[clang] [llvm] [AMDGPU] Adding the amdgpu-num-work-groups function attribute (PR #79035)

[Erich Keane via llvm-commits]

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@@ -8069,6 +8069,67 @@ static void handleAMDGPUNumVGPRAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
   D->addAttr(::new (S.Context) AMDGPUNumVGPRAttr(S.Context, AL, NumVGPR));
 }
 
+// Returns true if error
+static bool
+checkAMDGPUMaxNumWorkGroupsArguments(Sema &S, Expr *XExpr, Expr *YExpr,
+                                     Expr *ZExpr,
+                                     const AMDGPUMaxNumWorkGroupsAttr &Attr) {
+  if (S.DiagnoseUnexpandedParameterPack(XExpr) ||
+      S.DiagnoseUnexpandedParameterPack(YExpr) ||
+      S.DiagnoseUnexpandedParameterPack(ZExpr))
+    return true;
+
+  // Accept template arguments for now as they depend on something else.
+  // We'll get to check them when they eventually get instantiated.
+  if (XExpr->isValueDependent() || YExpr->isValueDependent() ||
+      ZExpr->isValueDependent())
+    return false;
+
+  uint32_t NumWG[3];
+  Expr *Exprs[3] = {XExpr, YExpr, ZExpr};
+  for (int i = 0; i < 3; i++) {
+    if (!checkUInt32Argument(S, Attr, Exprs[i], NumWG[i], i,
+                             /*StrictlyUnsigned=*/true))
+      return true;
+    if (NumWG[i] == 0) {
+      S.Diag(Attr.getLoc(), diag::err_attribute_argument_is_zero)
+          << &Attr << Exprs[i]->getSourceRange();
+      return true;
+    }
+  }
+
+  return false;
+}
+
+AMDGPUMaxNumWorkGroupsAttr *
+Sema::CreateAMDGPUMaxNumWorkGroupsAttr(const AttributeCommonInfo &CI,
+                                       Expr *XExpr, Expr *YExpr, Expr *ZExpr) {
+  AMDGPUMaxNumWorkGroupsAttr TmpAttr(Context, CI, XExpr, YExpr, ZExpr);
+
+  if (checkAMDGPUMaxNumWorkGroupsArguments(*this, XExpr, YExpr, ZExpr, TmpAttr))
+    return nullptr;
+
+  return ::new (Context)
+      AMDGPUMaxNumWorkGroupsAttr(Context, CI, XExpr, YExpr, ZExpr);
+}
+
+void Sema::addAMDGPUMaxNumWorkGroupsAttr(Decl *D, const AttributeCommonInfo &CI,
+                                         Expr *XExpr, Expr *YExpr,
+                                         Expr *ZExpr) {
+  if (auto *Attr = CreateAMDGPUMaxNumWorkGroupsAttr(CI, XExpr, YExpr, ZExpr))
+    D->addAttr(Attr);
+}
+
+static void handleAMDGPUMaxNumWorkGroupsAttr(Sema &S, Decl *D,
+                                             const ParsedAttr &AL) {
+  if (AL.getNumArgs() != 3) {
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erichkeane wrote:

The Attr.td stuff should take care of argument count, are you not finding this to be the case?

https://github.com/llvm/llvm-project/pull/79035