x50,0x65]
+# CHECK-INST-ALIAS: csrr t1, hviph
+# uimm12
+# CHECK-INST: csrrs t2, hviph, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x50,0x65]
+# CHECK-INST-ALIAS: csrr t2, hviph
+# name
+csrrs t1, hviph, zero
+# uimm12
+csrrs t2, 0x655, zero
+
+# hviprio1h
+# name
+# CHECK-INST: csrrs t1, hviprio1h, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x60,0x65]
+# CHECK-INST-ALIAS: csrr t1, hviprio1h
+# uimm12
+# CHECK-INST: csrrs t2, hviprio1h, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x60,0x65]
+# CHECK-INST-ALIAS: csrr t2, hviprio1h
+# name
+csrrs t1, hviprio1h, zero
+# uimm12
+csrrs t2, 0x656, zero
+
+# hviprio2h
+# name
+# CHECK-INST: csrrs t1, hviprio2h, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x70,0x65]
+# CHECK-INST-ALIAS: csrr t1, hviprio2h
+# uimm12
+# CHECK-INST: csrrs t2, hviprio2h, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x70,0x65]
+# CHECK-INST-ALIAS: csrr t2, hviprio2h
+# name
+csrrs t1, hviprio2h, zero
+# uimm12
+csrrs t2, 0x657, zero
+
+# vsieh
+# name
+# CHECK-INST: csrrs t1, vsieh, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x40,0x21]
+# CHECK-INST-ALIAS: csrr t1, vsieh
+# uimm12
+# CHECK-INST: csrrs t2, vsieh, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x40,0x21]
+# CHECK-INST-ALIAS: csrr t2, vsieh
+# name
+csrrs t1, vsieh, zero
+# uimm12
+csrrs t2, 0x214, zero
+
+# vsiph
+# name
+# CHECK-INST: csrrs t1, vsiph, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x40,0x25]
+# CHECK-INST-ALIAS: csrr t1, vsiph
+# uimm12
+# CHECK-INST: csrrs t2, vsiph, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x40,0x25]
+# CHECK-INST-ALIAS: csrr t2, vsiph
+# name
+csrrs t1, vsiph, zero
+# uimm12
+csrrs t2, 0x254, zero
diff --git a/llvm/test/MC/RISCV/rv32-machine-csr-names.s b/llvm/test/MC/RISCV/rv32-machine-csr-names.s
--- a/llvm/test/MC/RISCV/rv32-machine-csr-names.s
+++ b/llvm/test/MC/RISCV/rv32-machine-csr-names.s
@@ -1075,3 +1075,77 @@
 csrrs t1, mstateen3h, zero
 # uimm12
 csrrs t2, 0x31F, zero
+
+#########################################
+# Advanced Interrupt Architecture (Smaia and Ssaia)
+#########################################
+
+# midelegh
+# name
+# CHECK-INST: csrrs t1, midelegh, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x30,0x31]
+# CHECK-INST-ALIAS: csrr t1, midelegh
+# uimm12
+# CHECK-INST: csrrs t2, midelegh, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x30,0x31]
+# CHECK-INST-ALIAS: csrr t2, midelegh
+# name
+csrrs t1, midelegh, zero
+# uimm12
+csrrs t2, 0x313, zero
+
+# mieh
+# name
+# CHECK-INST: csrrs t1, mieh, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x40,0x31]
+# CHECK-INST-ALIAS: csrr t1, mieh
+# uimm12
+# CHECK-INST: csrrs t2, mieh, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x40,0x31]
+# CHECK-INST-ALIAS: csrr t2, mieh
+# name
+csrrs t1, mieh, zero
+# uimm12
+csrrs t2, 0x314, zero
+
+# mvienh
+# name
+# CHECK-INST: csrrs t1, mvienh, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x80,0x31]
+# CHECK-INST-ALIAS: csrr t1, mvienh
+# uimm12
+# CHECK-INST: csrrs t2, mvienh, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x80,0x31]
+# CHECK-INST-ALIAS: csrr t2, mvienh
+# name
+csrrs t1, mvienh, zero
+# uimm12
+csrrs t2, 0x318, zero
+
+# mviph
+# name
+# CHECK-INST: csrrs t1, mviph, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x90,0x31]
+# CHECK-INST-ALIAS: csrr t1, mviph
+# uimm12
+# CHECK-INST: csrrs t2, mviph, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x90,0x31]
+# CHECK-INST-ALIAS: csrr t2, mviph
+# name
+csrrs t1, mviph, zero
+# uimm12
+csrrs t2, 0x319, zero
+
+# miph
+# name
+# CHECK-INST: csrrs t1, miph, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x40,0x35]
+# CHECK-INST-ALIAS: csrr t1, miph
+# uimm12
+# CHECK-INST: csrrs t2, miph, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x40,0x35]
+# CHECK-INST-ALIAS: csrr t2, miph
+# name
+csrrs t1, miph, zero
+# uimm12
+csrrs t2, 0x354, zero
diff --git a/llvm/test/MC/RISCV/rv32-only-csr-names.s b/llvm/test/MC/RISCV/rv32-only-csr-names.s
--- a/llvm/test/MC/RISCV/rv32-only-csr-names.s
+++ b/llvm/test/MC/RISCV/rv32-only-csr-names.s
@@ -131,3 +131,18 @@
 
