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152 lines
4.0 KiB
152 lines
4.0 KiB
; RUN: opt < %s -analyze -scalar-evolution | FileCheck %s
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; Trip counts with trivial exit conditions.
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; CHECK: Determining loop execution counts for: @a
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; CHECK: Loop %loop: Unpredictable backedge-taken count.
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; CHECK: Loop %loop: Unpredictable max backedge-taken count.
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; CHECK: Determining loop execution counts for: @b
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; CHECK: Loop %loop: backedge-taken count is false
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; CHECK: Loop %loop: max backedge-taken count is false
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; CHECK: Determining loop execution counts for: @c
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; CHECK: Loop %loop: backedge-taken count is false
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; CHECK: Loop %loop: max backedge-taken count is false
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; CHECK: Determining loop execution counts for: @d
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; CHECK: Loop %loop: Unpredictable backedge-taken count.
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; CHECK: Loop %loop: Unpredictable max backedge-taken count.
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define void @a(i64 %n) nounwind {
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entry:
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%t0 = icmp sgt i64 %n, 0
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br i1 %t0, label %loop, label %return
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loop:
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%i = phi i64 [ %i.next, %loop ], [ 0, %entry ]
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%i.next = add nsw i64 %i, 1
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%exitcond = icmp eq i64 %i.next, %n
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br i1 false, label %return, label %loop
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return:
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ret void
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}
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define void @b(i64 %n) nounwind {
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entry:
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%t0 = icmp sgt i64 %n, 0
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br i1 %t0, label %loop, label %return
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loop:
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%i = phi i64 [ %i.next, %loop ], [ 0, %entry ]
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%i.next = add nsw i64 %i, 1
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%exitcond = icmp eq i64 %i.next, %n
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br i1 true, label %return, label %loop
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return:
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ret void
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}
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define void @c(i64 %n) nounwind {
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entry:
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%t0 = icmp sgt i64 %n, 0
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br i1 %t0, label %loop, label %return
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loop:
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%i = phi i64 [ %i.next, %loop ], [ 0, %entry ]
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%i.next = add nsw i64 %i, 1
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%exitcond = icmp eq i64 %i.next, %n
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br i1 false, label %loop, label %return
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return:
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ret void
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}
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define void @d(i64 %n) nounwind {
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entry:
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%t0 = icmp sgt i64 %n, 0
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br i1 %t0, label %loop, label %return
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loop:
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%i = phi i64 [ %i.next, %loop ], [ 0, %entry ]
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%i.next = add nsw i64 %i, 1
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%exitcond = icmp eq i64 %i.next, %n
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br i1 true, label %loop, label %return
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return:
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ret void
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}
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; Trip counts for non-polynomial iterations. It's theoretically possible
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; to compute a maximum count for these, but short of that, ScalarEvolution
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; should return unknown.
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; PR7416
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; CHECK: Determining loop execution counts for: @nonpolynomial
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; CHECK-NEXT: Loop %loophead: Unpredictable backedge-taken count
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; CHECK-NEXT: Loop %loophead: Unpredictable max backedge-taken count
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declare i1 @g() nounwind
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define void @nonpolynomial() {
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entry:
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br label %loophead
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loophead:
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%x = phi i32 [0, %entry], [%x.1, %bb1], [%x.2, %bb2]
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%y = icmp slt i32 %x, 100
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br i1 %y, label %loopbody, label %retbb
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loopbody:
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%z = call i1 @g()
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br i1 %z, label %bb1, label %bb2
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bb1:
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%x.1 = add i32 %x, 2
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br label %loophead
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bb2:
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%x.2 = add i32 %x, 3
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br label %loophead
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retbb:
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ret void
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}
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; PHI nodes with all constant operands.
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; CHECK: Determining loop execution counts for: @constant_phi_operands
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; CHECK: Loop %loop: backedge-taken count is 1
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; CHECK: Loop %loop: max backedge-taken count is 1
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define void @constant_phi_operands() nounwind {
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entry:
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br label %loop
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loop:
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%i = phi i64 [ 1, %loop ], [ 0, %entry ]
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%exitcond = icmp eq i64 %i, 1
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br i1 %exitcond, label %return, label %loop
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return:
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ret void
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}
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; PR16130: Loop exit depends on an 'or' expression.
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; One side of the expression test against a value that will be skipped.
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; We can't assume undefined behavior just because we have an NSW flag.
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;
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; CHECK: Determining loop execution counts for: @exit_orcond_nsw
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; CHECK: Loop %for.body.i: Unpredictable backedge-taken count.
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; CHECK: Loop %for.body.i: max backedge-taken count is 1
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define void @exit_orcond_nsw(i32 *%a) nounwind {
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entry:
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br label %for.body.i
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for.body.i: ; preds = %for.body.i, %entry
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%b.01.i = phi i32 [ 0, %entry ], [ %add.i, %for.body.i ]
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%tobool.i = icmp ne i32 %b.01.i, 0
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%add.i = add nsw i32 %b.01.i, 8
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%cmp.i = icmp eq i32 %add.i, 13
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%or.cond = or i1 %tobool.i, %cmp.i
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br i1 %or.cond, label %exit, label %for.body.i
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exit: ; preds = %for.body.i
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%b.01.i.lcssa = phi i32 [ %b.01.i, %for.body.i ]
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store i32 %b.01.i.lcssa, i32* %a, align 4
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ret void
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}
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