[clang] [Clang] Allow vector and matrix type attributes for sub-byte _BitInt (PR #140253)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Dmitry Sidorov (MrSidims)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/140253.diff


4 Files Affected:

- (modified) clang/include/clang/Basic/DiagnosticSemaKinds.td (+1-2) 
- (modified) clang/lib/Sema/SemaType.cpp (+2-2) 
- (modified) clang/test/SemaCXX/ext-int.cpp (+2-10) 
- (modified) clang/test/SemaCXX/matrix-type.cpp (+1-2) 


``````````diff
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index f0bd5a1174020..9f20c07882901 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -3257,8 +3257,7 @@ def err_attribute_too_few_arguments : Error<
   "%0 attribute takes at least %1 argument%s1">;
 def err_attribute_invalid_vector_type : Error<"invalid vector element type %0">;
 def err_attribute_invalid_bitint_vector_type : Error<
-  "'_BitInt' %select{vector|matrix}0 element width must be %select{a power of 2|"
-  "at least as wide as 'CHAR_BIT'}1">;
+  "'_BitInt' %select{vector|matrix}0 element width must be a power of 2">;
 def err_attribute_invalid_matrix_type : Error<"invalid matrix element type %0">;
 def err_attribute_bad_neon_vector_size : Error<
   "Neon vector size must be 64 or 128 bits">;
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 9ed2326f151a3..28d441234262b 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -2321,9 +2321,9 @@ static bool CheckBitIntElementType(Sema &S, SourceLocation AttrLoc,
                                    bool ForMatrixType = false) {
   // Only support _BitInt elements with byte-sized power of 2 NumBits.
   unsigned NumBits = BIT->getNumBits();
-  if (!llvm::isPowerOf2_32(NumBits) || NumBits < 8)
+  if (!llvm::isPowerOf2_32(NumBits))
     return S.Diag(AttrLoc, diag::err_attribute_invalid_bitint_vector_type)
-           << ForMatrixType << (NumBits < 8);
+           << ForMatrixType;
   return false;
 }
 
diff --git a/clang/test/SemaCXX/ext-int.cpp b/clang/test/SemaCXX/ext-int.cpp
index d974221e774a7..5c566dafed931 100644
--- a/clang/test/SemaCXX/ext-int.cpp
+++ b/clang/test/SemaCXX/ext-int.cpp
@@ -84,17 +84,9 @@ struct is_same<T,T> {
 };
 
 // Reject vector types:
-// expected-error at +1{{'_BitInt' vector element width must be at least as wide as 'CHAR_BIT'}}
-typedef _BitInt(2) __attribute__((vector_size(16))) VecTy;
-// expected-error at +1{{'_BitInt' vector element width must be at least as wide as 'CHAR_BIT'}}
-typedef _BitInt(2) __attribute__((ext_vector_type(32))) OtherVecTy;
-// expected-error at +1{{'_BitInt' vector element width must be at least as wide as 'CHAR_BIT'}}
-typedef _BitInt(4) __attribute__((vector_size(16))) VecTy2;
-// expected-error at +1{{'_BitInt' vector element width must be at least as wide as 'CHAR_BIT'}}
-typedef _BitInt(4) __attribute__((ext_vector_type(32))) OtherVecTy2;
-// expected-error at +1{{'_BitInt' vector element width must be at least as wide as 'CHAR_BIT'}}
+// expected-error at +1{{'_BitInt' vector element width must be a power of 2}}
 typedef _BitInt(5) __attribute__((vector_size(16))) VecTy3;
-// expected-error at +1{{'_BitInt' vector element width must be at least as wide as 'CHAR_BIT'}}
+// expected-error at +1{{'_BitInt' vector element width must be a power of 2}}
 typedef _BitInt(5) __attribute__((ext_vector_type(32))) OtherVecTy3;
 // expected-error at +1{{'_BitInt' vector element width must be a power of 2}}
 typedef _BitInt(37) __attribute__((vector_size(16))) VecTy4;
diff --git a/clang/test/SemaCXX/matrix-type.cpp b/clang/test/SemaCXX/matrix-type.cpp
index bb7a8421ca9e3..186d3b6b35208 100644
--- a/clang/test/SemaCXX/matrix-type.cpp
+++ b/clang/test/SemaCXX/matrix-type.cpp
@@ -31,8 +31,7 @@ void matrix_unsupported_element_type() {
 }
 
 void matrix_unsupported_bit_int() {
-  using m1 = _BitInt(2) __attribute__((matrix_type(4, 4))); // expected-error{{'_BitInt' matrix element width must be at least as wide as 'CHAR_BIT'}}
-  using m2 = _BitInt(7) __attribute__((matrix_type(4, 4))); // expected-error{{'_BitInt' matrix element width must be at least as wide as 'CHAR_BIT'}}
+  using m2 = _BitInt(7) __attribute__((matrix_type(4, 4))); // expected-error{{'_BitInt' matrix element width must be a power of 2}}
   using m3 = _BitInt(9) __attribute__((matrix_type(4, 4))); // expected-error{{'_BitInt' matrix element width must be a power of 2}}
   using m4 = _BitInt(12) __attribute__((matrix_type(4, 4))); // expected-error{{'_BitInt' matrix element width must be a power of 2}}
   using m5 = _BitInt(8) __attribute__((matrix_type(4, 4)));

``````````

</details>


https://github.com/llvm/llvm-project/pull/140253