[clang] [llvm] [Clang][AArch64] Add customisable immediate range checking to NEON (PR #100278)

[via llvm-commits]

================
@@ -403,142 +368,183 @@ enum ArmSMEState : unsigned {
   ArmZT0Mask = 0b11 << 2
 };
 
+bool SemaARM::CheckImmediateArg(CallExpr *TheCall, unsigned CheckTy,
+                                unsigned ArgIdx, unsigned EltBitWidth,
+                                unsigned VecBitWidth) {
+
+  typedef bool (*OptionSetCheckFnTy)(int64_t Value);
+
+  // Function that checks whether the operand (ArgIdx) is an immediate
+  // that is one of the predefined values.
+  auto CheckImmediateInSet = [&](OptionSetCheckFnTy CheckImm,
+                                 int ErrDiag) -> bool {
+    // We can't check the value of a dependent argument.
+    Expr *Arg = TheCall->getArg(ArgIdx);
+    if (Arg->isTypeDependent() || Arg->isValueDependent())
+      return false;
+
+    // Check constant-ness first.
+    llvm::APSInt Imm;
+    if (SemaRef.BuiltinConstantArg(TheCall, ArgIdx, Imm))
+      return true;
+
+    if (!CheckImm(Imm.getSExtValue()))
+      return Diag(TheCall->getBeginLoc(), ErrDiag) << Arg->getSourceRange();
+    return false;
+  };
+
+  switch ((ImmCheckType)CheckTy) {
+  case ImmCheckType::ImmCheck0_31:
+    if (SemaRef.BuiltinConstantArgRange(TheCall, ArgIdx, 0, 31))
+      return true;
+    break;
+  case ImmCheckType::ImmCheck0_13:
+    if (SemaRef.BuiltinConstantArgRange(TheCall, ArgIdx, 0, 13))
+      return true;
+    break;
+  case ImmCheckType::ImmCheck0_63:
+    if (SemaRef.BuiltinConstantArgRange(TheCall, ArgIdx, 0, 63))
+      return true;
+    break;
+  case ImmCheckType::ImmCheck1_16:
+    if (SemaRef.BuiltinConstantArgRange(TheCall, ArgIdx, 1, 16))
+      return true;
+    break;
+  case ImmCheckType::ImmCheck0_7:
+    if (SemaRef.BuiltinConstantArgRange(TheCall, ArgIdx, 0, 7))
+      return true;
+    break;
+  case ImmCheckType::ImmCheck1_1:
+    if (SemaRef.BuiltinConstantArgRange(TheCall, ArgIdx, 1, 1))
+      return true;
+    break;
+  case ImmCheckType::ImmCheck1_3:
+    if (SemaRef.BuiltinConstantArgRange(TheCall, ArgIdx, 1, 3))
+      return true;
+    break;
+  case ImmCheckType::ImmCheck1_7:
+    if (SemaRef.BuiltinConstantArgRange(TheCall, ArgIdx, 1, 7))
+      return true;
+    break;
+  case ImmCheckType::ImmCheckExtract:
+    if (SemaRef.BuiltinConstantArgRange(TheCall, ArgIdx, 0,
+                                        (2048 / EltBitWidth) - 1))
+      return true;
+    break;
+  case ImmCheckType::ImmCheckCvt:
+  case ImmCheckType::ImmCheckShiftRight:
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SpencerAbson wrote:

Ok sounds good, they both do `1..sizeinbits(elt)` so I could replace them both with `ImmCheck1_EltSize`.

https://github.com/llvm/llvm-project/pull/100278