Re: [patch, fortran] Handling of .and. and .or. expressions

[Steve Kargl <sgk at troutmask dot apl dot washington dot edu>]

> 2018-06-27 10:09 GMT+02:00 Janne Blomqvist <blomqvist.janne@gmail.com>:
> >
> > How about committing a patch changing to use TRUTH_{AND|OR}_EXPR, and then
> > check benchmark results (polyhedron, spec etc.)? If performance worsens, we
> > revert, if it improves, great, lets keep it?
> 
> I would definitely support that. I cannot imagine that it will have a
> large impact on benchmarks, but it's certainly a good idea to check.
> (After all: ifort, which is usually perceived as being slightly ahead
> of GCC in terms of performance, does not do this kind of
> short-circuiting either.)

Polyhedron benchmark

Compiler options:
  -static -ffpe-summary=none -O3 -pipe -mtune=native
  -march=native -ffast-math -ftree-vectorize

   Benchmark  Unpatched   Patched
        Name   (secs)      (sec)
   ---------  --------   -------- 
          ac    8.06        8.08   0.3%
      aermod   20.17       20.88   3.5%
         air    3.57        3.58   0.3%
    capacita   42.00       42.66   1.6%
     channel    1.84        1.88   2.2%
       doduc   20.53       20.65   0.6%
     fatigue    4.32        4.38   1.4%
     gas_dyn    2.20        2.15  (2.3%)
      induct    6.19        6.20   0.2%
       linpk    7.23        7.79   7.8%
        mdbx    7.18        7.26   1.1%
          nf    8.12        8.15   0.4%
     protein   26.72       26.98   1.0%
      rnflow   35.69       35.51  (0.5%)
    test_fpu    5.93        6.01   1.4%
        tfft    1.82        1.90   4.4%

14 of 16 tests experience a slow down.  As this is unscientific,
anything within 1% to 2% may not be significant.  However, linpk
is 7.8% slower, tfft is 4.4% slower, and aermod is 3.5% slower.

More importantly, with TRUTH_ANDIF_EXPR and TRUTH_ORIF_EXPR
(the status quo) on x86_64-*-freebsd, I see

                === gfortran Summary ===

# of expected passes            47564
# of expected failures          104
# of unsupported tests          85
/safe/sgk/gcc/obj/gcc/gfortran  version 9.0.0 20180626 (experimental) (GCC) 

while with TRUTH_AND_EXPR and TRUTH_OR_EXPR, I get


                === gfortran Summary ===

# of expected passes            47558
# of unexpected failures        6
# of expected failures          104
# of unsupported tests          85

FAIL: gfortran.dg/actual_pointer_function_1.f90   -O0  execution test
FAIL: gfortran.dg/actual_pointer_function_1.f90   -O1  execution test
FAIL: gfortran.dg/actual_pointer_function_1.f90   -O2  execution test
FAIL: gfortran.dg/actual_pointer_function_1.f90   -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer -finline-functions  execution test
FAIL: gfortran.dg/actual_pointer_function_1.f90   -O3 -g  execution test
FAIL: gfortran.dg/actual_pointer_function_1.f90   -Os  execution test

Execution timeout is: 300
spawn [open ...]

Program received signal SIGSEGV: Segmentation fault - invalid memory reference.

Backtrace for this error:
#0  0x7ffffffff1a2 in ???
#1  0x400c09 in ???
#2  0x400b91 in ???
#3  0x400c51 in ???
#4  0x400854 in _start
        at /usr/src/lib/csu/amd64/crt1.c:74
#5  0x200627fff in ???

-- 
Steve