{{- /*
--------------------------------------------------------------------------------
Template file for use with tools/src/cmd/gen to generate the wgsl files in the
./literal/...  and ./var/... subdirectories

See:
* tools/src/cmd/gen for structures used by this template
* https://golang.org/pkg/text/template/ for documentation on the template syntax
--------------------------------------------------------------------------------
*/ -}}

{{- $I := LoadIntrinsics "src/tint/lang/wgsl/wgsl.def" -}}

{{- /* For each permutation of each overload of each function... */ -}}
{{- range $I.Sem.Builtins -}}
{{    if not (HasPrefix .Name "_") }}
{{-     range .Overloads  -}}
{{-       range $I.Permute . -}}
{{- /*      Generate a ./literal/<function>/<permuataion-hash>.wgsl file using
            the Permutation macro defined below                             */ -}}
{{-         $file := printf "./literal/%v/%v.wgsl" .Intrinsic.Name .Hash -}}
{{-         $content := Eval "Permutation" "Overload" . "Mode" "literal" -}}
{{-         WriteFile $file $content -}}
{{- /*      Generate a ./var/<function>/<permuataion-hash>.wgsl file using
            the Permutation macro defined below                             */ -}}
{{-         $file := printf "./var/%v/%v.wgsl" .Intrinsic.Name .Hash -}}
{{-         $content := Eval "Permutation" "Overload" . "Mode" "var" -}}
{{-         WriteFile $file $content -}}
{{-       end  }}
{{-     end  }}
{{-   end  }}
{{- end  }}

{{- /* ------------------------------------------------------------------ */ -}}
{{-                          define "Permutation"                            -}}
{{- /* Emits the body of the intrinsic permuation .wgsl file              */ -}}
{{- /* ------------------------------------------------------------------ */ -}}
{{-   $overload    := .Overload -}}
{{-   $mode        := .Mode -}}
{{-   $builtin     := $overload.Intrinsic.Name -}}
{{-   $permutation := printf "%v_%v" $builtin $overload.Hash -}}
{{-   $args        := Map -}}

{{- /* Generate the optional flag on HLSL shader model */ -}}
{{- template "HLSLShaderModel" $overload -}}

{{- /* Generate enable directives */ -}}
{{- template "EnableDirectives" $overload -}}

{{- /* Keep track of binding numbers to satisfy limitations of the MSL backend with the Tint executable interface: https://crbug.com/42250109 */ -}}
{{- $b := 0 -}}
{{- if and (or $overload.CanBeUsedInStage.Fragment $overload.CanBeUsedInStage.Compute) (and $overload.ReturnType (IsDeclarable $overload.ReturnType))}}
{{-   if and (IsHostShareable $overload.ReturnType) (not (HasPrefix $overload.ReturnType.Target.Name "mat"))}}
@group(0) @binding({{$b}}) var<storage, read_write> prevent_dce : {{template "Type" $overload.ReturnType -}};
{{-   else}}
@group(0) @binding({{$b}}) var<storage, read_write> prevent_dce : i32;
{{    end}}
{{    $b = 1}}
{{  end}}

{{- /* Generate RW storage buffer parameters */ -}}
{{-   $sb_rw_fields := Eval "EmitBufferFields" "overload"          $overload
                                               "var_name"          "sb_rw"
                                               "address_space"     "storage"
                                               "access"            "read_write"
                                               "args"              $args -}}
{{-   if $sb_rw_fields -}}
struct SB_RW {
{{- $sb_rw_fields -}}
};
@group(0) @binding({{$b}}) var<storage, read_write> sb_rw : SB_RW;
{{    end -}}

{{- /* Generate RO storage buffer parameters */ -}}
{{-   $sb_ro_fields := Eval "EmitBufferFields" "overload"          $overload
                                               "var_name"          "sb_ro"
                                               "address_space"     "storage"
                                               "access"            "read"
                                               "args"              $args -}}
{{-   if $sb_ro_fields -}}
struct SB_RO {
{{- $sb_ro_fields -}}
};
@group(0) @binding({{$b}}) var<storage, read> sb_ro : SB_RO;
{{    end -}}

{{- /* Generate uniform buffer parameters */ -}}
{{-   $ub_fields := Eval "EmitBufferFields" "overload"          $overload
                                            "var_name"          "ub"
                                            "address_space"     "uniform"
                                            "access"            "read"
                                            "args"              $args -}}
{{-   if $ub_fields -}}
struct UB {
{{- $ub_fields -}}
};
@group(0) @binding({{$b}}) var<uniform> ub : UB;
{{    end -}}

