1 files changed, 36 insertions, 0 deletions
diff --git a/test/Transforms/LoopStrengthReduce/X86/2011-11-29-postincphi.ll b/test/Transforms/LoopStrengthReduce/X86/2011-11-29-postincphi.ll
new file mode 100644
index 0000000..cb23ad0
--- /dev/null
+++ b/test/Transforms/LoopStrengthReduce/X86/2011-11-29-postincphi.ll
@@ -0,0 +1,36 @@
+; RUN: llc < %s | FileCheck %s
+;
+; PR11431: handle a phi operand that is replaced by a postinc user.
+; LSR first expands %t3 to %t2 in %phi
+; LSR then expands %t2 in %phi into two decrements, one on each loop exit.
+
+target datalayout = "e-p:64:64:64-S128-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-f128:128:128-n8:16:32:64"
+target triple = "x86_64-unknown-linux-gnu"
+
+declare i1 @check() nounwind
+
+; Check that LSR did something close to the behavior at the time of the bug.
+; CHECK: @sqlite3DropTriggerPtr
+; CHECK: incq %rax
+; CHECK: jne
+; CHECK: decq %rax
+; CHECK: ret
+define i64 @sqlite3DropTriggerPtr() nounwind {
+bb:
+  %cmp = call zeroext i1 @check()
+  br label %bb1
+
+bb1:                                              ; preds = %bb4, %bb
+  %t0 = phi i64 [ 0, %bb ], [ %t3, %bb4 ]
+  %t2 = phi i64 [ 1, %bb ], [ %t5, %bb4 ]
+  %t3 = add nsw i64 %t0, 1
+  br i1 %cmp, label %bb4, label %bb8
+
+bb4:                                              ; preds = %bb1
+  %t5 = add nsw i64 %t2, 1
+  br i1 %cmp, label %bb1, label %bb8
+
+bb8:                                              ; preds = %bb8, %bb4
+  %phi = phi i64 [ %t3, %bb1 ], [ %t2, %bb4 ]
+  ret i64 %phi
+}