en Copyright 2015 Java http://172.16.0.5:8080/history/llvm-project-15.0.7/clang/test/Analysis/solver-sym-simplification-ptr-bool.cl#918bda12 [analyzer] Do not assume that all pointers have the same bitwidth as void*This change addresses this assertion that occurs in a downstreamcompiler with a custom target.```APInt.h:1151: bool llvm::APInt::operator==(const llvm::APInt &) const: Assertion `BitWidth == RHS.BitWidth && "Comparison requires equal bit widths"'```No covering test case is susbmitted with this change since this crashcannot be reproduced using any upstream supported target. The test casethat exposes this issue is as simple as:```lang=c++ void test(int * p) { int * q = p-1; if (q) {} if (q) {} // crash (void)q; }```The custom target that exposes this problem supports two address spaces,16-bit `char`s, and a `_Bool` type that maps to 16-bits. There are no upstreamsupported targets with similar attributes.The assertion appears to be happening as a result of evaluating the`SymIntExpr` `(reg_$0<int * p>) != 0U` in `VisitSymIntExpr` located in`SimpleSValBuilder.cpp`. The `LHS` is evaluated to `32b` and the `RHS` isevaluated to `16b`. This eventually leads to the assertion in `APInt.h`.While this change addresses the crash and passes LITs, two follow-upsare required: 1) The remainder of `getZeroWithPtrWidth()` and `getIntWithPtrWidth()` should be cleaned up following this model to prevent future confusion. 2) We're not sure why references are found along with the modified code path, that should not be the case. A more principled fix may be found after some further comprehension of why this is the case.Acks: Thanks to @steakhal and @martong for the discussions leading to thisfix.Reviewed By: NoQDifferential Revision: https://reviews.llvm.org/D105974 List of files: /llvm-project-15.0.7/clang/test/Analysis/solver-sym-simplification-ptr-bool.cl Wed, 14 Jul 2021 12:00:14 +0000 Vince Bridgers <vince.a.bridgers@gmail.com>