[CHERI-RISC-V] Default to emitting compressed CHERI instructions

Both hardware implementations and QEMU have supported these for a long
time, so it makes sense for the compiler to default to emitting them if
the "C" extension is enabled. This retains the flags that were used to
enable the instructions but turns them into an opt-out flag instead.
Once the exact impact of compressed CHERI instructions has been evaluated,
these command line options and the SubtargetFeature can be removed.

See CTSRD-CHERI#681

clang/include/clang/Driver/Options.td

@@ -3389,10 +3389,14 @@ def mcmodel_EQ_medany : Flag<["-"], "mcmodel=medany">, Group<m_riscv_Features_Gr
   HelpText<"Equivalent to -mcmodel=medium, compatible with RISC-V gcc.">;
 def menable_experimental_extensions : Flag<["-"], "menable-experimental-extensions">, Group<m_Group>,
   HelpText<"Enable use of experimental RISC-V extensions.">;
-def mxcheri_rvc : Flag<["-"], "mxcheri-rvc">, Group<m_riscv_Features_Group>,
-  HelpText<"Enable using compressed CHERI instructions">;
-def mno_xcheri_rvc : Flag<["-"], "mno-xcheri-rvc">, Group<m_riscv_Features_Group>,
+// TODO: Remove these options (https://github.com/CTSRD-CHERI/llvm-project/issues/681)
+def mxcheri_norvc : Flag<["-"], "mxcheri-norvc">, Group<m_riscv_Features_Group>,
   HelpText<"Disable using compressed CHERI instructions">;
+def mno_xcheri_rvc : Flag<["-"], "mno-xcheri-rvc">, Alias<mxcheri_norvc>;
+// Positive (i.e. double negated) flag for backwards compatibility/consistency.
+def mno_xcheri_norvc : Flag<["-"], "mno-xcheri-norvc">, Group<m_riscv_Features_Group>,
+  HelpText<"Enable using compressed CHERI instructions">;
+def mxcheri_rvc : Flag<["-"], "mxcheri-rvc">, Alias<mno_xcheri_norvc>;
 
 def munaligned_access : Flag<["-"], "munaligned-access">, Group<m_arm_Features_Group>,
   HelpText<"Allow memory accesses to be unaligned (AArch32/AArch64 only)">;

clang/test/CodeGen/cheri/riscv/riscv-default-ir-features.c

@@ -8,37 +8,37 @@
 // RUN: %clang --target=riscv64 -march=rv64ixcheri -S -emit-llvm %s -o - \
 // RUN:   | FileCheck %s --check-prefixes=CHECK,RV64-XCHERI '-DFEATURES=+64bit,+relax,+xcheri,-save-restore'
 // RUN: %clang --target=riscv32 -march=rv32ixcheri -S -mxcheri-rvc -emit-llvm %s -o - \
-// RUN:   | FileCheck %s --check-prefixes=CHECK,RV32-XCHERI '-DFEATURES=+relax,+xcheri,+xcheri-rvc,-save-restore'
+// RUN:   | FileCheck %s --check-prefixes=CHECK,RV32-XCHERI '-DFEATURES=+relax,+xcheri,-save-restore,-xcheri-norvc'
 // RUN: %clang --target=riscv64 -march=rv64ixcheri -S -mxcheri-rvc -emit-llvm %s -o - \
-// RUN:   | FileCheck %s --check-prefixes=CHECK,RV64-XCHERI '-DFEATURES=+64bit,+relax,+xcheri,+xcheri-rvc,-save-restore'
+// RUN:   | FileCheck %s --check-prefixes=CHECK,RV64-XCHERI '-DFEATURES=+64bit,+relax,+xcheri,-save-restore,-xcheri-norvc'
 // RUN: %clang --target=riscv32 -march=rv32ixcheri -S -mno-xcheri-rvc -emit-llvm %s -o - \
-// RUN:   | FileCheck %s --check-prefixes=CHECK,RV32-XCHERI '-DFEATURES=+relax,+xcheri,-save-restore,-xcheri-rvc'
+// RUN:   | FileCheck %s --check-prefixes=CHECK,RV32-XCHERI '-DFEATURES=+relax,+xcheri,+xcheri-norvc,-save-restore'
 // RUN: %clang --target=riscv64 -march=rv64ixcheri -S -mno-xcheri-rvc -emit-llvm %s -o - \
-// RUN:   | FileCheck %s --check-prefixes=CHECK,RV64-XCHERI '-DFEATURES=+64bit,+relax,+xcheri,-save-restore,-xcheri-rvc'
+// RUN:   | FileCheck %s --check-prefixes=CHECK,RV64-XCHERI '-DFEATURES=+64bit,+relax,+xcheri,+xcheri-norvc,-save-restore'
 
