[clang] [llvm] [HLSL] Implement the `smoothstep` intrinsic (PR #132288)

[Farzon Lotfi via llvm-commits]

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@@ -0,0 +1,43 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --version 5
+
+// RUN: %clang_cc1 -O1 -triple spirv-pc-vulkan-compute %s -emit-llvm -o - | FileCheck %s
+
+typedef float float2 __attribute__((ext_vector_type(2)));
+typedef float float3 __attribute__((ext_vector_type(3)));
+typedef float float4 __attribute__((ext_vector_type(4)));
+
+// CHECK-LABEL: define spir_func float @test_smoothstep_float(
+// CHECK-SAME: float noundef [[MIN:%.*]], float noundef [[MAX:%.*]], float noundef [[X:%.*]]) local_unnamed_addr #[[ATTR0:[0-9]+]] {
+// CHECK-NEXT:  [[ENTRY:.*:]]
+// CHECK-NEXT:    [[CONV:%.*]] = fpext float [[MIN]] to double
+// CHECK-NEXT:    [[CONV1:%.*]] = fpext float [[MAX]] to double
+// CHECK-NEXT:    [[CONV2:%.*]] = fpext float [[X]] to double
+// CHECK-NEXT:    [[SPV_SMOOTHSTEP:%.*]] = tail call double @llvm.spv.smoothstep.f64(double [[CONV]], double [[CONV1]], double [[CONV2]])
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farzonl wrote:

should be
`float @llvm.spv.smoothstep.f32(float [[MIN]], float [[Max]], float [[X]])`

https://github.com/llvm/llvm-project/pull/132288