1 files changed, 81 insertions, 0 deletions
diff --git a/test/CodeGen/X86/switch-density.ll b/test/CodeGen/X86/switch-density.ll
new file mode 100644
index 0000000000000..52216fb4d7c2a
--- /dev/null
+++ b/test/CodeGen/X86/switch-density.ll
@@ -0,0 +1,81 @@
+; RUN: llc -mtriple=x86_64-linux-gnu %s -o - -jump-table-density=25 | FileCheck %s --check-prefix=DENSE --check-prefix=CHECK
+; RUN: llc -mtriple=x86_64-linux-gnu %s -o - -jump-table-density=10 | FileCheck %s --check-prefix=SPARSE --check-prefix=CHECK
+
+declare void @g(i32)
+
+define void @sparse(i32 %x) {
+entry:
+  switch i32 %x, label %return [
+    i32 300, label %bb0
+    i32 100, label %bb1
+    i32 400, label %bb1
+    i32 500, label %bb2
+  ]
+bb0: tail call void @g(i32 0) br label %return
+bb1: tail call void @g(i32 1) br label %return
+bb2: tail call void @g(i32 1) br label %return
+return: ret void
+
+; Should pivot around 400 for two subtrees with two jump tables each.
+; CHECK-LABEL: sparse
+; CHECK-NOT: cmpl
+; CHECK: cmpl $399
+; CHECK: cmpl $100
+; CHECK: cmpl $300
+; CHECK: cmpl $400
+; CHECK: cmpl $500
+}
+
+define void @med(i32 %x) {
+entry:
+  switch i32 %x, label %return [
+    i32 30, label %bb0
+    i32 10, label %bb1
+    i32 40, label %bb1
+    i32 50, label %bb2
+    i32 20, label %bb3
+  ]
+bb0: tail call void @g(i32 0) br label %return
+bb1: tail call void @g(i32 1) br label %return
+bb2: tail call void @g(i32 1) br label %return
+bb3: tail call void @g(i32 2) br label %return
+return: ret void
+
+; Lowered as a jump table when sparse, and branches when dense.
+; CHECK-LABEL: med
+; SPARSE: addl $-10
+; SPARSE: cmpl $40
+; SPARSE: ja
+; SPARSE: jmpq *.LJTI
+; DENSE-NOT: cmpl
+; DENSE: cmpl $29
+; DENSE-DAG: cmpl $10
+; DENSE-DAG: cmpl $20
+; DENSE-DAG: cmpl $30
+; DENSE-DAG: cmpl $40
+; DENSE-DAG: cmpl $50
+; DENSE: retq
+}
+
+define void @dense(i32 %x) {
+entry:
+  switch i32 %x, label %return [
+    i32 12, label %bb0
+    i32 4,  label %bb1
+    i32 16, label %bb1
+    i32 20, label %bb2
+    i32 8,  label %bb3
+  ]
+bb0: tail call void @g(i32 0) br label %return
+bb1: tail call void @g(i32 1) br label %return
+bb2: tail call void @g(i32 1) br label %return
+bb3: tail call void @g(i32 2) br label %return
+return: ret void
+
+; Lowered as a jump table when sparse, and branches when dense.
+; CHECK-LABEL: dense
+; CHECK: addl $-4
+; CHECK: cmpl $16
+; CHECK: ja
+; CHECK: jmpq *.LJTI
+}