120 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			120 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			LLVM
		
	
	
	
| ; RUN: llc < %s -mtriple=arm-apple-darwin -relocation-model=dynamic-no-pic -mcpu=cortex-a8 -asm-verbose=false | FileCheck %s
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| 
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| declare void @bar(i32)
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| declare void @car(i32)
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| declare void @dar(i32)
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| declare void @ear(i32)
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| declare void @far(i32)
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| declare i1 @qux()
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| 
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| @GHJK = global i32 0
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| 
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| declare i8* @choose(i8*, i8*)
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| 
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| ; BranchFolding should tail-duplicate the indirect jump to avoid
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| ; redundant branching.
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| 
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| ; CHECK-LABEL: tail_duplicate_me:
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| ; CHECK:      qux
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| ; CHECK:      movw r{{[0-9]+}}, :lower16:_GHJK
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| ; CHECK:      movt r{{[0-9]+}}, :upper16:_GHJK
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| ; CHECK:      str r
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| ; CHECK-NEXT: bx r
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| ; CHECK:      qux
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| ; CHECK:      movw r{{[0-9]+}}, :lower16:_GHJK
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| ; CHECK:      movt r{{[0-9]+}}, :upper16:_GHJK
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| ; CHECK:      str r
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| ; CHECK-NEXT: bx r
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| ; CHECK:      movw r{{[0-9]+}}, :lower16:_GHJK
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| ; CHECK:      movt r{{[0-9]+}}, :upper16:_GHJK
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| ; CHECK:      str r
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| ; CHECK-NEXT: bx r
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| 
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| define void @tail_duplicate_me() nounwind {
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| entry:
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|   %a = call i1 @qux()
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|   %c = call i8* @choose(i8* blockaddress(@tail_duplicate_me, %return),
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|                         i8* blockaddress(@tail_duplicate_me, %altret))
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|   br i1 %a, label %A, label %next
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| next:
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|   %b = call i1 @qux()
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|   br i1 %b, label %B, label %C
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| 
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| A:
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|   call void @bar(i32 0)
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|   store i32 0, i32* @GHJK
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|   br label %M
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| 
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| B:
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|   call void @car(i32 1)
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|   store i32 0, i32* @GHJK
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|   br label %M
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| 
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| C:
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|   call void @dar(i32 2)
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|   store i32 0, i32* @GHJK
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|   br label %M
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| 
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| M:
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|   indirectbr i8* %c, [label %return, label %altret]
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| 
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| return:
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|   call void @ear(i32 1000)
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|   ret void
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| altret:
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|   call void @far(i32 1001)
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|   ret void
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| }
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| 
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| ; Use alternating abort functions so that the blocks we wish to merge are not
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| ; layout successors during branch folding.
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| 
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| ; CHECK-LABEL: merge_alternating_aborts:
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| ; CHECK-NOT: _abort
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| ; CHECK-NOT: _alt_abort
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| ; CHECK: bxne lr
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| ; CHECK-NOT: _abort
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| ; CHECK-NOT: _alt_abort
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| ; CHECK: LBB{{.*}}:
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| ; CHECK: mov lr, pc
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| ; CHECK: b _alt_abort
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| ; CHECK-NOT: _abort
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| ; CHECK-NOT: _alt_abort
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| ; CHECK: LBB{{.*}}:
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| ; CHECK: mov lr, pc
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| ; CHECK: b _abort
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| ; CHECK-NOT: _abort
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| ; CHECK-NOT: _alt_abort
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| 
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| declare void @abort()
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| declare void @alt_abort()
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| 
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| define void @merge_alternating_aborts() {
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| entry:
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|   %c1 = call i1 @qux()
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|   br i1 %c1, label %cont1, label %abort1
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| abort1:
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|   call void @abort()
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|   unreachable
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| cont1:
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|   %c2 = call i1 @qux()
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|   br i1 %c2, label %cont2, label %abort2
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| abort2:
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|   call void @alt_abort()
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|   unreachable
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| cont2:
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|   %c3 = call i1 @qux()
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|   br i1 %c3, label %cont3, label %abort3
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| abort3:
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|   call void @abort()
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|   unreachable
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| cont3:
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|   %c4 = call i1 @qux()
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|   br i1 %c4, label %cont4, label %abort4
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| abort4:
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|   call void @alt_abort()
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|   unreachable
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| cont4:
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|   ret void
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| }
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