[Bug target/111311] RISC-V regression testsuite errors with --param=riscv-autovec-preference=scalable

["juzhe.zhong at rivai dot ai" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111311

--- Comment #15 from JuzheZhong <juzhe.zhong at rivai dot ai> ---
Update status:

There are only these following dump FAILs:

FAIL: gcc.dg/signbit-2.c scan-tree-dump optimized "\\s+>\\s+{ 0(, 0)+ }"
FAIL: gcc.dg/signbit-2.c scan-tree-dump-not optimized "\\s+>>\\s+31"
XPASS: gcc.dg/uninit-pred-9_b.c bogus warning (test for bogus messages, line
20)
FAIL: gcc.dg/var-expand1.c scan-rtl-dump loop2_unroll "Expanding Accumulator"
FAIL: gcc.dg/tree-ssa/gen-vect-34.c scan-tree-dump-times vect "vectorized 1
loops" 1
FAIL: gcc.dg/tree-ssa/loop-bound-1.c scan-tree-dump ivopts "bounded by 254"
FAIL: gcc.dg/tree-ssa/loop-bound-2.c scan-tree-dump ivopts "bounded by 254"
XPASS: gcc.dg/tree-ssa/pr84512.c scan-tree-dump optimized "return 285;"
FAIL: gcc.dg/tree-ssa/predcom-4.c scan-tree-dump-times pcom "Combination" 1
FAIL: gcc.dg/tree-ssa/predcom-4.c scan-tree-dump-times pcom "Unrolling 3
times." 1
FAIL: gcc.dg/tree-ssa/predcom-5.c scan-tree-dump-times pcom "Combination" 2
FAIL: gcc.dg/tree-ssa/predcom-5.c scan-tree-dump-times pcom "Unrolling 3
times." 1
FAIL: gcc.dg/tree-ssa/predcom-9.c scan-tree-dump pcom "Executing predictive
commoning without unrolling"
FAIL: gcc.dg/tree-ssa/reassoc-46.c scan-tree-dump-times optimized
"(?:vect_)?sum_[\\d._]+ = (?:(?:vect_)?_[\\d._]+ \\+
(?:vect_)?sum_[\\d._]+|(?:vect_)?sum_[\\d._]+ \\+ (?:vect_)?_[\\d._]+)" 1
FAIL: gcc.dg/tree-ssa/scev-10.c scan-tree-dump-times ivopts " 
Type:\\tREFERENCE ADDRESS\n" 1
FAIL: gcc.dg/tree-ssa/scev-11.c scan-tree-dump-times ivopts " 
Type:\\tREFERENCE ADDRESS\n" 2
FAIL: gcc.dg/tree-ssa/scev-14.c scan-tree-dump ivopts "Overflowness wrto loop
niter:\tNo-overflow"
FAIL: gcc.dg/tree-ssa/scev-9.c scan-tree-dump-times ivopts "  Type:\\tREFERENCE
ADDRESS\n" 1
FAIL: gcc.dg/tree-ssa/split-path-11.c scan-tree-dump-times split-paths "join
point for if-convertable half-diamond" 1

Confirm these FAILs also happen on ARM SVE and they don't fix them.
So, it doesn't make sense we dedicate efforts to fix them.
Just ignore them.

Other than that, we have 2 more FAILs in vect testsuite, these 2 patches will
fix them:

https://gcc.gnu.org/pipermail/gcc-patches/2023-November/635589.html
https://gcc.gnu.org/pipermail/gcc-patches/2023-November/635591.html

After these 2 patches, no dump FAILs need to be fixed, just ignore other dump
FAILs should be reasonable.

Then, we move forward to fix execution FAILs.