Add FindLsb / FindMsb

gfx-rs · Oct 25, 2021 · 7506ddd · 7506ddd
1 parent 5cf11ab
commit 7506ddd
Show file tree

Hide file tree

Showing 10 changed files with 26 additions and 3 deletions.
diff --git a/src/back/glsl/mod.rs b/src/back/glsl/mod.rs
@@ -2443,6 +2443,8 @@ impl<'a, W: Write> Writer<'a, W> {
                     Mf::ReverseBits => "bitfieldReverse",
                     Mf::ExtractBits => "bitfieldExtract",
                     Mf::InsertBits => "bitfieldInsert",
+                    Mf::FindLsb => "findLSB",
+                    Mf::FindMsb => "findMSB",
                     // data packing
                     Mf::Pack4x8snorm => "packSnorm4x8",
                     Mf::Pack4x8unorm => "packUnorm4x8",

diff --git a/src/back/hlsl/writer.rs b/src/back/hlsl/writer.rs
@@ -1881,6 +1881,8 @@ impl<'a, W: fmt::Write> super::Writer<'a, W> {
                     // bits
                     Mf::CountOneBits => Function::Regular("countbits"),
                     Mf::ReverseBits => Function::Regular("reversebits"),
+                    Mf::FindLsb => Function::Regular("firstbit_lo"),
+                    Mf::FindMsb => Function::Regular("firstbit_hi"),
                     _ => return Err(Error::Unimplemented(format!("write_expr_math {:?}", fun))),
                 };
 

diff --git a/src/back/msl/writer.rs b/src/back/msl/writer.rs
@@ -1184,6 +1184,8 @@ impl<W: Write> Writer<W> {
                     Mf::ReverseBits => "reverse_bits",
                     Mf::ExtractBits => "extract_bits",
                     Mf::InsertBits => "insert_bits",
+                    Mf::FindLsb => return Err(Error::UnsupportedCall(format!("{:?}", fun))),
+                    Mf::FindMsb => return Err(Error::UnsupportedCall(format!("{:?}", fun))),
                     // data packing
                     Mf::Pack4x8snorm => "pack_float_to_unorm4x8",
                     Mf::Pack4x8unorm => "pack_float_to_snorm4x8",

diff --git a/src/back/spv/block.rs b/src/back/spv/block.rs
@@ -633,6 +633,12 @@ impl<'w> BlockContext<'w> {
                         arg2_id,
                         arg3_id,
                     )),
+                    Mf::FindLsb => MathOp::Ext(spirv::GLOp::FindILsb),
+                    Mf::FindMsb => MathOp::Ext(match arg_scalar_kind {
+                        Some(crate::ScalarKind::Uint) => spirv::GLOp::FindUMsb,
+                        Some(crate::ScalarKind::Sint) => spirv::GLOp::FindSMsb,
+                        other => unimplemented!("Unexpected findMSB({:?})", other),
+                    }),
                     Mf::Pack4x8unorm => MathOp::Ext(spirv::GLOp::PackUnorm4x8),
                     Mf::Pack4x8snorm => MathOp::Ext(spirv::GLOp::PackSnorm4x8),
                     Mf::Pack2x16float => MathOp::Ext(spirv::GLOp::PackHalf2x16),

diff --git a/src/front/glsl/builtins.rs b/src/front/glsl/builtins.rs
@@ -630,12 +630,15 @@ pub fn inject_builtin(declaration: &mut FunctionDeclaration, module: &mut Module
                 ))
             }
         }
-        "bitCount" | "bitfieldReverse" | "bitfieldExtract" | "bitfieldInsert" => {
+        "bitCount" | "bitfieldReverse" | "bitfieldExtract" | "bitfieldInsert" | "findLSB"
+        | "findMSB" => {
             let fun = match name {
                 "bitCount" => MathFunction::CountOneBits,
                 "bitfieldReverse" => MathFunction::ReverseBits,
                 "bitfieldExtract" => MathFunction::ExtractBits,
                 "bitfieldInsert" => MathFunction::InsertBits,
+                "findLSB" => MathFunction::FindLsb,
+                "findMSB" => MathFunction::FindMsb,
                 _ => unreachable!(),
             };
 

diff --git a/src/front/spv/mod.rs b/src/front/spv/mod.rs
@@ -2591,6 +2591,8 @@ impl<I: Iterator<Item = u32>> Parser<I> {
                             Glo::UnpackHalf2x16 => Mf::Unpack2x16float,
                             Glo::UnpackUnorm2x16 => Mf::Unpack2x16unorm,
                             Glo::UnpackSnorm2x16 => Mf::Unpack2x16snorm,
+                            Glo::FindILsb => Mf::FindLsb,
+                            Glo::FindUMsb | Glo::FindSMsb => Mf::FindMsb,
                             _ => return Err(Error::UnsupportedExtInst(inst_id)),
                         };
 

diff --git a/src/lib.rs b/src/lib.rs
@@ -938,6 +938,8 @@ pub enum MathFunction {
     ReverseBits,
     ExtractBits,
     InsertBits,
+    FindLsb,
+    FindMsb,
     // data packing
     Pack4x8snorm,
     Pack4x8unorm,

diff --git a/src/proc/mod.rs b/src/proc/mod.rs
@@ -247,6 +247,8 @@ impl super::MathFunction {
             Self::ReverseBits => 1,
             Self::ExtractBits => 3,
             Self::InsertBits => 4,
+            Self::FindLsb => 1,
+            Self::FindMsb => 1,
             // data packing
             Self::Pack4x8snorm => 1,
             Self::Pack4x8unorm => 1,

diff --git a/src/proc/typifier.rs b/src/proc/typifier.rs
@@ -784,7 +784,9 @@ impl<'a> ResolveContext<'a> {
                     Mf::CountOneBits |
                     Mf::ReverseBits |
                     Mf::ExtractBits |
-                    Mf::InsertBits => res_arg.clone(),
+                    Mf::InsertBits |
+                    Mf::FindLsb |
+                    Mf::FindMsb => res_arg.clone(),
                     // data packing
                     Mf::Pack4x8snorm |
                     Mf::Pack4x8unorm |

diff --git a/src/valid/expression.rs b/src/valid/expression.rs
@@ -1194,7 +1194,7 @@ impl super::Validator {
                             _ => return Err(ExpressionError::InvalidArgumentType(fun, 0, arg)),
                         }
                     }
-                    Mf::CountOneBits | Mf::ReverseBits => {
+                    Mf::CountOneBits | Mf::ReverseBits | Mf::FindLsb | Mf::FindMsb => {
                         if arg1_ty.is_some() | arg2_ty.is_some() | arg3_ty.is_some() {
                             return Err(ExpressionError::WrongArgumentCount(fun));
                         }