From d0ef4e9dbe27cadfe6f64765763db9cef2e30511 Mon Sep 17 00:00:00 2001
From: Anthony Cowley <acowley@gmail.com>
Date: Sat, 13 Feb 2021 03:33:23 -0500
Subject: [PATCH] [spv-out] support select expressions

---
 src/back/spv/instructions.rs | 16 ++++++++++++++++
 src/back/spv/writer.rs       | 23 +++++++++++++++++++++++
 2 files changed, 39 insertions(+)

diff --git a/src/back/spv/instructions.rs b/src/back/spv/instructions.rs
index f4b50afb3c..a4fe76706e 100644
--- a/src/back/spv/instructions.rs
+++ b/src/back/spv/instructions.rs
@@ -709,6 +709,22 @@ impl super::Instruction {
         instruction
     }
 
+    pub(super) fn select(
+        result_type_id: Word,
+        id: Word,
+        condition_id: Word,
+        accept_id: Word,
+        reject_id: Word,
+    ) -> Self {
+        let mut instruction = Self::new(Op::Select);
+        instruction.add_operand(result_type_id);
+        instruction.add_operand(id);
+        instruction.add_operand(condition_id);
+        instruction.add_operand(accept_id);
+        instruction.add_operand(reject_id);
+        instruction
+    }
+
     pub(super) fn kill() -> Self {
         Self::new(Op::Kill)
     }
diff --git a/src/back/spv/writer.rs b/src/back/spv/writer.rs
index b60f173dbd..709dd8b922 100644
--- a/src/back/spv/writer.rs
+++ b/src/back/spv/writer.rs
@@ -1734,6 +1734,29 @@ impl Writer {
                 block.body.push(main_instruction);
                 RawExpression::Value(id)
             }
+            crate::Expression::Select {
+                condition,
+                accept,
+                reject,
+            } => {
+                let id = self.generate_id();
+                let condition_id =
+                    self.write_expression(ir_module, ir_function, condition, block, function)?;
+                let accept_id =
+                    self.write_expression(ir_module, ir_function, accept, block, function)?;
+                let reject_id =
+                    self.write_expression(ir_module, ir_function, reject, block, function)?;
+
+                let instruction = Instruction::select(
+                    result_type_id,
+                    id,
+                    condition_id,
+                    accept_id,
+                    reject_id,
+                );
+                block.body.push(instruction);
+                RawExpression::Value(id)
+            }
             ref other => {
                 log::error!("unimplemented {:?}", other);
                 return Err(Error::FeatureNotImplemented("expression"));