 /// Same checks for purecap
 // RUN: %clang --target=riscv32 -march=rv32ixcheri -mabi=il32pc64 -S -emit-llvm %s -o - \
 // RUN:   | FileCheck %s --check-prefixes=CHECK,RV32-XCHERI-PURECAP '-DFEATURES=+cap-mode,+relax,+xcheri,-save-restore'
 // RUN: %clang --target=riscv64 -march=rv64ixcheri -mabi=l64pc128 -S -emit-llvm %s -o - \
 // RUN:   | FileCheck %s --check-prefixes=CHECK,RV64-XCHERI-PURECAP '-DFEATURES=+64bit,+cap-mode,+relax,+xcheri,-save-restore'
 // RUN: %clang --target=riscv32 -march=rv32ixcheri -mabi=il32pc64 -S -mxcheri-rvc -emit-llvm %s -o - \
-// RUN:   | FileCheck %s --check-prefixes=CHECK,RV32-XCHERI-PURECAP '-DFEATURES=+cap-mode,+relax,+xcheri,+xcheri-rvc,-save-restore'
+// RUN:   | FileCheck %s --check-prefixes=CHECK,RV32-XCHERI-PURECAP '-DFEATURES=+cap-mode,+relax,+xcheri,-save-restore,-xcheri-norvc'
 // RUN: %clang --target=riscv64 -march=rv64ixcheri -mabi=l64pc128 -S -mxcheri-rvc -emit-llvm %s -o - \
-// RUN:    | FileCheck %s --check-prefixes=CHECK,RV64-XCHERI-PURECAP '-DFEATURES=+64bit,+cap-mode,+relax,+xcheri,+xcheri-rvc,-save-restore'
+// RUN:    | FileCheck %s --check-prefixes=CHECK,RV64-XCHERI-PURECAP '-DFEATURES=+64bit,+cap-mode,+relax,+xcheri,-save-restore,-xcheri-norvc'
 // RUN: %clang --target=riscv32 -march=rv32ixcheri -mabi=il32pc64 -S -mno-xcheri-rvc -emit-llvm %s -o - \
-// RUN:    | FileCheck %s --check-prefixes=CHECK,RV32-XCHERI-PURECAP '-DFEATURES=+cap-mode,+relax,+xcheri,-save-restore,-xcheri-rvc'
+// RUN:    | FileCheck %s --check-prefixes=CHECK,RV32-XCHERI-PURECAP '-DFEATURES=+cap-mode,+relax,+xcheri,+xcheri-norvc,-save-restore'
 // RUN: %clang --target=riscv64 -march=rv64ixcheri -mabi=l64pc128 -S -mno-xcheri-rvc -emit-llvm %s -o - \
-// RUN:   | FileCheck %s --check-prefixes=CHECK,RV64-XCHERI-PURECAP '-DFEATURES=+64bit,+cap-mode,+relax,+xcheri,-save-restore,-xcheri-rvc'
+// RUN:   | FileCheck %s --check-prefixes=CHECK,RV64-XCHERI-PURECAP '-DFEATURES=+64bit,+cap-mode,+relax,+xcheri,+xcheri-norvc,-save-restore'
 
