[examples] Add VectorExp iteration pattern.

examples/VectorExpDialect/makefile

@@ -319,3 +319,24 @@ vector-exp-dynamic-vector-run:
 		-L${CROSS_MLIR_LIB} -lmlir_runner_utils -lmlir_c_runner_utils \
 		-o a.out
 	@LD_LIBRARY_PATH=${CROSS_MLIR_LIB} ${QEMU} -L ${RISCV_GNU_TOOLCHAIN_SYSROOT} -cpu max a.out
+
+vector-exp-iteration-aot:
+	@${BUDDY_OPT} ./vector-exp-iteration.mlir \
+		-lower-vector-exp \
+		-lower-affine \
+		-convert-vector-to-scf \
+		-convert-scf-to-cf \
+		-convert-vector-to-llvm \
+		-convert-index-to-llvm \
+		-convert-arith-to-llvm \
+		-convert-func-to-llvm \
+		-finalize-memref-to-llvm \
+		-reconcile-unrealized-casts | \
+	${BUDDY_TRANSLATE} -buddy-to-llvmir -o log.ll
+	${LOCAL_CLANG} -O3 log.ll \
+		-march=rv64gcv --target=riscv64-unknown-linux-gnu -fPIC \
+		--sysroot=${RISCV_GNU_TOOLCHAIN}/sysroot \
+		--gcc-toolchain=${RISCV_GNU_TOOLCHAIN} \
+		-L${CROSS_MLIR_LIB} -lmlir_runner_utils -lmlir_c_runner_utils \
+		-o a.out
+

examples/VectorExpDialect/vector-exp-iteration.mlir

@@ -0,0 +1,57 @@
+memref.global "private" @gv : memref<10xf32> = dense<[0. , 1. , 2. , 3. , 4. , 5. , 6. , 7. , 8. , 9.]>
+
+func.func private @printMemrefF32(memref<*xf32>)
+
+func.func @main() -> i32 {
+  %c0 = arith.constant 0 : index
+
+  // ---------------------------------------------------------------------------
+  // Iteration Pattern for RVV Dynamic Vector Length
+  // ---------------------------------------------------------------------------
+
+  // 1. Get the total length of the workload.
+  %mem = memref.get_global @gv : memref<10xf32>
+  %print_mem = memref.cast %mem : memref<10xf32> to memref<*xf32>
+  %vl_total = memref.dim %mem, %c0 : memref<10xf32>
+
+  // 2. Set the scale factor, iteration step, and mask.
+  %vs = vector.vscale
+  %factor = arith.constant 2 : index
+  %vl_step = arith.muli %vs, %factor : index
+  %mask = arith.constant dense<1> : vector<[2]xi1>
+  %vl_total_i32 = index.casts %vl_total : index to i32
+  %vl_step_i32 = index.casts %vl_step : index to i32
+
+  // 3. Perform the vectorization.
+  %iter_vl = scf.for %i = %c0 to %vl_total step %vl_step
+      iter_args(%iter_vl_i32 = %vl_total_i32) -> (i32) {
+
+    %load_vec1 = vector_exp.predication %mask, %iter_vl_i32 : vector<[2]xi1>, i32 {
+      %ele = vector.load %mem[%i] : memref<10xf32>, vector<[2]xf32>
+      vector.yield %ele : vector<[2]xf32>
+    } : vector<[2]xf32>
+
+    %load_vec2 = vector_exp.predication %mask, %iter_vl_i32 : vector<[2]xi1>, i32 {
+      %ele = vector.load %mem[%i] : memref<10xf32>, vector<[2]xf32>
+      vector.yield %ele : vector<[2]xf32>
+    } : vector<[2]xf32>
+
+    %res = "llvm.intr.vp.fadd" (%load_vec1, %load_vec2, %mask, %iter_vl_i32) : 
+        (vector<[2]xf32>, vector<[2]xf32>, vector<[2]xi1>, i32) -> vector<[2]xf32>
+
+    vector_exp.predication %mask, %iter_vl_i32 : vector<[2]xi1>, i32 {
+      vector.store %res, %mem[%i] : memref<10xf32>, vector<[2]xf32>
+      vector.yield
+    } : () -> ()
+
+    // Update dynamic vector length.
+    %new_vl = arith.subi %vl_total_i32, %vl_step_i32 : i32
+    scf.yield %new_vl : i32
+  }
+
+  // CHECK: [0,  2,  4,  6,  8,  10,  12,  14,  8,  9]
+  call @printMemrefF32(%print_mem) : (memref<*xf32>) -> ()
+
+  %ret = arith.constant 0 : i32
+  return %ret : i32
+}