Implement firstbitlow test

test/Feature/HLSLLib/firstbitlow.16.test

@@ -0,0 +1,88 @@
+#--- source.hlsl
+
+StructuredBuffer<uint16_t4> In1 : register(t0);
+StructuredBuffer<int16_t4> In2 : register(t1);
+RWStructuredBuffer<uint32_t4> Out : register(u2);
+
+[numthreads(1,1,1)]
+void main() {
+  Out[0] = firstbitlow(In1[0]);
+  uint32_t4 Out1 = {firstbitlow(In1[0].xyz), firstbitlow(In1[0].w)};
+  uint32_t4 Out2 = {firstbitlow(In2[0].xy), firstbitlow(In2[0].zw)};
+  Out[1] = Out1;
+  Out[2] = Out2;
+}
+
+//--- pipeline.yaml
+
+---
+Shaders:
+  - Stage: Compute
+    Entry: main
+    DispatchSize: [1, 1, 1]
+Buffers:
+  - Name: In1
+    Format: Hex16
+    Stride: 8
+    Data: [
+      0x0000,
+      0x00E8,
+      0x8000,
+      0xFFFF,
+    ]
+  - Name: In2
+    Format: Int16
+    Stride: 8
+    Data: [-1, -8, 8, 0]
+  - Name: Out
+    Format: UInt32
+    Stride: 16
+    ZeroInitSize: 48
+  - Name: ExpectedOut # The result we expect
+    Format: UInt32
+    Stride: 16
+    # All bits set (4294967295) is returned when no bit is set on the input
+    Data: [4294967295, 3, 15, 0, 4294967295, 3, 15, 0, 0, 3, 3, 4294967295]
+Results:
+  - Result: Test1
+    Rule: BufferExact
+    Actual: Out
+    Expected: ExpectedOut
+DescriptorSets:
+  - Resources:
+    - Name: In1
+      Kind: StructuredBuffer
+      DirectXBinding:
+        Register: 0
+        Space: 0
+      VulkanBinding:
+        Binding: 0
+    - Name: In2
+      Kind: StructuredBuffer
+      DirectXBinding:
+        Register: 1
+        Space: 0
+      VulkanBinding:
+        Binding: 1
+    - Name: Out
+      Kind: RWStructuredBuffer
+      DirectXBinding:
+        Register: 2
+        Space: 0
+      VulkanBinding:
+        Binding: 2
+...
+#--- end
+
+# REQUIRES: Int16
+
+# Fails with 'gpu-exec: error: Failed to materializeAll.:'
+# XFAIL: Metal
+
+# 16/64 bit firstbitlow doesn't have a DXC-Vulkan lowering
+# https://github.com/microsoft/DirectXShaderCompiler/blob/48d6e3c635f0ab3ae79580c37003e6faeca6c671/tools/clang/test/CodeGenSPIRV/intrinsics.firstbitlow.64bit.hlsl#L5
+# UNSUPPORTED: DXC-Vulkan
+
+# RUN: split-file %s %t
+# RUN: %dxc_target -T cs_6_5 -enable-16bit-types -Fo %t.o %t/source.hlsl
+# RUN: %offloader %t/pipeline.yaml %t.o

test/Feature/HLSLLib/firstbitlow.32.test

@@ -0,0 +1,79 @@
+#--- source.hlsl
+
+StructuredBuffer<uint4> In1 : register(t0);
+StructuredBuffer<int4> In2 : register(t1);
+RWStructuredBuffer<uint4> Out : register(u2);
+
+[numthreads(1,1,1)]
+void main() {
+  Out[0] = firstbitlow(In1[0]);
+  uint4 Out1 = {firstbitlow(In1[0].xyz), firstbitlow(In1[0].w)};
+  uint4 Out2 = {firstbitlow(In2[0].xy), firstbitlow(In2[0].zw)};
+  Out[1] = Out1;
+  Out[2] = Out2;
+}
+
+//--- pipeline.yaml
+
+---
+Shaders:
+  - Stage: Compute
+    Entry: main
+    DispatchSize: [1, 1, 1]
+Buffers:
+  - Name: In1
+    Format: Hex32
+    Stride: 16
+    Data: [
+      0x00000000,
+      0x000000E8,
+      0x80000000,
+      0xFFFFFFFF,
+    ]
+  - Name: In2
+    Format: Int32
+    Stride: 16
+    Data: [-1, -8, 8, 0]
+  - Name: Out
+    Format: UInt32
+    Stride: 16
+    ZeroInitSize: 48
+  - Name: ExpectedOut # The result we expect
+    Format: UInt32
+    Stride: 16
+    # All bits set (4294967295) is returned when no bit is set on the input
+    Data: [4294967295, 3, 31, 0, 4294967295, 3, 31, 0, 0, 3, 3, 4294967295]
+Results:
+  - Result: Test1
+    Rule: BufferExact
+    Actual: Out
+    Expected: ExpectedOut
+DescriptorSets:
+  - Resources:
+    - Name: In1
+      Kind: StructuredBuffer
+      DirectXBinding:
+        Register: 0
+        Space: 0
+      VulkanBinding:
+        Binding: 0
+    - Name: In2
+      Kind: StructuredBuffer
+      DirectXBinding:
+        Register: 1
+        Space: 0
+      VulkanBinding:
+        Binding: 1
+    - Name: Out
+      Kind: RWStructuredBuffer
+      DirectXBinding:
+        Register: 2
+        Space: 0
+      VulkanBinding:
+        Binding: 2
+...
+#--- end
+
+# RUN: split-file %s %t
+# RUN: %dxc_target -T cs_6_5 -Fo %t.o %t/source.hlsl
+# RUN: %offloader %t/pipeline.yaml %t.o

