[PATCH] D16749: [OpenMP] Map clause codegeneration.

[Samuel Antao via cfe-commits]

sfantao added a comment.

Hi Alexey,

Thanks for the feedback!


================
Comment at: lib/CodeGen/CGOpenMPRuntime.cpp:3901-3932
@@ +3900,34 @@
+    // Reference types are ignored for mapping purposes.
+    if (auto *RefTy = ExprTy->getAs<ReferenceType>())
+      ExprTy = RefTy->getPointeeType().getCanonicalType();
+
+    // Given that an array section is considered a built-in type, we need to
+    // do the calculation based on the length of the section instead of relying
+    // on CGF.getTypeSize(E->getType()).
+    if (const auto *OAE = dyn_cast<OMPArraySectionExpr>(E)) {
+      auto BaseTy =
+          OAE->getBase()->IgnoreParenImpCasts()->getType().getCanonicalType();
+      // Reference types are ignored for mapping purposes.
+      if (auto *RefTy = BaseTy->getAs<ReferenceType>())
+        BaseTy = RefTy->getPointeeType().getCanonicalType();
+
+      // If there is no length associated with the expression, that means we
+      // are using the whole length of the base.
+      if (!OAE->getLength())
+        return CGF.getTypeSize(BaseTy);
+
+      llvm::Value *ElemSize;
+      if (auto *PTy = BaseTy->getAs<PointerType>()) {
+        ElemSize = CGF.getTypeSize(PTy->getPointeeType().getCanonicalType());
+      } else {
+        auto *ATy = cast<ArrayType>(BaseTy.getTypePtr());
+        assert(ATy && "Expecting array type if not a pointer type.");
+        ElemSize = CGF.getTypeSize(ATy->getElementType().getCanonicalType());
+      }
+
+      auto *LengthVal = CGF.EmitScalarExpr(OAE->getLength());
+      LengthVal =
+          CGF.Builder.CreateIntCast(LengthVal, CGF.SizeTy, /*isSigned=*/false);
+      return CGF.Builder.CreateNUWMul(LengthVal, ElemSize);
+    }
+    return CGF.getTypeSize(ExprTy);
----------------
ABataev wrote:
> Did not find any with array sections as base. Could please point a test where I can find something like 'marr[:][0:2][0:2]' as a mapped expression?
> Also, it will produce some recalculation for VLAs. Add a test for it, please.
> Did not find any with array sections as base. Could please point a test where I can find something like 'marr[:][0:2][0:2]' as a mapped expression?

Oh, a map that uses an array expression that is not in the rightmost subexpression is illegal because it would correspond to non-contiguous storage. Sema is already taking care of that. I added your specific example to the Sema tests anyway.

> Also, it will produce some recalculation for VLAs. Add a test for it, please.

Added tests for multidimensional VLAs.







http://reviews.llvm.org/D16749