Imported Upstream version 5.18.0.167

Former-commit-id: 289509151e0fee68a1b591a20c9f109c3c789d3a

external/llvm/test/Transforms/CodeGenPrepare/bitreverse-hang.ll

@@ -1,53 +0,0 @@
-; RUN: opt < %s -loop-unroll -codegenprepare -S | FileCheck %s
-
-; This test is a worst-case scenario for bitreversal/byteswap detection.
-; After loop unrolling (the unrolled loop is unreadably large so it has been kept
-; rolled here), we have a binary tree of OR operands (as bitreversal detection
-; looks straight through shifts):
-;
-;  OR
-;  | \
-;  |  LSHR
-;  | /
-;  OR
-;  | \
-;  |  LSHR
-;  | /
-;  OR
-;
-; This results in exponential runtime. The loop here is 32 iterations which will
-; totally hang if we don't deal with this case cleverly.
-
-@b = common global i32 0, align 4
-
-; CHECK: define i32 @fn1
-define i32 @fn1() #0 {
-entry:
-  %b.promoted = load i32, i32* @b, align 4, !tbaa !2
-  br label %for.body
-
-for.body:                                         ; preds = %for.body, %entry
-  %or4 = phi i32 [ %b.promoted, %entry ], [ %or, %for.body ]
-  %i.03 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
-  %shr = lshr i32 %or4, 1
-  %or = or i32 %shr, %or4
-  %inc = add nuw nsw i32 %i.03, 1
-  %exitcond = icmp eq i32 %inc, 32
-  br i1 %exitcond, label %for.end, label %for.body
-
-for.end:                                          ; preds = %for.body
-  store i32 %or, i32* @b, align 4, !tbaa !2
-  ret i32 undef
-}
-
-attributes #0 = { norecurse nounwind ssp uwtable "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="core2" "target-features"="+cx16,+fxsr,+mmx,+sse,+sse2,+sse3,+ssse3" "unsafe-fp-math"="false" "use-soft-float"="false" }
-
-!llvm.module.flags = !{!0}
-!llvm.ident = !{!1}
-
-!0 = !{i32 1, !"PIC Level", i32 2}
-!1 = !{!"clang version 3.8.0 (http://llvm.org/git/clang.git eb70f4e9cc9a4dc3dd57b032fb858d56b4b64a0e)"}
-!2 = !{!3, !3, i64 0}
-!3 = !{!"int", !4, i64 0}
-!4 = !{!"omnipotent char", !5, i64 0}
-!5 = !{!"Simple C/C++ TBAA"}