llvm-6502/test/Analysis/ScalarEvolution/2007-08-06-Unsigned.ll
Nick Lewycky 3e63076980 Add 'umax' similar to 'smax' SCEV. Closes PR2003.
Parse reversed smax and umax as smin and umin and express them with negative
or binary-not SCEVs (which are really just subtract under the hood).

Parse 'xor %x, -1' as (-1 - %x).

Remove dead code (ConstantInt::get always returns a ConstantInt).

Don't use getIntegerSCEV(-1, Ty). The first value is an int, then it gets
passed into a uint64_t. Instead, create the -1 directly from
ConstantInt::getAllOnesValue().


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47360 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-20 06:48:22 +00:00

31 lines
1.0 KiB
LLVM

; RUN: llvm-as < %s | opt -scalar-evolution -analyze | grep {Loop bb: ( -1 + ( -1 \\* %x) + (( 1 + %x) umax %y)) iterations!}
; PR1597
define i32 @f(i32 %x, i32 %y) {
entry:
%tmp63 = icmp ult i32 %x, %y ; <i1> [#uses=1]
br i1 %tmp63, label %bb.preheader, label %bb8
bb.preheader: ; preds = %entry
br label %bb
bb: ; preds = %bb3, %bb.preheader
%x_addr.0 = phi i32 [ %tmp2, %bb3 ], [ %x, %bb.preheader ] ; <i32> [#uses=1]
%tmp2 = add i32 %x_addr.0, 1 ; <i32> [#uses=3]
br label %bb3
bb3: ; preds = %bb
%tmp6 = icmp ult i32 %tmp2, %y ; <i1> [#uses=1]
br i1 %tmp6, label %bb, label %bb8.loopexit
bb8.loopexit: ; preds = %bb3
br label %bb8
bb8: ; preds = %bb8.loopexit, %entry
%x_addr.1 = phi i32 [ %x, %entry ], [ %tmp2, %bb8.loopexit ] ; <i32> [#uses=1]
br label %return
return: ; preds = %bb8
ret i32 %x_addr.1
}