first self review

Author: spall

clang/lib/AST/ExprConstant.cpp

@@ -3843,9 +3843,8 @@ static bool handleScalarCast(EvalInfo &Info, const FPOptions FPO, const Expr *E,
       if (!HandleConversionToBool(Original, BoolResult))
         return false;
       uint64_t IntResult = BoolResult;
-      Result = APValue(Info.Ctx.MakeIntValue(IntResult, DestTy));
-      // TODO destty is wrong here if destty is float....
-      // can we use sourcety here?
+      Result = APValue(Info.Ctx.MakeIntValue(
+          IntResult, Info.Ctx.getIntTypeForBitwidth(64, true)));
     }
     if (DestTy->isFloatingType()) {
       APValue Result2 = APValue(APFloat(0.0));
@@ -3897,8 +3896,6 @@ static bool handleScalarCast(EvalInfo &Info, const FPOptions FPO, const Expr *E,
     }
   }
 
-  // Info.FFDiag(E, diag::err_convertvector_constexpr_unsupported_vector_cast)
-  //   << SourceTy << DestTy;
   return false;
 }
 
@@ -3917,7 +3914,7 @@ static bool constructAggregate(EvalInfo &Info, const FPOptions FPO,
   while (!WorkList.empty() && ElI < Elements.size()) {
     auto [Res, Type, BitWidth] = WorkList.pop_back_val();
 
-    if (Type->isRealFloatingType() || Type->isBooleanType()) {
+    if (Type->isRealFloatingType()) {
       if (!handleScalarCast(Info, FPO, E, ElTypes[ElI], Type, Elements[ElI],
                             *Res))
         return false;
@@ -3978,10 +3975,10 @@ static bool constructAggregate(EvalInfo &Info, const FPOptions FPO,
       // we need to traverse backwards
       // Visit the base classes.
       if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD)) {
-        // todo assert there is only 1 base at most
-        for (size_t I = 0, E = CXXRD->getNumBases(); I != E; ++I) {
-          const CXXBaseSpecifier &BS = CXXRD->bases_begin()[I];
-          ReverseList.emplace_back(&Res->getStructBase(I), BS.getType(), 0u);
+        if (CXXRD->getNumBases() > 0) {
+          assert(CXXRD->getNumBases() == 1);
+          const CXXBaseSpecifier &BS = CXXRD->bases_begin()[0];
+          ReverseList.emplace_back(&Res->getStructBase(0), BS.getType(), 0u);
         }
       }
 
@@ -4057,13 +4054,12 @@ static unsigned elementwiseSize(EvalInfo &Info, QualType BaseTy) {
     }
     if (Type->isRecordType()) {
       const RecordDecl *RD = Type->getAsRecordDecl();
-      // const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
 
       // Visit the base classes.
       if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD)) {
-        // todo assert there is only 1 base at most
-        for (size_t I = 0, E = CXXRD->getNumBases(); I != E; ++I) {
-          const CXXBaseSpecifier &BS = CXXRD->bases_begin()[I];
+        if (CXXRD->getNumBases() > 0) {
+          assert(CXXRD->getNumBases() == 1);
+          const CXXBaseSpecifier &BS = CXXRD->bases_begin()[0];
           WorkList.push_back(BS.getType());
         }
       }
@@ -4126,7 +4122,6 @@ static bool flattenAPValue(const ASTContext &Ctx, APValue Value,
       for (FieldDecl *FD : RD->fields()) {
         if (FD->isUnnamedBitField())
           continue;
-        // if (FD->isBitField()) {
         ReverseList.emplace_back(Work.getStructField(FD->getFieldIndex()),
                                  FD->getType());
       }

clang/test/SemaHLSL/Types/BuiltinVector/TruncationConstantExpr.hlsl

@@ -6,27 +6,8 @@
 // good way to constexpr `any` for bool vector conditions, and the condition for
 // _Static_assert must be an integral constant.
 
-struct S {
-  int3 A;
-  float B;
-};
-
 export void fn() {
 
-  _Static_assert(((float4)(int[6]){1,2,3,4,5,6}).x == 1.0, "Woo!");
-
-  // This compiling successfully verifies that the array constant expression
-  // gets truncated to a float at compile time for instantiation via the
-  // flat cast
-  _Static_assert(((int)(int[2]){1,2}) == 1, "Woo!");
-
-  // This compiling successfully verifies that the struct constant expression
-  // gets truncated to an integer at compile time for instatiation via the
-  // flat cast
-  _Static_assert(((int)(S){{1,2,3},1.0}) == 1, "Woo!");
-
-  _Static_assert(((float)(float[2]){1.0,2.0}) == 1.0, "Woo!");
-
   // This compiling successfully verifies that the vector constant expression
   // gets truncated to an integer at compile time for instantiation.
   _Static_assert(((int)1.xxxx) + 0 == 1, "Woo!");

clang/test/SemaHLSL/Types/ElementwiseCastConstantExpr.hlsl

@@ -27,6 +27,13 @@ struct B2 : B1 {
 };
 
 export void fn() {
+/*
+  _Static_assert(((float4)(int[6]){1,2,3,4,5,6}).x == 1.0, "Woo!");
+
+  // This compiling successfully verifies that the array constant expression
+  // gets truncated to a float at compile time for instantiation via the
+  // flat cast
+  _Static_assert(((int)(int[2]){1,2}) == 1, "Woo!");
 
   // truncation tests
   // result type int
@@ -73,4 +80,13 @@ export void fn() {
   _Static_assert(SB.U[1] == 1000, "Woo!");
   _Static_assert(SB.I == 8, "Woo!");
   _Static_assert(SB.I2 == 0, "Woo!");
+*/
+  // Make sure we read bitfields correctly
+  constexpr Base BB = {222.22, {100, 200}, -2, 7};
+  constexpr int Arr[5] = (int[5])BB;
+  _Static_assert(Arr[0] == 222, "Woo!");
+  _Static_assert(Arr[1] == 100, "Woo!");
+  _Static_assert(Arr[2] == 200, "Woo!");
+  _Static_assert(Arr[3] == -2, "Woo!");
+  _Static_assert(Arr[4] == 7, "Woo!");
 }