diff --git a/mlir/lib/Dialect/Affine/Transforms/SimplifyAffineStructures.cpp b/mlir/lib/Dialect/Affine/Transforms/SimplifyAffineStructures.cpp
--- a/mlir/lib/Dialect/Affine/Transforms/SimplifyAffineStructures.cpp
+++ b/mlir/lib/Dialect/Affine/Transforms/SimplifyAffineStructures.cpp
@@ -14,7 +14,7 @@
 
 #include "mlir/Dialect/Affine/Analysis/Utils.h"
 #include "mlir/Dialect/Affine/IR/AffineOps.h"
-#include "mlir/Dialect/Affine/Utils.h"
+#include "mlir/Dialect/Affine/LoopUtils.h"
 #include "mlir/Dialect/Func/IR/FuncOps.h"
 #include "mlir/IR/IntegerSet.h"
 #include "mlir/Transforms/GreedyPatternRewriteDriver.h"
@@ -83,7 +83,12 @@
 }
 
 void SimplifyAffineStructures::runOnOperation() {
-  auto func = getOperation();
+  func::FuncOp func = getOperation();
+
+  // Promote any single iteration affine loops. This relies on an
+  // analysis utility, and is thus not part of canonicalization.
+  func.walk([&](AffineForOp forOp) { (void)promoteIfSingleIteration(forOp); });
+
   simplifiedAttributes.clear();
   RewritePatternSet patterns(func.getContext());
   AffineApplyOp::getCanonicalizationPatterns(patterns, func.getContext());
diff --git a/mlir/test/Dialect/Affine/simplify-structures.mlir b/mlir/test/Dialect/Affine/simplify-structures.mlir
--- a/mlir/test/Dialect/Affine/simplify-structures.mlir
+++ b/mlir/test/Dialect/Affine/simplify-structures.mlir
@@ -232,6 +232,16 @@
   return
 }
 
+// CHECK-LABEL: func.func @promote_single_iter
+func.func @promote_single_iter(%N: index) {
+  // CHECK-NEXT: test.foo
+  // CHECK-NEXT: return
+  affine.for %i = %N to affine_map<(d0) -> (d0 + 1)>(%N) {
+    "test.foo"() : () -> ()
+  }
+  return
+}
+
 // -----
 
 // An external function that we will use in bodies to avoid DCE.