194 lines
		
	
	
		
			5.4 KiB
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			194 lines
		
	
	
		
			5.4 KiB
		
	
	
	
		
			LLVM
		
	
	
	
| ; RUN: opt < %s -indvars -S | FileCheck %s
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| 
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| ; These tests ensure that we can compute the trip count of various forms of
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| ; loops.  If the trip count of the loop is computable, then we will know what
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| ; the exit value of the loop will be for some value, allowing us to substitute
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| ; it directly into users outside of the loop, making the loop dead.
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| 
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| ; CHECK-LABEL: @linear_setne(
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| ; CHECK: ret i32 100
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| 
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| define i32 @linear_setne() {
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| entry:
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| 	br label %loop
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| 
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| loop:		; preds = %loop, %entry
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| 	%i = phi i32 [ 0, %entry ], [ %i.next, %loop ]		; <i32> [#uses=3]
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| 	%i.next = add i32 %i, 1		; <i32> [#uses=1]
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| 	%c = icmp ne i32 %i, 100		; <i1> [#uses=1]
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| 	br i1 %c, label %loop, label %loopexit
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| 
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| loopexit:		; preds = %loop
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| 	ret i32 %i
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| }
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| 
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| ; CHECK-LABEL: @linear_setne_2(
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| ; CHECK: ret i32 100
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| 
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| define i32 @linear_setne_2() {
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| entry:
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| 	br label %loop
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| 
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| loop:		; preds = %loop, %entry
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| 	%i = phi i32 [ 0, %entry ], [ %i.next, %loop ]		; <i32> [#uses=3]
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| 	%i.next = add i32 %i, 2		; <i32> [#uses=1]
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| 	%c = icmp ne i32 %i, 100		; <i1> [#uses=1]
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| 	br i1 %c, label %loop, label %loopexit
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| 
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| loopexit:		; preds = %loop
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| 	ret i32 %i
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| }
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| 
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| ; CHECK-LABEL: @linear_setne_overflow(
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| ; CHECK: ret i32 0
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| 
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| define i32 @linear_setne_overflow() {
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| entry:
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| 	br label %loop
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| 
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| loop:		; preds = %loop, %entry
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| 	%i = phi i32 [ 1024, %entry ], [ %i.next, %loop ]		; <i32> [#uses=3]
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| 	%i.next = add i32 %i, 1024		; <i32> [#uses=1]
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| 	%c = icmp ne i32 %i, 0		; <i1> [#uses=1]
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| 	br i1 %c, label %loop, label %loopexit
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| 
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| loopexit:		; preds = %loop
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| 	ret i32 %i
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| }
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| 
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| ; CHECK-LABEL: @linear_setlt(
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| ; CHECK: ret i32 100
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| 
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| define i32 @linear_setlt() {
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| entry:
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| 	br label %loop
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| 
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| loop:		; preds = %loop, %entry
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| 	%i = phi i32 [ 0, %entry ], [ %i.next, %loop ]		; <i32> [#uses=3]
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| 	%i.next = add i32 %i, 1		; <i32> [#uses=1]
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| 	%c = icmp slt i32 %i, 100		; <i1> [#uses=1]
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| 	br i1 %c, label %loop, label %loopexit
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| 
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| loopexit:		; preds = %loop
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| 	ret i32 %i
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| }
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| 
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| ; CHECK-LABEL: @quadratic_setlt(
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| ; CHECK: ret i32 34
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| 
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| define i32 @quadratic_setlt() {
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| entry:
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| 	br label %loop
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| 
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| loop:		; preds = %loop, %entry
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| 	%i = phi i32 [ 7, %entry ], [ %i.next, %loop ]		; <i32> [#uses=4]
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| 	%i.next = add i32 %i, 3		; <i32> [#uses=1]
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| 	%i2 = mul i32 %i, %i		; <i32> [#uses=1]
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| 	%c = icmp slt i32 %i2, 1000		; <i1> [#uses=1]
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| 	br i1 %c, label %loop, label %loopexit
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| 
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| loopexit:		; preds = %loop
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| 	ret i32 %i
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| }
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| 
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| ; CHECK-LABEL: @chained(
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| ; CHECK: ret i32 200
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| 
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| define i32 @chained() {
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| entry:
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| 	br label %loop
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| 
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| loop:		; preds = %loop, %entry
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| 	%i = phi i32 [ 0, %entry ], [ %i.next, %loop ]		; <i32> [#uses=3]
