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[RISCV] Basic Objdump Mapping Symbol Support #151452

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@lenary lenary commented Jul 31, 2025

This implements very basic support for RISC-V mapping symbols in llvm-objdump, sharing the implementation with how Arm/AArch64/CSKY implement this feature.

This only supports the $x (instruction) and $d (data) mapping symbols for RISC-V, and not the version of $x which includes an architecture string suffix.

@lenary
[RISCV] Basic Objdump Mapping Symbol Support
3d39706 
This implements very basic support for RISC-V mapping symbols in
llvm-objdump, sharing the implementation with how Arm/AArch64/CSKY
implement this feature.

This only supports the `$x` (instruction) and `$d` (data) mapping
symbols for RISC-V, and not the version of `$x` which includes an
architecture suffix.
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llvmbot commented Jul 31, 2025 •
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@llvm/pr-subscribers-backend-risc-v

@llvm/pr-subscribers-llvm-binary-utilities

Author: Sam Elliott (lenary)

Changes

This implements very basic support for RISC-V mapping symbols in llvm-objdump, sharing the implementation with how Arm/AArch64/CSKY implement this feature.

This only supports the $x (instruction) and $d (data) mapping symbols for RISC-V, and not the version of $x which includes an architecture string suffix.

Full diff: https://github.com/llvm/llvm-project/pull/151452.diff

8 Files Affected:

  • (modified) llvm/docs/ReleaseNotes.md (+5)
  • (modified) llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp (+2)
  • (added) llvm/test/MC/Disassembler/RISCV/riscv-mapping-symbols.s (+20)
  • (removed) llvm/test/MC/RISCV/large-instructions.s (-29)
  • (added) llvm/test/MC/RISCV/large-instructions.test (+88)
  • (modified) llvm/test/MC/RISCV/nop-slide.s (+5-8)
  • (modified) llvm/test/MC/RISCV/rvv/vsetvl-invalid.s (+12-12)
  • (modified) llvm/tools/llvm-objdump/llvm-objdump.cpp (+6-1)
diff --git a/llvm/docs/ReleaseNotes.md b/llvm/docs/ReleaseNotes.md
index 021f321bd9dc2..4c84411bd9ed8 100644
--- a/llvm/docs/ReleaseNotes.md
+++ b/llvm/docs/ReleaseNotes.md
@@ -104,6 +104,11 @@ Changes to the PowerPC Backend
 Changes to the RISC-V Backend
 -----------------------------
 
+* `llvm-objdump` now has basic support for switching between disassembling code
+  and data using mapping symbols such as `$x` and `$d`. Switching architectures
+  using `$x` with an architecture string suffix is not yet supported.
+
+
 Changes to the WebAssembly Backend
 ----------------------------------
 
diff --git a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp
index 82e3b5ceb4ef6..782c5670c983e 100644
--- a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp
+++ b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp
@@ -482,6 +482,8 @@ bool RISCVAsmBackend::writeNopData(raw_ostream &OS, uint64_t Count,
     Count -= 1;
   }
 
