From: Mikko Rasa <tdb@tdb.fi>
Date: Sat, 24 Apr 2021 18:04:10 +0000 (+0300)
Subject: Clear variable load cache before a loop in the SPIR-V generator
X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=commitdiff_plain;h=513dd710045f66c4e79e1db56cdad87e9ad143a0

Clear variable load cache before a loop in the SPIR-V generator

Variables may get assigned in the loop and the next iteration needs to
read those values, not the cached pre-loop values.

This could be done better by only clearing loads for the variables which
are actually assigned in the loop, but I'm not sure how exactly I want
to do that.
---

diff --git a/source/glsl/spirv.cpp b/source/glsl/spirv.cpp
index 70d5fe78..35d46ab7 100644
--- a/source/glsl/spirv.cpp
+++ b/source/glsl/spirv.cpp
@@ -1832,6 +1832,8 @@ void SpirVGenerator::visit(Iteration &iter)
 	if(iter.init_statement)
 		iter.init_statement->visit(*this);
 
+	variable_load_ids.clear();
+
 	Id header_id = next_id++;
 	Id continue_id = next_id++;
 	Id merge_block_id = next_id++;
@@ -1859,7 +1861,6 @@ void SpirVGenerator::visit(Iteration &iter)
 	writer.write_op(content.function_body, OP_BRANCH, header_id);
 
 	writer.write_op_label(merge_block_id);
-	prune_loads(header_id);
 	reachable = true;
 }