[Bug tree-optimization/107195] [13 Regression] wrong code with "-O1 -fno-tree-ccp" on x86_64-linux-gnu since r13-3090-gdf4c584c567263fd

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107195

--- Comment #11 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Thomas Schwinge <tschwinge@gcc.gnu.org>:

https://gcc.gnu.org/g:a9de836c2b22f878cff592b96e11c1b95d4d36ee

commit r13-3434-ga9de836c2b22f878cff592b96e11c1b95d4d36ee
Author: Thomas Schwinge <thomas@codesourcery.com>
Date:   Sun Oct 16 00:07:20 2022 +0200

    Restore 'libgomp.oacc-c-c++-common/nvptx-sese-1.c' SESE regions checking
[PR107195, PR107344]

    That is, adjust for optimization introduced with recent
    commit r13-3217-gc4d15dddf6b9eacb36f535807ad2ee364af46e04
    "[PR107195] Set range to zero when nonzero mask is 0", where GCC now
    understands that after 'r *= 2;', 'r & 1' will never hold here, and thus
    transforms/optimizes/"disturbs" the original code such that GCC/nvptx's
later
    "Neuter whole SESE regions" optimization no longer is applicable to it:

        UNSUPPORTED: libgomp.oacc-c/../libgomp.oacc-c-c++-common/nvptx-sese-1.c
-DACC_DEVICE_TYPE_nvidia=1 -DACC_MEM_SHARED=0 -foffload=nvptx-none  -O0
        PASS: libgomp.oacc-c/../libgomp.oacc-c-c++-common/nvptx-sese-1.c
-DACC_DEVICE_TYPE_nvidia=1 -DACC_MEM_SHARED=0 -foffload=nvptx-none  -O2  (test
for excess errors)
        PASS: libgomp.oacc-c/../libgomp.oacc-c-c++-common/nvptx-sese-1.c
-DACC_DEVICE_TYPE_nvidia=1 -DACC_MEM_SHARED=0 -foffload=nvptx-none  -O2 
execution test
        [-PASS:-]{+FAIL:+}
libgomp.oacc-c/../libgomp.oacc-c-c++-common/nvptx-sese-1.c
-DACC_DEVICE_TYPE_nvidia=1 -DACC_MEM_SHARED=0 -foffload=nvptx-none  -O2  
scan-nvptx-none-offload-rtl-dump mach "SESE regions:.*
[0-9]+{[0-9]+->[0-9]+(\\.[0-9]+)+}"

    Same for C++.

    It's unclear to me if this is an actual "problem", which optimization is
"more
    important", so I've filed PR107344 "GCC/nvptx SESE region optimization" to
    capture this question, and here restore what we intend to be testing (to my
    understanding) in 'libgomp.oacc-c-c++-common/nvptx-sese-1.c'.

            PR tree-optimization/107195
            PR target/107344
            libgomp/
            * testsuite/libgomp.oacc-c-c++-common/nvptx-sese-1.c: Restore SESE
            regions checking.