Implement rcp instruction

ptx/src/ast.rs

@@ -510,6 +510,7 @@ pub enum Instruction<P: ArgParams> {
     Sub(ArithDetails, Arg3<P>),
     Min(MinMaxDetails, Arg3<P>),
     Max(MinMaxDetails, Arg3<P>),
+    Rcp(RcpDetails, Arg2<P>),
 }
 
 #[derive(Copy, Clone)]
@@ -520,6 +521,12 @@ pub struct AbsDetails {
     pub flush_to_zero: bool,
     pub typ: ScalarType,
 }
+#[derive(Copy, Clone)]
+pub struct RcpDetails {
+    pub rounding: Option<RoundingMode>,
+    pub flush_to_zero: bool,
+    pub is_f64: bool,
+}
 
 pub struct CallInst<P: ArgParams> {
     pub uniform: bool,

ptx/src/ptx.lalrpop

@@ -35,6 +35,7 @@ match {
     ".address_size",
     ".align",
     ".and",
+    ".approx",
     ".b16",
     ".b32",
     ".b64",
@@ -134,6 +135,7 @@ match {
     "mul",
     "not",
     "or",
+    "rcp",
     "ret",
     "setp",
     "shl",
@@ -166,6 +168,7 @@ ExtendedID : &'input str = {
     "mul",
     "not",
     "or",
+    "rcp",
     "ret",
     "setp",
     "shl",
@@ -542,6 +545,7 @@ Instruction: ast::Instruction<ast::ParsedArgParams<'input>> = {
     InstSub,
     InstMin,
     InstMax,
+    InstRcp
 };
 
 // https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#data-movement-and-conversion-instructions-ld
@@ -1119,6 +1123,31 @@ OrType: ast::OrType = {
     ".b64" => ast::OrType::B64,
 }
 
+// https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#floating-point-instructions-rcp
+InstRcp: ast::Instruction<ast::ParsedArgParams<'input>> = {
+    "rcp" <rounding:RcpRoundingMode> <ftz:".ftz"?> ".f32" <a:Arg2> => {
+        let details = ast::RcpDetails {
+            rounding,
+            flush_to_zero: ftz.is_some(),
+            is_f64: false,
+        };
+        ast::Instruction::Rcp(details, a)
+    },
+    "rcp" <rn:RoundingModeFloat> ".f64" <a:Arg2> => {
+        let details = ast::RcpDetails {
+            rounding: Some(rn),
+            flush_to_zero: false,
+            is_f64: true,
+        };
+        ast::Instruction::Rcp(details, a)
+    }
+};
+
+RcpRoundingMode: Option<ast::RoundingMode> = {
+    ".approx" => None,
+    <r:RoundingModeFloat> => Some(r)
+};
+
 // https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#integer-arithmetic-instructions-sub
 // https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#floating-point-instructions-sub
 // https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#half-precision-floating-point-instructions-sub

ptx/src/test/spirv_run/mod.rs

@@ -80,6 +80,7 @@ test_ptx!(max, [555i32, 444i32], [555i32]);
 test_ptx!(global_array, [0xDEADu32], [1u32]);
 test_ptx!(extern_shared, [127u64], [127u64]);
 test_ptx!(extern_shared_call, [121u64], [123u64]);
+test_ptx!(rcp, [2f32], [0.5f32]);
 
 struct DisplayError<T: Debug> {
     err: T,

ptx/src/test/spirv_run/rcp.ptx

@@ -0,0 +1,21 @@
+.version 6.5
+.target sm_30
+.address_size 64
+
+.visible .entry rcp(
+	.param .u64 input,
+	.param .u64 output
+)
+{
+	.reg .u64 	    in_addr;
+    .reg .u64 	    out_addr;
+    .reg .f32 	    temp;
+
+	ld.param.u64 	in_addr, [input];
+    ld.param.u64 	out_addr, [output];
+
+    ld.f32          temp, [in_addr];
+	rcp.approx.f32  temp, temp;
+    st.f32          [out_addr], temp;
+	ret;
+}