+  // TODO: emit a mapping symbol right here
+
   if (Count % 4 == 2) {
     // The canonical nop with Zca is c.nop.
     OS.write(STI->hasFeature(RISCV::FeatureStdExtZca) ? "\x01\0" : "\0\0", 2);
diff --git a/llvm/test/MC/Disassembler/RISCV/riscv-mapping-symbols.s b/llvm/test/MC/Disassembler/RISCV/riscv-mapping-symbols.s
new file mode 100644
index 0000000000000..ff15008b8e3f8
--- /dev/null
+++ b/llvm/test/MC/Disassembler/RISCV/riscv-mapping-symbols.s
@@ -0,0 +1,20 @@
+# RUN: llvm-mc --triple=riscv32-unknown-none-elf %s -filetype=obj -o - \
+# RUN: | llvm-objdump -dr - \
+# RUN: | FileCheck %s
+# RUN: llvm-mc --triple=riscv64-unknown-none-elf %s -filetype=obj -o - \
+# RUN: | llvm-objdump -dr - \
+# RUN: | FileCheck %s
+
+
+  # CHECK: 00000013 nop
+  nop
+
+  # CHECK-NEXT: 55 55 55 55 .word 0x55555555
+  .word 0x55555555
+
+  # CHECK-NEXT: 00 00 00 00 .word 0x00000000
+  # CHECK-NEXT: R_RISCV_32 foo
+  .word foo
+
+  # CHECK-NEXT: 00000013 nop
+  nop
diff --git a/llvm/test/MC/RISCV/large-instructions.s b/llvm/test/MC/RISCV/large-instructions.s
deleted file mode 100644
index b50dbde17d380..0000000000000
--- a/llvm/test/MC/RISCV/large-instructions.s
+++ /dev/null
@@ -1,29 +0,0 @@
-# RUN: llvm-mc -filetype=obj -triple riscv32 < %s \
-# RUN:     | llvm-objdump -d - | FileCheck %s
-
-# CHECK: 011f 4523 8967 <unknown>
-.byte 0x1f, 0x01, 0x23, 0x45, 0x67, 0x89
-
-# CHECK: 4523013f cdab8967 <unknown>
-.byte 0x3f, 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd
-
-# CHECK: 007f 4523 8967 cdab feef <unknown>
-.byte 0x7f, 0x00, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0xfe
-
-# CHECK: 4523107f cdab8967 badcfeef <unknown>
-.byte 0x7f, 0x10, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0xfe, 0xdc, 0xba
-
-# CHECK: 207f 4523 8967 cdab feef badc 7698 <unknown>
-.byte 0x7f, 0x20, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0xfe, 0xdc, 0xba, 0x98, 0x76
-
-# CHECK: 4523307f cdab8967 badcfeef 32547698 <unknown>
-.byte 0x7f, 0x30, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54, 0x32
-
-# CHECK: 407f 4523 8967 cdab feef badc 7698 3254 1210 <unknown>
-.byte 0x7f, 0x40, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54, 0x32, 0x10, 0x12
-
-# CHECK: 4523507f cdab8967 badcfeef 32547698 56341210 <unknown>
-.byte 0x7f, 0x50, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54, 0x32, 0x10, 0x12, 0x34, 0x56
-
-# CHECK: 607f 4523 8967 cdab feef badc 7698 3254 1210 5634 9a78 <unknown>
-.byte 0x7f, 0x60, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54, 0x32, 0x10, 0x12, 0x34, 0x56, 0x78, 0x9a
diff --git a/llvm/test/MC/RISCV/large-instructions.test b/llvm/test/MC/RISCV/large-instructions.test
new file mode 100644
index 0000000000000..0552c94c34d64
--- /dev/null
+++ b/llvm/test/MC/RISCV/large-instructions.test
@@ -0,0 +1,88 @@
+# RUN: yaml2obj -o - %s \
+# RUN:     | llvm-objdump -d - | FileCheck %s
+
+## This CHECKs objdump's handling of wide instruction encodings, and how it
+## groups the instruction bytes when disassembling.
+##
+## This is written in YAML because using `.byte` emits the wrong mapping
+## symbols.
+
+--- !ELF
+FileHeader:
+  Class:           ELFCLASS32
+  Data:            ELFDATA2LSB
+  Type:            ET_REL
+  Machine:         EM_RISCV
+  SectionHeaderStringTable: .strtab
+Sections:
+  - Name:            .text.six_byte
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x1
+    Content:         1F0123456789
+    # CHECK: 011f 4523 8967 <unknown>
+  - Name:            .text.eight_byte
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x1
+    Content:         3F0123456789ABCD
+    # CHECK: 4523013f cdab8967 <unknown>
+  - Name:            .text.ten_byte
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x1
+    Content:         7F0023456789ABCDEFFE
+    # CHECK: 007f 4523 8967 cdab feef <unknown>
+  - Name:            .text.twelve_byte
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x1
+    Content:         7F1023456789ABCDEFFEDCBA
+    # CHECK: 4523107f cdab8967 badcfeef <unknown>
+  - Name:            .text.fourteen_byte
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x1
+    Content:         7F2023456789ABCDEFFEDCBA9876
+    # CHECK: 207f 4523 8967 cdab feef badc 7698 <unknown>
+  - Name:            .text.sixteen_byte
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x1
+    Content:         7F3023456789ABCDEFFEDCBA98765432
+    # CHECK: 4523307f cdab8967 badcfeef 32547698 <unknown>
+  - Name:            .text.eighteen_byte
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x1
+    Content:         7F4023456789ABCDEFFEDCBA987654321012
+    # CHECK: 407f 4523 8967 cdab feef badc 7698 3254 1210 <unknown>
+  - Name:            .text.twenty_byte
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x1
+    Content:         7F5023456789ABCDEFFEDCBA9876543210123456
+    # CHECK: 4523507f cdab8967 badcfeef 32547698 56341210 <unknown>
+  - Name:            .text.twentytwo_byte
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x1
+    Content:         7F6023456789ABCDEFFEDCBA9876543210123456789A
+    # CHECK: 607f 4523 8967 cdab feef badc 7698 3254 1210 5634 9a78 <unknown>
+  - Type:            SectionHeaderTable
+    Sections:
+      - Name:            .strtab
+      - Name:            .text.six_byte
+      - Name:            .text.eight_byte
+      - Name:            .text.ten_byte
+      - Name:            .text.twelve_byte
+      - Name:            .text.fourteen_byte
+      - Name:            .text.sixteen_byte
+      - Name:            .text.eighteen_byte
+      - Name:            .text.twenty_byte
+      - Name:            .text.twentytwo_byte
+      - Name:            .symtab
+Symbols:
+  - Name:            '$x'
+    Section:         .text.six_byte
+...
diff --git a/llvm/test/MC/RISCV/nop-slide.s b/llvm/test/MC/RISCV/nop-slide.s
index 4dc888b3ba777..a49ffdc0e420c 100644
--- a/llvm/test/MC/RISCV/nop-slide.s
+++ b/llvm/test/MC/RISCV/nop-slide.s
@@ -10,18 +10,15 @@
 auipc a0, 0
 
