Bring LICM into compliance with the new "Memory Model for Concurrent Operations" in LangRef.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135625 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 37 insertions, 0 deletions

diff --git a/test/Transforms/LICM/scalar-promote-memmodel.ll b/test/Transforms/LICM/scalar-promote-memmodel.ll
new file mode 100644
index 0000000000..23d70f5135
--- /dev/null
+++ b/test/Transforms/LICM/scalar-promote-memmodel.ll
@@ -0,0 +1,37 @@
+; RUN: opt < %s -basicaa -licm -S | FileCheck %s
+
+; Make sure we don't hoist a conditionally-executed store out of the loop;
+; it would violate the concurrency memory model
+
+@g = common global i32 0, align 4
+
+define void @bar(i32 %n, i32 %b) nounwind uwtable ssp {
+entry:
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.inc, %entry
+  %i.0 = phi i32 [ 0, %entry ], [ %inc5, %for.inc ]
+  %cmp = icmp slt i32 %i.0, %n
+  br i1 %cmp, label %for.body, label %for.end
+
+for.body:                                         ; preds = %for.cond
+  %tobool = icmp eq i32 %b, 0
+  br i1 %tobool, label %for.inc, label %if.then
+
+if.then:                                          ; preds = %for.body
+  %tmp3 = load i32* @g, align 4
+  %inc = add nsw i32 %tmp3, 1
+  store i32 %inc, i32* @g, align 4
+  br label %for.inc
+
+; CHECK: load i32*
+; CHECK-NEXT: add
+; CHECK-NEXT: store i32
+
+for.inc:                                          ; preds = %for.body, %if.then
+  %inc5 = add nsw i32 %i.0, 1
+  br label %for.cond
+
+for.end:                                          ; preds = %for.cond
+  ret void
+}