diff --git a/flang/lib/Optimizer/CodeGen/CodeGen.cpp b/flang/lib/Optimizer/CodeGen/CodeGen.cpp
--- a/flang/lib/Optimizer/CodeGen/CodeGen.cpp
+++ b/flang/lib/Optimizer/CodeGen/CodeGen.cpp
@@ -893,6 +893,21 @@
       // Conversion from narrow logical to wide logical may be implemented
       // as a zero or sign extension of the input, but it may use value
       // normalization as well.
+
+      if (isFloatingPointTy(fromTy)) {
+        // convert fp to integer
+        auto integer = rewriter.create<mlir::LLVM::FPToSIOp>(loc, toTy, op0);
+        // normalise integer
+        mlir::Value zero = genConstantIndex(loc, toTy, rewriter, 0);
+        auto isTrue = rewriter.create<mlir::LLVM::ICmpOp>(
+            loc, mlir::LLVM::ICmpPredicate::ne, integer, zero);
+        rewriter.replaceOpWithNewOp<mlir::LLVM::ZExtOp>(convert, toTy, isTrue);
+        return mlir::success();
+      }
+      if (isFloatingPointTy(toTy)) {
+        rewriter.replaceOpWithNewOp<mlir::LLVM::SIToFPOp>(convert, toTy, op0);
+        return mlir::success();
+      }
       if (!fromTy.isa<mlir::IntegerType>() || !toTy.isa<mlir::IntegerType>())
         return mlir::emitError(loc)
                << "unsupported types for logical conversion: " << fromTy
diff --git a/flang/test/Fir/logical-convert.fir b/flang/test/Fir/logical-convert.fir
--- a/flang/test/Fir/logical-convert.fir
+++ b/flang/test/Fir/logical-convert.fir
@@ -511,3 +511,47 @@
   %0 = fir.convert %arg0 : (!fir.logical<8>) -> !fir.logical<4>
   return %0 : !fir.logical<4>
 }
+// -----
+// CHECK-LABEL: @test_f32_l4
+// CHECK: %[[INT:.*]] = llvm.fptosi %arg0 : f32 to i32
+// CHECK: %[[ZERO:.*]] = llvm.mlir.constant(0 : i64) : i32
+// CHECK: %[[CMP:.*]] = llvm.icmp "ne" %[[INT]], %[[ZERO]] : i32
+// CHECK: %[[EXT:.*]] = llvm.zext %[[CMP]] : i1 to i32
+// CHECK: llvm.return %[[EXT]]
+func.func @test_f32_l4(%arg0: f32) -> !fir.logical<4> {
+  %0 = fir.convert %arg0 : (f32) -> !fir.logical<4>
+  return %0 : !fir.logical<4>
+}
+// -----
+// CHECK-LABEL: @test_f64_l4
+// CHECK: %[[INT:.*]] = llvm.fptosi %arg0 : f64 to i32
+// CHECK: %[[ZERO:.*]] = llvm.mlir.constant(0 : i64) : i32
+// CHECK: %[[CMP:.*]] = llvm.icmp "ne" %[[INT]], %[[ZERO]] : i32
+// CHECK: %[[EXT:.*]] = llvm.zext %[[CMP]] : i1 to i32
+// CHECK: llvm.return %[[EXT]]
+func.func @test_f64_l4(%arg0: f64) -> !fir.logical<4> {
+  %0 = fir.convert %arg0 : (f64) -> !fir.logical<4>
+  return %0 : !fir.logical<4>
+}
+// -----
+// CHECK-LABEL: @test_f32_l8
+// CHECK: %[[INT:.*]] = llvm.fptosi %arg0 : f32 to i64
+// CHECK: %[[ZERO:.*]] = llvm.mlir.constant(0 : i64) : i64
+// CHECK: %[[CMP:.*]] = llvm.icmp "ne" %[[INT]], %[[ZERO]] : i64
+// CHECK: %[[EXT:.*]] = llvm.zext %[[CMP]] : i1 to i64
+// CHECK: llvm.return %[[EXT]]
+func.func @test_f32_l8(%arg0: f32) -> !fir.logical<8> {
+  %0 = fir.convert %arg0 : (f32) -> !fir.logical<8>
+  return %0 : !fir.logical<8>
+}
+// -----
+// CHECK-LABEL: @test_f64_l8
+// CHECK: %[[INT:.*]] = llvm.fptosi %arg0 : f64 to i64
+// CHECK: %[[ZERO:.*]] = llvm.mlir.constant(0 : i64) : i64
+// CHECK: %[[CMP:.*]] = llvm.icmp "ne" %[[INT]], %[[ZERO]] : i64
+// CHECK: %[[EXT:.*]] = llvm.zext %[[CMP]] : i1 to i64
+// CHECK: llvm.return %[[EXT]]
+func.func @test_f64_l8(%arg0: f64) -> !fir.logical<8> {
+  %0 = fir.convert %arg0 : (f64) -> !fir.logical<8>
+  return %0 : !fir.logical<8>
+}