ptx/src/test/spirv_run/rcp.spvtxt

@@ -0,0 +1,51 @@
+               OpCapability GenericPointer
+               OpCapability Linkage
+               OpCapability Addresses
+               OpCapability Kernel
+               OpCapability Int8
+               OpCapability Int16
+               OpCapability Int64
+               OpCapability Float16
+               OpCapability Float64
+         %23 = OpExtInstImport "OpenCL.std"
+               OpMemoryModel Physical64 OpenCL
+               OpEntryPoint Kernel %1 "rcp"
+               OpDecorate %15 FPFastMathMode AllowRecip
+       %void = OpTypeVoid
+      %ulong = OpTypeInt 64 0
+         %26 = OpTypeFunction %void %ulong %ulong
+%_ptr_Function_ulong = OpTypePointer Function %ulong
+      %float = OpTypeFloat 32
+%_ptr_Function_float = OpTypePointer Function %float
+%_ptr_Generic_float = OpTypePointer Generic %float
+    %float_1 = OpConstant %float 1
+          %1 = OpFunction %void None %26
+          %7 = OpFunctionParameter %ulong
+          %8 = OpFunctionParameter %ulong
+         %21 = OpLabel
+          %2 = OpVariable %_ptr_Function_ulong Function
+          %3 = OpVariable %_ptr_Function_ulong Function
+          %4 = OpVariable %_ptr_Function_ulong Function
+          %5 = OpVariable %_ptr_Function_ulong Function
+          %6 = OpVariable %_ptr_Function_float Function
+               OpStore %2 %7
+               OpStore %3 %8
+         %10 = OpLoad %ulong %2
+          %9 = OpCopyObject %ulong %10
+               OpStore %4 %9
+         %12 = OpLoad %ulong %3
+         %11 = OpCopyObject %ulong %12
+               OpStore %5 %11
+         %14 = OpLoad %ulong %4
+         %19 = OpConvertUToPtr %_ptr_Generic_float %14
+         %13 = OpLoad %float %19
+               OpStore %6 %13
+         %16 = OpLoad %float %6
+         %15 = OpFDiv %float %float_1 %16
+               OpStore %6 %15
+         %17 = OpLoad %ulong %5
+         %18 = OpLoad %float %6
+         %20 = OpConvertUToPtr %_ptr_Generic_float %17
+               OpStore %20 %18
+               OpReturn
+               OpFunctionEnd

ptx/src/translate.rs

@@ -1144,6 +1144,9 @@ fn convert_to_typed_statements(
                 ast::Instruction::Max(d, a) => {
                     result.push(Statement::Instruction(ast::Instruction::Max(d, a.cast())))
                 }
+                ast::Instruction::Rcp(d, a) => {
+                    result.push(Statement::Instruction(ast::Instruction::Rcp(d, a.cast())))
+                }
             },
             Statement::Label(i) => result.push(Statement::Label(i)),
             Statement::Variable(v) => result.push(Statement::Variable(v)),
@@ -2179,6 +2182,9 @@ fn emit_function_body_ops(
                 ast::Instruction::Max(d, a) => {
                     emit_max(builder, map, opencl, d, a)?;
                 }
+                ast::Instruction::Rcp(d, a) => {
+                    emit_rcp(builder, map, d, a)?;
+                }
             },
             Statement::LoadVar(arg, typ) => {
                 let type_id = map.get_or_add(builder, SpirvType::from(typ.clone()));
@@ -2209,6 +2215,40 @@ fn emit_function_body_ops(
     Ok(())
 }
 
