--keepnops flag in "uni export" does not keep the "nops" in mips

romits800 commented 5 years ago

I compile the following program test-issue.c:

int global_var =  21;
int test(int n) {
    if (n>0) {
        return n;
    } else {
        return global_var - n;
    }
}

I use the following procedure to generate the .mir and .asm.mir files: Generate the .ll file:

clang -O2 -S -target mips -emit-llvm test-issue.c

Generate the .mir, .asm.mir files (which also generates an error):

llc test-issue.ll -O2 -march=mips -mcpu=mips32 -unison -unison-no-clean

Copy the generated files (/tmp/unison-20eb1e.*):

cp /tmp/unison-20eb1e.asm.mir test-issue.asm.mir
cp /tmp/unison-20eb1e.mir test-issue.mir

Run unsion as follows:

uni import --target=Mips test-issue.mir -o test-issue.uni --function=test --maxblocksize=25 --goal=speed
uni linearize --target=Mips test-issue.uni -o test-issue.lssa.uni
uni extend --target=Mips test-issue.lssa.uni -o test-issue.ext.uni
uni augment --target=Mips test-issue.ext.uni -o test-issue.alt.uni
uni normalize --target=Mips test-issue.asm.mir -o test-issue.llvm.mir
uni model --target=Mips test-issue.alt.uni -o test-issue.json --basefile=test-issue.llvm.mir +RTS -K20M -RTS
gecode-presolver -o test-issue.ext.json -dzn test-issue.dzn --verbose test-issue.json
gecode-solver -o test-issue.out.json --verbose test-issue.ext.json

Then, by running uni export:

uni export --keepnops --target=Mips test-issue.alt.uni -o test-issue.unison.mir --basefile=test-issue.llvm.mir --solfile=test-issue.out.json

The result test-issue.out.json does not contain nops after the LW instructions:

....
bb.0 (freq 1):
    %v0 = LUi $_gp_disp
    %v0 = ADDiu %v0, $_gp_disp
    %at = ADDu %v0, %t9
    %at = LW %at, @global_var
    %at = LW %at, 0
    %v0 = SUBu %at, %a0
    %at = SLTi %a0, 1
    PseudoReturn %ra {
      %v0 = MOVZ_I_I %a0, %at, %v0
    }
...

The version of uni I use is:

$ uni -V
Unison v0, Roberto Castaneda Lozano [roberto.castaneda@ri.se]

The version of clang I use is:

$ clang --version
clang version 3.8.0-2ubuntu4 (tags/RELEASE_380/final)
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin

The version of llc that I use is:

$ llc --version
LLVM (http://llvm.org/):
  LLVM version 3.8.1
  DEBUG build with assertions.
  Built Mar 13 2019 (19:05:44).
  Default target: x86_64-unknown-linux-gnu
  Host CPU: broadwell

  Registered Targets:
    arm      - ARM
    armeb    - ARM (big endian)
    hexagon  - Hexagon
    mips     - Mips
    mips64   - Mips64 [experimental]
    mips64el - Mips64el [experimental]
    mipsel   - Mipsel
    thumb    - Thumb
    thumbeb  - Thumb (big endian)

robcasloz commented 5 years ago

Hi @romits800, thanks for the detailed report! Could you also attach the test-issue.mir and test-issue.asm.mir files to make it easier to reproduce?

romits800 commented 5 years ago

Hi @robcasloz, I attach the files. test-issue.tar.gz

unison-code / unison

--keepnops flag in "uni export" does not keep the "nops" in mips #39