From f504ec22988b9d566124de49a72817afe25fa685 Mon Sep 17 00:00:00 2001 From: Benjamin Kramer Date: Sun, 22 Jun 2014 12:22:04 +0000 Subject: [PATCH] Add a description to the test from r211433 explaining why it's written that way. llvm-svn: 211465 --- .../test/Transforms/IndVarSimplify/2014-06-21-congruent-constant.ll | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/llvm/test/Transforms/IndVarSimplify/2014-06-21-congruent-constant.ll b/llvm/test/Transforms/IndVarSimplify/2014-06-21-congruent-constant.ll index 3df4c21..2c738de 100644 --- a/llvm/test/Transforms/IndVarSimplify/2014-06-21-congruent-constant.ll +++ b/llvm/test/Transforms/IndVarSimplify/2014-06-21-congruent-constant.ll @@ -1,5 +1,11 @@ ; RUN: opt -S -loop-unswitch -instcombine -indvars < %s | FileCheck %s +; This used to crash in SCEVExpander when there were congruent phis with and +; undef incoming value from the loop header. The -loop-unswitch -instcombine is +; necessary to create just this pattern, which is essentially a nop and gets +; folded away aggressively if spelled out in IR directly. +; PR 20093 + @c = external global i32**, align 8 define void @test1() { -- 2.7.4