 csrrs t1, stimecmph, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system register use requires an option to be enabled
 csrrs t1, vstimecmph, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system register use requires an option to be enabled
+
+csrrs t1, midelegh, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system register use requires an option to be enabled
+csrrs t1, mieh, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system register use requires an option to be enabled
+csrrs t1, mvienh, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system register use requires an option to be enabled
+csrrs t1, mviph, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system register use requires an option to be enabled
+csrrs t1, miph, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system register use requires an option to be enabled
+csrrs t1, sieh, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system register use requires an option to be enabled
+csrrs t1, siph, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system register use requires an option to be enabled
+csrrs t1, hidelegh, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system register use requires an option to be enabled
+csrrs t1, hvienh, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system register use requires an option to be enabled
+csrrs t1, hviph, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system register use requires an option to be enabled
+csrrs t1, hviprio1h, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system register use requires an option to be enabled
+csrrs t1, hviprio2h, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system register use requires an option to be enabled
+csrrs t1, vsieh, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system register use requires an option to be enabled
+csrrs t1, vsiph, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system register use requires an option to be enabled
diff --git a/llvm/test/MC/RISCV/rv32-supervisor-csr-names.s b/llvm/test/MC/RISCV/rv32-supervisor-csr-names.s
--- a/llvm/test/MC/RISCV/rv32-supervisor-csr-names.s
+++ b/llvm/test/MC/RISCV/rv32-supervisor-csr-names.s
@@ -21,3 +21,35 @@
 csrrs t1, stimecmph, zero
 # uimm12
 csrrs t2, 0x15D, zero
+
+#########################################
+# Advanced Interrupt Architecture (Smaia and Ssaia)
+#########################################
+
+# sieh
+# name
+# CHECK-INST: csrrs t1, sieh, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x40,0x11]
+# CHECK-INST-ALIAS: csrr t1, sieh
+# uimm12
+# CHECK-INST: csrrs t2, sieh, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x40,0x11]
+# CHECK-INST-ALIAS: csrr t2, sieh
+# name
+csrrs t1, sieh, zero
+# uimm12
+csrrs t2, 0x114, zero
+
+# siph
+# name
+# CHECK-INST: csrrs t1, siph, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x40,0x15]
+# CHECK-INST-ALIAS: csrr t1, siph
+# uimm12
+# CHECK-INST: csrrs t2, siph, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x40,0x15]
+# CHECK-INST-ALIAS: csrr t2, siph
+# name
+csrrs t1, siph, zero
+# uimm12
+csrrs t2, 0x154, zero
diff --git a/llvm/test/MC/RISCV/rvi-aliases-valid.s b/llvm/test/MC/RISCV/rvi-aliases-valid.s
--- a/llvm/test/MC/RISCV/rvi-aliases-valid.s
+++ b/llvm/test/MC/RISCV/rvi-aliases-valid.s
@@ -207,8 +207,8 @@
 # CHECK-S-OBJ: rdtime s9
 rdtime x25
 
-# CHECK-S-OBJ-NOALIAS: csrrs  s0, 336, zero
-# CHECK-S-OBJ: csrr s0, 336
+# CHECK-S-OBJ-NOALIAS: csrrs s0, siselect, zero
+# CHECK-S-OBJ: csrr s0, siselect
 csrr x8, 0x150
 # CHECK-S-OBJ-NOALIAS: csrrw zero, sscratch, s1
 # CHECK-S-OBJ: csrw sscratch, s1
@@ -220,8 +220,8 @@
 # CHECK-S-OBJ: csrc 4095, s7
 csrc 0xfff, x23
 
