llvm-6502/test/Transforms/IndVarsSimplify/tripcount_compute.llx

; These tests ensure that we can compute the trip count of various forms of 
; loops.  If the trip count of the loop is computable, then we will know what
; the exit value of the loop will be for some value, allowing us to substitute
; it directly into users outside of the loop, making the loop dead.
;
; RUN: llvm-as < %s | opt -indvars -adce -simplifycfg | llvm-dis | not grep br

int %linear_setne() {   ;; for (i = 0; i != 100; ++i)
entry:
	br label %loop
loop:
	%i = phi int [ 0, %entry ], [ %i.next, %loop ]
	%i.next = add int %i, 1
	%c = setne int %i, 100
	br bool %c, label %loop, label %loopexit
loopexit:
	ret int %i
}

int %linear_setne_2() {   ;; for (i = 0; i != 100; i += 2)
entry:
	br label %loop
loop:
	%i = phi int [ 0, %entry ], [ %i.next, %loop ]
	%i.next = add int %i, 2
	%c = setne int %i, 100
	br bool %c, label %loop, label %loopexit
loopexit:
	ret int %i
}


int %linear_setne_overflow() {   ;; for (i = 1024; i != 0; i += 1024)
entry:
	br label %loop
loop:
	%i = phi int [ 1024, %entry ], [ %i.next, %loop ]
	%i.next = add int %i, 1024
	%c = setne int %i, 0
	br bool %c, label %loop, label %loopexit
loopexit:
	ret int %i
}

int %linear_setlt() {   ;; for (i = 0; i < 100; ++i)
entry:
	br label %loop
loop:
	%i = phi int [ 0, %entry ], [ %i.next, %loop ]
	%i.next = add int %i, 1
	%c = setlt int %i, 100
	br bool %c, label %loop, label %loopexit
loopexit:
	ret int %i
}

int %quadratic_setlt() {   ;; for (i = 7; i*i < 1000; i+=3)
entry:
        br label %loop
loop:
        %i = phi int [ 7, %entry ], [ %i.next, %loop ]
        %i.next = add int %i, 3
        %i2 = mul int %i, %i
        %c = setlt int %i2, 1000
        br bool %c, label %loop, label %loopexit
loopexit:
        ret int %i
}

;; Chained loop test - The exit value of the second loop depends on the exit
;; value of the first being computed.
int %chained() {
entry:
	br label %loop
loop:   ;; for (i = 0; i != 100; ++i)
	%i = phi int [ 0, %entry ], [ %i.next, %loop ]
	%i.next = add int %i, 1
	%c = setne int %i, 100
	br bool %c, label %loop, label %loopexit
loopexit:
	br label %loop2
loop2:  ;; for (j = i; j != 200; ++j)
	%j = phi int [ %i, %loopexit ], [ %j.next, %loop2 ]
	%j.next = add int %j, 1
	%c2 = setne int %j, 200
	br bool %c2, label %loop2, label %loopexit2
loopexit2:
	ret int %j
}