[SPARC] llvm-objdump doesn't recognize V9 instructions in 32-bit SPARC object files

[koachan]

Found this while working on another thing.

reproducer:
  retl
   popc %g0, %g0 ! a V9 instruction

Assembles successfully with e.g. clang -target sparc -mcpu=v9 -c reproducer.s, but llvm-objdump doesn't recognize the popc:

$ llvm-objdump -d reproducer.o 

reproducer.o:	file format elf32-sparc

Disassembly of section .text:

00000000 <reproducer>:
       0: 81 c3 e0 08  	retl
       4: 81 70 00 00  	<unknown>

As a comparison, GNU objdump does recognize the instruction.

[llvmbot]

@llvm/issue-subscribers-tools-llvm-objdump

Author: Koakuma (koachan)

Found this while working on another thing. ``` reproducer: retl popc %g0, %g0 ! a V9 instruction ```

Assembles successfully with e.g. clang -target sparc -mcpu=v9 -c reproducer.s, but llvm-objdump doesn't recognize the popc:

$ llvm-objdump -d reproducer.o 

reproducer.o:	file format elf32-sparc

Disassembly of section .text:

00000000 <reproducer>:
       0: 81 c3 e0 08  	retl
       4: 81 70 00 00  	<unknown>

As a comparison, GNU objdump does recognize the instruction.

[Zck1996]

you should add mcpu for llvm-objdump，llvm-objdump --mcpu=v9 -d

[koachan]

you should add mcpu for llvm-objdump，llvm-objdump --mcpu=v9 -d

Yes, but it should set the -mcpu automatically since the ELF flags already contains said info.