[PATCH] D30667: GVNHoist: handled BB with UnreachableInst

[Aditya Kumar via Phabricator via llvm-commits]

hiraditya created this revision.

https://bugs.llvm.org/show_bug.cgi?id=32153


https://reviews.llvm.org/D30667

Files:
  llvm/lib/Analysis/ValueTracking.cpp
  llvm/test/Transforms/GVNHoist/hoist-very-busy.ll


Index: llvm/test/Transforms/GVNHoist/hoist-very-busy.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/GVNHoist/hoist-very-busy.ll
@@ -0,0 +1,34 @@
+; RUN: opt -S -gvn-hoist < %s | FileCheck %s
+
+%struct.__jmp_buf_tag = type { [8 x i64], i32 }
+
+; Check that hoisting only happens when the expression is very busy.
+; CHECK: store
+; CHECK: store
+
+ at test_exit_buf = global %struct.__jmp_buf_tag zeroinitializer
+ at G = global i32 0
+
+define void @test_command(i32 %c1) {
+entry:
+  switch i32 %c1, label %exit [
+    i32 0, label %sw0
+    i32 1, label %sw1
+  ]
+
+sw0:
+  store i32 1, i32* @G
+  br label %exit
+
+sw1:
+  store i32 1, i32* @G
+  br label %exit
+
+exit:
+  call void @longjmp(%struct.__jmp_buf_tag* @test_exit_buf, i32 1) #0
+  unreachable
+}
+
+declare void @longjmp(%struct.__jmp_buf_tag*, i32) #0
+
+attributes #0 = { noreturn nounwind }
Index: llvm/lib/Analysis/ValueTracking.cpp
===================================================================
--- llvm/lib/Analysis/ValueTracking.cpp
+++ llvm/lib/Analysis/ValueTracking.cpp
@@ -3781,6 +3781,8 @@
     return false;
   if (isa<ReturnInst>(I))
     return false;
+  if (isa<UnreachableInst>(I))
+    return false;
 
   // Calls can throw, or contain an infinite loop, or kill the process.
   if (auto CS = ImmutableCallSite(I)) {


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