Added more tests for rangeable register ops, clarified error msg

Author: smada3

mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td

@@ -291,8 +291,13 @@ class NVVM_PureSpecialRangeableRegisterOp<string mnemonic, list<Trait> traits =
       const ::llvm::APInt &upper = rangeAttr->getUpper();
 
       // Check LLVM ConstantRange constructor condition
-      if (!(lower != upper || (lower.isMaxValue() || lower.isMinValue()))) {
-        return emitOpError("invalid range attribute: range must be a valid constant range");
+      if (lower == upper && !lower.isMaxValue() && !lower.isMinValue()) {
+        unsigned bitWidth = lower.getBitWidth();
+        ::llvm::APInt minVal = ::llvm::APInt::getMinValue(bitWidth);
+        ::llvm::APInt maxVal = ::llvm::APInt::getMaxValue(bitWidth);
+        return emitOpError("invalid range attribute: Lower == Upper, but they aren't min (")
+               << ::llvm::toString(minVal, 10, false) << ") or max (" 
+               << ::llvm::toString(maxVal, 10, false) << ") value! This is an invalid constant range.";
       }
 
       return ::mlir::success();

mlir/test/Target/LLVMIR/nvvmir-invalid.mlir

@@ -565,7 +565,7 @@ llvm.func @clusterlaunchcontrol_query_cancel_get_first_cta_id_invalid_return_typ
 
 // Test for range validation - invalid range where lower == upper but not at extremes
 func.func @invalid_range_equal_bounds() {
-  // expected-error @below {{invalid range attribute: range must be a valid constant range}}
+  // expected-error @below {{invalid range attribute: Lower == Upper, but they aren't min (0) or max (4294967295) value! This is an invalid constant range.}}
   %0 = nvvm.read.ptx.sreg.warpsize range <i32, 32, 32> : i32
   return
 }

mlir/test/Target/LLVMIR/nvvmir.mlir

@@ -152,6 +152,10 @@ llvm.func @nvvm_special_regs() -> i32 {
   %74 = nvvm.read.ptx.sreg.lanemask.ge : i32
   //CHECK: call i32 @llvm.nvvm.read.ptx.sreg.lanemask.gt
   %75 = nvvm.read.ptx.sreg.lanemask.gt : i32
+  // CHECK: %76 = call range(i32 0, 0) i32 @llvm.nvvm.read.ptx.sreg.tid.x()
+  %76 = nvvm.read.ptx.sreg.tid.x range <i32, 0, 0> : i32
+  // CHECK: %77 = call i32 @llvm.nvvm.read.ptx.sreg.tid.x()
+  %77 = nvvm.read.ptx.sreg.tid.x range <i32, 4294967295, 4294967295> : i32
   llvm.return %1 : i32
 }