[llvm-bugs] [Bug 51147] New: [AArch64] Extremely slow code generation for series of function calls/addition

[via llvm-bugs]

https://bugs.llvm.org/show_bug.cgi?id=51147

            Bug ID: 51147
           Summary: [AArch64] Extremely slow code generation for series of
                    function calls/addition
           Product: new-bugs
           Version: trunk
          Hardware: PC
                OS: Linux
            Status: NEW
          Severity: enhancement
          Priority: P
         Component: new bugs
          Assignee: unassignedbugs at nondot.org
          Reporter: jstenglein at gmail.com
                CC: htmldeveloper at gmail.com, llvm-bugs at lists.llvm.org

Created attachment 25038
  --> https://bugs.llvm.org/attachment.cgi?id=25038&action=edit
.c file producing failure

In a function containing about 1000 calls and adds, we see the aarch64 target
taking about 30 minutes to do code generation.  The slow pass is:

BISECT: running pass (96) AArch64 Instruction Selection on function
(len_internal)

Other targets have no issue and complete quickly.

gcc time: 0.617u 0.022s 0:00.65 96.9%     0+0k 32+160io 0pf+0w
clang aarch64 time: 1998.064u 0.135s 33:23.82 99.7% 0+0k 0+256io 0pf+0w
clang time default target: 0.706u 0.020s 0:00.74 97.2%     0+0k 0+144io 0pf+0w

Command that is slow: clang --target=aarch64-unknown-linux  -O3  -c simple.c 

Clang version - latest from trunk:
clang version 13.0.0 (https://github.com/llvm/llvm-project
9da70ab3d43c79116f80fc06aa7cf517374ce42c)

Attached the file that causes the slowdown

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