mirror of
				https://github.com/c64scene-ar/llvm-6502.git
				synced 2025-10-31 08:16:47 +00:00 
			
		
		
		
	We already have HoistThenElseCodeToIf, this patch implements SinkThenElseCodeToEnd. When END block has only two predecessors and each predecessor terminates with unconditional branches, we compare instructions in IF and ELSE blocks backwards and check whether we can sink the common instructions down. rdar://12191395 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164325 91177308-0d34-0410-b5e6-96231b3b80d8
		
			
				
	
	
		
			54 lines
		
	
	
		
			1.2 KiB
		
	
	
	
		
			LLVM
		
	
	
	
	
	
			
		
		
	
	
			54 lines
		
	
	
		
			1.2 KiB
		
	
	
	
		
			LLVM
		
	
	
	
	
	
| ; RUN: opt < %s -simplifycfg -S | FileCheck %s
 | |
| 
 | |
| define zeroext i1 @test1(i1 zeroext %flag, i32 %blksA, i32 %blksB, i32 %nblks) {
 | |
| entry:
 | |
|   br i1 %flag, label %if.then, label %if.else
 | |
| 
 | |
| ; CHECK: test1
 | |
| ; CHECK: add
 | |
| ; CHECK: select
 | |
| ; CHECK: icmp
 | |
| ; CHECK-NOT: br
 | |
| if.then:
 | |
|   %cmp = icmp uge i32 %blksA, %nblks
 | |
|   %frombool1 = zext i1 %cmp to i8
 | |
|   br label %if.end
 | |
| 
 | |
| if.else:
 | |
|   %add = add i32 %nblks, %blksB
 | |
|   %cmp2 = icmp ule i32 %add, %blksA
 | |
|   %frombool3 = zext i1 %cmp2 to i8
 | |
|   br label %if.end
 | |
| 
 | |
| if.end:
 | |
|   %obeys.0 = phi i8 [ %frombool1, %if.then ], [ %frombool3, %if.else ]
 | |
|   %tobool4 = icmp ne i8 %obeys.0, 0
 | |
|   ret i1 %tobool4
 | |
| }
 | |
| 
 | |
| define zeroext i1 @test2(i1 zeroext %flag, i32 %blksA, i32 %blksB, i32 %nblks) {
 | |
| entry:
 | |
|   br i1 %flag, label %if.then, label %if.else
 | |
| 
 | |
| ; CHECK: test2
 | |
| ; CHECK: add
 | |
| ; CHECK: select
 | |
| ; CHECK: icmp
 | |
| ; CHECK-NOT: br
 | |
| if.then:
 | |
|   %cmp = icmp uge i32 %blksA, %nblks
 | |
|   %frombool1 = zext i1 %cmp to i8
 | |
|   br label %if.end
 | |
| 
 | |
| if.else:
 | |
|   %add = add i32 %nblks, %blksB
 | |
|   %cmp2 = icmp uge i32 %blksA, %add
 | |
|   %frombool3 = zext i1 %cmp2 to i8
 | |
|   br label %if.end
 | |
| 
 | |
| if.end:
 | |
|   %obeys.0 = phi i8 [ %frombool1, %if.then ], [ %frombool3, %if.else ]
 | |
|   %tobool4 = icmp ne i8 %obeys.0, 0
 | |
|   ret i1 %tobool4
 | |
| }
 |