From 58bc0ca37b66bf49bc20661fd2748319a06808c3 Mon Sep 17 00:00:00 2001 From: Juergen Ributzka Date: Thu, 6 Feb 2014 04:09:06 +0000 Subject: [DAG] Don't pull the binary operation though the shift if the operands have opaque constants. During DAGCombine visitShiftByConstant assumes that certain binary operations with only constant operands can always be folded successfully. This is no longer true when the constant is opaque. This commit fixes visitShiftByConstant by not performing the optimization for opaque constants. Otherwise we would end up in an infinite DAGCombine loop. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200900 91177308-0d34-0410-b5e6-96231b3b80d8 --- test/CodeGen/Generic/2014-02-05-OpaqueConstants.ll | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) create mode 100644 test/CodeGen/Generic/2014-02-05-OpaqueConstants.ll (limited to 'test') diff --git a/test/CodeGen/Generic/2014-02-05-OpaqueConstants.ll b/test/CodeGen/Generic/2014-02-05-OpaqueConstants.ll new file mode 100644 index 0000000000..5c1cd05325 --- /dev/null +++ b/test/CodeGen/Generic/2014-02-05-OpaqueConstants.ll @@ -0,0 +1,19 @@ +; Test that opaque constants are not creating an infinite DAGCombine loop +; RUN: llc < %s +; XFAIL: r600, xcore + +@a = common global i32* null, align 8 +@c = common global i32 0, align 4 +@b = common global i32* null, align 8 + +; Function Attrs: nounwind ssp uwtable +define void @fn() { + store i32* inttoptr (i64 68719476735 to i32*), i32** @a, align 8 + %1 = load i32* @c, align 4 + %2 = sext i32 %1 to i64 + %3 = lshr i64 %2, 12 + %4 = and i64 %3, 68719476735 + %5 = getelementptr inbounds i32* null, i64 %4 + store i32* %5, i32** @b, align 8 + ret void +} -- cgit v1.2.3