[llvm] [SPIR-V] Fix `asdouble` issue in SPIRV codegen to correctly generate `OpBitCast` instruction. (PR #161891)

[Lucie Choi via llvm-commits]

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@@ -0,0 +1,28 @@
+; RUN: llc -verify-machineinstrs -O0 -mtriple=spirv-unknown-vulkan-compute %s -o - | FileCheck %s --match-full-lines
+; RUN: %if spirv-tools %{ llc -O0 -mtriple=spirv-unknown-vulkan %s -o - -filetype=obj | spirv-val %}
+
+; CHECK-DAG:        %[[#uint:]] = OpTypeInt 32 0
+; CHECK-DAG:     %[[#v2_uint:]] = OpTypeVector %[[#uint]] 2
+; CHECK-DAG:      %[[#double:]] = OpTypeFloat 64
+; CHECK-DAG:   %[[#v2_double:]] = OpTypeVector %[[#double]] 2
+; CHECK-DAG:     %[[#v4_uint:]] = OpTypeVector %[[#uint]] 4
+ at .str = private unnamed_addr constant [3 x i8] c"In\00", align 1
+ at .str.2 = private unnamed_addr constant [4 x i8] c"Out\00", align 1
+
+define void @main() local_unnamed_addr #0 {
+entry:
+  %0 = tail call target("spirv.VulkanBuffer", [0 x <2 x i32>], 12, 0) @llvm.spv.resource.handlefrombinding.tspirv.VulkanBuffer_a0v2i32_12_0t(i32 0, i32 0, i32 1, i32 0, ptr nonnull @.str)
+  %1 = tail call target("spirv.VulkanBuffer", [0 x <2 x double>], 12, 1) @llvm.spv.resource.handlefrombinding.tspirv.VulkanBuffer_a0v2f64_12_1t(i32 0, i32 2, i32 1, i32 0, ptr nonnull @.str.2)
+  %2 = tail call noundef align 8 dereferenceable(8) ptr addrspace(11) @llvm.spv.resource.getpointer.p11.tspirv.VulkanBuffer_a0v2i32_12_0t(target("spirv.VulkanBuffer", [0 x <2 x i32>], 12, 0) %0, i32 0)
+  %3 = load <2 x i32>, ptr addrspace(11) %2, align 8
+  %4 = tail call noundef align 8 dereferenceable(8) ptr addrspace(11) @llvm.spv.resource.getpointer.p11.tspirv.VulkanBuffer_a0v2i32_12_0t(target("spirv.VulkanBuffer", [0 x <2 x i32>], 12, 0) %0, i32 1)
+  %5 = load <2 x i32>, ptr addrspace(11) %4, align 8
+; CHECK: %[[#tmp:]] = OpVectorShuffle %[[#v4_uint]] {{%[0-9]+}} {{%[0-9]+}} 0 2 1 3
----------------
luciechoi wrote:

The final SPIRV for this function had lots of verbose `OpCopyObject`, so I left some variables unmatched/ignored.

```spv
        %36 = OpFunction %2 DontInline %3       ; -- Begin function main
        %1 = OpLabel
        %37 = OpVariable %23 Function %32
        %38 = OpVariable %22 Function %33
        %39 = OpCopyObject %16 %34
        %40 = OpCopyObject %13 %35
        %41 = OpAccessChain %10 %39 %24 %24
        %42 = OpLoad %9 %41 Aligned 8
        %43 = OpAccessChain %10 %39 %24 %25
        %44 = OpLoad %9 %43 Aligned 8
        %45 = OpVectorShuffle %8 %42 %44 0 2 1 3
        %46 = OpAccessChain %6 %40 %24 %24
        %47 = OpBitcast %5 %45
        %48 = OpCopyObject %13 %35
        OpStore %46 %47 Aligned 16
        OpReturn
        OpFunctionEnd
                                        ; -- End function
```

https://github.com/llvm/llvm-project/pull/161891