[Mlir-commits] [mlir] [mlir][python] Support Arbitrary Precision Integers in MLIR C API and Python Bindings (PR #177733)

[Maksim Levental]

================
@@ -343,8 +343,50 @@ void PyFloatAttribute::bindDerived(ClassTy &c) {
 void PyIntegerAttribute::bindDerived(ClassTy &c) {
   c.def_static(
       "get",
-      [](PyType &type, int64_t value) {
-        MlirAttribute attr = mlirIntegerAttrGet(type, value);
+      [](PyType &type, nb::object value) {
+        // Handle IndexType - it doesn't have a bit width or signedness.
+        if (mlirTypeIsAIndex(type)) {
+          int64_t intValue = nb::cast<int64_t>(value);
+          MlirAttribute attr = mlirIntegerAttrGet(type, intValue);
+          return PyIntegerAttribute(type.getContext(), attr);
+        }
+
+        // Get the bit width of the integer type.
+        unsigned bitWidth = mlirIntegerTypeGetWidth(type);
+
+        // Try to use the fast path for small integers.
+        if (bitWidth <= 64) {
+          int64_t intValue = nb::cast<int64_t>(value);
+          MlirAttribute attr = mlirIntegerAttrGet(type, intValue);
+          return PyIntegerAttribute(type.getContext(), attr);
+        }
+
+        // For larger integers, convert Python int to array of 64-bit words.
+        unsigned numWords = (bitWidth + 63) / 64;
----------------
makslevental wrote:

nit: 

```suggestion
        unsigned numWords = std::ceil(bitWidth / 64);
```

you might need to do `#include <cmath>`...

https://github.com/llvm/llvm-project/pull/177733