180 lines
		
	
	
		
			4.8 KiB
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			180 lines
		
	
	
		
			4.8 KiB
		
	
	
	
		
			LLVM
		
	
	
	
; RUN: opt < %s -loop-unroll -unroll-runtime -unroll-allow-partial -S | FileCheck %s
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declare void @f() convergent
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; Although this loop contains a convergent instruction, it should be
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; fully unrolled.
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;
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; CHECK-LABEL: @full_unroll(
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define i32 @full_unroll() {
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entry:
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  br label %l3
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l3:
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  %x.0 = phi i32 [ 0, %entry ], [ %inc, %l3 ]
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; CHECK: call void @f()
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; CHECK: call void @f()
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; CHECK: call void @f()
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; CHECK-NOT: call void @f()
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  call void @f() ;convergent
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  %inc = add nsw i32 %x.0, 1
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  %exitcond = icmp eq i32 %inc, 3
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  br i1 %exitcond, label %exit, label %l3
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exit:
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  ret i32 0
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}
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; This loop contains a convergent instruction, but it should be partially
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; unrolled.  The unroll count is the largest power of 2 that divides the
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; multiple -- 4, in this case.
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;
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; CHECK-LABEL: @runtime_unroll(
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define i32 @runtime_unroll(i32 %n) {
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entry:
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  %loop_ctl = mul nsw i32 %n, 12
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  br label %l3
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l3:
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  %x.0 = phi i32 [ 0, %entry ], [ %inc, %l3 ]
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; CHECK: call void @f()
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; CHECK: call void @f()
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; CHECK: call void @f()
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; CHECK: call void @f()
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; CHECK-NOT: call void @f()
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  call void @f() convergent
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  %inc = add nsw i32 %x.0, 1
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  %exitcond = icmp eq i32 %inc, %loop_ctl
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  br i1 %exitcond, label %exit, label %l3
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exit:
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  ret i32 0
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}
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; This loop contains a convergent instruction, so its partial unroll
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; count must divide its trip multiple.  This overrides its unroll
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; pragma -- we unroll exactly 8 times, even though 16 is requested.
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; CHECK-LABEL: @pragma_unroll
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define i32 @pragma_unroll(i32 %n) {
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entry:
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  %loop_ctl = mul nsw i32 %n, 24
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  br label %l3, !llvm.loop !0
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l3:
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  %x.0 = phi i32 [ 0, %entry ], [ %inc, %l3 ]
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; CHECK: call void @f()
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; CHECK: call void @f()
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; CHECK: call void @f()
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; CHECK: call void @f()
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; CHECK: call void @f()
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; CHECK: call void @f()
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; CHECK: call void @f()
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; CHECK: call void @f()
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; CHECK-NOT: call void @f()
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  call void @f() convergent
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  %inc = add nsw i32 %x.0, 1
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  %exitcond = icmp eq i32 %inc, %loop_ctl
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  br i1 %exitcond, label %exit, label %l3, !llvm.loop !0
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exit:
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  ret i32 0
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}
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; This loop contains a convergent instruction. Since the pragma loop unroll
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; count 2 divides trip count 4. The loop unroll should respect the pragma.
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; CHECK-LABEL: @pragma_unroll_divisible_trip_count
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define void @pragma_unroll_divisible_trip_count() {
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entry:
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  br label %l3, !llvm.loop !1
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l3:
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  %x.0 = phi i32 [ 0, %entry ], [ %inc, %l3 ]
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; CHECK: call void @f()
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; CHECK: call void @f()
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; CHECK-NOT: call void @f()
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  call void @f() convergent
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  %inc = add nsw i32 %x.0, 1
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  %exitcond = icmp eq i32 %inc, 4
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  br i1 %exitcond, label %exit, label %l3, !llvm.loop !1
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exit:
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  ret void
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}
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; This loop contains a convergent instruction. Since the pragma loop unroll
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; count 2 divides trip multiple 2. The loop unroll should respect the pragma.
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; CHECK-LABEL: @pragma_unroll_divisible_trip_multiple
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define i32 @pragma_unroll_divisible_trip_multiple(i32 %n) {
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entry:
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  %loop_ctl = mul nsw i32 %n, 2
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  br label %l3, !llvm.loop !1
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l3:
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  %x.0 = phi i32 [ 0, %entry ], [ %inc, %l3 ]
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; CHECK: call void @f()
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; CHECK: call void @f()
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; CHECK-NOT: call void @f()
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  call void @f() convergent
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  %inc = add nsw i32 %x.0, 1
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  %exitcond = icmp eq i32 %inc, %loop_ctl
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  br i1 %exitcond, label %exit, label %l3, !llvm.loop !1
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exit:
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  ret i32 0
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}
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; This loop contains a convergent instruction. Since the pragma loop unroll
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; count 2 is unknown to divide runtime trip count, the loop is not unrolled
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; since remainder is forbidden for unrolling convergent loop.
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; ToDo: Forbidding remainder for unrolling convergent loop may be relaxed
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; in the future.
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; CHECK-LABEL: @pragma_unroll_indivisible_runtime_trip_count
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define i32 @pragma_unroll_indivisible_runtime_trip_count(i32 %n) {
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entry:
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  br label %l3, !llvm.loop !1
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l3:
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  %x.0 = phi i32 [ 0, %entry ], [ %inc, %l3 ]
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; CHECK: call void @f()
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; CHECK-NOT: call void @f()
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  call void @f() convergent
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  %inc = add nsw i32 %x.0, 1
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  %exitcond = icmp eq i32 %inc, %n
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  br i1 %exitcond, label %exit, label %l3, !llvm.loop !1
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exit:
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  ret i32 0
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}
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; This loop contains a convergent instruction. Since the pragma loop unroll
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; count 2 does not divide trip count 5, the loop is not unrolled by 2
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; since remainder is forbidden for unrolling convergent loop. Instead, the
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; loop gets fully unrolled.
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; ToDo: Forbidding remainder for unrolling convergent loop may be relaxed
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; in the future.
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; CHECK-LABEL: @pragma_unroll_indivisible_trip_count
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define i32 @pragma_unroll_indivisible_trip_count() {
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entry:
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  br label %l3, !llvm.loop !1
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l3:
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  %x.0 = phi i32 [ 0, %entry ], [ %inc, %l3 ]
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; CHECK: call void @f()
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; CHECK: call void @f()
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; CHECK: call void @f()
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; CHECK: call void @f()
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; CHECK: call void @f()
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; CHECK-NOT: call void @f()
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  call void @f() convergent
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  %inc = add nsw i32 %x.0, 1
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  %exitcond = icmp eq i32 %inc, 5
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  br i1 %exitcond, label %exit, label %l3, !llvm.loop !1
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exit:
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  ret i32 0
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}
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!0 = !{!0, !{!"llvm.loop.unroll.count", i32 16}}
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!1 = !{!1, !{!"llvm.loop.unroll.count", i32 2}}
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