From 12f3b3b44fabdd242da46eeb16b299b8c696709e Mon Sep 17 00:00:00 2001 From: Duncan Sands Date: Thu, 18 Nov 2010 20:05:18 +0000 Subject: The DAGCombiner was threading select over pairs of extending loads even if the extension types were not the same. The result was that if you fed a select with sext and zext loads, as in the testcase, then it would get turned into a zext (or sext) of the select, which is wrong in the cases when it should have been an sext (resp. zext). Reported and diagnosed by Sebastien Deldon. llvm-svn: 119728 --- llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'llvm/lib/CodeGen/SelectionDAG') diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 1a0f503378d..53b449309c7 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -6658,6 +6658,11 @@ bool DAGCombiner::SimplifySelectOps(SDNode *TheSelect, SDValue LHS, LLD->isVolatile() || RLD->isVolatile() || // If this is an EXTLOAD, the VT's must match. LLD->getMemoryVT() != RLD->getMemoryVT() || + // If this is an EXTLOAD, the kind of extension must match. + (LLD->getExtensionType() != RLD->getExtensionType() && + // The only exception is if one of the extensions is anyext. + LLD->getExtensionType() != ISD::EXTLOAD && + RLD->getExtensionType() != ISD::EXTLOAD) || // FIXME: this discards src value information. This is // over-conservative. It would be beneficial to be able to remember // both potential memory locations. Since we are discarding -- cgit v1.2.3