40 lines
		
	
	
		
			907 B
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			40 lines
		
	
	
		
			907 B
		
	
	
	
		
			LLVM
		
	
	
	
| ; RUN: opt -S -jump-threading < %s | FileCheck %s
 | |
| 
 | |
| declare i8* @escape()
 | |
| declare void @llvm.assume(i1)
 | |
| 
 | |
| define i1 @test1(i1 %cond) {
 | |
| entry:
 | |
|     br i1 %cond, label %taken, label %not_taken
 | |
| 
 | |
| ; CHECK-LABEL: @test1
 | |
| ; CHECK: br i1 %cond, label %no, label %yes
 | |
| ; CHECK: ret i1 true
 | |
| 
 | |
| taken:
 | |
|     %res1 = call i8* @escape()
 | |
|     %a = icmp eq i8* %res1, null
 | |
|     tail call void @llvm.assume(i1 %a)
 | |
|     br label %done
 | |
| not_taken:
 | |
|     %res2 = call i8* @escape()
 | |
|     %b = icmp ne i8* %res2, null
 | |
|     tail call void @llvm.assume(i1 %b)
 | |
|     br label %done
 | |
| 
 | |
| ; An assume that can be used to simplify this comparison dominates each
 | |
| ; predecessor branch (although no assume dominates the cmp itself). Make sure
 | |
| ; this still can be simplified.
 | |
| 
 | |
| done:
 | |
|     %res = phi i8* [ %res1, %taken ], [ %res2, %not_taken ]
 | |
|     %cnd = icmp ne i8* %res, null
 | |
|     br i1 %cnd, label %yes, label %no
 | |
| 
 | |
| yes:
 | |
|     ret i1 true
 | |
| no:
 | |
|     ret i1 false
 | |
| }
 | |
| 
 |