 # CHECK-RVC-NORELAX: 0000000000000000 <.text>:
-# CHECK-RVC-NORELAX-NEXT: 0: 0000      	unimp
-# CHECK-RVC-NORELAX-NEXT: 2: 0001      	nop
+# CHECK-RVC-NORELAX-NEXT: 0: 00 00 01 00 .word 0x00010000
 # CHECK-RVC-NORELAX-NEXT: 4: 00000517  	auipc	a0, 0x0
 
 # CHECK-RVC-RELAX: 0000000000000000 <.text>:
 # CHECK-RVC-RELAX-NEXT:   0: 0001      	nop
-# CHECK-RVC-RELAX-NEXT:   2: 0100      	addi	s0, sp, 0x80
-# CHECK-RVC-RELAX-NEXT:   4: 1700      	addi	s0, sp, 0x3a0
-# CHECK-RVC-RELAX-NEXT:   6: 0005      	c.nop	0x1
-# CHECK-RVC-RELAX-NEXT:   8: 00        	<unknown>
+# CHECK-RVC-RELAX-NEXT:   2: 00 01      .short 0x0100
+# CHECK-RVC-RELAX-NEXT:   4: 00         .byte 0x00
+# CHECK-RVC-RELAX-NEXT:   5: 00000517  	auipc	a0, 0x0
 
