Add MC support of RISCV Zcd Extension

[VincentWu]

Summary

This patch add the instructions of Zcd extension.

Zcd is a subset of C Ext which include the double-precision floating-point instructions (c.fld, c.fldsp, c.fsd, c.fsdsp).

[craig.topper]

Need to add Zcd command lines to compress-rv32d.s

clang/test/Preprocessor/riscv-target-features.c

47–48

Need to update this too.

llvm/lib/Target/RISCV/RISCVInstrInfoC.td

881

CompressPats need their predicates updated too. They are used by the assembler so they are MC layer.

llvm/test/MC/RISCV/rv32dc-valid.s

1

Need to add Zcd command lines

[craig.topper]

llvm/lib/Target/RISCV/RISCV.td

366

This predicate isn't used

[VincentWu]

address comments

[VincentWu]

fix testcase

[craig.topper]

Need to add Zcd command lines to compress-rv32d.s

[VincentWu]

address comment

[craig.topper]

LGTM

[VincentWu]

rebase

clang/test/Preprocessor/riscv-target-features.c

 // CHECK-NOT: __riscv_zknd
 // CHECK-NOT: __riscv_zknh
 // CHECK-NOT: __riscv_zksh
 // CHECK-NOT: __riscv_zksed
 // CHECK-NOT: __riscv_zkr
 // CHECK-NOT: __riscv_zkt
 // CHECK-NOT: __riscv_zk
 // CHECK-NOT: __riscv_zicbom
 // CHECK-NOT: __riscv_zicboz
+// CHECK-NOT: __riscv_zcd
 
 // RUN: %clang -target riscv32-unknown-linux-gnu -march=rv32im -x c -E -dM %s \
 // RUN: -o - | FileCheck --check-prefix=CHECK-M-EXT %s
 // RUN: %clang -target riscv64-unknown-linux-gnu -march=rv64im -x c -E -dM %s \
 // RUN: -o - | FileCheck --check-prefix=CHECK-M-EXT %s
 // CHECK-M-EXT: __riscv_div 1
 // CHECK-M-EXT: __riscv_m 2000000{{$}}
 // CHECK-M-EXT: __riscv_mul 1

 
 // RUN: %clang -target riscv32-unknown-linux-gnu -menable-experimental-extensions \
 // RUN: -march=rv32iztso0p1 -x c -E -dM %s \
 // RUN: -o - | FileCheck --check-prefix=CHECK-ZTSO-EXT %s
 // RUN: %clang -target riscv64-unknown-linux-gnu -menable-experimental-extensions \
 // RUN: -march=rv64iztso0p1 -x c -E -dM %s \
 // RUN: -o - | FileCheck --check-prefix=CHECK-ZTSO-EXT %s
 // CHECK-ZTSO-EXT: __riscv_ztso 1000{{$}}
+
+// RUN: %clang -target riscv32 -march=rv32izcd0p70 -menable-experimental-extensions \
+// RUN: -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-ZCD-EXT %s
+// RUN: %clang -target riscv64 -march=rv64izcd0p70 -menable-experimental-extensions \
+// RUN: -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-ZCD-EXT %s
+// CHECK-ZCD-EXT: __riscv_zcd 70000{{$}}

llvm/lib/Support/RISCVISAInfo.cpp

static const RISCVSupportedExtension SupportedExperimentalExtensions[] = {
 
     {"zbe", RISCVExtensionVersion{0, 93}},
     {"zbf", RISCVExtensionVersion{0, 93}},
     {"zbm", RISCVExtensionVersion{0, 93}},
     {"zbp", RISCVExtensionVersion{0, 93}},
     {"zbr", RISCVExtensionVersion{0, 93}},
     {"zbt", RISCVExtensionVersion{0, 93}},
     {"zca", RISCVExtensionVersion{0, 70}},
+    {"zcd", RISCVExtensionVersion{0, 70}},
     {"zvfh", RISCVExtensionVersion{0, 1}},
     {"ztso", RISCVExtensionVersion{0, 1}},
 };
 
 static bool stripExperimentalPrefix(StringRef &Ext) {
   return Ext.consume_front("experimental-");
 }
 

llvm/lib/Target/RISCV/RISCV.td

def HasStdExtZca : Predicate<"Subtarget->hasStdExtZca()">,
                            "'Zca' (part of the C extension, excluding compressed floating point loads/stores)">;
 
 def HasStdExtCOrZca
     : Predicate<"Subtarget->hasStdExtC() || Subtarget->hasStdExtZca()">,
                 AssemblerPredicate<(any_of FeatureStdExtC, FeatureExtZca),
                                    "'C' (Compressed Instructions) or "
                                    "'Zca' (part of the C extension, excluding compressed floating point loads/stores)">;
 
