forked from OSchip/llvm-project
				
			
		
			
				
	
	
		
			70 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			70 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			LLVM
		
	
	
	
| ; RUN: opt < %s -indvars -S | FileCheck %s
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| 
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| ; This tests that the IV is not recomputed outside of the loop when it is known
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| ; to be computed by the loop and used in the loop any way. In the example below
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| ; although a's value can be computed outside of the loop, there is no benefit
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| ; in doing so as it has to be computed by the loop anyway.
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| ;
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| ; extern void func(unsigned val);
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| ;
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| ; void test(unsigned m)
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| ; {
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| ;   unsigned a = 0;
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| ;
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| ;   for (int i=0; i<186; i++) {
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| ;     a += m;
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| ;     func(a);
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| ;   }
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| ;
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| ;   func(a);
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| ; }
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| 
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| declare void @func(i32)
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| 
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| ; CHECK-LABEL: @test(
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| define void @test(i32 %m) nounwind uwtable {
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| entry:
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|   br label %for.body
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| 
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| for.body:                                         ; preds = %for.body, %entry
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|   %i.06 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
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|   %a.05 = phi i32 [ 0, %entry ], [ %add, %for.body ]
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|   %add = add i32 %a.05, %m
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| ; CHECK: tail call void @func(i32 %add)
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|   tail call void @func(i32 %add)
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|   %inc = add nsw i32 %i.06, 1
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|   %exitcond = icmp eq i32 %inc, 186
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|   br i1 %exitcond, label %for.end, label %for.body
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| 
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| for.end:                                          ; preds = %for.body
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| ; CHECK: for.end:
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| ; CHECK-NOT: mul i32 %m, 186
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| ; CHECK:%add.lcssa = phi i32 [ %add, %for.body ]
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| ; CHECK-NEXT: tail call void @func(i32 %add.lcssa)
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|   tail call void @func(i32 %add)
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|   ret void
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| }
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| 
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| ; CHECK-LABEL: @test2(
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| define i32 @test2(i32 %m) nounwind uwtable {
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| entry:
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|   br label %for.body
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| 
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| for.body:                                         ; preds = %for.body, %entry
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|   %i.06 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
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|   %a.05 = phi i32 [ 0, %entry ], [ %add, %for.body ]
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|   %add = add i32 %a.05, %m
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| ; CHECK: tail call void @func(i32 %add)
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|   tail call void @func(i32 %add)
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|   %inc = add nsw i32 %i.06, 1
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|   %exitcond = icmp eq i32 %inc, 186
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|   br i1 %exitcond, label %for.end, label %for.body
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| 
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| for.end:                                          ; preds = %for.body
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| ; CHECK: for.end:
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| ; CHECK-NOT: mul i32 %m, 186
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| ; CHECK:%add.lcssa = phi i32 [ %add, %for.body ]
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| ; CHECK-NEXT: ret i32 %add.lcssa
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|   ret i32 %add
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| }
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