More aggressively prune unreachable code as follows.
When no control flow edges reach a merge block or continue target:
- delete their contents so that:
  - a merge block becomes OpLabel, then OpUnreachable
  - a continue target becomes OpLabel, then an OpBranch back to the
    loop header
- any basic block which is dominated by such a merge block or continue
  target is removed as well.
- decorations targeting the removed instructions are removed.
Enables the SPIR-V builder post-processing step the GLSLANG_WEB case.
		
	
			
		
			
				
	
	
		
			24 lines
		
	
	
		
			292 B
		
	
	
	
		
			GLSL
		
	
	
	
	
	
			
		
		
	
	
			24 lines
		
	
	
		
			292 B
		
	
	
	
		
			GLSL
		
	
	
	
	
	
#version 450
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layout(location =0 ) in int c;
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layout(location =0 ) out int o;
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void main() {
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  int i = 0;
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  o = 1;
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  do {
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    o = 2;
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    return;
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    o = 3;
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  } while(i++ < 5);
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  // All this is a dead merge block.
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  o = 4;
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  if (c==4) {
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     o = 100;
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  } else {
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     o = 200;
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  }
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  o = 300;
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}
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