+def FeatureExtZcd
+    : SubtargetFeature<"experimental-zcd", "HasStdExtZcd", "true",
+                       "'Zcd' (Compressed Double-Precision Floating-Point Instructions)">;
+
+def HasStdExtCOrZcd
+    : Predicate<"Subtarget->hasStdExtC() || Subtarget->hasStdExtZcd()">,
+                AssemblerPredicate<(any_of FeatureStdExtC, FeatureExtZcd),
+                                   "'C' (Compressed Instructions) or "
+                                   "'Zcd' (Compressed Double-Precision Floating-Point Instructions)">;
+
 def FeatureNoRVCHints
     : SubtargetFeature<"no-rvc-hints", "EnableRVCHintInstrs", "false",
                        "Disable RVC Hint Instructions.">;
 def HasRVCHints : Predicate<"Subtarget->enableRVCHintInstrs()">,
                   AssemblerPredicate<(all_of(not FeatureNoRVCHints)),
                                       "RVC Hint Instructions">;
 
 def FeatureStdExtZvl32b : SubtargetFeature<"zvl32b", "ZvlLen", "32",

llvm/lib/Target/RISCV/RISCVInstrInfoC.td

def C_ADDI4SPN : RVInst16CIW<0b000, 0b00, (outs GPRC:$rd),
                              Sched<[WriteIALU, ReadIALU]> {
   bits<5> rs1;
   let Inst{12-11} = imm{5-4};
   let Inst{10-7} = imm{9-6};
   let Inst{6} = imm{2};
   let Inst{5} = imm{3};
 }
 
-let Predicates = [HasStdExtC, HasStdExtD] in
+let Predicates = [HasStdExtCOrZcd, HasStdExtD] in
 def C_FLD  : CLoad_ri<0b001, "c.fld", FPR64C, uimm8_lsb000>,
              Sched<[WriteFLD64, ReadMemBase]> {
   bits<8> imm;
   let Inst{12-10} = imm{5-3};
   let Inst{6-5} = imm{7-6};
 }
 
 def C_LW : CLoad_ri<0b010, "c.lw", GPRC, uimm7_lsb00>,

 let Predicates = [HasStdExtCOrZca, IsRV64] in
 def C_LD : CLoad_ri<0b011, "c.ld", GPRC, uimm8_lsb000>,
            Sched<[WriteLDD, ReadMemBase]> {
   bits<8> imm;
   let Inst{12-10} = imm{5-3};
   let Inst{6-5} = imm{7-6};
 }
 
-let Predicates = [HasStdExtC, HasStdExtD] in
+let Predicates = [HasStdExtCOrZcd, HasStdExtD] in
 def C_FSD  : CStore_rri<0b101, "c.fsd", FPR64C, uimm8_lsb000>,
              Sched<[WriteFST64, ReadStoreData, ReadMemBase]> {
   bits<8> imm;
   let Inst{12-10} = imm{5-3};
   let Inst{6-5} = imm{7-6};
 }
 
 def C_SW : CStore_rri<0b110, "c.sw", GPRC, uimm7_lsb00>,

 def C_SLLI : RVInst16CI<0b000, 0b10, (outs GPRNoX0:$rd_wb),
                         (ins GPRNoX0:$rd, uimmlog2xlennonzero:$imm),
                         "c.slli", "$rd, $imm">,
              Sched<[WriteShiftImm, ReadShiftImm]> {
   let Constraints = "$rd = $rd_wb";
   let Inst{6-2} = imm{4-0};
 }
 
