Now that we look at all the header PHIs, we need to consider all the header PHIs

when deciding that the loop has stopped evolving. Fixes miscompile in the gcc
torture testsuite!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142843 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 29 insertions, 0 deletions

diff --git a/test/Analysis/ScalarEvolution/trip-count11.ll b/test/Analysis/ScalarEvolution/trip-count11.ll
new file mode 100644
index 0000000..7191503
--- /dev/null
+++ b/test/Analysis/ScalarEvolution/trip-count11.ll
@@ -0,0 +1,29 @@
+; RUN: opt < %s -analyze -scalar-evolution | FileCheck %s
+
+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-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+@foo.a = internal constant [8 x i32] [i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7], align 16
+
+define i32 @foo() nounwind uwtable noinline {
+entry:
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.inc, %entry
+  %sum.0 = phi i32 [ 0, %entry ], [ %add, %for.inc ]
+; CHECK: --> %sum.0 Exits: 28
+  %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.inc ]
+  %cmp = icmp ult i32 %i.0, 8
+  br i1 %cmp, label %for.inc, label %for.end
+
+for.inc:                                          ; preds = %for.cond
+  %idxprom = sext i32 %i.0 to i64
+  %arrayidx = getelementptr inbounds [8 x i32]* @foo.a, i64 0, i64 %idxprom
+  %0 = load i32* %arrayidx, align 4
+  %add = add nsw i32 %sum.0, %0
+  %inc = add nsw i32 %i.0, 1
+  br label %for.cond
+
+for.end:                                          ; preds = %for.cond
+  ret i32 %sum.0
+}