127 lines
3.1 KiB
LLVM
127 lines
3.1 KiB
LLVM
; RUN: opt < %s -analyze -scalar-evolution | FileCheck %s
|
|
|
|
; Trip counts with trivial exit conditions.
|
|
|
|
; CHECK: Determining loop execution counts for: @a
|
|
; CHECK: Loop %loop: Unpredictable backedge-taken count.
|
|
; CHECK: Loop %loop: Unpredictable max backedge-taken count.
|
|
|
|
; CHECK: Determining loop execution counts for: @b
|
|
; CHECK: Loop %loop: backedge-taken count is false
|
|
; CHECK: Loop %loop: max backedge-taken count is false
|
|
|
|
; CHECK: Determining loop execution counts for: @c
|
|
; CHECK: Loop %loop: backedge-taken count is false
|
|
; CHECK: Loop %loop: max backedge-taken count is false
|
|
|
|
; CHECK: Determining loop execution counts for: @d
|
|
; CHECK: Loop %loop: Unpredictable backedge-taken count.
|
|
; CHECK: Loop %loop: Unpredictable max backedge-taken count.
|
|
|
|
define void @a(i64 %n) nounwind {
|
|
entry:
|
|
%t0 = icmp sgt i64 %n, 0
|
|
br i1 %t0, label %loop, label %return
|
|
|
|
loop:
|
|
%i = phi i64 [ %i.next, %loop ], [ 0, %entry ]
|
|
%i.next = add nsw i64 %i, 1
|
|
%exitcond = icmp eq i64 %i.next, %n
|
|
br i1 false, label %return, label %loop
|
|
|
|
return:
|
|
ret void
|
|
}
|
|
define void @b(i64 %n) nounwind {
|
|
entry:
|
|
%t0 = icmp sgt i64 %n, 0
|
|
br i1 %t0, label %loop, label %return
|
|
|
|
loop:
|
|
%i = phi i64 [ %i.next, %loop ], [ 0, %entry ]
|
|
%i.next = add nsw i64 %i, 1
|
|
%exitcond = icmp eq i64 %i.next, %n
|
|
br i1 true, label %return, label %loop
|
|
|
|
return:
|
|
ret void
|
|
}
|
|
define void @c(i64 %n) nounwind {
|
|
entry:
|
|
%t0 = icmp sgt i64 %n, 0
|
|
br i1 %t0, label %loop, label %return
|
|
|
|
loop:
|
|
%i = phi i64 [ %i.next, %loop ], [ 0, %entry ]
|
|
%i.next = add nsw i64 %i, 1
|
|
%exitcond = icmp eq i64 %i.next, %n
|
|
br i1 false, label %loop, label %return
|
|
|
|
return:
|
|
ret void
|
|
}
|
|
define void @d(i64 %n) nounwind {
|
|
entry:
|
|
%t0 = icmp sgt i64 %n, 0
|
|
br i1 %t0, label %loop, label %return
|
|
|
|
loop:
|
|
%i = phi i64 [ %i.next, %loop ], [ 0, %entry ]
|
|
%i.next = add nsw i64 %i, 1
|
|
%exitcond = icmp eq i64 %i.next, %n
|
|
br i1 true, label %loop, label %return
|
|
|
|
return:
|
|
ret void
|
|
}
|
|
|
|
; Trip counts for non-polynomial iterations. It's theoretically possible
|
|
; to compute a maximum count for these, but short of that, ScalarEvolution
|
|
; should return unknown.
|
|
|
|
; PR7416
|
|
; CHECK: Determining loop execution counts for: @nonpolynomial
|
|
; CHECK-NEXT: Loop %loophead: Unpredictable backedge-taken count
|
|
; CHECK-NEXT: Loop %loophead: Unpredictable max backedge-taken count
|
|
|
|
declare i1 @g() nounwind
|
|
|
|
define void @nonpolynomial() {
|
|
entry:
|
|
br label %loophead
|
|
loophead:
|
|
%x = phi i32 [0, %entry], [%x.1, %bb1], [%x.2, %bb2]
|
|
%y = icmp slt i32 %x, 100
|
|
br i1 %y, label %loopbody, label %retbb
|
|
loopbody:
|
|
%z = call i1 @g()
|
|
br i1 %z, label %bb1, label %bb2
|
|
bb1:
|
|
%x.1 = add i32 %x, 2
|
|
br label %loophead
|
|
bb2:
|
|
%x.2 = add i32 %x, 3
|
|
br label %loophead
|
|
retbb:
|
|
ret void
|
|
}
|
|
|
|
; PHI nodes with all constant operands.
|
|
|
|
; CHECK: Determining loop execution counts for: @constant_phi_operands
|
|
; CHECK: Loop %loop: backedge-taken count is 1
|
|
; CHECK: Loop %loop: max backedge-taken count is 1
|
|
|
|
define void @constant_phi_operands() nounwind {
|
|
entry:
|
|
br label %loop
|
|
|
|
loop:
|
|
%i = phi i64 [ 1, %loop ], [ 0, %entry ]
|
|
%exitcond = icmp eq i64 %i, 1
|
|
br i1 %exitcond, label %return, label %loop
|
|
|
|
return:
|
|
ret void
|
|
}
|