-let Predicates = [HasStdExtC, HasStdExtD] in
+let Predicates = [HasStdExtCOrZcd, HasStdExtD] in
 def C_FLDSP  : CStackLoad<0b001, "c.fldsp", FPR64, uimm9_lsb000>,
                Sched<[WriteFLD64, ReadMemBase]> {
   let Inst{6-5} = imm{4-3};
   let Inst{4-2} = imm{8-6};
 }
 
 def C_LWSP : CStackLoad<0b010, "c.lwsp", GPRNoX0, uimm8_lsb00>,
              Sched<[WriteLDW, ReadMemBase]> {

 let hasSideEffects = 0, mayLoad = 0, mayStore = 0 in
 def C_ADD : RVInst16CR<0b1001, 0b10, (outs GPRNoX0:$rs1_wb),
                        (ins GPRNoX0:$rs1, GPRNoX0:$rs2),
                        "c.add", "$rs1, $rs2">,
             Sched<[WriteIALU, ReadIALU, ReadIALU]> {
   let Constraints = "$rs1 = $rs1_wb";
 }
 
-let Predicates = [HasStdExtC, HasStdExtD] in
+let Predicates = [HasStdExtCOrZcd, HasStdExtD] in
 def C_FSDSP  : CStackStore<0b101, "c.fsdsp", FPR64, uimm9_lsb000>,
                Sched<[WriteFST64, ReadStoreData, ReadMemBase]> {
   let Inst{12-10} = imm{5-3};
   let Inst{9-7}   = imm{8-6};
 }
 
 def C_SWSP : CStackStore<0b110, "c.swsp", GPR, uimm8_lsb00>,
              Sched<[WriteSTW, ReadStoreData, ReadMemBase]> {

 
 let Predicates = [HasStdExtC, HasStdExtF, IsRV32] in {
 def : InstAlias<"c.flw $rd, (${rs1})", (C_FLW FPR32C:$rd, GPRC:$rs1, 0)>;
 def : InstAlias<"c.fsw $rs2, (${rs1})", (C_FSW FPR32C:$rs2, GPRC:$rs1, 0)>;
 def : InstAlias<"c.flwsp $rd, (${rs1})", (C_FLWSP FPR32C:$rd, SP:$rs1, 0)>;
 def : InstAlias<"c.fswsp $rs2, (${rs1})", (C_FSWSP FPR32C:$rs2, SP:$rs1, 0)>;
 }
 
-let Predicates = [HasStdExtC, HasStdExtD] in {
+let Predicates = [HasStdExtCOrZcd, HasStdExtD] in {
 def : InstAlias<"c.fld $rd, (${rs1})", (C_FLD FPR64C:$rd, GPRC:$rs1, 0)>;
 def : InstAlias<"c.fsd $rs2, (${rs1})", (C_FSD FPR64C:$rs2, GPRC:$rs1, 0)>;
 def : InstAlias<"c.fldsp $rd, (${rs1})", (C_FLDSP FPR64C:$rd, SP:$rs1, 0)>;
 def : InstAlias<"c.fsdsp $rs2, (${rs1})", (C_FSDSP FPR64C:$rs2, SP:$rs1, 0)>;
 }
 } // EmitPriority = 0
 
 //===----------------------------------------------------------------------===/i
 // Compress Instruction tablegen backend.
 //===----------------------------------------------------------------------===//
 
 // Patterns are defined in the same order the compressed instructions appear
 // on page 82 of the ISA manual.
 
 // Quadrant 0
 let Predicates = [HasStdExtC] in {
 def : CompressPat<(ADDI GPRC:$rd, SP:$rs1, uimm10_lsb00nonzero:$imm),
                   (C_ADDI4SPN GPRC:$rd, SP:$rs1, uimm10_lsb00nonzero:$imm)>;
 } // Predicates = [HasStdExtC]
 
-let Predicates = [HasStdExtC, HasStdExtD] in {
+let Predicates = [HasStdExtCOrZcd, HasStdExtD] in {
 def : CompressPat<(FLD FPR64C:$rd, GPRC:$rs1, uimm8_lsb000:$imm),
                   (C_FLD FPR64C:$rd, GPRC:$rs1, uimm8_lsb000:$imm)>;
-} // Predicates = [HasStdExtC, HasStdExtD]
+} // Predicates = [HasStdExtCOrZcd, HasStdExtD]
 
 let Predicates = [HasStdExtC] in {
 def : CompressPat<(LW GPRC:$rd, GPRC:$rs1, uimm7_lsb00:$imm),
                   (C_LW GPRC:$rd, GPRC:$rs1, uimm7_lsb00:$imm)>;
 } // Predicates = [HasStdExtC]
 