{{- /* Generate module-scoped handle variables */ -}}
{{-   range $i, $p := $overload.Parameters  }}
{{-     $class := Eval "AddressSpace" $p.Type -}}
{{-     if eq "ptr" $p.Type.Target.Name -}}
{{-       $el_type := Eval "Type" (index $p.Type.TemplateArguments 1)}}
{{-       if eq "handle" $class -}}
{{-         if HasPrefix $el_type "input_attachment" -}}
              @input_attachment_index(3)
{{          end -}}
            @group(1) @binding({{$i}}) var arg_{{$i}}: {{$el_type}};
{{          $args.Put $i (printf "&arg_%v" $i) -}}
{{-       else if eq "workgroup" $class -}}
            var<workgroup> arg_{{$i}}: {{$el_type}};
{{          $args.Put $i (printf "&arg_%v" $i) -}}
{{-       else if eq "private" $class -}}
            var<private> arg_{{$i}}: {{$el_type}};
{{          $args.Put $i (printf "&arg_%v" $i) -}}
{{-       end -}}
{{-     else -}}
{{-       $type := Eval "Type" $p.Type}}
{{-       if eq "handle" $class -}}
{{-         if HasPrefix $type "input_attachment" -}}
              @input_attachment_index(3)
{{          end -}}
            @group(1) @binding({{$i}}) var arg_{{$i}}: {{$type}};
{{          $args.Put $i (printf "arg_%v" $i) -}}
{{-       else if eq "workgroup" $class -}}
            var<workgroup> arg_{{$i}}: {{$type}};
{{          $args.Put $i (printf "arg_%v" $i) -}}
{{-       else if eq "private" $class -}}
            var<private> arg_{{$i}}: {{$type}};
{{          $args.Put $i (printf "arg_%v" $i) -}}
{{-       end -}}
{{-     end -}}
{{-   end -}}

{{- /* Generate the function that calls the intrinsic */ -}}
{{- /*newline*/}}
// {{$.Overload}}
fn {{$permutation}}() {{/* preserve space after () */ -}}
{{-   if and $overload.ReturnType (IsDeclarable $overload.ReturnType) -}}
{{- /* Matrices can't be assigned to shader outputs, so wrap them in a check and select */ -}}
{{-     if and (IsHostShareable $overload.ReturnType) (not (HasPrefix $overload.ReturnType.Target.Name "mat")) -}}
-> {{template "Type" $overload.ReturnType}}
{{-     else -}}
-> i32
{{-     end -}}
{{-   end -}}{
{{/* Build the parameters either as 'var' or inline values */ -}}
{{-   range $i, $p := $overload.Parameters -}}
{{-     $class       := Eval "AddressSpace" $p.Type -}}
{{-     $is_abstract := DeepestElementType $p.Type | IsAbstract -}}
{{-     if eq "function" $class -}}
{{-       if eq "ptr" $p.Type.Target.Name -}}
{{template "Type" index $p.Type.TemplateArguments 1}};
{{- /*indent*/}}  var arg_{{$i}}: {{template "Type" index $p.Type.TemplateArguments 1}};
{{          $args.Put $i (printf "&arg_%v" $i) -}}
{{-       else if eq "var" $mode -}}
{{-         if or $is_abstract $p.IsConst }}  const arg_{{$i}} = {{Eval "ArgumentValue" $p}};
{{          else                          }}  var arg_{{$i}} = {{Eval "ArgumentValue" $p}};
{{          end                           }}
{{-         $args.Put $i (printf "arg_%v" $i) -}}
{{-       else -}}
{{-         $args.Put $i (Eval "ArgumentValue" $p) -}}
{{-       end -}}
{{-     end -}}
{{-   end -}}

{{- /* Make the call to the intrinsic */ -}}
{{- /*indent*/}}  {{/*indent*/ -}}
{{-   if $overload.ReturnType -}}
  var res{{if IsDeclarable $overload.ReturnType}}: {{template "Type" $overload.ReturnType}}{{end}} = {{/* preserve space after = */ -}}
{{-   end -}}
  {{$builtin}}{{Eval "TemplateArguments" $overload.ExplicitTemplateArgs}}(
{{-   range $i, $p := $overload.Parameters -}}
{{-     if $i -}}, {{end}}{{$args.Get $i -}}
{{-   end -}}
  );
{{- /* Return the result to be stored somewhere that ensures it isn't dead-code eliminated */ -}}
{{-   if and $overload.ReturnType (IsDeclarable $overload.ReturnType)}}
{{-     if HasPrefix $overload.ReturnType.Target.Name "mat"}}
  return select(0, 1, res[0][0] == 0);
{{-     else if IsHostShareable $overload.ReturnType}}
  return res;
{{-     else}}
  return select(0, 1, all(res == {{template "Type" $overload.ReturnType}}()));
{{-     end}}
{{-   end}}
}

