[llvm] [DirectX] Lower `llvm.lifetime.*` intrinsics to stores when DXIL version is lower than 1.6 (PR #147432)

[Farzon Lotfi via llvm-commits]

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@@ -3,9 +3,9 @@
 ; CHECK-LABEL: define void @test_legal_lifetime() {
 ; CHECK-NEXT:    [[ACCUM_I_FLAT:%.*]] = alloca [1 x i32], align 4
 ; CHECK-NEXT:    [[GEP:%.*]] = getelementptr i32, ptr [[ACCUM_I_FLAT]], i32 0
-; CHECK-NEXT:    call void @llvm.lifetime.start.p0(i64 4, ptr nonnull [[ACCUM_I_FLAT]])
+; CHECK-NEXT:    store [1 x i32] zeroinitializer, ptr [[ACCUM_I_FLAT]], align 4
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farzonl wrote:

What does the 1.5 mean in this title? is that DXIL version? How are you specifying version in this testcase? All I see in the runline is shader model 6.3.

https://github.com/llvm/llvm-project/pull/147432