 let Predicates = [HasStdExtC, HasStdExtF, IsRV32] in {
 def : CompressPat<(FLW FPR32C:$rd, GPRC:$rs1, uimm7_lsb00:$imm),
                   (C_FLW FPR32C:$rd, GPRC:$rs1, uimm7_lsb00:$imm)>;
 } // Predicates = [HasStdExtC, HasStdExtF, IsRV32]
 
 let Predicates = [HasStdExtC, IsRV64] in {
 def : CompressPat<(LD GPRC:$rd, GPRC:$rs1, uimm8_lsb000:$imm),
                   (C_LD GPRC:$rd, GPRC:$rs1, uimm8_lsb000:$imm)>;
 } // Predicates = [HasStdExtC, IsRV64]
 
-let Predicates = [HasStdExtC, HasStdExtD] in {
+let Predicates = [HasStdExtCOrZcd, HasStdExtD] in {
 def : CompressPat<(FSD FPR64C:$rs2, GPRC:$rs1, uimm8_lsb000:$imm),
                   (C_FSD FPR64C:$rs2, GPRC:$rs1, uimm8_lsb000:$imm)>;
-} // Predicates = [HasStdExtC, HasStdExtD]
+} // Predicates = [HasStdExtCOrZcd, HasStdExtD]
 
 let Predicates = [HasStdExtC] in {
 def : CompressPat<(SW GPRC:$rs2, GPRC:$rs1, uimm7_lsb00:$imm),
                   (C_SW GPRC:$rs2, GPRC:$rs1, uimm7_lsb00:$imm)>;
 } // Predicates = [HasStdExtC]
 
 let Predicates = [HasStdExtC, HasStdExtF, IsRV32] in {
 def : CompressPat<(FSW FPR32C:$rs2, GPRC:$rs1, uimm7_lsb00:$imm),

 } // Predicates = [HasStdExtC]
 
 // Quadrant 2
 let Predicates = [HasStdExtC] in {
 def : CompressPat<(SLLI GPRNoX0:$rs1, GPRNoX0:$rs1, uimmlog2xlennonzero:$imm),
                   (C_SLLI GPRNoX0:$rs1, uimmlog2xlennonzero:$imm)>;
 } // Predicates = [HasStdExtC]
 
-let Predicates = [HasStdExtC, HasStdExtD] in {
+let Predicates = [HasStdExtCOrZcd, HasStdExtD] in {
 def : CompressPat<(FLD FPR64:$rd, SP:$rs1, uimm9_lsb000:$imm),
                   (C_FLDSP FPR64:$rd, SP:$rs1, uimm9_lsb000:$imm)>;
-} // Predicates = [HasStdExtC, HasStdExtD]
+} // Predicates = [HasStdExtCOrZcd, HasStdExtD]
 
 let Predicates = [HasStdExtC] in {
 def : CompressPat<(LW GPRNoX0:$rd, SP:$rs1,  uimm8_lsb00:$imm),
                   (C_LWSP GPRNoX0:$rd, SP:$rs1, uimm8_lsb00:$imm)>;
 } // Predicates = [HasStdExtC]
 
 let Predicates = [HasStdExtC, HasStdExtF, IsRV32] in {
 def : CompressPat<(FLW FPR32:$rd, SP:$rs1, uimm8_lsb00:$imm),
def : CompressPat<(JALR X1, GPRNoX0:$rs1, 0),
                   (C_JALR GPRNoX0:$rs1)>;
 def : CompressPat<(ADD GPRNoX0:$rs1, GPRNoX0:$rs1, GPRNoX0:$rs2),
                   (C_ADD GPRNoX0:$rs1, GPRNoX0:$rs2)>;
 let isCompressOnly = true in
 def : CompressPat<(ADD GPRNoX0:$rs1, GPRNoX0:$rs2, GPRNoX0:$rs1),
                   (C_ADD GPRNoX0:$rs1, GPRNoX0:$rs2)>;
 } // Predicates = [HasStdExtC]
 
