[clang] [llvm] [HLSL] Move length support out of the DirectX Backend (PR #121611)

[Farzon Lotfi via llvm-commits]

================
@@ -1,32 +1,53 @@
-// RUN: %clang_cc1 -finclude-default-header -triple dxil-pc-shadermodel6.6-library %s -fnative-half-type -disable-llvm-passes -verify -verify-ignore-unexpected
-
+// RUN: %clang_cc1 -finclude-default-header -triple dxil-pc-shadermodel6.6-library %s -fnative-half-type -emit-llvm-only -disable-llvm-passes -verify
 
 void test_too_few_arg()
 {
-  return __builtin_hlsl_length();
-  // expected-error at -1 {{too few arguments to function call, expected 1, have 0}}
+  return length();
+  // expected-error at -1 {{no matching function for call to 'length'}}
+  // expected-note at hlsl/hlsl_intrinsics.h:* {{candidate function not viable: requires single argument 'X', but no arguments were provided}}
+  // expected-note at hlsl/hlsl_intrinsics.h:* {{candidate function not viable: requires single argument 'X', but no arguments were provided}}
+  // expected-note at hlsl/hlsl_intrinsics.h:* {{candidate function template not viable: requires single argument 'X', but no arguments were provided}}
+  // expected-note at hlsl/hlsl_intrinsics.h:* {{candidate function template not viable: requires single argument 'X', but no arguments were provided}}
 }
 
 void test_too_many_arg(float2 p0)
 {
-  return __builtin_hlsl_length(p0, p0);
-  // expected-error at -1 {{too many arguments to function call, expected 1, have 2}}
+  return length(p0, p0);
+  // expected-error at -1 {{no matching function for call to 'length'}}
+  // expected-note at hlsl/hlsl_intrinsics.h:* {{candidate function not viable: requires single argument 'X', but 2 arguments were provided}}
+  // expected-note at hlsl/hlsl_intrinsics.h:* {{candidate function template not viable: requires single argument 'X', but 2 arguments were provided}}
+  // expected-note at hlsl/hlsl_intrinsics.h:* {{candidate function not viable: requires single argument 'X', but 2 arguments were provided}}
+  // expected-note at hlsl/hlsl_intrinsics.h:* {{candidate function template not viable: requires single argument 'X', but 2 arguments were provided}}
+}
+
+float double_to_float_type(double p0) {
+  return length(p0);
+  // expected-error at -1  {{call to 'length' is ambiguous}}
+  // expected-note at hlsl/hlsl_intrinsics.h:* {{candidate function}}
+  // expected-note at hlsl/hlsl_intrinsics.h:* {{candidate function}}
 }
 
-bool builtin_bool_to_float_type_promotion(bool p1)
+
+float bool_to_float_type_promotion(bool p1)
 {
-  return __builtin_hlsl_length(p1);
-  // expected-error at -1 {passing 'bool' to parameter of incompatible type 'float'}}
+  return length(p1);
+  // expected-error at -1  {{call to 'length' is ambiguous}}
+  // expected-note at hlsl/hlsl_intrinsics.h:* {{candidate function}}
+  // expected-note at hlsl/hlsl_intrinsics.h:* {{candidate function}}
 }
 
-bool builtin_length_int_to_float_promotion(int p1)
+float length_int_to_float_promotion(int p1)
 {
-  return __builtin_hlsl_length(p1);
-  // expected-error at -1 {{passing 'int' to parameter of incompatible type 'float'}}
+  return length(p1);
+  // expected-error at -1  {{call to 'length' is ambiguous}}
+  // expected-note at hlsl/hlsl_intrinsics.h:* {{candidate function}}
+  // expected-note at hlsl/hlsl_intrinsics.h:* {{candidate function}}
 }
 
-bool2 builtin_length_int2_to_float2_promotion(int2 p1)
+float2 length_int2_to_float2_promotion(int2 p1)
 {
-  return __builtin_hlsl_length(p1);
-  // expected-error at -1 {{passing 'int2' (aka 'vector<int, 2>') to parameter of incompatible type '__attribute__((__vector_size__(2 * sizeof(float)))) float' (vector of 2 'float' values)}}
+  return length(p1);
+  // expected-error at -1  {{call to 'length' is ambiguous}}
+  // expected-note at hlsl/hlsl_intrinsics.h:* {{candidate function}}
+  // expected-note at hlsl/hlsl_intrinsics.h:* {{candidate function}}
----------------
farzonl wrote:

There was no int/bool/double `length` intrinsic in `hlsl_intrinsics.h` and this test was already an error case. All that has changed here is instead of explicit sema checks for the builtin we are depending on HLSL overload resolution rules for function arguments. Thats partly because the builtin `__builtin_hlsl_length` doesn't exist anymore.

https://github.com/llvm/llvm-project/pull/121611