1 files changed, 246 insertions, 0 deletions
diff --git a/llvm/test/Transforms/JumpThreading/fold-not-thread.ll b/llvm/test/Transforms/JumpThreading/fold-not-thread.ll
new file mode 100644
index 00000000000..85cdcc0d9b3
--- /dev/null
+++ b/llvm/test/Transforms/JumpThreading/fold-not-thread.ll
@@ -0,0 +1,246 @@
+; RUN: opt -jump-threading -S -verify < %s | FileCheck %s
+
+declare i32 @f1()
+declare i32 @f2()
+declare void @f3()
+declare void @f4(i32)
+
+
+; Make sure we update the phi node properly.
+;
+; CHECK-LABEL: define void @test_br_folding_not_threading_update_phi(
+; CHECK: br label %L1
+; Make sure we update the phi node properly here, i.e. we only have 2 predecessors, entry and L0
+; CHECK: %res.0 = phi i32 [ 0, %L0 ], [ 1, %entry ]
+define void @test_br_folding_not_threading_update_phi(i32 %val) nounwind {
+entry:
+  %cmp = icmp eq i32 %val, 32
+  br i1 %cmp, label %L0, label %L1
+L0:
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  switch i32 %val, label %L2 [
+    i32 0, label %L1
+    i32 32, label %L1
+  ]
+
+L1:
+	%res.0 = phi i32 [ 0, %L0 ], [ 0, %L0 ], [1, %entry]
+  call void @f4(i32 %res.0)
+  ret void
+L2:
+  call void @f3()
+  ret void
+}
+
+; Make sure we can fold this branch ... We will not be able to thread it as
+; L0 is too big to duplicate. L2 is the unreachable block here.
+;
+; CHECK-LABEL: @test_br_folding_not_threading(
+; CHECK: L1:
+; CHECK: call i32 @f2()
+; CHECK: call void @f3()
+; CHECK-NEXT: ret void
+; CHECK-NOT: br
+; CHECK: L3:
+define void @test_br_folding_not_threading(i1 %cond) nounwind {
+entry:
+  br i1 %cond, label %L0, label %L3 
+L0:
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  br i1 %cond, label %L1, label %L2 
+
+L1:
+  call void @f3()
+  ret void
+L2:
+  call void @f3()
+  ret void
+L3:
+  call void @f3()
+  ret void
+}
+
+
+; Make sure we can fold this branch ... We will not be able to thread it as
+; L0 is too big to duplicate. L2 is the unreachable block here.
+; With more than 1 predecessors.
+;
+; CHECK-LABEL: @test_br_folding_not_threading_multiple_preds(
+; CHECK: L1:
+; CHECK: call i32 @f2()
+; CHECK: call void @f3()
+; CHECK-NEXT: ret void
+; CHECK-NOT: br
+; CHECK: L3:
+define void @test_br_folding_not_threading_multiple_preds(i1 %condx, i1 %cond) nounwind {
+entry:
+  br i1 %condx, label %X0, label %X1
+
+X0:
+  br i1 %cond, label %L0, label %L3 
+
+X1:
+  br i1 %cond, label %L0, label %L3 
+
+L0:
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  br i1 %cond, label %L1, label %L2 
+
+L1:
+  call void @f3()
+  ret void
+L2:
+  call void @f3()
+  ret void
+L3:
+  call void @f3()
+  ret void
+}
+
+; Make sure we can do the RAUW for %add...
+;
+; CHECK-LABEL: @rauw_if_possible(
+; CHECK: call void @f4(i32 96)
+define void @rauw_if_possible(i32 %value) nounwind {
+entry:
+  %cmp = icmp eq i32 %value, 32
+  br i1 %cmp, label %L0, label %L3 
+L0:
+  call i32 @f2()
+  call i32 @f2()
+  %add = add i32 %value, 64
+  switch i32 %add, label %L3 [
+    i32 32, label %L1
+    i32 96, label %L2
+    ]
+
+L1:
+  call void @f3()
+  ret void
+L2:
+  call void @f4(i32 %add)
+  ret void
+L3:
+  call void @f3()
+  ret void
+}
+
+; Make sure we can NOT do the RAUW for %add...
+;
+; CHECK-LABEL: @rauw_if_possible2(
+; CHECK: call void @f4(i32 %add) 
+define void @rauw_if_possible2(i32 %value) nounwind {
+entry:
+  %cmp = icmp eq i32 %value, 32
+  %add = add i32 %value, 64
+  br i1 %cmp, label %L0, label %L2 
+L0:
+  call i32 @f2()
+  call i32 @f2()
+  switch i32 %add, label %L3 [
+    i32 32, label %L1
+    i32 96, label %L2
+    ]
+
+L1:
+  call void @f3()
+  ret void
+L2:
+  call void @f4(i32 %add)
+  ret void
+L3:
+  call void @f3()
+  ret void
+}
+
+; Make sure we can fold this branch ... We will not be able to thread it as
+; L0 is too big to duplicate.
+; We do not attempt to rewrite the indirectbr target here, but we still take
+; its target after L0 into account and that enables us to fold.
+;
+; L2 is the unreachable block here.
+; 
+; CHECK-LABEL: @test_br_folding_not_threading_indirect_branch(
+; CHECK: L1:
+; CHECK: call i32 @f2()
+; CHECK: call void @f3()
+; CHECK-NEXT: ret void
+; CHECK-NOT: br
+; CHECK: L3:
+define void @test_br_folding_not_threading_indirect_branch(i1 %condx, i1 %cond) nounwind {
+entry:
+  br i1 %condx, label %X0, label %X1
+
+X0:
+  br i1 %cond, label %L0, label %L3
+
+X1:
+  br i1 %cond, label %XX1, label %L3
+
+XX1:
+  indirectbr i8* blockaddress(@test_br_folding_not_threading_indirect_branch, %L0), [label %L0]
+
+L0:
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  br i1 %cond, label %L1, label %L2
+
+L1:
+  call void @f3()
+  ret void
+
+L2:
+  call void @f3()
+  ret void
+
+L3:
+  call void @f3()
+  ret void
+}