AuroraMiddleware/SPIRV-Cross
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Deal with switch block fallthrough more correctly ...

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This commit is contained in:
Hans-Kristian Arntzen 2019-06-20 12:14:19 +02:00
parent bc3bf47446
commit 22e3beaab9
2 changed files with 40 additions and 17 deletions
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28
spirv_glsl.cpp
View File

@ -11554,14 +11554,14 @@ void CompilerGLSL::emit_block_chain(SPIRBlock &block)
for (size_t i = 0; i < num_blocks; i++)
{
auto &case_block = get<SPIRBlock>(block_declaration_order[i]);
if (case_block.merge == SPIRBlock::MergeNone && case_block.next_block == block.default_block)
if (case_block.terminator == SPIRBlock::Direct && case_block.next_block == block.default_block)
{
// Fallthrough to default block, we must inject the default block here.
block_declaration_order.insert(begin(block_declaration_order) + i + 1, block.default_block);
injected_block = true;
break;
}
else if (default_block.merge == SPIRBlock::MergeNone && default_block.next_block == case_block.self)
else if (default_block.terminator == SPIRBlock::Direct && default_block.next_block == case_block.self)
{
// Default case is falling through to another case label, we must inject the default block here.
block_declaration_order.insert(begin(block_declaration_order) + i, block.default_block);
@ -11577,8 +11577,10 @@ void CompilerGLSL::emit_block_chain(SPIRBlock &block)
case_constructs[block.default_block] = {};
}
for (auto &target_block : block_declaration_order)
size_t num_blocks = block_declaration_order.size();
for (size_t i = 0; i < num_blocks; i++)
{
uint32_t target_block = block_declaration_order[i];
auto &literals = case_constructs[target_block];
if (literals.empty())
@ -11597,9 +11599,25 @@ void CompilerGLSL::emit_block_chain(SPIRBlock &block)
}
}
auto &case_block = get<SPIRBlock>(target_block);
if (i + 1 < num_blocks &&
case_block.terminator == SPIRBlock::Direct &&
case_block.next_block == block_declaration_order[i + 1])
{
// We will fall through here, so just terminate the block chain early.
// We still need to deal with Phi potentially.
// No need for a stack-like thing here since we only do fall-through when there is a
// single trivial branch to fall-through target..
current_emitting_switch_fallthrough = true;
}
else
current_emitting_switch_fallthrough = false;
begin_scope();
branch(block.self, target_block);
end_scope();
current_emitting_switch_fallthrough = false;
}
// Might still have to flush phi variables if we branch from loop header directly to merge target.
@ -11699,6 +11717,9 @@ void CompilerGLSL::emit_block_chain(SPIRBlock &block)
if (block.merge != SPIRBlock::MergeSelection)
flush_phi(block.self, block.next_block);
// For switch fallthrough cases, we terminate the chain here, but we still need to handle Phi.
if (!current_emitting_switch_fallthrough)
{
// For merge selects we might have ignored the fact that a merge target
// could have been a break; or continue;
// We will need to deal with it here.
@ -11716,6 +11737,7 @@ void CompilerGLSL::emit_block_chain(SPIRBlock &block)
else if (block.self != block.next_block)
emit_block_chain(get<SPIRBlock>(block.next_block));
}
}
if (block.merge == SPIRBlock::MergeLoop)
{

1
spirv_glsl.hpp
View File

@ -223,6 +223,7 @@ protected:
SPIRBlock *current_emitting_block = nullptr;
SPIRBlock *current_emitting_switch = nullptr;
bool current_emitting_switch_fallthrough = false;
virtual void emit_instruction(const Instruction &instr);
void emit_block_instructions(SPIRBlock &block);