-# CHECK-S-OBJ-NOALIAS: csrrwi zero, 336, 15
-# CHECK-S-OBJ: csrwi 336, 15
+# CHECK-S-OBJ-NOALIAS: csrrwi zero, siselect, 15
+# CHECK-S-OBJ: csrwi siselect, 15
 csrwi 0x150, 0xf
 # CHECK-S-OBJ-NOALIAS: csrrsi zero, 4095, 16
 # CHECK-S-OBJ: csrsi 4095, 16
@@ -230,18 +230,18 @@
 # CHECK-S-OBJ: csrci sscratch, 17
 csrci 0x140, 0x11
 
-# CHECK-S-OBJ-NOALIAS: csrrwi zero, 336, 7
-# CHECK-S-OBJ: csrwi 336, 7
+# CHECK-S-OBJ-NOALIAS: csrrwi zero, siselect, 7
+# CHECK-S-OBJ: csrwi siselect, 7
 csrw 0x150, 7
-# CHECK-S-OBJ-NOALIAS: csrrsi zero, 336, 7
-# CHECK-S-OBJ: csrsi 336, 7
+# CHECK-S-OBJ-NOALIAS: csrrsi zero, siselect, 7
+# CHECK-S-OBJ: csrsi siselect, 7
 csrs 0x150, 7
-# CHECK-S-OBJ-NOALIAS: csrrci zero, 336, 7
-# CHECK-S-OBJ: csrci 336, 7
+# CHECK-S-OBJ-NOALIAS: csrrci zero, siselect, 7
+# CHECK-S-OBJ: csrci siselect, 7
 csrc 0x150, 7
 
-# CHECK-S-OBJ-NOALIAS: csrrwi t0, 336, 15
-# CHECK-S-OBJ: csrrwi t0, 336, 15
+# CHECK-S-OBJ-NOALIAS: csrrwi t0, siselect, 15
+# CHECK-S-OBJ: csrrwi t0, siselect, 15
 csrrw t0, 0x150, 0xf
 # CHECK-S-OBJ-NOALIAS: csrrsi t0, 4095, 16
 # CHECK-S-OBJ: csrrsi t0, 4095, 16
diff --git a/llvm/test/MC/RISCV/supervisor-csr-names.s b/llvm/test/MC/RISCV/supervisor-csr-names.s
--- a/llvm/test/MC/RISCV/supervisor-csr-names.s
+++ b/llvm/test/MC/RISCV/supervisor-csr-names.s
@@ -319,3 +319,63 @@
 csrrs t1, sstateen3, zero
 # uimm12
 csrrs t2, 0x10F, zero
+
+#########################################
+# Advanced Interrupt Architecture (Smaia and Ssaia)
+#########################################
+
+# siselect
+# name
+# CHECK-INST: csrrs t1, siselect, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x00,0x15]
+# CHECK-INST-ALIAS: csrr t1, siselect
+# uimm12
+# CHECK-INST: csrrs t2, siselect, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x00,0x15]
+# CHECK-INST-ALIAS: csrr t2, siselect
+# name
+csrrs t1, siselect, zero
+# uimm12
+csrrs t2, 0x150, zero
+
+# sireg
+# name
+# CHECK-INST: csrrs t1, sireg, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x10,0x15]
+# CHECK-INST-ALIAS: csrr t1, sireg
+# uimm12
+# CHECK-INST: csrrs t2, sireg, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x10,0x15]
+# CHECK-INST-ALIAS: csrr t2, sireg
+# name
+csrrs t1, sireg, zero
+# uimm12
+csrrs t2, 0x151, zero
+
+# stopei
+# name
+# CHECK-INST: csrrs t1, stopei, zero
+# CHECK-ENC: encoding: [0x73,0x23,0xc0,0x15]
+# CHECK-INST-ALIAS: csrr t1, stopei
+# uimm12
+# CHECK-INST: csrrs t2, stopei, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0xc0,0x15]
+# CHECK-INST-ALIAS: csrr t2, stopei
+# name
+csrrs t1, stopei, zero
+# uimm12
+csrrs t2, 0x15C, zero
+
+# stopi
+# name
+# CHECK-INST: csrrs t1, stopi, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x00,0xdb]
+# CHECK-INST-ALIAS: csrr t1, stopi
+# uimm12
+# CHECK-INST: csrrs t2, stopi, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x00,0xdb]
+# CHECK-INST-ALIAS: csrr t2, stopi
+# name
+csrrs t1, stopi, zero
+# uimm12
+csrrs t2, 0xDB0, zero