{{- if $overload.CanBeUsedInStage.Fragment }}
@fragment
fn fragment_main() {
  {{   if and $overload.ReturnType (IsDeclarable $overload.ReturnType) -}}
  prevent_dce = {{/* preserve space after = */ -}}
  {{-   end -}}
  {{$permutation}}();
}
{{ end -}}

{{- if $overload.CanBeUsedInStage.Compute }}
@compute @workgroup_size(1)
fn compute_main() {
  {{   if and $overload.ReturnType (IsDeclarable $overload.ReturnType) -}}
  prevent_dce = {{/* preserve space after = */ -}}
  {{-   end -}}
  {{$permutation}}();
}
{{ end -}}

{{- /* Vertex shader must be moved to the end due to crbug.com/42250109 */ -}}
{{- if $overload.CanBeUsedInStage.Vertex }}
struct VertexOutput {
    @builtin(position) pos: vec4<f32>,
{{-   if and $overload.ReturnType (IsDeclarable $overload.ReturnType)}}
{{-     if and (IsHostShareable $overload.ReturnType) (not (HasPrefix $overload.ReturnType.Target.Name "mat"))}}
    @location(0) @interpolate(flat) prevent_dce : {{template "Type" $overload.ReturnType}}
{{-     else}}
    @location(0) @interpolate(flat) prevent_dce : i32
{{-     end}}
{{-  end}}
};

@vertex
fn vertex_main() -> VertexOutput {
  var out : VertexOutput;
  out.pos = vec4<f32>();
  {{   if and $overload.ReturnType (IsDeclarable $overload.ReturnType) -}}
  out.prevent_dce = {{/* preserve space after = */ -}}
  {{-   end -}}
  {{$permutation}}();
  return out;
}
{{ end -}}

{{- end -}}


{{- /* ------------------------------------------------------------------ */ -}}
{{-                        define "HLSLShaderModel"                          -}}
{{- /* Emits the optional HLSL shader model for a given overload          */ -}}
{{- /* ------------------------------------------------------------------ */ -}}
{{-   $permutation  := . -}}
{{-   $overload := $permutation.Overload -}}
{{-   $builtin_name := $permutation.Intrinsic.Name -}}

{{/* Check and emit dot4I8Packed and dot4U8Packed */}}
{{-   if or (eq "pack4xI8" $builtin_name) (eq "pack4xU8" $builtin_name) (eq "pack4xI8Clamp" $builtin_name) (eq "unpack4xI8" $builtin_name) (eq "unpack4xU8" $builtin_name)}}
// [hlsl-dxc] flags: --hlsl_shader_model 66

{{-   else if or (eq "dot4I8Packed" $builtin_name) (eq "dot4U8Packed" $builtin_name)}}
// [hlsl-dxc] flags: --hlsl_shader_model 64

{{/* Check and emit f16 */}}
{{-   else if OverloadUsesType $overload "f16"}}
// flags: --hlsl_shader_model 62

{{/* HLSL Wave operations require Shader Model 6.0 (DXC) */}}
{{-   else if or (HasPrefix $builtin_name "subgroup") (HasPrefix $builtin_name "quad")}}
// [hlsl-dxc] flags: --hlsl_shader_model 60

{{    end -}}

{{- end -}}


{{- /* ------------------------------------------------------------------ */ -}}
{{-                        define "EnableDirectives"                         -}}
{{- /* Emits the required enable directives for a given overload          */ -}}
{{- /* ------------------------------------------------------------------ */ -}}
{{-   $permutation  := . -}}
{{-   $overload := $permutation.Overload -}}
{{-   $builtin_name := $permutation.Intrinsic.Name -}}

{{- /* Emit 'enable subgroups' and 'enable subgroups_f16' if required */ -}}
{{-   if or (HasPrefix $builtin_name "subgroup") (HasPrefix $builtin_name "quad")}}
enable subgroups;
{{-     if OverloadUsesType $overload "f16"}}
enable subgroups_f16;
{{      end -}}
{{    end -}}


