[Bug tree-optimization/59303] New: [ARM/AArch32//AArch64] regressions in uninit-pred-8_b.c and uninit-pred-9_b.c

["christophe.lyon at st dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59303

            Bug ID: 59303
           Summary: [ARM/AArch32//AArch64] regressions in
                    uninit-pred-8_b.c and uninit-pred-9_b.c
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: christophe.lyon at st dot com

Since commit 204194 from Andrew Pinski:
    2013-10-29  Andrew Pinski <apinski@cavium.com>

            * tree-ssa-ifcombine.c: Include rtl.h and tm_p.h.
            (ifcombine_ifandif): Handle cases where
            maybe_fold_and_comparisons fails, combining the branches
            anyways.
            (tree_ssa_ifcombine): Inverse the order of
            the basic block walk, increases the number of combinings.
            * gimple.h (gsi_start_nondebug_after_labels_bb): New function.

    2013-10-29  Andrew Pinski <apinski@cavium.com>
                Zhenqiang Chen  <zhenqiang.chen@linaro.org>

            * gcc.dg/tree-ssa/ssa-ifcombine-ccmp-1.c: New test case.
            * gcc.dg/tree-ssa/ssa-ifcombine-ccmp-2.c: New test case.
            * gcc.dg/tree-ssa/ssa-ifcombine-ccmp-3.c: New test case.
            * gcc.dg/tree-ssa/ssa-ifcombine-ccmp-4.c: New test case.
            * gcc.dg/tree-ssa/ssa-ifcombine-ccmp-5.c: New test case.
            * gcc.dg/tree-ssa/ssa-ifcombine-ccmp-6.c: New test case.
            * gcc.dg/tree-ssa/phi-opt-9.c: Use a function call to prevent
            conditional move to be used.
            * gcc.dg/tree-ssa/ssa-dom-thread-3.c: Remove.


I have noticed regressions on ARM targets. The 2 mentioned testcases now FAIL
(used to PASS):
  gcc.dg/uninit-pred-8_b.c bogus warning (test for bogus messages, line 20)
  gcc.dg/uninit-pred-9_b.c bogus warning (test for bogus messages, line 24)

It is the case in the following configurations:
targets: arm-none-linux-gnueabi, arm-none-linux-gnueabihf,
armeb-none-linux-gnueabihf
mode: arm,thumb
cpu: cortex-a9
fpu: default, vfpv3, neon-fp16

targets: aarch64-none-elf, aarch64-none-linux

These 2 regressions do not appear when configuring --target
arm-none-linux-gnueabihf --with-cpu=cortex-a5 --with-fpu=vfpv3-d16-fp16


However, when configuring --target arm-none-linux-gnueabihf
--with-cpu=cortex-a5 --with-fpu=vfpv3-d16-fp16, some of the newly introduced
tests fail:
  gcc.dg/tree-ssa/ssa-ifcombine-ccmp-1.c scan-tree-dump optimized "&"
  gcc.dg/tree-ssa/ssa-ifcombine-ccmp-4.c scan-tree-dump optimized "&"
  gcc.dg/tree-ssa/ssa-ifcombine-ccmp-5.c scan-tree-dump-times optimized "&" 2
  gcc.dg/tree-ssa/ssa-ifcombine-ccmp-6.c scan-tree-dump-times optimized "\\|" 2