-/// Enabling -mxcheri-rvc with a non-CHERI triple shouldn't enable the CHERI datalayout
-// RUN: %clang --target=riscv32 -mxcheri-rvc -S -emit-llvm %s -o - \
-// RUN:   | FileCheck %s --check-prefixes=CHECK,RV32-NOCHERI '-DFEATURES=+a,+c,+m,+relax,+xcheri-rvc,-save-restore'
-// RUN: %clang --target=riscv64 -mxcheri-rvc -S -emit-llvm %s -o - \
-// RUN:   | FileCheck %s --check-prefixes=CHECK,RV64-NOCHERI '-DFEATURES=+64bit,+a,+c,+m,+relax,+xcheri-rvc,-save-restore'
-// RUN: %clang --target=riscv32 -mno-xcheri-rvc -S -emit-llvm %s -o - \
-// RUN:   | FileCheck %s --check-prefixes=CHECK,RV32-NOCHERI '-DFEATURES=+a,+c,+m,+relax,-save-restore,-xcheri-rvc'
-// RUN: %clang --target=riscv64 -mno-xcheri-rvc -S -emit-llvm %s -o - \
-// RUN:   | FileCheck %s --check-prefixes=CHECK,RV64-NOCHERI '-DFEATURES=+64bit,+a,+c,+m,+relax,-save-restore,-xcheri-rvc'
+/// Enabling -mxcheri-norvc with a non-CHERI triple shouldn't enable the CHERI datalayout
+// RUN: %clang --target=riscv32 -mxcheri-norvc -S -emit-llvm %s -o - \
+// RUN:   | FileCheck %s --check-prefixes=CHECK,RV32-NOCHERI '-DFEATURES=+a,+c,+m,+relax,+xcheri-norvc,-save-restore'
+// RUN: %clang --target=riscv64 -mxcheri-norvc -S -emit-llvm %s -o - \
+// RUN:   | FileCheck %s --check-prefixes=CHECK,RV64-NOCHERI '-DFEATURES=+64bit,+a,+c,+m,+relax,+xcheri-norvc,-save-restore'
+// RUN: %clang --target=riscv32 -mno-xcheri-norvc -S -emit-llvm %s -o - \
+// RUN:   | FileCheck %s --check-prefixes=CHECK,RV32-NOCHERI '-DFEATURES=+a,+c,+m,+relax,-save-restore,-xcheri-norvc'
+// RUN: %clang --target=riscv64 -mno-xcheri-norvc -S -emit-llvm %s -o - \
+// RUN:   | FileCheck %s --check-prefixes=CHECK,RV64-NOCHERI '-DFEATURES=+64bit,+a,+c,+m,+relax,-save-restore,-xcheri-norvc'
 
 // RV32-NOCHERI: target datalayout = "e-m:e-p:32:32-i64:64-n32-S128"
 // RV64-NOCHERI: target datalayout = "e-m:e-p:64:64-i64:64-i128:128-n64-S128"

clang/test/Driver/riscv-default-features.c

@@ -3,21 +3,28 @@
 
 // RUN: %clang --target=riscv32-unknown-elf -march=rv32ixcheri -S -emit-llvm %s -o - | FileCheck %s -check-prefix=RV32-XCHERI
 // RUN: %clang --target=riscv64-unknown-elf -march=rv64ixcheri -S -emit-llvm %s -o - | FileCheck %s -check-prefix=RV64-XCHERI
-// RUN: %clang --target=riscv32-unknown-elf -march=rv32ixcheri -S -mxcheri-rvc -emit-llvm %s -o - | FileCheck %s -check-prefix=RV32-XCHERI-RVC
-// RUN: %clang --target=riscv64-unknown-elf -march=rv64ixcheri -S -mxcheri-rvc -emit-llvm %s -o - | FileCheck %s -check-prefix=RV64-XCHERI-RVC
 // RUN: %clang --target=riscv32-unknown-elf -march=rv32ixcheri -S -mno-xcheri-rvc -emit-llvm %s -o - | FileCheck %s -check-prefix=RV32-XCHERI-NORVC
 // RUN: %clang --target=riscv64-unknown-elf -march=rv64ixcheri -S -mno-xcheri-rvc -emit-llvm %s -o - | FileCheck %s -check-prefix=RV64-XCHERI-NORVC
+// RUN: %clang --target=riscv32-unknown-elf -march=rv32ixcheri -S -mxcheri-norvc -emit-llvm %s -o - | FileCheck %s -check-prefix=RV32-XCHERI-NORVC
+// RUN: %clang --target=riscv64-unknown-elf -march=rv64ixcheri -S -mxcheri-norvc -emit-llvm %s -o - | FileCheck %s -check-prefix=RV64-XCHERI-NORVC
+// The -mxcheri-rvc flag to explicitly disable xcheri-norvc:
+// RUN: %clang --target=riscv32-unknown-elf -march=rv32ixcheri -S -mxcheri-rvc -emit-llvm %s -o - | FileCheck %s -check-prefix=RV32-XCHERI-EXPLICIT-RVC
+// RUN: %clang --target=riscv64-unknown-elf -march=rv64ixcheri -S -mxcheri-rvc -emit-llvm %s -o - | FileCheck %s -check-prefix=RV64-XCHERI-EXPLICIT-RVC
+// RUN: %clang --target=riscv32-unknown-elf -march=rv32ixcheri -S -mno-xcheri-norvc -emit-llvm %s -o - | FileCheck %s -check-prefix=RV32-XCHERI-EXPLICIT-RVC
+// RUN: %clang --target=riscv64-unknown-elf -march=rv64ixcheri -S -mno-xcheri-norvc -emit-llvm %s -o - | FileCheck %s -check-prefix=RV64-XCHERI-EXPLICIT-RVC
 
