From 9a2f93121b31bf6345d1552bdc43037f89714d86 Mon Sep 17 00:00:00 2001 From: Nick Lewycky Date: Thu, 27 Sep 2007 14:12:54 +0000 Subject: [PATCH] Build the correct range for loops with unusual bounds. Fix from Jay Foad. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@42394 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Analysis/ScalarEvolution.cpp | 2 +- .../2007-09-27-LargeStepping.ll | 21 +++++++++++++++++++ 2 files changed, 22 insertions(+), 1 deletion(-) create mode 100644 test/Analysis/ScalarEvolution/2007-09-27-LargeStepping.ll diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp index aaba49eacd9..069f6ec714c 100644 --- a/lib/Analysis/ScalarEvolution.cpp +++ b/lib/Analysis/ScalarEvolution.cpp @@ -2470,7 +2470,7 @@ SCEVHandle SCEVAddRecExpr::getNumIterationsInRange(ConstantRange Range) const { APInt End = A.sge(One) ? (Range.getUpper() - One) : Range.getLower(); // The exit value should be (End+A)/A. - APInt ExitVal = (End + A).sdiv(A); + APInt ExitVal = (End + A).udiv(A); ConstantInt *ExitValue = ConstantInt::get(ExitVal); // Evaluate at the exit value. If we really did fall out of the valid diff --git a/test/Analysis/ScalarEvolution/2007-09-27-LargeStepping.ll b/test/Analysis/ScalarEvolution/2007-09-27-LargeStepping.ll new file mode 100644 index 00000000000..d7a0bafe5d6 --- /dev/null +++ b/test/Analysis/ScalarEvolution/2007-09-27-LargeStepping.ll @@ -0,0 +1,21 @@ +; RUN: llvm-as < %s | opt -analyze -scalar-evolution 2>&1 | grep "13 iterations" +; PR1706 + +define i32 @f() { +entry: + br label %bb5 + +bb: ; preds = %bb5 + %tmp2 = shl i32 %j.0, 1 ; [#uses=1] + %tmp4 = add i32 %i.0, 268435456 ; [#uses=1] + br label %bb5 + +bb5: ; preds = %bb, %entry + %j.0 = phi i32 [ 1, %entry ], [ %tmp2, %bb ] ; [#uses=2] + %i.0 = phi i32 [ -1879048192, %entry ], [ %tmp4, %bb ] ; [#uses=2] + %tmp7 = icmp slt i32 %i.0, 1610612736 ; [#uses=1] + br i1 %tmp7, label %bb, label %return + +return: ; preds = %bb5 + ret i32 %j.0 +}