{{- /* Emit 'enable chromium_internal_input_attachments' if required */ -}}
{{-   if eq "inputAttachmentLoad" $builtin_name}}
enable chromium_internal_input_attachments;
{{    end -}}

{{- /* Emit 'enable f16' if required */ -}}
{{-   if OverloadUsesType $overload "f16"}}
enable f16;
{{    end -}}

{{- /* Emit 'enable chromium_internal_graphite' if required */ -}}
{{-   if OverloadUsesType $overload "r8unorm"}}
enable chromium_internal_graphite;
{{    end -}}

{{- end -}}


{{- /* ------------------------------------------------------------------ */ -}}
{{-                       define "EmitBufferFields"                          -}}
{{- /* Emits a struct with the fields that match the given address space  */ -}}
{{- /* and access.                                                        */ -}}
{{- /* Argument is a map with the following expected keys:                */ -}}
{{- /*  'overload'       - the current overload                           */ -}}
{{- /*  'var_name'       - name of the variable of the structure type     */ -}}
{{- /*  'address_space'  - filtered address space                         */ -}}
{{- /*  'access'         - filtered access                                */ -}}
{{- /*  'args'           - argument map that's populated with the fields  */ -}}
{{- /* ------------------------------------------------------------------ */ -}}
{{- $overload             := .Get "overload" -}}
{{- $var_name             := .Get "var_name" -}}
{{- $filter_address_space := .Get "address_space"  -}}
{{- $filter_access        := .Get "access"   -}}
{{- $args                 := .Get "args"     -}}
{{-   range $i, $p := $overload.Parameters  }}
{{-     $address_space := Eval "AddressSpace" $p.Type -}}
{{-     $access  := Eval "Access"       $p.Type -}}
{{-     if and (eq $filter_address_space $address_space) (eq $filter_access $access) }}
{{-       if eq "ptr" $p.Type.Target.Name  }}
  arg_{{$i}}: {{template "Type" (index $p.Type.TemplateArguments 1)}},
{{          $args.Put $i (printf "&%v.arg_%v" $var_name $i) -}}
{{-       else  }}
  arg_{{$i}}: {{template "Type" $p.Type}},
{{          $args.Put $i (printf "%v.arg_%v" $var_name $i) -}}
{{-       end -}}
{{-     end -}}
{{-   end -}}
{{ end -}}


{{- /* ------------------------------------------------------------------ */ -}}
{{-                           define "AddressSpace"                          -}}
{{- /* Returns the address space for the given Fully Qualified Name       */ -}}
{{- /* ------------------------------------------------------------------ */ -}}
{{-   $name := .Target.Name -}}
{{-   if             eq $name "array"   -}}storage
{{-   else if HasPrefix $name "texture" -}}handle
{{-   else if HasPrefix $name "sampler" -}}handle
{{-   else if HasPrefix $name "input_attachment" -}}handle
{{-   else if        eq $name "ptr"     -}}{{(index .TemplateArguments 0).Target.Name}}
{{-   else                              -}}function
{{-   end -}}
{{- end -}}


{{- /* ------------------------------------------------------------------ */ -}}
{{-                           define "Access"                                -}}
{{- /* Returns the access for the given Fully Qualified Name              */ -}}
{{- /* ------------------------------------------------------------------ */ -}}
{{-   $name := .Target.Name -}}
{{-   if eq $name "ptr"     -}}{{(index .TemplateArguments 2).Target.Name}}
{{-   else -}}
{{- /*  Emit the default for the address space */ -}}
{{- /*  https://gpuweb.github.io/gpuweb/wgsl/#address-space */ -}}
{{-     $address_space := Eval "AddressSpace" . -}}
{{-          if eq $address_space "function"  -}}read_write
{{-     else if eq $address_space "private"   -}}read_write
{{-     else if eq $address_space "workgroup" -}}read_write
{{-     else if eq $address_space "uniform"   -}}read
{{-     else if eq $address_space "storage"   -}}read
{{-     else if eq $address_space "handle"    -}}read
{{-     end -}}
{{-   end -}}
{{- end -}}