 # CHECK: 0000000000000000 <.text>:
-# CHECK-NEXT: 0: 0000      	<unknown>
-# CHECK-NEXT: 2: 0000      	<unknown>
+# CHECK-NEXT: 0: 00 00 00 00 .word 0x00000000
 # CHECK-NEXT: 4: 00000517  	auipc	a0, 0x0
diff --git a/llvm/test/MC/RISCV/rvv/vsetvl-invalid.s b/llvm/test/MC/RISCV/rvv/vsetvl-invalid.s
index b45f3f2dfc854..d97b53803b97a 100644
--- a/llvm/test/MC/RISCV/rvv/vsetvl-invalid.s
+++ b/llvm/test/MC/RISCV/rvv/vsetvl-invalid.s
@@ -4,37 +4,37 @@
 # RUN:     | llvm-objdump -d --mattr=+v - | FileCheck %s
 
 # CHECK: vsetvli a1, a0, e64, m1, tu, mu
-.word 0x018575d7
+.insn 4, 0x018575d7
 
 # CHECK: vsetvli a1, a0, 0x1c
-.word 0x01c575d7
+.insn 4, 0x01c575d7
 
 # CHECK: vsetvli a1, a0, 0x24
-.word 0x024575d7
+.insn 4, 0x024575d7
 
 # CHECK: vsetvli a1, a0, 0x29
-.word 0x029575d7
+.insn 4, 0x029575d7
 
 # CHECK: vsetvli a1, a0, 0x110
-.word 0x110575d7
+.insn 4, 0x110575d7
 
 # CHECK: vsetvli a1, a0, e64, mf8, tu, mu
-.word 0x01d575d7
+.insn 4, 0x01d575d7
 
 # CHECK: vsetivli a1, 0x10, e8, m4, tu, mu
-.word 0xc02875d7
+.insn 4, 0xc02875d7
 
 # CHECK: vsetivli a1, 0x10, 0xc
-.word 0xc0c875d7
+.insn 4, 0xc0c875d7
 
 # CHECK: vsetivli a1, 0x10, 0x14
-.word 0xc14875d7
+.insn 4, 0xc14875d7
 
 # CHECK: vsetivli a1, 0x10, 0x38
-.word 0xc38875d7
+.insn 4, 0xc38875d7
 
 # CHECK: vsetivli a1, 0x10, 0x103
-.word 0xd03875d7
+.insn 4, 0xd03875d7
 
 # CHECK: vsetivli a1, 0x10, e8, mf4, tu, mu
-.word 0xc06875d7
+.insn 4, 0xc06875d7
diff --git a/llvm/tools/llvm-objdump/llvm-objdump.cpp b/llvm/tools/llvm-objdump/llvm-objdump.cpp
index 0316c4ba51da6..541b09a297621 100644
--- a/llvm/tools/llvm-objdump/llvm-objdump.cpp
+++ b/llvm/tools/llvm-objdump/llvm-objdump.cpp
@@ -633,8 +633,13 @@ static bool isCSKYElf(const ObjectFile &Obj) {
   return Elf && Elf->getEMachine() == ELF::EM_CSKY;
 }
 
+static bool isRISCVElf(const ObjectFile &Obj) {
+  const auto *Elf = dyn_cast<ELFObjectFileBase>(&Obj);
+  return Elf && Elf->getEMachine() == ELF::EM_RISCV;
+}
+
 static bool hasMappingSymbols(const ObjectFile &Obj) {
-  return isArmElf(Obj) || isAArch64Elf(Obj) || isCSKYElf(Obj);
+  return isArmElf(Obj) || isAArch64Elf(Obj) || isCSKYElf(Obj) || isRISCVElf(Obj);
 }
 
 static void printRelocation(formatted_raw_ostream &OS, StringRef FileName,

@llvmbot
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llvmbot commented Jul 31, 2025

@llvm/pr-subscribers-mc

Author: Sam Elliott (lenary)

Changes

This implements very basic support for RISC-V mapping symbols in llvm-objdump, sharing the implementation with how Arm/AArch64/CSKY implement this feature.

This only supports the $x (instruction) and $d (data) mapping symbols for RISC-V, and not the version of $x which includes an architecture string suffix.