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| 	%i.next = add i32 %i, 1		; <i32> [#uses=1]
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| 	%c = icmp ne i32 %i, 100		; <i1> [#uses=1]
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| 	br i1 %c, label %loop, label %loopexit
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| 
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| loopexit:		; preds = %loop
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| 	br label %loop2
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| 
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| loop2:		; preds = %loop2, %loopexit
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| 	%j = phi i32 [ %i, %loopexit ], [ %j.next, %loop2 ]		; <i32> [#uses=3]
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| 	%j.next = add i32 %j, 1		; <i32> [#uses=1]
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| 	%c2 = icmp ne i32 %j, 200		; <i1> [#uses=1]
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| 	br i1 %c2, label %loop2, label %loopexit2
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| 
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| loopexit2:		; preds = %loop2
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| 	ret i32 %j
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| }
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| 
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| ; CHECK-LABEL: @chained4(
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| ; CHECK: ret i32 400
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| 
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| define i32 @chained4() {
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| entry:
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|   br label %loop
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| 
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| loop:                                             ; preds = %loop, %entry
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|   %i = phi i32 [ 0, %entry ], [ %i.next, %loop ]  ; <i32> [#uses=3]
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|   %i.next = add i32 %i, 1                         ; <i32> [#uses=1]
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|   %c = icmp ne i32 %i.next, 100                   ; <i1> [#uses=1]
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|   br i1 %c, label %loop, label %loopexit
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| 
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| loopexit:                                         ; preds = %loop
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|   br label %loop2
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| 
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| loop2:                                            ; preds = %loop2, %loopexit
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|   %j = phi i32 [ %i.next, %loopexit ], [ %j.next, %loop2 ] ; <i32> [#uses=3]
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|   %j.next = add i32 %j, 1                         ; <i32> [#uses=1]
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|   %c2 = icmp ne i32 %j.next, 200                  ; <i1> [#uses=1]
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|   br i1 %c2, label %loop2, label %loopexit2
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| 
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| loopexit2:                                        ; preds = %loop
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|   br label %loop8
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| 
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| loop8:                                            ; preds = %loop2, %loopexit
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|   %k = phi i32 [ %j.next, %loopexit2 ], [ %k.next, %loop8 ] ; <i32> [#uses=3]
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|   %k.next = add i32 %k, 1                         ; <i32> [#uses=1]
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|   %c8 = icmp ne i32 %k.next, 300                  ; <i1> [#uses=1]
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|   br i1 %c8, label %loop8, label %loopexit8
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| 
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| loopexit8:                                        ; preds = %loop2
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|   br label %loop9
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| 
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| loop9:                                            ; preds = %loop2, %loopexit
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|   %l = phi i32 [ %k.next, %loopexit8 ], [ %l.next, %loop9 ] ; <i32> [#uses=3]
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|   %l.next = add i32 %l, 1                         ; <i32> [#uses=1]
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|   %c9 = icmp ne i32 %l.next, 400                  ; <i1> [#uses=1]
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|   br i1 %c9, label %loop9, label %loopexit9
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| 
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| loopexit9:                                        ; preds = %loop2
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|   ret i32 %l.next
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| }
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| 
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| ; PR18449. Check that the early exit is reduced to never taken.
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| ;
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| ; CHECK-LABEL: @twoexit
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| ; CHECK-LABEL: loop:
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| ; CHECK: phi
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| ; CHECK: br i1 false
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| ; CHECK: br
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| ; CHECK: ret
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| define void @twoexit() {
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| "function top level":
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|   br label %loop
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| 
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| loop:                                             ; preds = %body, %"function top level"
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|   %0 = phi i64 [ 0, %"function top level" ], [ %2, %body ]
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|   %1 = icmp ugt i64 %0, 2
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|   br i1 %1, label %fail, label %body
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| 
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| fail:                                             ; preds = %loop
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|   tail call void @bounds_fail()
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|   unreachable
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| 
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| body:                                             ; preds = %loop
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|   %2 = add i64 %0, 1
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|   %3 = icmp slt i64 %2, 3
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|   br i1 %3, label %loop, label %out
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| 
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| out:                                              ; preds = %body
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|   ret void
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| }
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| declare void @bounds_fail()
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