Add test for exit to an unrelated loop

test/HLSL/passes/dxil_remove_unstructured_loop_exits/exit-to-unrelated-loop.ll

@@ -0,0 +1,93 @@
+; RUN: opt %s -analyze -loops | FileCheck -check-prefix=LOOPBEFORE %s
+; RUN: opt %s -dxil-remove-unstructured-loop-exits -o %t.bc
+; RUN: opt %t.bc -S | FileCheck %s
+; RUN: opt %t.bc -analyze -loops | FileCheck -check-prefix=LOOPAFTER %s
+
+; The exiting edge goes to the header of a completely unrelated loop.
+; That edge is 'critical' in CFG terms, and will be split before attempting
+; to restructure the exit.
+
+
+;   entry
+;    |                        +---------+
+;    v                        v         |
+;   header.1 --> if.1 -----> header.u2 -+
+;    ^            |           |
+;    |            |           |
+;    | +-------- endif.1     end.u2
+;    | |
+;    | v
+;   latch.1
+;    |
+;    v
+;   end
+;
+
+; LOOPBEFORE-DAG:  Loop at depth 1 containing: %header.u2<header><latch><exiting>
+; LOOPBEFORE-DAG:  Loop at depth 1 containing: %header.1<header>,%if.1<exiting>,%endif.1,%latch.1<latch><exiting>
+; LOOPBEFORE-NOT:  Loop at depth
+
+; LOOPAFTER-DAG:   Loop at depth 1 containing: %header.u2<header><latch><exiting>
+; LOOPAFTER-DAG:   Loop at depth 1 containing: %header.1<header>,%if.1<exiting>,%endif.1,%latch.1<latch><exiting>
+; LOOPAFTER-NOT:  Loop at depth
+
+
+target datalayout = "e-m:e-p:32:32-i1:32-i8:32-i16:32-i32:32-i64:64-f16:32-f32:32-f64:64-n8:16:32:64"
+target triple = "dxil-ms-dx"
+
+
+define void @main(i1 %cond) {
+entry:
+  br label %header.1
+
+header.1:
+  br label %if.1
+
+if.1:
+  br i1 %cond, label %header.u2, label %endif.1
+
+endif.1:
+  br label %latch.1
+
+latch.1:
+  br i1 %cond, label %end, label %header.1
+
+end:
+ ret void
+
+header.u2:
+  br i1 %cond, label %end.u2, label %header.u2
+
+end.u2:
+ ret void
+}
+
+
+; CHECK: define void @main
+; CHECK: entry:
+; CHECK:   br label %header.1
+
+; CHECK: header.1:
+; CHECK:   br label %if.1
+
+; CHECK: if.1:
+; CHECK:   br i1 %cond, label %if.1.header.u2_crit_edge, label %endif.1
+
+; CHECK: if.1.header.u2_crit_edge:
+; CHECK:   br label %header.u2
+
+; CHECK: endif.1:
+; CHECK:   br label %latch.1
+
+; CHECK: latch.1:
+; CHECK:   br i1 %cond, label %end, label %header.1
+
+; CHECK: end:
+; CHECK:   ret void
+
+; CHECK: header.u2:
+; CHECK:   br i1 %cond, label %end.u2, label %header.u2
+
+; CHECK: end.u2:
+; CHECK:   ret void
+; CHECK: }