Full diff: https://github.com/llvm/llvm-project/pull/151452.diff

8 Files Affected:

  • (modified) llvm/docs/ReleaseNotes.md (+5)
  • (modified) llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp (+2)
  • (added) llvm/test/MC/Disassembler/RISCV/riscv-mapping-symbols.s (+20)
  • (removed) llvm/test/MC/RISCV/large-instructions.s (-29)
  • (added) llvm/test/MC/RISCV/large-instructions.test (+88)
  • (modified) llvm/test/MC/RISCV/nop-slide.s (+5-8)
  • (modified) llvm/test/MC/RISCV/rvv/vsetvl-invalid.s (+12-12)
  • (modified) llvm/tools/llvm-objdump/llvm-objdump.cpp (+6-1)
diff --git a/llvm/docs/ReleaseNotes.md b/llvm/docs/ReleaseNotes.md
index 021f321bd9dc2..4c84411bd9ed8 100644
--- a/llvm/docs/ReleaseNotes.md
+++ b/llvm/docs/ReleaseNotes.md
@@ -104,6 +104,11 @@ Changes to the PowerPC Backend
 Changes to the RISC-V Backend
 -----------------------------
 
+* `llvm-objdump` now has basic support for switching between disassembling code
+  and data using mapping symbols such as `$x` and `$d`. Switching architectures
+  using `$x` with an architecture string suffix is not yet supported.
+
+
 Changes to the WebAssembly Backend
 ----------------------------------
 
diff --git a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp
index 82e3b5ceb4ef6..782c5670c983e 100644
--- a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp
+++ b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp
@@ -482,6 +482,8 @@ bool RISCVAsmBackend::writeNopData(raw_ostream &OS, uint64_t Count,
     Count -= 1;
   }
 
