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; 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
}
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