 // RV32: "target-features"="+a,+c,+m,+relax,-save-restore"
 // RV64: "target-features"="+64bit,+a,+c,+m,+relax,-save-restore"
 
 // RV32-XCHERI: "target-features"="+relax,+xcheri,-save-restore"
 // RV64-XCHERI: "target-features"="+64bit,+relax,+xcheri,-save-restore"
 
-// RV32-XCHERI-RVC: "target-features"="+relax,+xcheri,+xcheri-rvc,-save-restore"
-// RV64-XCHERI-RVC: "target-features"="+64bit,+relax,+xcheri,+xcheri-rvc,-save-restore"
-// RV32-XCHERI-NORVC: "target-features"="+relax,+xcheri,-save-restore,-xcheri-rvc"
-// RV64-XCHERI-NORVC: "target-features"="+64bit,+relax,+xcheri,-save-restore,-xcheri-rvc"
+// RV32-XCHERI-RVC: "target-features"="+relax,+xcheri,-save-restore"
+// RV64-XCHERI-RVC: "target-features"="+64bit,+relax,+xcheri,-save-restore"
+// RV32-XCHERI-NORVC: "target-features"="+relax,+xcheri,+xcheri-norvc,-save-restore"
+// RV64-XCHERI-NORVC: "target-features"="+64bit,+relax,+xcheri,+xcheri-norvc,-save-restore"
+// RV32-XCHERI-EXPLICIT-RVC: "target-features"="+relax,+xcheri,-save-restore,-xcheri-norvc"
+// RV64-XCHERI-EXPLICIT-RVC: "target-features"="+64bit,+relax,+xcheri,-save-restore,-xcheri-norvc"
 
 // Dummy function
 int foo(){

clang/test/Driver/riscv-features.c

@@ -21,13 +21,16 @@
 // DEFAULT: "-target-feature" "-save-restore"
 // DEFAULT-NOT: "-target-feature" "+save-restore"
 
-// RUN: %clang -target riscv32 -### %s -march=rv32ixcheri 2>&1 | FileCheck %s --check-prefixes=XCHERI,XCHERI-NORVC
-// RUN: %clang -target riscv64 -### %s -march=rv64ixcheri 2>&1 | FileCheck %s --check-prefixes=XCHERI,XCHERI-NORVC
-// RUN: %clang -target riscv32-unknown-elf -### %s -march=rv64ixcheri -mxcheri-rvc 2>&1 | FileCheck %s --check-prefixes=XCHERI,XCHERI-RVC
+// RUN: %clang -target riscv32 -### %s -march=rv32ixcheri 2>&1 | FileCheck %s --check-prefixes=XCHERI
+// RUN: %clang -target riscv64 -### %s -march=rv64ixcheri 2>&1 | FileCheck %s --check-prefixes=XCHERI
+// RUN: %clang -target riscv32-unknown-elf -### %s -march=rv64ixcheri -mxcheri-rvc 2>&1 | FileCheck %s --check-prefixes=XCHERI,XCHERI-EXPLICIT-RVC
+// RUN: %clang -target riscv32-unknown-elf -### %s -march=rv64ixcheri -mxcheri-norvc 2>&1 | FileCheck %s --check-prefixes=XCHERI,XCHERI-NORVC
 // RUN: %clang -target riscv32-unknown-elf -### %s -march=rv64ixcheri -mno-xcheri-rvc 2>&1 | FileCheck %s --check-prefixes=XCHERI,XCHERI-NORVC
 // XCHERI: "-target-feature" "+xcheri"
-// XCHERI-RVC: "-target-feature" "+xcheri-rvc"
-// XCHERI-NORVC: "-target-feature" "-xcheri-rvc"
+// XCHERI-NOT: "{{[+|-]}}xcheri-
+// XCHERI-EXPLICIT-RVC: "-target-feature" "-xcheri-norvc"
+// XCHERI-NORVC: "-target-feature" "+xcheri-norvc"
+// XCHERI-NOT: "{{[+|-]}}xcheri-
 
