121 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			121 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			LLVM
		
	
	
	
; RUN: llc -mtriple=i686-linux < %s | FileCheck %s
 | 
						|
 | 
						|
; Don't rotate the loop if the number of fall through to exit is not larger
 | 
						|
; than the number of fall through to header.
 | 
						|
define void @no_rotate() {
 | 
						|
; CHECK-LABEL: no_rotate
 | 
						|
; CHECK: %entry
 | 
						|
; CHECK: %header
 | 
						|
; CHECK: %middle
 | 
						|
; CHECK: %latch1
 | 
						|
; CHECK: %latch2
 | 
						|
; CHECK: %end
 | 
						|
entry:
 | 
						|
  br label %header
 | 
						|
 | 
						|
header:
 | 
						|
  %val1 = call i1 @foo()
 | 
						|
  br i1 %val1, label %middle, label %end
 | 
						|
 | 
						|
middle:
 | 
						|
  %val2 = call i1 @foo()
 | 
						|
  br i1 %val2, label %latch1, label %end
 | 
						|
 | 
						|
latch1:
 | 
						|
  %val3 = call i1 @foo()
 | 
						|
  br i1 %val3, label %latch2, label %header
 | 
						|
 | 
						|
latch2:
 | 
						|
  %val4 = call i1 @foo()
 | 
						|
  br label %header
 | 
						|
 | 
						|
end:
 | 
						|
  ret void
 | 
						|
}
 | 
						|
 | 
						|
define void @do_rotate() {
 | 
						|
; CHECK-LABEL: do_rotate
 | 
						|
; CHECK: %entry
 | 
						|
; CHECK: %then
 | 
						|
; CHECK: %else
 | 
						|
; CHECK: %latch1
 | 
						|
; CHECK: %latch2
 | 
						|
; CHECK: %header
 | 
						|
; CHECK: %end
 | 
						|
entry:
 | 
						|
  %val0 = call i1 @foo()
 | 
						|
  br i1 %val0, label %then, label %else
 | 
						|
 | 
						|
then:
 | 
						|
  call void @a()
 | 
						|
  br label %header
 | 
						|
 | 
						|
else:
 | 
						|
  call void @b()
 | 
						|
  br label %header
 | 
						|
 | 
						|
header:
 | 
						|
  %val1 = call i1 @foo()
 | 
						|
  br i1 %val1, label %latch1, label %end
 | 
						|
 | 
						|
latch1:
 | 
						|
  %val3 = call i1 @foo()
 | 
						|
  br i1 %val3, label %latch2, label %header
 | 
						|
 | 
						|
latch2:
 | 
						|
  %val4 = call i1 @foo()
 | 
						|
  br label %header
 | 
						|
 | 
						|
end:
 | 
						|
  ret void
 | 
						|
}
 | 
						|
 | 
						|
; The loop structure is same as in @no_rotate, but the loop header's predecessor
 | 
						|
; doesn't fall through to it, so it should be rotated to get exit fall through.
 | 
						|
define void @do_rotate2() {
 | 
						|
; CHECK-LABEL: do_rotate2
 | 
						|
; CHECK: %entry
 | 
						|
; CHECK: %then
 | 
						|
; CHECK: %middle
 | 
						|
; CHECK: %latch1
 | 
						|
; CHECK: %latch2
 | 
						|
; CHECK: %header
 | 
						|
; CHECK: %exit
 | 
						|
entry:
 | 
						|
  %val0 = call i1 @foo()
 | 
						|
  br i1 %val0, label %then, label %header, !prof !1
 | 
						|
 | 
						|
then:
 | 
						|
  call void @a()
 | 
						|
  br label %end
 | 
						|
 | 
						|
header:
 | 
						|
  %val1 = call i1 @foo()
 | 
						|
  br i1 %val1, label %middle, label %exit
 | 
						|
 | 
						|
middle:
 | 
						|
  %val2 = call i1 @foo()
 | 
						|
  br i1 %val2, label %latch1, label %exit
 | 
						|
 | 
						|
latch1:
 | 
						|
  %val3 = call i1 @foo()
 | 
						|
  br i1 %val3, label %latch2, label %header
 | 
						|
 | 
						|
latch2:
 | 
						|
  %val4 = call i1 @foo()
 | 
						|
  br label %header
 | 
						|
 | 
						|
exit:
 | 
						|
  call void @b()
 | 
						|
  br label %end
 | 
						|
 | 
						|
end:
 | 
						|
  ret void
 | 
						|
}
 | 
						|
 | 
						|
declare i1 @foo()
 | 
						|
declare void @a()
 | 
						|
declare void @b()
 | 
						|
 | 
						|
!1 = !{!"branch_weights", i32 10, i32 1}
 |