add the Vector16 capability for both vec8 and vec16 types (KhronosGroup#229)

* add the Vector16 capability for both vec8 and vec16 types

* added test to verify Vector16 capability is added for vectors with eight elements

Author: bashbaug

lib/SPIRV/libSPIRV/SPIRVType.h

@@ -281,7 +281,9 @@ class SPIRVTypeVector:public SPIRVType {
   bool isValidIndex(SPIRVWord Index) const { return Index < CompCount;}
   SPIRVCapVec getRequiredCapability() const {
     SPIRVCapVec V(getComponentType()->getRequiredCapability());
-    if (CompCount > 8)
+    // Even though the capability name is "Vector16", it describes
+    // usage of 8-component or 16-component vectors.
+    if (CompCount >= 8)
       V.push_back(CapabilityVector16);
     return std::move(V);
   }

test/transcoding/vec8.ll

@@ -0,0 +1,45 @@
+; This test verifies that the Vector16 capability is correctly added
+; if an OpenCL kernel uses a vector of eight elements.
+;
+;Source:
+;__kernel void test( int8 v ) {}
+
+; RUN: llvm-as %s -o %t.bc
+; RUN: llvm-spirv %t.bc -o - -spirv-text | FileCheck %s --check-prefix=CHECK-SPIRV
+; RUN: llvm-spirv %t.bc -o %t.spv
+; RUN: llvm-spirv -r %t.spv -o %t.rev.bc
+; RUN: llvm-dis < %t.rev.bc | FileCheck %s --check-prefix=CHECK-LLVM
+
+; CHECK-SPIRV: Capability Vector16
+
+target datalayout = "e-p:32:32-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-v256:256-v512:512-v1024:1024-n8:16:32:64"
+target triple = "spir"
+
+; Function Attrs: nounwind
+define spir_kernel void @test(<8 x i32> %v) #0 {
+; CHECK-LLVM: <8 x i32>
+  %1 = alloca <8 x i32>, align 32
+  store <8 x i32> %v, <8 x i32>* %1, align 32
+  ret void
+}
+
+attributes #0 = { nounwind "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-realign-stack" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+!opencl.kernels = !{!0}
+!opencl.enable.FP_CONTRACT = !{}
+!opencl.spir.version = !{!6}
+!opencl.ocl.version = !{!6}
+!opencl.used.extensions = !{!7}
+!opencl.used.optional.core.features = !{!7}
+!opencl.compiler.options = !{!7}
+!llvm.ident = !{!8}
+
+!0 = !{void (<8 x i32>)* @test, !1, !2, !3, !4, !5}
+!1 = !{!"kernel_arg_addr_space", i32 0}
+!2 = !{!"kernel_arg_access_qual", !"none"}
+!3 = !{!"kernel_arg_type", !"int8"}
+!4 = !{!"kernel_arg_base_type", !"int8"}
+!5 = !{!"kernel_arg_type_qual", !""}
+!6 = !{i32 1, i32 2}
+!7 = !{}
+!8 = !{!"clang version 3.6.1 (https://github.com/KhronosGroup/SPIR 2b577882b436ba3133457f27e0aa999f2ac8b11c) (https://github.com/KhronosGroup/SPIRV-LLVM.git 44ec76519179879c7900a5da4e724c751ce516a9)"}