test/Feature/HLSLLib/firstbitlow.64.test

@@ -0,0 +1,91 @@
+#--- source.hlsl
+
+StructuredBuffer<uint64_t4> In1 : register(t0);
+StructuredBuffer<int64_t4> In2 : register(t1);
+RWStructuredBuffer<uint32_t4> Out : register(u2);
+
+[numthreads(1,1,1)]
+void main() {
+  Out[0] = firstbitlow(In1[0]);
+  uint32_t4 Out1 = {firstbitlow(In1[0].xyz), firstbitlow(In1[0].w)};
+  uint32_t4 Out2 = {firstbitlow(In2[0].xy), firstbitlow(In2[0].zw)};
+  Out[1] = Out1;
+  Out[2] = Out2;
+}
+
+//--- pipeline.yaml
+
+---
+Shaders:
+  - Stage: Compute
+    Entry: main
+    DispatchSize: [1, 1, 1]
+Buffers:
+  - Name: In1
+    Format: Hex64
+    Stride: 32
+    Data: [
+      0x0000000000000000,
+      0x00000000000000E8,
+      0x8000000000000000,
+      0xFFFFFFFFFFFFFFFF,
+    ]
+  - Name: In2
+    Format: Int64
+    Stride: 32
+    Data: [-1, -8, 8, 0]
+  - Name: Out
+    Format: UInt32
+    Stride: 16
+    ZeroInitSize: 48
+  - Name: ExpectedOut # The result we expect
+    Format: UInt32
+    Stride: 16
+    # All bits set (4294967295) is returned when no bit is set on the input
+    Data: [4294967295, 3, 63, 0, 4294967295, 3, 63, 0, 0, 3, 3, 4294967295]
+Results:
+  - Result: Test1
+    Rule: BufferExact
+    Actual: Out
+    Expected: ExpectedOut
+DescriptorSets:
+  - Resources:
+    - Name: In1
+      Kind: StructuredBuffer
+      DirectXBinding:
+        Register: 0
+        Space: 0
+      VulkanBinding:
+        Binding: 0
+    - Name: In2
+      Kind: StructuredBuffer
+      DirectXBinding:
+        Register: 1
+        Space: 0
+      VulkanBinding:
+        Binding: 1
+    - Name: Out
+      Kind: RWStructuredBuffer
+      DirectXBinding:
+        Register: 2
+        Space: 0
+      VulkanBinding:
+        Binding: 2
+...
+#--- end
+
+# REQUIRES: Int64
+
+# Fails with 'gpu-exec: error: Failed to materializeAll.:'
+# XFAIL: Metal
+
+# 16/64 bit firstbitlow doesn't have a DXC-Vulkan lowering
+# https://github.com/microsoft/DirectXShaderCompiler/blob/48d6e3c635f0ab3ae79580c37003e6faeca6c671/tools/clang/test/CodeGenSPIRV/intrinsics.firstbitlow.64bit.hlsl#L5
+# UNSUPPORTED: DXC-Vulkan
+
+# https://github.com/llvm/llvm-project/issues/143003
+# XFAIL: Clang-Vulkan
+
+# RUN: split-file %s %t
+# RUN: %dxc_target -T cs_6_5 -Fo %t.o %t/source.hlsl
+# RUN: %offloader %t/pipeline.yaml %t.o