+  // TODO: emit a mapping symbol right here
+
   if (Count % 4 == 2) {
     // The canonical nop with Zca is c.nop.
     OS.write(STI->hasFeature(RISCV::FeatureStdExtZca) ? "\x01\0" : "\0\0", 2);
diff --git a/llvm/test/MC/Disassembler/RISCV/riscv-mapping-symbols.s b/llvm/test/MC/Disassembler/RISCV/riscv-mapping-symbols.s
new file mode 100644
index 0000000000000..ff15008b8e3f8
--- /dev/null
+++ b/llvm/test/MC/Disassembler/RISCV/riscv-mapping-symbols.s
@@ -0,0 +1,20 @@
+# RUN: llvm-mc --triple=riscv32-unknown-none-elf %s -filetype=obj -o - \
+# RUN: | llvm-objdump -dr - \
+# RUN: | FileCheck %s
+# RUN: llvm-mc --triple=riscv64-unknown-none-elf %s -filetype=obj -o - \
+# RUN: | llvm-objdump -dr - \
+# RUN: | FileCheck %s
+
+
+  # CHECK: 00000013 nop
+  nop
+
+  # CHECK-NEXT: 55 55 55 55 .word 0x55555555
+  .word 0x55555555
+
+  # CHECK-NEXT: 00 00 00 00 .word 0x00000000
+  # CHECK-NEXT: R_RISCV_32 foo
+  .word foo
+
+  # CHECK-NEXT: 00000013 nop
+  nop
diff --git a/llvm/test/MC/RISCV/large-instructions.s b/llvm/test/MC/RISCV/large-instructions.s
deleted file mode 100644
index b50dbde17d380..0000000000000
--- a/llvm/test/MC/RISCV/large-instructions.s
+++ /dev/null
@@ -1,29 +0,0 @@
-# RUN: llvm-mc -filetype=obj -triple riscv32 < %s \
-# RUN:     | llvm-objdump -d - | FileCheck %s
-
-# CHECK: 011f 4523 8967 <unknown>
-.byte 0x1f, 0x01, 0x23, 0x45, 0x67, 0x89
-
-# CHECK: 4523013f cdab8967 <unknown>
-.byte 0x3f, 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd
-
-# CHECK: 007f 4523 8967 cdab feef <unknown>
-.byte 0x7f, 0x00, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0xfe
-
-# CHECK: 4523107f cdab8967 badcfeef <unknown>
-.byte 0x7f, 0x10, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0xfe, 0xdc, 0xba
-
-# CHECK: 207f 4523 8967 cdab feef badc 7698 <unknown>
-.byte 0x7f, 0x20, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0xfe, 0xdc, 0xba, 0x98, 0x76
-
-# CHECK: 4523307f cdab8967 badcfeef 32547698 <unknown>
-.byte 0x7f, 0x30, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54, 0x32
-
-# CHECK: 407f 4523 8967 cdab feef badc 7698 3254 1210 <unknown>
-.byte 0x7f, 0x40, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54, 0x32, 0x10, 0x12
-
-# CHECK: 4523507f cdab8967 badcfeef 32547698 56341210 <unknown>
-.byte 0x7f, 0x50, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54, 0x32, 0x10, 0x12, 0x34, 0x56
-
-# CHECK: 607f 4523 8967 cdab feef badc 7698 3254 1210 5634 9a78 <unknown>
-.byte 0x7f, 0x60, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54, 0x32, 0x10, 0x12, 0x34, 0x56, 0x78, 0x9a
diff --git a/llvm/test/MC/RISCV/large-instructions.test b/llvm/test/MC/RISCV/large-instructions.test
new file mode 100644
index 0000000000000..0552c94c34d64
--- /dev/null
+++ b/llvm/test/MC/RISCV/large-instructions.test
@@ -0,0 +1,88 @@
+# RUN: yaml2obj -o - %s \
+# RUN:     | llvm-objdump -d - | FileCheck %s
+
+## This CHECKs objdump's handling of wide instruction encodings, and how it
+## groups the instruction bytes when disassembling.
+##
+## This is written in YAML because using `.byte` emits the wrong mapping
+## symbols.
+
+--- !ELF
+FileHeader:
+  Class:           ELFCLASS32
+  Data:            ELFDATA2LSB
+  Type:            ET_REL
+  Machine:         EM_RISCV
+  SectionHeaderStringTable: .strtab
+Sections:
+  - Name:            .text.six_byte
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x1
+    Content:         1F0123456789
+    # CHECK: 011f 4523 8967 <unknown>
+  - Name:            .text.eight_byte
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x1
+    Content:         3F0123456789ABCD
+    # CHECK: 4523013f cdab8967 <unknown>
+  - Name:            .text.ten_byte
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x1
+    Content:         7F0023456789ABCDEFFE
+    # CHECK: 007f 4523 8967 cdab feef <unknown>
+  - Name:            .text.twelve_byte
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x1
+    Content:         7F1023456789ABCDEFFEDCBA
+    # CHECK: 4523107f cdab8967 badcfeef <unknown>
+  - Name:            .text.fourteen_byte
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x1
+    Content:         7F2023456789ABCDEFFEDCBA9876
+    # CHECK: 207f 4523 8967 cdab feef badc 7698 <unknown>
+  - Name:            .text.sixteen_byte
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x1
+    Content:         7F3023456789ABCDEFFEDCBA98765432
+    # CHECK: 4523307f cdab8967 badcfeef 32547698 <unknown>
+  - Name:            .text.eighteen_byte
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x1
+    Content:         7F4023456789ABCDEFFEDCBA987654321012
+    # CHECK: 407f 4523 8967 cdab feef badc 7698 3254 1210 <unknown>
+  - Name:            .text.twenty_byte
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x1
+    Content:         7F5023456789ABCDEFFEDCBA9876543210123456
+    # CHECK: 4523507f cdab8967 badcfeef 32547698 56341210 <unknown>
+  - Name:            .text.twentytwo_byte
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x1
+    Content:         7F6023456789ABCDEFFEDCBA9876543210123456789A
+    # CHECK: 607f 4523 8967 cdab feef badc 7698 3254 1210 5634 9a78 <unknown>
+  - Type:            SectionHeaderTable
+    Sections:
+      - Name:            .strtab
+      - Name:            .text.six_byte
+      - Name:            .text.eight_byte
+      - Name:            .text.ten_byte
+      - Name:            .text.twelve_byte
+      - Name:            .text.fourteen_byte
+      - Name:            .text.sixteen_byte
+      - Name:            .text.eighteen_byte
+      - Name:            .text.twenty_byte
+      - Name:            .text.twentytwo_byte
+      - Name:            .symtab
+Symbols:
+  - Name:            '$x'
+    Section:         .text.six_byte
+...
diff --git a/llvm/test/MC/RISCV/nop-slide.s b/llvm/test/MC/RISCV/nop-slide.s
index 4dc888b3ba777..a49ffdc0e420c 100644
--- a/llvm/test/MC/RISCV/nop-slide.s
+++ b/llvm/test/MC/RISCV/nop-slide.s
@@ -10,18 +10,15 @@
 auipc a0, 0
 
