[Mlir-commits] [mlir] [MLIR] Add a getStaticTripCount method to LoopLikeOpInterface (PR #158679)

[Mehdi Amini]

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@@ -264,22 +274,108 @@ getValuesSortedByKey(ArrayRef<Attribute> keys, ArrayRef<int64_t> values,
 
 /// Return the number of iterations for a loop with a lower bound `lb`, upper
 /// bound `ub` and step `step`.
-std::optional<int64_t> constantTripCount(OpFoldResult lb, OpFoldResult ub,
-                                         OpFoldResult step) {
+std::optional<APInt> constantTripCount(
+    OpFoldResult lb, OpFoldResult ub, OpFoldResult step, bool isSigned,
+    llvm::function_ref<std::optional<llvm::APSInt>(Value, Value, bool)>
+        computeUbMinusLb) {
+  // This is the bitwidth used to return 0 when loop does not execute.
+  // We infer it from the type of the bound if it isn't an index type.
+  bool isIndex = true;
+  auto getBitwidth = [&](OpFoldResult ofr) -> int {
+    if (auto attr = dyn_cast<Attribute>(ofr)) {
+      if (auto intAttr = dyn_cast<IntegerAttr>(attr)) {
+        if (auto intType = dyn_cast<IntegerType>(intAttr.getType())) {
+          isIndex = intType.isIndex();
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joker-eph wrote:

History of how the code was written :)

https://github.com/llvm/llvm-project/pull/158679