diff --git a/mlir/lib/Transforms/LoopFusion.cpp b/mlir/lib/Transforms/LoopFusion.cpp
--- a/mlir/lib/Transforms/LoopFusion.cpp
+++ b/mlir/lib/Transforms/LoopFusion.cpp
@@ -70,19 +70,20 @@
 namespace {
 
 // LoopNestStateCollector walks loop nests and collects load and store
-// operations, and whether or not an IfInst was encountered in the loop nest.
+// operations, and whether or not a non-region operation, except IfOp, was
+// encountered in the loop nest.
 struct LoopNestStateCollector {
   SmallVector<AffineForOp, 4> forOps;
   SmallVector<Operation *, 4> loadOpInsts;
   SmallVector<Operation *, 4> storeOpInsts;
-  bool hasNonForRegion = false;
+  bool hasNonForRegionExceptIfOp = false;
 
   void collect(Operation *opToWalk) {
     opToWalk->walk([&](Operation *op) {
       if (isa<AffineForOp>(op))
         forOps.push_back(cast<AffineForOp>(op));
-      else if (op->getNumRegions() != 0)
-        hasNonForRegion = true;
+      else if (op->getNumRegions() != 0 && !isa<AffineIfOp>(op))
+        hasNonForRegionExceptIfOp = true;
       else if (isa<AffineReadOpInterface>(op))
         loadOpInsts.push_back(op);
       else if (isa<AffineWriteOpInterface>(op))
@@ -745,8 +746,8 @@
       LoopNestStateCollector collector;
       collector.collect(&op);
       // Return false if a non 'affine.for' region was found (not currently
-      // supported).
-      if (collector.hasNonForRegion)
+      // supported), except 'affine.if' which is handled by 'canFuseLoops'.
+      if (collector.hasNonForRegionExceptIfOp)
         return false;
       Node node(nextNodeId++, &op);
       for (auto *opInst : collector.loadOpInsts) {
diff --git a/mlir/test/Transforms/loop-fusion.mlir b/mlir/test/Transforms/loop-fusion.mlir
--- a/mlir/test/Transforms/loop-fusion.mlir
+++ b/mlir/test/Transforms/loop-fusion.mlir
@@ -502,6 +502,90 @@
 
 // -----
 
+#set = affine_set<(d0) : (d0 - 1 >= 0)>
+
+// CHECK-LABEL: func @should_fuse_if_inst_in_loop_nest_not_sandwiched() -> memref<10xf32> {
+func @should_fuse_if_inst_in_loop_nest_not_sandwiched() -> memref<10xf32> {
+  %a = memref.alloc() : memref<10xf32>
+  %b = memref.alloc() : memref<10xf32>
+  %cf7 = constant 7.0 : f32
+
+  affine.for %i0 = 0 to 10 {
+    affine.store %cf7, %a[%i0] : memref<10xf32>
+  }
+  affine.for %i1 = 0 to 10 {
+    %v0 = affine.load %a[%i1] : memref<10xf32>
+    affine.store %v0, %b[%i1] : memref<10xf32>
+  }
+  affine.for %i2 = 0 to 10 {
+    affine.if #set(%i2) {
+      %v0 = affine.load %b[%i2] : memref<10xf32>
+    }
+  }
+
+  // IfOp in ForInst should not prevent fusion if it does not in between the
+  // source and dest ForInst ops.
+
+  // CHECK:      affine.for %{{.*}} = 0 to 10 {
+  // CHECK-NEXT:   affine.store %{{.*}}, %{{.*}}[%{{.*}}] : memref<10xf32>
+  // CHECK-NEXT:   %{{.*}} = affine.load %{{.*}}[%{{.*}}] : memref<10xf32>
+  // CHECK-NEXT:   affine.store %{{.*}}, %{{.*}}[%{{.*}}] : memref<10xf32>
+  // CHECK-NEXT: }
+  // CHECK-NEXT: affine.for %{{.*}} = 0 to 10 {
+  // CHECK-NEXT:   affine.if #set(%{{.*}}) {
+  // CHECK-NEXT:     %{{.*}} = affine.load %{{.*}}[%{{.*}}] : memref<10xf32>
+  // CHECK-NEXT:   }
+  // CHECK-NEXT: }
+  // CHECK-NOT:  affine.for
+  // CHECK-NEXT: return
+
+  return %a : memref<10xf32>
+}
+
+// -----
+
+#set = affine_set<(d0) : (d0 - 1 >= 0)>
+
+// CHECK-LABEL: func @should_not_fuse_if_inst_in_loop_nest_between_src_and_dest() -> memref<10xf32> {
+func @should_not_fuse_if_inst_in_loop_nest_between_src_and_dest() -> memref<10xf32> {
+  %a = memref.alloc() : memref<10xf32>
+  %b = memref.alloc() : memref<10xf32>
+  %cf7 = constant 7.0 : f32
+
+  affine.for %i0 = 0 to 10 {
+    affine.store %cf7, %a[%i0] : memref<10xf32>
+  }
+  affine.for %i1 = 0 to 10 {
+    affine.if #set(%i1) {
+      affine.store %cf7, %a[%i1] : memref<10xf32>
+    }
+  }
+  affine.for %i3 = 0 to 10 {
+    %v0 = affine.load %a[%i3] : memref<10xf32>
+    affine.store %v0, %b[%i3] : memref<10xf32>
+  }
+  return %b : memref<10xf32>
+
+  // IfOp in ForInst which modifies the memref should prevent fusion if it is in
+  // between the source and dest ForInst ops.
+
+  // CHECK:      affine.for %{{.*}} = 0 to 10 {
+  // CHECK-NEXT:   affine.store %{{.*}}, %{{.*}}[%{{.*}}] : memref<10xf32>
+  // CHECK-NEXT: }
+  // CHECK-NEXT: affine.for %{{.*}} = 0 to 10 {
+  // CHECK-NEXT:   affine.if #set(%{{.*}}) {
+  // CHECK-NEXT:     affine.store %{{.*}}, %{{.*}}[%{{.*}}] : memref<10xf32>
+  // CHECK-NEXT:   }
+  // CHECK-NEXT: }
+  // CHECK-NEXT: affine.for %{{.*}} = 0 to 10 {
+  // CHECK-NEXT:   %{{.*}} = affine.load %{{.*}}[%{{.*}}] : memref<10xf32>
+  // CHECK-NEXT:   affine.store %{{.*}}, %{{.*}}[%{{.*}}] : memref<10xf32>
+  // CHECK-NEXT: }
+  // CHECK-NEXT: return
+}
+
+// -----
+
 // CHECK-LABEL: func @permute_and_fuse() {
 func @permute_and_fuse() {
   %m = memref.alloc() : memref<10x20x30xf32>