commit 638090e32fa4c18e1251e265e2b16d990ff96e28
author Sean Fertile <sfertile@ca.ibm.com> Tue Feb 12 20:03:04 2019 +0000
committer Sean Fertile <sfertile@ca.ibm.com> Tue Feb 12 20:03:04 2019 +0000
tree ba676890c8412a341296d773ede47bbea0c883f3
parent 02f8fc49ff4ad5f37a0bd7ad4264e7fb98745b99

Fix undefined behaviour in PPCInstPrinter::printBranchOperand.

Fix the undefined behaviour introduced by my previous patch r353865 (left
shifting a potentially negative value), which was caught by the bots that run
UBSan.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@353874 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp

diff --git a/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp b/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp
index 49e7389..7720649 100644
--- a/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp
+++ b/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp
@@ -382,7 +382,7 @@
   // Branches can take an immediate operand.  This is used by the branch
   // selection pass to print .+8, an eight byte displacement from the PC.
   O << ".";
-  int32_t Imm = MI->getOperand(OpNo).getImm() << 2;
+  int32_t Imm = SignExtend32<32>((unsigned)MI->getOperand(OpNo).getImm() << 2);
   if (Imm >= 0)
     O << "+";
   O << Imm;