Fix PR24469 resulting from r245025 and re-enable dead store elimination across basicb...

[oota-llvm.git] / test / Transforms / DeadStoreElimination / cross_block_dse.ll

diff --git a/test/Transforms/DeadStoreElimination/cross_block_dse.ll b/test/Transforms/DeadStoreElimination/cross_block_dse.ll
new file mode 100644 (file)
index 0000000..dfab855
--- /dev/null
+++ b/test/Transforms/DeadStoreElimination/cross_block_dse.ll
@@ -0,0 +1,104 @@
+; RUN: opt < %s -basicaa -dse -S | FileCheck %s
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+@x = common global i32 0
+@y = common global i32 0
+@a = external global i32
+@b = external global i32
+
+define void @test_01(i32 %N) {
+  %1 = alloca i32
+  store i32 %N, i32* %1
+  store i32 10, i32* @x
+  %2 = load i32, i32* %1
+  %3 = icmp ne i32 %2, 0
+  br i1 %3, label %4, label %5
+
+; <label>:4
+  store i32 5, i32* @x
+  br label %5
+
+; <label>:5
+  store i32 15, i32* @x
+  ret void
+}
+; CHECK-LABEL: @test_01(
+; CHECK-NOT: store i32 10, i32* @x
+; CHECK-NOT: store i32 5, i32* @x
+; CHECK: store i32 15, i32* @x
+
+
+define void @test_02(i32 %N) {
+  %1 = alloca i32
+  store i32 %N, i32* %1
+  store i32 10, i32* @x
+  %2 = load i32, i32* %1
+  %3 = icmp ne i32 %2, 0
+  br i1 %3, label %4, label %5
+
+; <label>:4
+  store i32 5, i32* @x
+  br label %7
+
+; <label>:5
+  %6 = load i32, i32* @x
+  store i32 %6, i32* @y
+  br label %7
+
+; <label>:7
+  store i32 15, i32* @x
+  ret void
+}
+; CHECK-LABEL: @test_02(
+; CHECK: store i32 10, i32* @x
+; CHECK-NOT: store i32 5, i32* @x
+; CHECK: store i32 %6, i32* @y
+
+
+define void @test_03(i32 %N) #0 {
+  %1 = alloca i32
+  store i32 %N, i32* %1
+  store i32 10, i32* @x
+  %2 = load i32, i32* %1
+  %3 = icmp ne i32 %2, 0
+  br i1 %3, label %4, label %6
+
+; <label>:4                                       ; preds = %0
+  %5 = load i32, i32* @x
+  store i32 %5, i32* @y
+  br label %6
+
+; <label>:6                                       ; preds = %4, %0
+  store i32 15, i32* @x
+  ret void
+}
+; CHECK-LABEL: @test_03(
+; CHECK: store i32 10, i32* @x
+; CHECK: store i32 %5, i32* @y
+; CHECK: store i32 15, i32* @x
+
+
+
+; Check we safely delete store i32 %g.02, i32* @b below.(PR24469)
+define void @test_04() {
+entry:
+  br i1 false, label %for.body, label %for.end.9
+
+for.cond.1.loopexit:                              ; preds = %for.body
+  store i32 0, i32* @b
+  %0 = load i32, i32* @a
+  br i1 false, label %for.body, label %for.end.9
+
+for.body:                                         ; preds = %for.cond.1.loopexit, %entry
+  %g.02 = phi i32 [ undef, %entry ], [ %0, %for.cond.1.loopexit ]
+  store i32 %g.02, i32* @b
+  br label %for.cond.1.loopexit
+
+for.end.9:                                        ; preds = %for.cond.1.loopexit, %entry
+  ret void
+}
+
+; CHECK-LABEL: @test_04(
+; CHECK-NOT: store i32 %g.02, i32* @b
+; CHECK-NOT: %g.02 = phi i32 [ undef, %entry ], [ %0, %for.cond.1.loopexit ]
+; CHECK-NOT: %0 = load i32, i32* @a