-let Predicates = [HasStdExtC, HasStdExtD] in {
+let Predicates = [HasStdExtCOrZcd, HasStdExtD] in {
 def : CompressPat<(FSD FPR64:$rs2, SP:$rs1, uimm9_lsb000:$imm),
                   (C_FSDSP FPR64:$rs2, SP:$rs1, uimm9_lsb000:$imm)>;
-} // Predicates = [HasStdExtC, HasStdExtD]
+} // Predicates = [HasStdExtCOrZcd, HasStdExtD]
 
 let Predicates = [HasStdExtC] in {
 def : CompressPat<(SW GPR:$rs2, SP:$rs1, uimm8_lsb00:$imm),
                   (C_SWSP GPR:$rs2, SP:$rs1, uimm8_lsb00:$imm)>;
 } // Predicates = [HasStdExtC]
 
 let Predicates = [HasStdExtC, HasStdExtF, IsRV32] in {
 def : CompressPat<(FSW FPR32:$rs2, SP:$rs1, uimm8_lsb00:$imm),
                   (C_FSWSP FPR32:$rs2, SP:$rs1, uimm8_lsb00:$imm)>;
 } // Predicates = [HasStdExtC, HasStdExtF, IsRV32]
 
 let Predicates = [HasStdExtC, IsRV64] in {
 def : CompressPat<(SD GPR:$rs2, SP:$rs1, uimm9_lsb000:$imm),
                   (C_SDSP GPR:$rs2, SP:$rs1, uimm9_lsb000:$imm)>;
 } // Predicates = [HasStdExtC, IsRV64]

llvm/lib/Target/RISCV/RISCVSubtarget.h

private:
   bool HasStdExtZbe = false;
   bool HasStdExtZbf = false;
   bool HasStdExtZbm = false;
   bool HasStdExtZbp = false;
   bool HasStdExtZbr = false;
   bool HasStdExtZbs = false;
   bool HasStdExtZbt = false;
   bool HasStdExtZca = false;
+  bool HasStdExtZcd = false;
   bool HasStdExtV = false;
   bool HasStdExtZve32x = false;
   bool HasStdExtZve32f = false;
   bool HasStdExtZve64x = false;
   bool HasStdExtZve64f = false;
   bool HasStdExtZve64d = false;
   bool HasStdExtZvfh = false;
   bool HasStdExtZfhmin = false;
public:
   bool hasStdExtZbe() const { return HasStdExtZbe; }
   bool hasStdExtZbf() const { return HasStdExtZbf; }
   bool hasStdExtZbm() const { return HasStdExtZbm; }
   bool hasStdExtZbp() const { return HasStdExtZbp; }
   bool hasStdExtZbr() const { return HasStdExtZbr; }
   bool hasStdExtZbs() const { return HasStdExtZbs; }
   bool hasStdExtZbt() const { return HasStdExtZbt; }
   bool hasStdExtZca() const { return HasStdExtZca; }
+  bool hasStdExtZcd() const { return HasStdExtZcd; }
   bool hasStdExtZvl() const { return ZvlLen != 0; }
   bool hasStdExtZvfh() const { return HasStdExtZvfh; }
   bool hasStdExtZfhmin() const { return HasStdExtZfhmin; }
   bool hasStdExtZfh() const { return HasStdExtZfh; }
   bool hasStdExtZfinx() const { return HasStdExtZfinx; }
   bool hasStdExtZdinx() const { return HasStdExtZdinx; }
   bool hasStdExtZhinxmin() const { return HasStdExtZhinxmin; }
   bool hasStdExtZhinx() const { return HasStdExtZhinx; }

llvm/test/MC/RISCV/rv32dc-valid.s

 # RUN: llvm-mc %s -triple=riscv32 -mattr=+c,+d -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,+d < %s \
 # RUN:     | llvm-objdump --mattr=+c,+d -M no-aliases -d -r - \
 # RUN:     | FileCheck --check-prefix=CHECK-ASM-AND-OBJ %s
+# RUN: llvm-mc %s -triple=riscv32 -mattr=+experimental-zcd,+d -riscv-no-aliases -show-encoding \
+# RUN:     | FileCheck -check-prefixes=CHECK-ASM,CHECK-ASM-AND-OBJ %s
+# RUN: llvm-mc -filetype=obj -triple=riscv32 -mattr=+experimental-zcd,+d < %s \
+# RUN:     | llvm-objdump --mattr=+experimental-zcd,+d -M no-aliases -d -r - \
+# RUN:     | FileCheck --check-prefix=CHECK-ASM-AND-OBJ %s
 #
 # RUN: not llvm-mc -triple riscv32 -mattr=+c \
 # RUN:     -riscv-no-aliases -show-encoding < %s 2>&1 \
 # RUN:     | FileCheck -check-prefixes=CHECK-NO-EXT-D %s
+# RUN: not llvm-mc -triple riscv32 -mattr=+experimental-zcd \
+# RUN:     -riscv-no-aliases -show-encoding < %s 2>&1 \
+# RUN:     | FileCheck -check-prefixes=CHECK-NO-EXT-D %s
 # RUN: not llvm-mc -triple riscv32 -riscv-no-aliases -show-encoding < %s 2>&1 \
 # RUN:     | FileCheck -check-prefixes=CHECK-NO-EXT-DC %s
 
