testsuite: Add C++ testcase for the recent PTA bug
Adds a C++ test case to cover a Pointer Analysis regression.
This commit adds a new C++ test case to the GCC testsuite. The testcase is designed to expose a regression related to Pointer Analysis (PTA) and function return values, specifically involving __builtin_memcpy and conditional memory allocation.
This regression was introduced by a previous fix for PR tree-optimization/112653 and affects multiple GCC branches. The new test ensures this specific scenario is covered and verified.
In Details
Adds a C++ testcase (g++.dg/opt/20260703-1.C) to reproduce a regression in Pointer Analysis (PTA) and DSE (Dead Store Elimination). The regression, introduced by the fix for PR tree-optimization/112653, occurs when DSE incorrectly eliminates a call to __builtin_memcpy whose destination is an alloca'd buffer conditionally returned from a function.
- Pointer Analysis (PTA)
- A static analysis technique that determines the possible memory locations a pointer can refer to during program execution. Crucial for many optimizations.
- DSE (Dead Store Elimination)
- An optimization pass that removes stores to memory locations that are never read afterwards.
- PR
- Problem Report. GCC uses a bug tracking system where issues are filed as PRs.