Fix the the ceiling-division used in computing the MaxBECount so that it doesn't
have trouble with an intermediate add overflowing. Also, be more conservative
about the case where the induction variable in an SLT loop exit can step past
the RHS of the SLT and overflow in a single step.
Make getSignedRange more aggressive, to recover for some common cases which
the above fixes pessimized.
This addresses rdar://7561161.
llvm-svn: 94512
diff --git a/llvm/test/Analysis/ScalarEvolution/nsw-offset.ll b/llvm/test/Analysis/ScalarEvolution/nsw-offset.ll
index fd0dfe6..ed97de6 100644
--- a/llvm/test/Analysis/ScalarEvolution/nsw-offset.ll
+++ b/llvm/test/Analysis/ScalarEvolution/nsw-offset.ll
@@ -6,8 +6,9 @@
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128"
-define void @foo(i32 %n, double* nocapture %d, double* nocapture %q) nounwind {
+define void @foo(i32 %no, double* nocapture %d, double* nocapture %q) nounwind {
entry:
+ %n = and i32 %no, 4294967294
%0 = icmp sgt i32 %n, 0 ; <i1> [#uses=1]
br i1 %0, label %bb.nph, label %return
@@ -73,4 +74,4 @@
}
; CHECK: Loop %bb: backedge-taken count is ((-1 + %n) /u 2)
-; CHECK: Loop %bb: max backedge-taken count is 1073741823
+; CHECK: Loop %bb: max backedge-taken count is 1073741822