 // RUN: %clang -target riscv32-linux -### %s -fsyntax-only 2>&1 \
 // RUN:   | FileCheck %s -check-prefix=DEFAULT-LINUX

llvm/lib/Object/ELFObjectFile.cpp

@@ -306,7 +306,6 @@ SubtargetFeatures ELFObjectFileBase::getRISCVFeatures() const {
 
   if (PlatformFlags & ELF::EF_RISCV_CAP_MODE) {
     Features.AddFeature("xcheri");
-    Features.AddFeature("xcheri-rvc");
     Features.AddFeature("cap-mode");
   }
 

llvm/lib/Target/RISCV/RISCV.td

@@ -375,11 +375,11 @@ def FeatureCheri
 def HasCheri : Predicate<"Subtarget->hasCheri()">,
                          AssemblerPredicate<(all_of FeatureCheri),
                          "CHERI Extension">;
-def FeatureCheriRVC
-    : SubtargetFeature<"xcheri-rvc", "EnableCheriRVCInstrs", "true",
-                       "Enable CHERI RVC Instructions.">;
+def FeatureCheriNoRVC
+    : SubtargetFeature<"xcheri-norvc", "EnableCheriRVCInstrs", "false",
+                       "Disable CHERI RVC Instructions.">;
 def HasCheriRVC : Predicate<"Subtarget->enableCheriRVCInstrs()">,
-                  AssemblerPredicate<(all_of FeatureCheriRVC),
+                  AssemblerPredicate<(all_of (not FeatureCheriNoRVC)),
                                      "CHERI RVC Instructions">;
 
 def FeatureCapMode

llvm/lib/Target/RISCV/RISCVSubtarget.h

@@ -103,7 +103,7 @@ class RISCVSubtarget : public RISCVGenSubtargetInfo {
   bool IsCapMode = false;
   bool EnableLinkerRelax = false;
   bool EnableRVCHintInstrs = true;
-  bool EnableCheriRVCInstrs = false;
+  bool EnableCheriRVCInstrs = true;
   bool EnableSaveRestore = false;
   unsigned XLen = 32;
   ExtZvl ZvlLen = ExtZvl::NotSet;

llvm/test/CodeGen/RISCV/cheri/compress.ll

@@ -4,23 +4,23 @@
 ;
 ; RUN: cat %s > %t.tgtattr
 ; RUN: echo 'attributes #0 = { nounwind }' >> %t.tgtattr
-; RUN: %riscv32_cheri_purecap_llc -mattr=+c,+xcheri,+cap-mode,+xcheri-rvc -filetype=obj < %t.tgtattr \
-; RUN:   | llvm-objdump -d -M no-aliases - | FileCheck %s
-; RUN: %riscv64_cheri_purecap_llc -mattr=+c,+xcheri,+cap-mode,+xcheri-rvc -filetype=obj < %t.tgtattr \
+; RUN: %riscv32_cheri_purecap_llc -mattr=+c,+xcheri,+cap-mode -filetype=obj < %t.tgtattr \
 ; RUN:   | llvm-objdump -d -M no-aliases - | FileCheck %s
 ; RUN: %riscv64_cheri_purecap_llc -mattr=+c,+xcheri,+cap-mode -filetype=obj < %t.tgtattr \
+; RUN:   | llvm-objdump -d -M no-aliases - | FileCheck %s
+; RUN: %riscv64_cheri_purecap_llc -mattr=+c,+xcheri,+cap-mode,+xcheri-norvc -filetype=obj < %t.tgtattr \
 ; RUN:   | llvm-objdump -d -M no-aliases - | FileCheck %s --check-prefix=CHECK-NORVC
 
