[llvm] ValueTracking/test: cover recur limit in non-equal PHIs (PR #113205)

[Nikita Popov via llvm-commits]

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@@ -316,6 +316,56 @@ exit:
   ret i1 %cmp
 }
 
+define i1 @known_non_equal_phis_max_recursion_limit(i1 %cond, i32 %switch.cond) {
+; CHECK-LABEL: @known_non_equal_phis_max_recursion_limit(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[BB0:%.*]]
+; CHECK:       bb0:
+; CHECK-NEXT:    [[PHIA_0:%.*]] = phi i32 [ [[PHIA_1:%.*]], [[BB1:%.*]] ], [ 0, [[ENTRY:%.*]] ]
+; CHECK-NEXT:    [[PHIB_0:%.*]] = phi i32 [ [[PHIB_1:%.*]], [[BB1]] ], [ 0, [[ENTRY]] ]
+; CHECK-NEXT:    br i1 [[COND:%.*]], label [[SWITCH_BLOCK:%.*]], label [[EXIT:%.*]]
+; CHECK:       switch.block:
+; CHECK-NEXT:    switch i32 [[SWITCH_COND:%.*]], label [[BB1]] [
+; CHECK-NEXT:      i32 0, label [[EPILOGUE:%.*]]
+; CHECK-NEXT:      i32 1, label [[EPILOGUE]]
+; CHECK-NEXT:    ]
+; CHECK:       bb1:
+; CHECK-NEXT:    [[PHIA_1]] = phi i32 [ [[PHIA_0]], [[SWITCH_BLOCK]] ], [ 0, [[EPILOGUE]] ]
+; CHECK-NEXT:    [[PHIB_1]] = phi i32 [ [[PHIB_0]], [[SWITCH_BLOCK]] ], [ 0, [[EPILOGUE]] ]
+; CHECK-NEXT:    br label [[BB0]]
+; CHECK:       epilogue:
+; CHECK-NEXT:    br label [[BB1]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[RET:%.*]] = icmp eq i32 [[PHIA_0]], [[PHIB_0]]
+; CHECK-NEXT:    ret i1 [[RET]]
+;
+entry:
+  br label %bb0
+
+bb0:
+  %phiA.0 = phi i32 [ %phiA.1, %bb1 ], [ 0, %entry ]
+  %phiB.0 = phi i32 [ %phiB.1, %bb1 ], [ 0, %entry ]
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nikic wrote:

So this is supposed to be a negative test, even without the recursion limit?

https://github.com/llvm/llvm-project/pull/113205