[Bug tree-optimization/123541] New: Load merging missing

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123541

            Bug ID: 123541
           Summary: Load merging missing
           Product: gcc
           Version: 16.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
            Blocks: 94094
  Target Milestone: ---

Take:
```
unsigned int f(unsigned char *a)
{
  unsigned short *b = (unsigned short*)a;
  return (*b<<8) | a[1];
}
```

We should only get one load but currently there are 2.

This testcase is reduced from store_merging_18.c after a match patch.


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94094
[Bug 94094] [meta-bug] store-merging and/or bswap load/store-merging missed
optimizations