[clang] [llvm] [HLSL] Add wave prefix count bits function (PR #178059)

[Tex Riddell via cfe-commits]

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@@ -0,0 +1,30 @@
+// RUN: %clang_cc1 -finclude-default-header -fnative-int16-type -fnative-half-type \
+// RUN:   -fmath-errno -ffp-contract=on -fno-rounding-math -finclude-default-header \
+// RUN:   -triple dxil-pc-shadermodel6.6-library %s -emit-llvm-only -disable-llvm-passes -verify
+
+int test_too_few_arg() {
+  return __builtin_hlsl_wave_prefix_count_bits();
+  // expected-error at -1 {{too few arguments to function call, expected 1, have 0}}
+}
+
+int test_too_many_arg(bool p0) {
+  return __builtin_hlsl_wave_prefix_count_bits(p0, p0);
+  // expected-error at -1 {{too many arguments to function call, expected 1, have 2}}
+}
+
+float test_expr_bool_type_check(float p0) {
+  return __builtin_hlsl_wave_prefix_count_bits(p0);
+  // expected-error at -1 {{invalid operand of type 'float'}}
+}
+
+float2 test_expr_bool_vec_type_check(float2 p0) {
+  return __builtin_hlsl_wave_prefix_count_bits(p0);
+  // expected-error at -1 {{invalid operand of type 'float2' (aka 'vector<float, 2>')}}
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tex3d wrote:

nit: Testing `bool2` might have been better, since it's the vector we want to reject even if the component type is correct.

https://github.com/llvm/llvm-project/pull/178059