[clang] [Clang] Fix assertion "unsigned range includes negative?" in AnalyzeComparison during Sema of vector comparison with mismatched signed/unsigned types and __builtin_convertvector (PR #182627)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Yutong Zhu (YutongZhuu)

<details>
<summary>Changes</summary>

This PR attempts to fix #<!-- -->173614.

The ``TryGetExprRange`` function now checks if the oprand is an unsigned vector when computing the ranges.

Thanks for reviewing.

---
Full diff: https://github.com/llvm/llvm-project/pull/182627.diff


3 Files Affected:

- (modified) clang/docs/ReleaseNotes.rst (+2) 
- (modified) clang/lib/Sema/SemaChecking.cpp (+18) 
- (added) clang/test/Sema/compare.cpp (+14) 


``````````diff
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 77e2078a5ffbf..18c3667894172 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -498,6 +498,8 @@ Improvements to Clang's diagnostics
 - Clang now generates a fix-it for C++20 designated initializers when the 
   initializers do not match the declaration order in the structure. 
 
+- Clang now doesn't throw assertion errors when comparing unsigned vectors(#173614)
+
 Improvements to Clang's time-trace
 ----------------------------------
 
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index ba4b25961d70d..052828107a867 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -11500,6 +11500,15 @@ static std::optional<IntRange> TryGetExprRange(ASTContext &C, const Expr *E,
                                Approximate);
       }
 
+      QualType T = E->getType();
+      if (const auto *VT = T->getAs<VectorType>()) {
+        QualType ElemTy = VT->getElementType();
+        if (ElemTy->isUnsignedIntegerType()) {
+          return TryGetExprRange(C, UO->getSubExpr(), MaxWidth,
+                                 InConstantContext, Approximate);
+        }
+      }
+
       std::optional<IntRange> SubRange = TryGetExprRange(
           C, UO->getSubExpr(), MaxWidth, InConstantContext, Approximate);
 
@@ -11518,6 +11527,15 @@ static std::optional<IntRange> TryGetExprRange(ASTContext &C, const Expr *E,
                                Approximate);
       }
 
+      QualType T = E->getType();
+
+      if (const auto *VT = T->getAs<VectorType>()) {
+        QualType ElemTy = VT->getElementType();
+        if (ElemTy->isUnsignedIntegerType()) {
+          return TryGetExprRange(C, UO->getSubExpr(), MaxWidth,
+                                 InConstantContext, Approximate);
+        }
+      }
       std::optional<IntRange> SubRange = TryGetExprRange(
           C, UO->getSubExpr(), MaxWidth, InConstantContext, Approximate);
 
diff --git a/clang/test/Sema/compare.cpp b/clang/test/Sema/compare.cpp
new file mode 100644
index 0000000000000..fb5d82847e2a0
--- /dev/null
+++ b/clang/test/Sema/compare.cpp
@@ -0,0 +1,14 @@
+// RUN: %clang_cc1 -fsyntax-only
+// Expect no assertion failures in this file (#173614).
+typedef unsigned long __attribute__((__vector_size__(8))) W;
+
+int i;
+W g;
+
+void negation(void) {
+  W w = i == (-g);
+}
+
+void bitwiseNot(void) {
+  W w = i == (~g);
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/182627