 ; RUN: cat %s > %t.fnattr
-; RUN: echo 'attributes #0 = { nounwind "target-features"="+c,+xcheri,+cap-mode,+xcheri-rvc" }' >> %t.fnattr
+; RUN: echo 'attributes #0 = { nounwind "target-features"="+c,+xcheri,+cap-mode" }' >> %t.fnattr
 ; RUN: %riscv32_cheri_purecap_llc -filetype=obj < %t.fnattr \
-; RUN:   | llvm-objdump -d --mattr=+c,+xcheri-rvc -M no-aliases - | FileCheck %s
+; RUN:   | llvm-objdump -d --mattr=+c -M no-aliases - | FileCheck %s
 ; RUN: %riscv64_cheri_purecap_llc -filetype=obj < %t.fnattr \
-; RUN:   | llvm-objdump -d --mattr=+c,+xcheri-rvc -M no-aliases - | FileCheck %s
+; RUN:   | llvm-objdump -d --mattr=+c -M no-aliases - | FileCheck %s
 ; RUN: cat %s > %t.fnattr
-; RUN: echo 'attributes #0 = { nounwind "target-features"="+c,+xcheri,+cap-mode" }' >> %t.fnattr
+; RUN: echo 'attributes #0 = { nounwind "target-features"="+c,+xcheri,+cap-mode,+xcheri-norvc" }' >> %t.fnattr
 ; RUN: %riscv64_cheri_purecap_llc -filetype=obj < %t.fnattr \
-; RUN:   | llvm-objdump -d --mattr=+c,+xcheri-rvc -M no-aliases - | FileCheck %s --check-prefix=CHECK-NORVC
+; RUN:   | llvm-objdump -d --mattr=+c -M no-aliases - | FileCheck %s --check-prefix=CHECK-NORVC
 
 ; Basic check that we can use CHERI compressed instructions
 

llvm/test/MC/RISCV/cheri/rv32cxcheri-cap-mode-invalid.s

@@ -1,32 +1,32 @@
-# RUN: not llvm-mc -triple riscv32 -mattr=+c,+xcheri,+xcheri-rvc,+cap-mode -filetype=null -riscv-no-aliases -show-encoding < %s 2>&1 \
+# RUN: not llvm-mc -triple riscv32 -mattr=+c,+xcheri,+cap-mode -filetype=null -riscv-no-aliases -show-encoding < %s 2>&1 \
 # RUN:     | FileCheck %s --check-prefixes=CHECK,CHECK-RV32,CHECK-RV32-C --implicit-check-not="error:"
 # RUN: not llvm-mc -triple riscv32 -mattr=+xcheri,+cap-mode -filetype=null -riscv-no-aliases -show-encoding < %s 2>&1 \
 # RUN:     | FileCheck %s --check-prefixes=CHECK,CHECK-RV32,CHECK-RV32-NO-C --implicit-check-not="error:"
-# RUN: not llvm-mc -triple riscv64 -mattr=+c,+xcheri,+xcheri-rvc,+cap-mode -filetype=null -riscv-no-aliases -show-encoding < %s 2>&1\
+# RUN: not llvm-mc -triple riscv64 -mattr=+c,+xcheri,+cap-mode -filetype=null -riscv-no-aliases -show-encoding < %s 2>&1\
 # RUN:     | FileCheck %s --check-prefixes=CHECK,CHECK-RV64-C --implicit-check-not="error:"
 # RUN: not llvm-mc -triple riscv64 -mattr=+xcheri,+cap-mode -filetype=null -riscv-no-aliases -show-encoding < %s 2>&1 \
 # RUN:     | FileCheck %s --check-prefixes=CHECK,CHECK-RV64-NO-C --implicit-check-not="error:"
 
