[RISCV] Support [mh]edelegh CSRs (#121634)

These RV32-only CSRs are defined in privileged spec v1.13.

Author: dong-miao

llvm/lib/Target/RISCV/RISCVSystemOperands.td

@@ -157,6 +157,8 @@ def : SysReg<"hideleg", 0x603>;
 def : SysReg<"hie", 0x604>;
 def : SysReg<"hcounteren", 0x606>;
 def : SysReg<"hgeie", 0x607>;
+let isRV32Only = 1 in
+def : SysReg<"hedelegh", 0x612>;
 
 //===----------------------------------------------------------------------===//
 // Hypervisor Trap Handling
@@ -233,8 +235,10 @@ def : SysReg<"mideleg", 0x303>;
 def : SysReg<"mie", 0x304>;
 def : SysReg<"mtvec", 0x305>;
 def : SysReg<"mcounteren", 0x306>;
-let isRV32Only = 1 in
+let isRV32Only = 1 in {
 def : SysReg<"mstatush", 0x310>;
+def : SysReg<"medelegh", 0x312>;
+} // isRV32Only
 
 //===----------------------------------------------------------------------===//
 // Machine Trap Handling

llvm/test/MC/RISCV/rv32-hypervisor-csr-names.s

@@ -219,3 +219,21 @@ csrrs t2, 0x214, zero
 csrrs t1, vsiph, zero
 # uimm12
 csrrs t2, 0x254, zero
+
+##################################
+# Hypervisor Trap Setup
+##################################
+
+# hedelegh
+# name
+# CHECK-INST: csrrs t1, hedelegh, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x20,0x61]
+# CHECK-INST-ALIAS: csrr t1, hedelegh
+# uimm12
+# CHECK-INST: csrrs t2, hedelegh, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x20,0x61]
+# CHECK-INST-ALIAS: csrr t2, hedelegh
+# name
+csrrs t1, hedelegh, zero
+# uimm12
+csrrs t2, 0x612, zero

llvm/test/MC/RISCV/rv32-machine-csr-names.s

@@ -22,6 +22,20 @@ csrrs t1, mstatush, zero
 # uimm12
 csrrs t2, 0x310, zero
 
+# medelegh
+# name
+# CHECK-INST: csrrs t1, medelegh, zero
+# CHECK-ENC: encoding: [0x73,0x23,0x20,0x31]
+# CHECK-INST-ALIAS: csrr t1, medelegh
+# uimm12
+# CHECK-INST: csrrs t2, medelegh, zero
+# CHECK-ENC: encoding: [0xf3,0x23,0x20,0x31]
+# CHECK-INST-ALIAS: csrr t2, medelegh
+# name
+csrrs t1, medelegh, zero
+# uimm12
+csrrs t2, 0x312, zero
+
 #########################
 # Machine Configuration
 #########################

llvm/test/MC/RISCV/rv32-only-csr-names.s

@@ -41,12 +41,16 @@ csrrs t1, henvcfgh, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system registe
 
 csrrs t1, htimedeltah, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system register 'htimedeltah' is RV32 only
 
+csrrs t1, hedelegh, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system register 'hedelegh' is RV32 only
+
 csrrs t1, mstatush, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system register 'mstatush' is RV32 only
 
 csrrs t1, menvcfgh, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system register 'menvcfgh' is RV32 only
 
 csrrs t1, mseccfgh, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system register 'mseccfgh' is RV32 only
 
+csrrs t1, medelegh, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system register 'medelegh' is RV32 only
+
 csrrs t1, pmpcfg1, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system register 'pmpcfg1' is RV32 only
 csrrs t1, pmpcfg3, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system register 'pmpcfg3' is RV32 only
 csrrs t1, pmpcfg5, zero # CHECK-NEED-RV32: :[[@LINE]]:11: error: system register 'pmpcfg5' is RV32 only