Fixed clang as assembly

[cielavenir]

Thanks to recent clang as update, it is possible to assemble isa-l with least modification.
I have tested compression/decompression using Android NDK r21b (NDK r20c is old and does not work)

Maybe we could work on #107 again.

Signed-off-by: Taiju Yamada [email protected]

[gbtucker]

Thanks @cielavenir, so these are the only changes necessary to build on android/clang? If so can someone test on linux/clang?

Was the sign extend to 64bit originally intended or promoted automatically before with GAS? Do you know why this was a tools issue?

[cielavenir]

gen_icf_map:

GAS assembled into sub x1, x4, w15, uxtw so my previous code (x1,x4,x15,uxtx) was wrong. I fixed it so that GAS (with/without my patch) and clang-as (with my patch) writes the same machine-code.

igzip_decode_huffman:

GAS (with/without my patch) and clang-as assembled into mov w4,w4 (already the same).

[cielavenir]

by the way the original errors were:

gen_icf_map:

igzip/aarch64/gen_icf_map.S:234:31: error: expected 'sxtx' 'uxtx' or 'lsl' with optional integer in range [0, 4]
 sub x_tmp1, next_in, x_dist, uxtw

igzip_decode_huffman:

<instantiation>:9:7: error: invalid operand for instruction
 uxtw read_in_length,read_in_length

[cielavenir]

For the "linux testing", clang needs to be at least rL360381 according to https://reviews.llvm.org/D61719 .

[yuhaoth]

Thanks @cielavenir . Just read this patch . It looks good for me .
I will setup internal CI test for clang and post the result here.

Do you know the release version of rL360381 ? I want to update the document about arm64 build

[cielavenir]

according to llvm/llvm-project@6ee7f31 and https://github.com/llvm/llvm-project/blob/release/9.x/llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp , LLVM9 supports .dword.

[cielavenir]

#164 includes this PR content. So please merge this only if #164 takes quite long.

[yuhaoth]

according to llvm/llvm-project@6ee7f31 and https://github.com/llvm/llvm-project/blob/release/9.x/llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp , LLVM9 supports .dword.

Thanks

[yuhaoth]

I re-org this patch into #168 .
@cielavenir I need your approve to merge #168

[cielavenir]

moved to #168