 ## C.JAL is only defined for RV32C:
 c.cjal 2046
 # CHECK-RV64-C: <stdin>:[[#@LINE-1]]:1: error: instruction requires the following: RV32I Base Instruction Set{{$}}
-# CHECK-RV32-NO-C: <stdin>:[[#@LINE-2]]:1: error: instruction requires the following: CHERI RVC Instructions, 'C' (Compressed Instructions){{$}}
-# CHECK-RV64-NO-C: <stdin>:[[#@LINE-3]]:1: error: instruction requires the following: CHERI RVC Instructions, 'C' (Compressed Instructions), RV32I Base Instruction Set{{$}}
+# CHECK-RV32-NO-C: <stdin>:[[#@LINE-2]]:1: error: instruction requires the following: 'C' (Compressed Instructions){{$}}
+# CHECK-RV64-NO-C: <stdin>:[[#@LINE-3]]:1: error: instruction requires the following: 'C' (Compressed Instructions), RV32I Base Instruction Set{{$}}
 
 ## C.CSD needs RV64C:
 c.csd a5, 124(ca3)
 # CHECK-RV32: <stdin>:[[#@LINE-1]]:11: error: invalid operand for instruction
 # CHECK-RV64-C: <stdin>:[[#@LINE-2]]:11: error: immediate must be a multiple of 8 bytes in the range [0, 248]
-# TODO-RV64-NO-C: <stdin>:[[#@LINE-3]]:11: error: instruction requires the following: CHERI RVC Instructions, 'C' (Compressed Instructions){{$}}
+# TODO-RV64-NO-C: <stdin>:[[#@LINE-3]]:11: error: instruction requires the following: 'C' (Compressed Instructions){{$}}
 # CHECK-RV64-NO-C: <stdin>:[[#@LINE-4]]:11: error: invalid operand for instruction
 
 ## misaligned immediate:
 c.csw a5, 1(ca3)
 # CHECK-RV32-C: <stdin>:[[#@LINE-1]]:11: error: immediate must be a multiple of 4 bytes in the range [0, 124]
-# TODO-RV32-NO-C: <stdin>:[[#@LINE-2]]:11: error: instruction requires the following: CHERI RVC Instructions, 'C' (Compressed Instructions){{$}}
+# TODO-RV32-NO-C: <stdin>:[[#@LINE-2]]:11: error: instruction requires the following: 'C' (Compressed Instructions){{$}}
 # CHECK-RV32-NO-C: <stdin>:[[#@LINE-3]]:11: error: invalid operand for instruction
 # CHECK-RV64-C: <stdin>:[[#@LINE-4]]:11: error: immediate must be a multiple of 4 bytes in the range [0, 124]
-# TODO-RV64-NO-C: <stdin>:[[#@LINE-5]]:11: error: instruction requires the following: CHERI RVC Instructions, 'C' (Compressed Instructions){{$}}
+# TODO-RV64-NO-C: <stdin>:[[#@LINE-5]]:11: error: instruction requires the following: 'C' (Compressed Instructions){{$}}
 # CHECK-RV64-NO-C: <stdin>:[[#@LINE-6]]:11: error: invalid operand for instruction
 
 # Bad operands:

llvm/test/MC/RISCV/cheri/rv32cxcheri-cap-mode-only-valid.s

@@ -1,7 +1,7 @@
-# RUN: llvm-mc %s -triple=riscv32 -mattr=+c,+xcheri,+xcheri-rvc,+cap-mode -riscv-no-aliases -show-encoding \
+# RUN: llvm-mc %s -triple=riscv32 -mattr=+c,+xcheri,+cap-mode -riscv-no-aliases -show-encoding \
 # RUN:     | FileCheck -check-prefixes=CHECK-ASM,CHECK-ASM-AND-OBJ %s
-# RUN: llvm-mc -filetype=obj -triple riscv32 -mattr=+c,+xcheri,+xcheri-rvc,+cap-mode < %s \
-# RUN:     | llvm-objdump -M no-aliases --mattr=+c,+xcheri,+xcheri-rvc,+cap-mode -d - \
+# RUN: llvm-mc -filetype=obj -triple riscv32 -mattr=+c,+xcheri,+cap-mode < %s \
+# RUN:     | llvm-objdump -M no-aliases --mattr=+c,+xcheri,+cap-mode -d - \
 # RUN:     | FileCheck -check-prefixes=CHECK-OBJ,CHECK-ASM-AND-OBJ %s
 
 ## Different encoding between RV64 and RV32 (see rv64cxcheri-cap-mode-only-valid.s)