 # CHECK-RVC-NORELAX: 0000000000000000 <.text>:
-# CHECK-RVC-NORELAX-NEXT: 0: 0000      	unimp
-# CHECK-RVC-NORELAX-NEXT: 2: 0001      	nop
+# CHECK-RVC-NORELAX-NEXT: 0: 00 00 01 00 .word 0x00010000
 # CHECK-RVC-NORELAX-NEXT: 4: 00000517  	auipc	a0, 0x0
 
 # CHECK-RVC-RELAX: 0000000000000000 <.text>:
 # CHECK-RVC-RELAX-NEXT:   0: 0001      	nop
-# CHECK-RVC-RELAX-NEXT:   2: 0100      	addi	s0, sp, 0x80
-# CHECK-RVC-RELAX-NEXT:   4: 1700      	addi	s0, sp, 0x3a0
-# CHECK-RVC-RELAX-NEXT:   6: 0005      	c.nop	0x1
-# CHECK-RVC-RELAX-NEXT:   8: 00        	<unknown>
+# CHECK-RVC-RELAX-NEXT:   2: 00 01      .short 0x0100
+# CHECK-RVC-RELAX-NEXT:   4: 00         .byte 0x00
+# CHECK-RVC-RELAX-NEXT:   5: 00000517  	auipc	a0, 0x0
 
 # CHECK: 0000000000000000 <.text>:
-# CHECK-NEXT: 0: 0000      	<unknown>
-# CHECK-NEXT: 2: 0000      	<unknown>
+# CHECK-NEXT: 0: 00 00 00 00 .word 0x00000000
 # CHECK-NEXT: 4: 00000517  	auipc	a0, 0x0
diff --git a/llvm/test/MC/RISCV/rvv/vsetvl-invalid.s b/llvm/test/MC/RISCV/rvv/vsetvl-invalid.s
index b45f3f2dfc854..d97b53803b97a 100644
--- a/llvm/test/MC/RISCV/rvv/vsetvl-invalid.s
+++ b/llvm/test/MC/RISCV/rvv/vsetvl-invalid.s
@@ -4,37 +4,37 @@
 # RUN:     | llvm-objdump -d --mattr=+v - | FileCheck %s
 
