Make Loop::getLoopLatch() work on loops which don't have preheaders, as

it may be used in contexts where preheader insertion may have failed due
to an indirectbr.

Make LoopSimplify's LoopSimplify::SeparateNestedLoop properly fail in
the case that it would require splitting an indirectbr edge.

These fix PR5502.

llvm-svn: 89484

2 files changed, 60 insertions, 0 deletions

diff --git a/llvm/test/Transforms/LoopRotate/indirectbr.ll b/llvm/test/Transforms/LoopRotate/indirectbr.ll
new file mode 100644
index 00000000000..9c82aa88346
--- /dev/null
+++ b/llvm/test/Transforms/LoopRotate/indirectbr.ll
@@ -0,0 +1,43 @@
+; RUN: opt < %s -S -loop-rotate -disable-output -verify-loop-info -verify-dom-info
+; PR5502
+
+define void @z80_do_opcodes() nounwind {
+entry:
+  br label %while.cond
+
+while.cond:                                       ; preds = %end_opcode, %entry
+  br label %while.body
+
+while.body:                                       ; preds = %while.cond
+  br label %indirectgoto
+
+run_opcode:                                       ; preds = %indirectgoto
+  %tmp276 = load i8* undef                        ; <i8> [#uses=1]
+  br label %indirectgoto
+
+if.else295:                                       ; preds = %divide_late
+  br label %end_opcode
+
+end_opcode:                                       ; preds = %indirectgoto, %sw.default42406, %sw.default, %if.else295
+  %opcode.2 = phi i8 [ %opcode.0, %indirectgoto ], [ 0, %sw.default42406 ], [ undef, %sw.default ], [ %opcode.0, %if.else295 ] ; <i8> [#uses=0]
+  switch i32 undef, label %while.cond [
+    i32 221, label %sw.bb11691
+    i32 253, label %sw.bb30351
+  ]
+
+sw.bb11691:                                       ; preds = %end_opcode
+  br label %sw.default
+
+sw.default:                                       ; preds = %sw.bb11691
+  br label %end_opcode
+
+sw.bb30351:                                       ; preds = %end_opcode
+  br label %sw.default42406
+
+sw.default42406:                                  ; preds = %sw.bb30351
+  br label %end_opcode
+
+indirectgoto:                                     ; preds = %run_opcode, %while.body
+  %opcode.0 = phi i8 [ undef, %while.body ], [ %tmp276, %run_opcode ] ; <i8> [#uses=2]
+  indirectbr i8* undef, [label %run_opcode, label %if.else295, label %end_opcode]
+}
diff --git a/llvm/test/Transforms/LoopSimplify/indirectbr.ll b/llvm/test/Transforms/LoopSimplify/indirectbr.ll
index b0238473b68..2e4549d1e9c 100644
--- a/llvm/test/Transforms/LoopSimplify/indirectbr.ll
+++ b/llvm/test/Transforms/LoopSimplify/indirectbr.ll
@@ -81,3 +81,20 @@ L1:
   %y = phi i64 [ %z, %L0 ], [ 1, %entry ]
   ret i64 %y
 }
+
+define void @pr5502() nounwind {
+entry:
+  br label %while.cond
+
+while.cond:
+  br i1 undef, label %while.body, label %while.end
+
+while.body:
+  indirectbr i8* undef, [label %end_opcode, label %end_opcode]
+
+end_opcode:
+  br i1 false, label %end_opcode, label %while.cond
+
+while.end:
+  ret void
+}