From cdefdb4b0f94613c2b41757fb33ae155efa9a205 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Mon, 3 Oct 2022 23:43:33 +0300
Subject: [PATCH 1/1] Handle OpPhi when specializing SPIR-V modules

---
 source/core/module.cpp | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/source/core/module.cpp b/source/core/module.cpp
index 5a736914..04a37fcc 100644
--- a/source/core/module.cpp
+++ b/source/core/module.cpp
@@ -38,6 +38,8 @@ enum SpirVConstants
 	OP_ACCESS_CHAIN = 65,
 	OP_DECORATE = 71,
 	OP_MEMBER_DECORATE = 72,
+	OP_COPY_OBJECT = 83,
+	OP_PHI = 245,
 	OP_SELECTION_MERGE = 247,
 	OP_LABEL = 248,
 	OP_BRANCH = 249,
@@ -393,6 +395,26 @@ SpirVModule *SpirVModule::specialize(const map<string, int> &spec_values) const
 					}
 				}
 			}
+			else if(opcode==OP_PHI)
+			{
+				unsigned active_count = 0;
+				unsigned result_id = 0;
+				for(unsigned i=3; i<word_count; i+=2)
+					if(flags[*(op+i+1)])
+					{
+						++active_count;
+						result_id = *(op+i);
+					}
+
+				if(active_count==1)
+				{
+					new_code.push_back(0x40000 | OP_COPY_OBJECT);
+					new_code.push_back(*(op+1));
+					new_code.push_back(*(op+2));
+					new_code.push_back(result_id);
+					copy = false;
+				}
+			}
 		}
 
 		if(copy)
-- 
2.43.0