{{- /* ------------------------------------------------------------------ */ -}}
{{-                          define "ArgumentValue"                          -}}
{{- /* Returns a value that can be used for the parameter argument        */ -}}
{{- /* ------------------------------------------------------------------ */ -}}
{{-   $ty := .Type -}}
{{-   $value := printf "%v" .TestValue }}
{{- /* $float_value is $value with a '.' suffix (if it wasn't a float already) */ -}}
{{-   $float_value := $value }}
{{-   if not (Contains $value ".") }}{{$float_value = printf "%v." $value}}{{end}}
{{- /* emit the value with any necessary suffixes */ -}}
{{-        if eq        $ty.Target.Name "i32"  -}}{{$value}}i
{{-   else if eq        $ty.Target.Name "u32"  -}}{{$value}}u
{{-   else if eq        $ty.Target.Name "f32"  -}}{{$float_value}}f
{{-   else if eq        $ty.Target.Name "f16"  -}}{{$float_value}}h
{{-   else if eq        $ty.Target.Name "fa"   -}}{{$float_value}}
{{-   else if eq        $ty.Target.Name "ia"   -}}{{$value}}
{{-   else if eq        $ty.Target.Name "bool" -}}true
{{-   else if HasPrefix $ty.Target.Name "vec"  -}}
{{-     $el := Eval "ArgumentValue" "Type" (ElementType .Type) "TestValue" .TestValue }}
{{-     template "Type" $ty}}({{$el}})
{{-   else if HasPrefix $ty.Target.Name "mat"  -}}{{template "Type" $ty}}(
{{-     $el := Eval "ArgumentValue" "Type" (ElementType .Type) "TestValue" .TestValue }}
{{-     range $col := Iterate (index $ty.TemplateArguments 0)     }}
{{-       range $row := Iterate (index $ty.TemplateArguments 1)   }}
{{-         if or $col $row -}}, {{end}}{{$el}}
{{-       end -}}
{{-     end -}})
{{-   else -}}{{template "Type" $ty}}()
{{-   end  -}}
{{- end -}}


{{- /* ------------------------------------------------------------------ */ -}}
{{-                                define "Type"                             -}}
{{- /* Emits the WGSL for the Fully Qualified Name argument               */ -}}
{{- /* ------------------------------------------------------------------ */ -}}
{{-   if IsType .Target -}}
{{-     if DeepestElementType . | IsAbstract -}}
{{-              if eq        .Target.Name "vec"  -}}vec{{index .TemplateArguments 0}}
{{-         else if eq        .Target.Name "vec2" -}}vec2
{{-         else if eq        .Target.Name "vec3" -}}vec3
{{-         else if eq        .Target.Name "vec4" -}}vec4
{{-         else if eq        .Target.Name "mat"  -}}mat{{index .TemplateArguments 0}}x{{index .TemplateArguments 1}}
{{-         else if HasPrefix .Target.Name "mat"  -}}mat{{.Target.Name}}
{{-         else                                  -}}
{{-         end                                   -}}
{{- /* note: intrinsics.def has different type definitions for 'vec<N: num, T>',
       'vec2<T>', 'vec3<T>'. Because of this we need to check whether the type
       name is exactly 'vec' and 'mat' and if not, then look for the prefix. */ -}}
{{-     else if eq .Target.Name "vec"        -}}vec{{index .TemplateArguments 0}}<{{template "Type" (ElementType .)}}>
{{-     else if eq .Target.Name "mat"        -}}mat{{index .TemplateArguments 0}}x{{index .TemplateArguments 1}}<{{template "Type" (ElementType .)}}>
{{-     else if HasPrefix .Target.Name "vec" -}}{{.Target.Name}}<{{template "Type" (ElementType .)}}>
{{-     else if HasPrefix .Target.Name "mat" -}}{{.Target.Name}}<{{template "Type" (ElementType .)}}>
{{-     else                                 -}}{{.Target.Name}}{{template "TemplateArguments" .TemplateArguments}}
{{-     end                                  -}}
{{-   else if IsEnumEntry   .Target -}}{{.Target.Name}}
{{-   else if IsEnumMatcher .Target -}}{{(index .Target.Options 0).Name}}
{{-   else                          -}}<unhandled-fully-qualified-name-target={{- printf "%T" .Target -}}>
{{-   end                           -}}
{{- end -}}


{{- /* ------------------------------------------------------------------ */ -}}
{{-                          define "TemplateArguments"                      -}}
{{- /* Emits the WGSL for the template argument list                      */ -}}
{{- /* ------------------------------------------------------------------ */ -}}
{{-   if . -}}
<
{{-    range $i, $a := . -}}
{{-      if $i -}}, {{  end -}}
{{-      if IsInt $a -}}{{- . -}}
{{-      else        -}}{{- template "Type" $a -}}
{{-      end -}}
{{-    end -}}
>
{{-   end -}}
{{- end -}}