 # CHECK-ASM-AND-OBJ: c.fldsp  fs0, 504(sp)
 # CHECK-ASM: encoding: [0x7e,0x34]
 # CHECK-NO-EXT-D:  error: instruction requires the following: 'D' (Double-Precision Floating-Point){{$}}
-# CHECK-NO-EXT-DC:  error: instruction requires the following: 'C' (Compressed Instructions), 'D' (Double-Precision Floating-Point){{$}}
+# CHECK-NO-EXT-DC:  error: instruction requires the following: 'C' (Compressed Instructions) or 'Zcd' (Compressed Double-Precision Floating-Point Instructions), 'D' (Double-Precision Floating-Point){{$}}
 c.fldsp  fs0, 504(sp)
 # CHECK-ASM-AND-OBJ: c.fsdsp  fa7, 504(sp)
 # CHECK-ASM: encoding: [0xc6,0xbf]
 # CHECK-NO-EXT-D:  error: instruction requires the following: 'D' (Double-Precision Floating-Point){{$}}
-# CHECK-NO-EXT-DC:  error: instruction requires the following: 'C' (Compressed Instructions), 'D' (Double-Precision Floating-Point){{$}}
+# CHECK-NO-EXT-DC:  error: instruction requires the following: 'C' (Compressed Instructions) or 'Zcd' (Compressed Double-Precision Floating-Point Instructions), 'D' (Double-Precision Floating-Point){{$}}
 c.fsdsp  fa7, 504(sp)
 
 # CHECK-ASM-AND-OBJ: c.fld  fa3, 248(a5)
 # CHECK-ASM: encoding: [0xf4,0x3f]
 # CHECK-NO-EXT-D:  error: instruction requires the following: 'D' (Double-Precision Floating-Point){{$}}
-# CHECK-NO-EXT-DC:  error: instruction requires the following: 'C' (Compressed Instructions), 'D' (Double-Precision Floating-Point){{$}}
+# CHECK-NO-EXT-DC:  error: instruction requires the following: 'C' (Compressed Instructions) or 'Zcd' (Compressed Double-Precision Floating-Point Instructions), 'D' (Double-Precision Floating-Point){{$}}
 c.fld  fa3, 248(a5)
 # CHECK-ASM-AND-OBJ: c.fsd  fa2, 248(a1)
 # CHECK-ASM: encoding: [0xf0,0xbd]
 # CHECK-NO-EXT-D:  error: instruction requires the following: 'D' (Double-Precision Floating-Point){{$}}
-# CHECK-NO-EXT-DC:  error: instruction requires the following: 'C' (Compressed Instructions), 'D' (Double-Precision Floating-Point){{$}}
+# CHECK-NO-EXT-DC:  error: instruction requires the following: 'C' (Compressed Instructions) or 'Zcd' (Compressed Double-Precision Floating-Point Instructions), 'D' (Double-Precision Floating-Point){{$}}
 c.fsd  fa2, 248(a1)

