[tir][Compute-at] Make compute-ated block simple when the predicate could be merged

src/tir/schedule/primitive/compute_at.cc

@@ -224,6 +224,10 @@ struct BlockVarDomainInfo {
                analyzer->CanProveEqual(bound.max(), intersect.max())) {
       dom = bound;
       bound = arith::IntSet::Nothing();
+    } else if (is_const_int(intersect.min()) && is_const_int(intersect.max())) {
+      // if the bound induce constant iter range, merge bound to loop domain
+      dom = intersect;
+      bound = arith::IntSet::Nothing();
     }
   }
 };

src/tir/schedule/primitive/decompose_padding.cc

@@ -393,15 +393,6 @@ class DecomposePaddingBlockReplacer : public StmtMutator {
     return std::move(new_loop);
   }
 
-  Stmt VisitStmt_(const SeqStmtNode* seq) final {
-    Array<Stmt> new_stmts;
-    new_stmts.reserve(seq->seq.size());
-    for (const Stmt& old_stmt : seq->seq) {
-      new_stmts.push_back(VisitStmt(old_stmt));
-    }
-    return SeqStmt::Flatten(new_stmts);
-  }
-
  private:
   const ReplaceDesc& desc_;
 };

tests/python/tir-schedule/test_tir_schedule_compute_at.py

@@ -1915,5 +1915,79 @@ def expected(A: T.Buffer((32, 1, 128), "float32"), b: T.handle, c: T.handle):
     )
 
 
+def test_compute_at_sliced_concatenate():
+    @T.prim_func
+    def before():
+        X = T.alloc_buffer((1, 16, 28, 64), "float32")
+        Y = T.alloc_buffer((1, 32, 28, 64), "float32")
+        Z = T.alloc_buffer((1, 53, 28, 64), "float32")
+        Concat = T.alloc_buffer((1, 101, 28, 64), "float32")
+        Slice = T.alloc_buffer((1, 87, 28, 64), "float32")
+        for ax0, ax1, ax2, ax3 in T.grid(1, 16, 28, 64):
+            with T.block("compute"):
+                v_ax0, v_ax1, v_ax2, v_ax3 = T.axis.remap("SSSS", [ax0, ax1, ax2, ax3])
+                X[v_ax0, v_ax1, v_ax2, v_ax3] = 1.0
+        for ax0, ax1, ax2, ax3 in T.grid(1, 101, 28, 64):
+            with T.block("T_concat"):
+                v_ax0, v_ax1, v_ax2, v_ax3 = T.axis.remap("SSSS", [ax0, ax1, ax2, ax3])
+                Concat[v_ax0, v_ax1, v_ax2, v_ax3] = T.if_then_else(
+                    85 <= v_ax1,
+                    X[v_ax0, v_ax1 - 85, v_ax2, v_ax3],
+                    T.if_then_else(
+                        53 <= v_ax1,
+                        Y[v_ax0, v_ax1 - 53, v_ax2, v_ax3],
+                        Z[v_ax0, v_ax1, v_ax2, v_ax3],
+                    ),
+                )
+        for ax0, ax1, ax2, ax3 in T.grid(1, 87, 28, 64):
+            with T.block("T_strided_slice"):
+                v_ax0, v_ax1, v_ax2, v_ax3 = T.axis.remap("SSSS", [ax0, ax1, ax2, ax3])
+                Slice[v_ax0, v_ax1, v_ax2, v_ax3] = Concat[v_ax0, v_ax1, v_ax2, v_ax3]
+
+    @T.prim_func
+    def expect():
+        X = T.alloc_buffer((1, 16, 28, 64))
+        Y = T.alloc_buffer((1, 32, 28, 64))
+        Z = T.alloc_buffer((1, 53, 28, 64))
+        Concat = T.alloc_buffer((1, 101, 28, 64))
+        Slice = T.alloc_buffer((1, 87, 28, 64))
+        for ax0 in range(1):
+            for ax0_1, ax1, ax2 in T.grid(2, 28, 64):
+                with T.block("compute"):
+                    v_ax0 = T.axis.spatial(1, 0)
+                    v_ax1 = T.axis.spatial(16, ax0_1)
+                    v_ax2, v_ax3 = T.axis.remap("SS", [ax1, ax2])
+                    X[v_ax0, v_ax1, v_ax2, v_ax3] = T.float32(1)
+            for ax0_1, ax1, ax2 in T.grid(87, 28, 64):
+                with T.block("T_concat"):
+                    v_ax0 = T.axis.spatial(1, 0)
+                    v_ax1 = T.axis.spatial(101, ax0_1)
+                    v_ax2, v_ax3 = T.axis.remap("SS", [ax1, ax2])
+                    Concat[v_ax0, v_ax1, v_ax2, v_ax3] = T.if_then_else(
+                        85 <= v_ax1,
+                        X[v_ax0, v_ax1 - 85, v_ax2, v_ax3],
+                        T.if_then_else(
+                            53 <= v_ax1,
+                            Y[v_ax0, v_ax1 - 53, v_ax2, v_ax3],
+                            Z[v_ax0, v_ax1, v_ax2, v_ax3],
+                        ),
+                    )
+            for ax1, ax2, ax3 in T.grid(87, 28, 64):
+                with T.block("T_strided_slice"):
+                    v_ax0, v_ax1, v_ax2, v_ax3 = T.axis.remap("SSSS", [ax0, ax1, ax2, ax3])
+                    Slice[v_ax0, v_ax1, v_ax2, v_ax3] = Concat[v_ax0, v_ax1, v_ax2, v_ax3]
+
+    sch = tir.Schedule(before, debug_mask="all")
+    blk1 = sch.get_block("compute")
+    blk2 = sch.get_block("T_concat")
+    blk3 = sch.get_block("T_strided_slice")
+    loop = sch.get_loops(blk3)[0]
+    sch.compute_at(blk2, loop)
+    sch.compute_at(blk1, loop)
+    after = sch.mod["main"]
+    assert_structural_equal_ignore_global_symbol(expect, after)
+    verify_trace_roundtrip(sch=sch, mod=before)
+
+
 if __name__ == "__main__":
     tvm.testing.main()