llvm-6502/test/Analysis/ScalarEvolution/2008-12-11-SMaxOverflow.ll
Dan Gohman 9f93d30a26 ScalarEvolution support for <= and >= loops.
Also, generalize ScalarEvolutions's min and max recognition to handle
some new forms of min and max that this change makes more common.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@102234 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-24 03:09:42 +00:00

31 lines
746 B
LLVM

; RUN: opt < %s -analyze -scalar-evolution | FileCheck %s
; CHECK: @f
; CHECK: Loop %bb16.preheader: backedge-taken count is (-1 + %c.idx.val)
define i32 @f(i32 %c.idx.val) {
bb2:
%k.018 = add i32 %c.idx.val, -1 ; <i32> [#uses=2]
%a14 = icmp slt i32 %k.018, 0 ; <i1> [#uses=1]
br i1 %a14, label %bb19, label %bb16.preheader
bb16.preheader:
%k.019 = phi i32 [ %k.0, %bb18 ], [ %k.018, %bb2 ] ; <i32> [#uses=5]
%x = phi i32 [ 0, %bb2 ], [ %x.1, %bb18]
br label %bb18
bb18: ; preds = %bb18.loopexit
%x.1 = add i32 %x, 1
%k.0 = add i32 %k.019, -1 ; <i32> [#uses=2]
%a107 = icmp slt i32 %k.0, 0 ; <i1> [#uses=1]
br i1 %a107, label %bb18.bb19_crit_edge, label %bb16.preheader
bb18.bb19_crit_edge:
ret i32 %x
bb19:
ret i32 0
}