+fn emit_rcp(
+    builder: &mut dr::Builder,
+    map: &mut TypeWordMap,
+    desc: &ast::RcpDetails,
+    a: &ast::Arg2<ExpandedArgParams>,
+) -> Result<(), TranslateError> {
+    if desc.flush_to_zero {
+        todo!()
+    }
+    let (instr_type, constant) = if desc.is_f64 {
+        (ast::ScalarType::F64, vec_repr(1.0f64))
+    } else {
+        (ast::ScalarType::F32, vec_repr(1.0f32))
+    };
+    let one = map.get_or_add_constant(builder, &ast::Type::Scalar(instr_type), &constant)?;
+    let result_type = map.get_or_add_scalar(builder, instr_type);
+    builder.f_div(result_type, Some(a.dst), one, a.src)?;
+    emit_rounding_decoration(builder, a.dst, desc.rounding);
+    builder.decorate(
+        a.dst,
+        spirv::Decoration::FPFastMathMode,
+        &[dr::Operand::FPFastMathMode(
+            spirv::FPFastMathMode::ALLOW_RECIP,
+        )],
+    );
+    Ok(())
+}
+
+fn vec_repr<T: Copy>(t: T) -> Vec<u8> {
+    let mut result = vec![0; mem::size_of::<T>()];
+    unsafe { std::ptr::copy_nonoverlapping(&t, result.as_mut_ptr() as *mut _, 1) };
+    result
+}
+
 fn emit_variable(
     builder: &mut dr::Builder,
     map: &mut TypeWordMap,
@@ -3735,7 +3775,7 @@ impl<T: ArgParamsEx> ast::Instruction<T> {
     ) -> Result<ast::Instruction<U>, TranslateError> {
         Ok(match self {
             ast::Instruction::Abs(d, arg) => {
-                ast::Instruction::Abs(d, arg.map(visitor, false, &ast::Type::Scalar(d.typ))?)
+                ast::Instruction::Abs(d, arg.map(visitor, &ast::Type::Scalar(d.typ))?)
             }
             // Call instruction is converted to a call statement early on
             ast::Instruction::Call(_) => return Err(TranslateError::Unreachable),
@@ -3766,9 +3806,7 @@ impl<T: ArgParamsEx> ast::Instruction<T> {
                 let inst_type = d.typ;
                 ast::Instruction::SetpBool(d, a.map(visitor, &ast::Type::Scalar(inst_type))?)
             }
-            ast::Instruction::Not(t, a) => {
+            ast::Instruction::Not(t, a) => ast::Instruction::Not(t, a.map(visitor, &t.to_type())?),
-                ast::Instruction::Not(t, a.map(visitor, false, &t.to_type())?)
-            }
             ast::Instruction::Cvt(d, a) => {
                 let (dst_t, src_t) = match &d {
                     ast::CvtDetails::FloatFromFloat(desc) => (
@@ -3806,7 +3844,7 @@ impl<T: ArgParamsEx> ast::Instruction<T> {
             ast::Instruction::Ret(d) => ast::Instruction::Ret(d),
             ast::Instruction::Cvta(d, a) => {
                 let inst_type = ast::Type::Scalar(ast::ScalarType::B64);
-                ast::Instruction::Cvta(d, a.map(visitor, false, &inst_type)?)
+                ast::Instruction::Cvta(d, a.map(visitor, &inst_type)?)
             }
             ast::Instruction::Mad(d, a) => {
                 let inst_type = d.get_type();
@@ -3829,6 +3867,14 @@ impl<T: ArgParamsEx> ast::Instruction<T> {
                 let typ = d.get_type();
                 ast::Instruction::Max(d, a.map_non_shift(visitor, &typ, false)?)
             }
+            ast::Instruction::Rcp(d, a) => {
+                let typ = ast::Type::Scalar(if d.is_f64 {
+                    ast::ScalarType::F64
+                } else {
+                    ast::ScalarType::F32
+                });
+                ast::Instruction::Rcp(d, a.map(visitor, &typ)?)
+            }
         })
     }
 }
@@ -4072,6 +4118,7 @@ impl ast::Instruction<ExpandedArgParams> {
             | ast::Instruction::Sub(_, _)
             | ast::Instruction::Min(_, _)
             | ast::Instruction::Max(_, _)
+            | ast::Instruction::Rcp(_, _)
             | ast::Instruction::Mad(_, _) => None,
         }
     }
@@ -4289,7 +4336,6 @@ impl<T: ArgParamsEx> ast::Arg2<T> {
     fn map<U: ArgParamsEx, V: ArgumentMapVisitor<T, U>>(
         self,
         visitor: &mut V,
-        src_is_addr: bool,
         t: &ast::Type,
     ) -> Result<ast::Arg2<U>, TranslateError> {
         let new_dst = visitor.id(
@@ -4304,11 +4350,7 @@ impl<T: ArgParamsEx> ast::Arg2<T> {
             ArgumentDescriptor {
                 op: self.src,
                 is_dst: false,
-                sema: if src_is_addr {
+                sema: ArgumentSemantics::Default,
-                    ArgumentSemantics::Address
-                } else {
-                    ArgumentSemantics::Default
-                },
             },
             t,
         )?;