[flang-commits] [flang] [flang] Add hlfir.index op to represent index intrinsic function (PR #157575)

[via flang-commits]

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@@ -513,6 +512,35 @@ mlir::Value HlfirReshapeLowering::lowerImpl(
                                     operands[2], operands[3]);
 }
 
+mlir::Value HlfirIndexLowering::lowerImpl(
+    const Fortran::lower::PreparedActualArguments &loweredActuals,
+    const fir::IntrinsicArgumentLoweringRules *argLowering,
+    mlir::Type stmtResultType) {
+  auto operands = getOperandVector(loweredActuals, argLowering);
+  assert(operands.size() == 4);
+  mlir::Value substr = operands[1];
+  mlir::Value str = operands[0];
+  mlir::Value back = operands[2];
+  mlir::Value kind = operands[3];
+
+  mlir::Type resultType;
+  if (kind) {
+    auto kindCst = fir::getIntIfConstant(kind);
+    assert(kindCst &&
+           "kind argument of index must be an integer constant expression");
+    unsigned bits = builder.getKindMap().getIntegerBitsize(*kindCst);
+    assert(bits != 0 && "failed to convert kind to integer bitsize");
+    resultType = builder.getIntegerType(bits);
+  } else {
+    resultType = builder.getDefaultIntegerType();
+  }
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jeanPerier wrote:

This is not needed, semantic resolution already did the type resolution for lowering (stmtResultType). If stmtResultType is not the integer type as defined by KIND, this is a semantics or lowering framework bug.

https://github.com/llvm/llvm-project/pull/157575