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authorAlexander Kornienko <alexfh@google.com>2013-03-26 02:28:59 +0000
committerAlexander Kornienko <alexfh@google.com>2013-03-26 02:28:59 +0000
commitd934545ae6a00aa8a8179a93d11cbd93a5240849 (patch)
treeab44db08aa63a8f94a3e09d6491c4156c624af96 /test/Transforms/IndVarSimplify/dont-recompute.ll
parent868d4470cdfa9472353ea2a49a6c456ddae9c95b (diff)
parentc204410d6bc435e7cb8ea768759a54135e8e92b5 (diff)
Updating branches/google/testing to r177703testing
git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/google/testing@177985 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/Transforms/IndVarSimplify/dont-recompute.ll')
-rw-r--r--test/Transforms/IndVarSimplify/dont-recompute.ll69
1 files changed, 69 insertions, 0 deletions
diff --git a/test/Transforms/IndVarSimplify/dont-recompute.ll b/test/Transforms/IndVarSimplify/dont-recompute.ll
new file mode 100644
index 0000000000..d37b0e21f8
--- /dev/null
+++ b/test/Transforms/IndVarSimplify/dont-recompute.ll
@@ -0,0 +1,69 @@
+; RUN: opt < %s -indvars -S | FileCheck %s
+
+; This tests that the IV is not recomputed outside of the loop when it is known
+; to be computed by the loop and used in the loop any way. In the example below
+; although a's value can be computed outside of the loop, there is no benefit
+; in doing so as it has to be computed by the loop anyway.
+;
+; extern void func(unsigned val);
+;
+; void test(unsigned m)
+; {
+; unsigned a = 0;
+;
+; for (int i=0; i<186; i++) {
+; a += m;
+; func(a);
+; }
+;
+; func(a);
+; }
+
+declare void @func(i32)
+
+; CHECK: @test
+define void @test(i32 %m) nounwind uwtable {
+entry:
+ br label %for.body
+
+for.body: ; preds = %for.body, %entry
+ %i.06 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
+ %a.05 = phi i32 [ 0, %entry ], [ %add, %for.body ]
+ %add = add i32 %a.05, %m
+; CHECK: tail call void @func(i32 %add)
+ tail call void @func(i32 %add)
+ %inc = add nsw i32 %i.06, 1
+ %exitcond = icmp eq i32 %inc, 186
+ br i1 %exitcond, label %for.end, label %for.body
+
+for.end: ; preds = %for.body
+; CHECK: for.end:
+; CHECK-NOT: mul i32 %m, 186
+; CHECK:%add.lcssa = phi i32 [ %add, %for.body ]
+; CHECK-NEXT: tail call void @func(i32 %add.lcssa)
+ tail call void @func(i32 %add)
+ ret void
+}
+
+; CHECK: @test2
+define i32 @test2(i32 %m) nounwind uwtable {
+entry:
+ br label %for.body
+
+for.body: ; preds = %for.body, %entry
+ %i.06 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
+ %a.05 = phi i32 [ 0, %entry ], [ %add, %for.body ]
+ %add = add i32 %a.05, %m
+; CHECK: tail call void @func(i32 %add)
+ tail call void @func(i32 %add)
+ %inc = add nsw i32 %i.06, 1
+ %exitcond = icmp eq i32 %inc, 186
+ br i1 %exitcond, label %for.end, label %for.body
+
+for.end: ; preds = %for.body
+; CHECK: for.end:
+; CHECK-NOT: mul i32 %m, 186
+; CHECK:%add.lcssa = phi i32 [ %add, %for.body ]
+; CHECK-NEXT: ret i32 %add.lcssa
+ ret i32 %add
+}