llvm/test/MC/RISCV/rv64dc-valid.s

 # RUN: llvm-mc %s -triple=riscv64 -mattr=+c,+d -riscv-no-aliases -show-encoding \
 # RUN:     | FileCheck -check-prefixes=CHECK-ASM,CHECK-ASM-AND-OBJ %s
 # RUN: llvm-mc -filetype=obj -triple=riscv64 -mattr=+c,+d < %s \
 # RUN:     | llvm-objdump --mattr=+c,+d -M no-aliases -d -r - \
 # RUN:     | FileCheck --check-prefix=CHECK-ASM-AND-OBJ %s
+# RUN: llvm-mc %s -triple=riscv64 -mattr=+experimental-zcd,+d -riscv-no-aliases -show-encoding \
+# RUN:     | FileCheck -check-prefixes=CHECK-ASM,CHECK-ASM-AND-OBJ %s
+# RUN: llvm-mc -filetype=obj -triple=riscv64 -mattr=+experimental-zcd,+d < %s \
+# RUN:     | llvm-objdump --mattr=+experimental-zcd,+d -M no-aliases -d -r - \
+# RUN:     | FileCheck --check-prefix=CHECK-ASM-AND-OBJ %s
 #
 # RUN: not llvm-mc -triple riscv64 -mattr=+c \
 # RUN:     -riscv-no-aliases -show-encoding < %s 2>&1 \
 # RUN:     | FileCheck -check-prefixes=CHECK-NO-EXT-D %s
+# RUN: not llvm-mc -triple riscv64 -mattr=+experimental-zcd \
+# RUN:     -riscv-no-aliases -show-encoding < %s 2>&1 \
+# RUN:     | FileCheck -check-prefixes=CHECK-NO-EXT-D %s
 # RUN: not llvm-mc -triple riscv64 -riscv-no-aliases -show-encoding < %s 2>&1 \
 # RUN:     | FileCheck -check-prefixes=CHECK-NO-EXT-DC %s
 
 # CHECK-ASM-AND-OBJ: c.fldsp  fs0, 504(sp)
 # CHECK-ASM: encoding: [0x7e,0x34]
 # CHECK-NO-EXT-D:  error: instruction requires the following: 'D' (Double-Precision Floating-Point){{$}}
-# CHECK-NO-EXT-DC:  error: instruction requires the following: 'C' (Compressed Instructions), 'D' (Double-Precision Floating-Point){{$}}
+# CHECK-NO-EXT-DC:  error: instruction requires the following: 'C' (Compressed Instructions) or 'Zcd' (Compressed Double-Precision Floating-Point Instructions), 'D' (Double-Precision Floating-Point){{$}}
 c.fldsp  fs0, 504(sp)
 # CHECK-ASM-AND-OBJ: c.fsdsp  fa7, 504(sp)
 # CHECK-ASM: encoding: [0xc6,0xbf]
 # CHECK-NO-EXT-D:  error: instruction requires the following: 'D' (Double-Precision Floating-Point){{$}}
-# CHECK-NO-EXT-DC:  error: instruction requires the following: 'C' (Compressed Instructions), 'D' (Double-Precision Floating-Point){{$}}
+# CHECK-NO-EXT-DC:  error: instruction requires the following: 'C' (Compressed Instructions) or 'Zcd' (Compressed Double-Precision Floating-Point Instructions), 'D' (Double-Precision Floating-Point){{$}}
 c.fsdsp  fa7, 504(sp)
 
 # CHECK-ASM-AND-OBJ: c.fld  fa3, 248(a5)
 # CHECK-ASM: encoding: [0xf4,0x3f]
 # CHECK-NO-EXT-D:  error: instruction requires the following: 'D' (Double-Precision Floating-Point){{$}}
-# CHECK-NO-EXT-DC:  error: instruction requires the following: 'C' (Compressed Instructions), 'D' (Double-Precision Floating-Point){{$}}
+# CHECK-NO-EXT-DC:  error: instruction requires the following: 'C' (Compressed Instructions) or 'Zcd' (Compressed Double-Precision Floating-Point Instructions), 'D' (Double-Precision Floating-Point){{$}}
 c.fld  fa3, 248(a5)
 # CHECK-ASM-AND-OBJ: c.fsd  fa2, 248(a1)
 # CHECK-ASM: encoding: [0xf0,0xbd]
 # CHECK-NO-EXT-D:  error: instruction requires the following: 'D' (Double-Precision Floating-Point){{$}}
-# CHECK-NO-EXT-DC:  error: instruction requires the following: 'C' (Compressed Instructions), 'D' (Double-Precision Floating-Point){{$}}
+# CHECK-NO-EXT-DC:  error: instruction requires the following: 'C' (Compressed Instructions) or 'Zcd' (Compressed Double-Precision Floating-Point Instructions), 'D' (Double-Precision Floating-Point){{$}}
 c.fsd  fa2, 248(a1)