Teach globalopt to not nuke all stores to globals. Keep them around of they

might be deliberate "one time" leaks, so that leak checkers can find them.
This is a reapply of r160602 with the fix that this time I'm committing the
code I thought I was committing last time; the I->eraseFromParent() goes
*after* the break out of the loop.

llvm-svn: 160664

2 files changed, 20 insertions, 1 deletions

diff --git a/llvm/test/Transforms/GlobalOpt/2009-11-16-BrokenPerformHeapAllocSRoA.ll b/llvm/test/Transforms/GlobalOpt/2009-11-16-BrokenPerformHeapAllocSRoA.ll
index 54e8f909790..40862bd038e 100644
--- a/llvm/test/Transforms/GlobalOpt/2009-11-16-BrokenPerformHeapAllocSRoA.ll
+++ b/llvm/test/Transforms/GlobalOpt/2009-11-16-BrokenPerformHeapAllocSRoA.ll
@@ -17,7 +17,7 @@ define void @test() nounwind ssp {
   %2 = sext i32 %1 to i64                         ; <i64> [#uses=1]
   %3 = mul i64 %2, ptrtoint (%struct.strchartype* getelementptr (%struct.strchartype* null, i64 1) to i64) ; <i64> [#uses=1]
   %4 = tail call i8* @malloc(i64 %3)              ; <i8*> [#uses=1]
-; CHECK: call i8* @malloc(i64
+; CHECK-NOT: call i8* @malloc(i64
   %5 = bitcast i8* %4 to %struct.strchartype*     ; <%struct.strchartype*> [#uses=1]
   store %struct.strchartype* %5, %struct.strchartype** @chartypes, align 8
   ret void
diff --git a/llvm/test/Transforms/GlobalOpt/cleanup-pointer-root-users.ll b/llvm/test/Transforms/GlobalOpt/cleanup-pointer-root-users.ll
new file mode 100644
index 00000000000..f426120e707
--- /dev/null
+++ b/llvm/test/Transforms/GlobalOpt/cleanup-pointer-root-users.ll
@@ -0,0 +1,19 @@
+; RUN: opt -globalopt -S -o - < %s | FileCheck %s
+
+@test1 = internal global i8* null
+
+define void @test1a() {
+; CHECK: @test1a
+; CHECK-NOT: store
+; CHECK-NEXT: ret void
+  store i8* null, i8** @test1
+  ret void
+}
+
+define void @test1b(i8* %p) {
+; CHECK: @test1b
+; CHECK-NEXT: store
+; CHECK-NEXT: ret void
+  store i8* %p, i8** @test1
+  ret void
+}