exact_iter_count.ll
1.32 KB
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; RUN: opt < %s -scalar-evolution -analyze -enable-new-pm=0 | FileCheck %s
; RUN: opt < %s "-passes=print<scalar-evolution>" -disable-output 2>&1 | FileCheck %s
; One side exit dominating the latch, exact backedge taken count is known.
define void @test_01() {
; CHECK-LABEL: Determining loop execution counts for: @test_01
; CHECK-NEXT: Loop %loop: <multiple exits> backedge-taken count is 50
entry:
br label %loop
loop:
%iv = phi i32 [ 0, %entry ], [ %iv.next, %backedge ]
%side.cond = icmp slt i32 %iv, 50
br i1 %side.cond, label %backedge, label %side.exit
backedge:
%iv.next = add i32 %iv, 1
%loop.cond = icmp slt i32 %iv, 100
br i1 %loop.cond, label %loop, label %exit
exit:
ret void
side.exit:
ret void
}
define void @test_02(i1 %c) {
; CHECK-LABEL: Determining loop execution counts for: @test_02
; CHECK-NEXT: Loop %loop: <multiple exits> backedge-taken count is 50
entry:
br label %loop
loop:
%iv = phi i32 [ 0, %entry ], [ %iv.next, %backedge ]
br i1 %c, label %if.true, label %if.false
if.true:
br label %merge
if.false:
br label %merge
merge:
%side.cond = icmp slt i32 %iv, 50
br i1 %side.cond, label %backedge, label %side.exit
backedge:
%iv.next = add i32 %iv, 1
%loop.cond = icmp slt i32 %iv, 100
br i1 %loop.cond, label %loop, label %exit
exit:
ret void
side.exit:
ret void
}