 # CHECK: vsetvli a1, a0, e64, m1, tu, mu
-.word 0x018575d7
+.insn 4, 0x018575d7
 
 # CHECK: vsetvli a1, a0, 0x1c
-.word 0x01c575d7
+.insn 4, 0x01c575d7
 
 # CHECK: vsetvli a1, a0, 0x24
-.word 0x024575d7
+.insn 4, 0x024575d7
 
 # CHECK: vsetvli a1, a0, 0x29
-.word 0x029575d7
+.insn 4, 0x029575d7
 
 # CHECK: vsetvli a1, a0, 0x110
-.word 0x110575d7
+.insn 4, 0x110575d7
 
 # CHECK: vsetvli a1, a0, e64, mf8, tu, mu
-.word 0x01d575d7
+.insn 4, 0x01d575d7
 
 # CHECK: vsetivli a1, 0x10, e8, m4, tu, mu
-.word 0xc02875d7
+.insn 4, 0xc02875d7
 
 # CHECK: vsetivli a1, 0x10, 0xc
-.word 0xc0c875d7
+.insn 4, 0xc0c875d7
 
 # CHECK: vsetivli a1, 0x10, 0x14
-.word 0xc14875d7
+.insn 4, 0xc14875d7
 
 # CHECK: vsetivli a1, 0x10, 0x38
-.word 0xc38875d7
+.insn 4, 0xc38875d7
 
 # CHECK: vsetivli a1, 0x10, 0x103
-.word 0xd03875d7
+.insn 4, 0xd03875d7
 
 # CHECK: vsetivli a1, 0x10, e8, mf4, tu, mu
-.word 0xc06875d7
+.insn 4, 0xc06875d7
diff --git a/llvm/tools/llvm-objdump/llvm-objdump.cpp b/llvm/tools/llvm-objdump/llvm-objdump.cpp
index 0316c4ba51da6..541b09a297621 100644
--- a/llvm/tools/llvm-objdump/llvm-objdump.cpp
+++ b/llvm/tools/llvm-objdump/llvm-objdump.cpp
@@ -633,8 +633,13 @@ static bool isCSKYElf(const ObjectFile &Obj) {
   return Elf && Elf->getEMachine() == ELF::EM_CSKY;
 }
 
+static bool isRISCVElf(const ObjectFile &Obj) {
+  const auto *Elf = dyn_cast<ELFObjectFileBase>(&Obj);
+  return Elf && Elf->getEMachine() == ELF::EM_RISCV;
+}
+
 static bool hasMappingSymbols(const ObjectFile &Obj) {
-  return isArmElf(Obj) || isAArch64Elf(Obj) || isCSKYElf(Obj);
+  return isArmElf(Obj) || isAArch64Elf(Obj) || isCSKYElf(Obj) || isRISCVElf(Obj);
 }
 
 static void printRelocation(formatted_raw_ostream &OS, StringRef FileName,

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github-actions bot commented Jul 31, 2025 •
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✅ With the latest revision this PR passed the C/C++ code formatter.

@lenary lenary requested review from asb, kito-cheng and jh7370 August 1, 2025 18:30
jh7370
jh7370 reviewed Aug 4, 2025
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This is more about RISC-V than the general objdump behaviour, so I can't really approve this myself, sorry.

llvm/docs/ReleaseNotes.md
* `llvm-objdump` now has basic support for switching between disassembling code
and data using mapping symbols such as `$x` and `$d`. Switching architectures
using `$x` with an architecture string suffix is not yet supported.

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Minor nit: single blank line, please.

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Done

llvm/test/MC/RISCV/large-instructions.test Outdated
Comment on lines 1 to 2
# RUN: yaml2obj -o - %s \
# RUN: | llvm-objdump -d - | FileCheck %s
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Suggested change
# RUN: yaml2obj -o - %s \
# RUN: | llvm-objdump -d - | FileCheck %s
# RUN: yaml2obj -o %t
# RUN: llvm-objdump -d %t | FileCheck %s

This is more normal in the tests I've seen and means the intermediate object can be inspected, if there's a failure.

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Done

llvm/test/MC/RISCV/large-instructions.test Outdated
Type: SHT_PROGBITS
Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
AddressAlign: 0x1
Content: 1F0123456789
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You might want to consider ContentArray instead, but I suspect it's down to personal preference with no real advantages either way in this case.

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Are there docs on ContentArray - I'm happy to use something less inscrutable, to be honest.

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That's much better, thanks.

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@jh7370 jh7370 jh7370 left review comments

@asb asb Awaiting requested review from asb

@kito-cheng kito-cheng Awaiting requested review from kito-cheng

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@lenary @llvmbot @jh7370