disassembly printing

This is based on the https://github.com/lowRISC/riscv-llvm-integration repo at Latest commit 74e4050 on 3 Oct 2017.

Running llvm-objdump does not disassemble the instructions from the M extension and the jalr is formatted differently from the gnu objdump. Is this expected?

My command line is: (on windows msys2):
$ ./llvm-objdump.exe -arch=riscv32 -disassemble my_folder/riscv_blocks.elf

Corresponding gnu command:
$ bin/riscv64-unknown-elf-objdump.exe -d -M no-aliases blocks.elf

Sample output 1:
42000028: b7 57 c6 41 lui a5, 269413
4200002c: 93 87 d7 e6 addi a5, a5, -403
42000030: 33 07 f7 02
42000034: b7 07 00 42 lui a5, 270336
42000038: 23 a6 e7 2a sw a4, 684(a5)
4200003c: b7 07 00 42 lui a5, 270336

gnu objdump output: multiplication instruction expected (ignore hex/$ formatting/comments)
42000028: 41c657b7 lui a5,0x41c65
4200002c: e6d78793 addi a5,a5,-403 # 41c64e6d <STACK_SIZE+0x41c64a6d>
42000030: 02f70733 mul a4,a4,a5
42000034: 420007b7 lui a5,0x42000
42000038: 2ae7a623 sw a4,684(a5) # 420002ac
4200003c: 420007b7 lui a5,0x42000

Sample output 1: uses comma formatting for jalr

gnu objdump output: uses register offset bracket formatting for jalr (ignore hex/$ formatting/comments)
42000118: f8f714e3 bne a4,a5,420000a0 <draw_block+0x2c>
4200011c: 00000013 addi zero,zero,0
42000120: 03c12403 lw s0,60(sp)
42000124: 04010113 addi sp,sp,64
42000128: 00008067 jalr zero,0(ra)

The jalr difference can can be seen by using table-gen with gen-asm-writer option
$ ./bin/llvm-tblgen.exe -gen-asm-writer -I=../include -I=../lib/Target/RISCV ../lib/Target/RISCV/RISCV.td

Reproduce the comparison with llvm-objdump.exe, riscv64-unknown-elf-objdump.exe, and the supplied ELF samples. Read lib/Target/RISCV/RISCV.td and inspect the output from llvm-tblgen with -gen-asm-writer. Done means determining whether M-extension instructions and jalr formatting should match the GNU disassembly and recording the required behavior.