Fix left shifts of negative integers in AArch64 InstPrinter/Disassembler

Summary:
Left shift of negative integer is an undefined behavior, and
is reported by UBSan. It's ok for imm values to be negative, so we can
just replace left shifts with multiplications.

Test Plan: check-llvm test suite

Reviewers: t.p.northover

Reviewed By: t.p.northover

Subscribers: aemerson, mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D5132

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216910 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/AArch64/Disassembler/AArch64Disassembler.cpp b/lib/Target/AArch64/Disassembler/AArch64Disassembler.cpp
index 9726b2ad6399e443d06513dbf9074c6229bf1f11..9e8618822eac892cbfd5419af83b2d057e973947 100644 (file)
--- a/lib/Target/AArch64/Disassembler/AArch64Disassembler.cpp
+++ b/lib/Target/AArch64/Disassembler/AArch64Disassembler.cpp
@@ -610,7 +610,7 @@ static DecodeStatus DecodePCRelLabel19(llvm::MCInst &Inst, unsigned Imm,
   if (ImmVal & (1 << (19 - 1)))
     ImmVal |= ~((1LL << 19) - 1);
 
-  if (!Dis->tryAddingSymbolicOperand(Inst, ImmVal << 2, Addr,
+  if (!Dis->tryAddingSymbolicOperand(Inst, ImmVal *  4, Addr,
                                      Inst.getOpcode() != AArch64::LDRXl, 0, 4))
     Inst.addOperand(MCOperand::CreateImm(ImmVal));
   return Success;
@@ -1506,7 +1506,7 @@ static DecodeStatus DecodeUnconditionalBranch(llvm::MCInst &Inst, uint32_t insn,
   if (imm & (1 << (26 - 1)))
     imm |= ~((1LL << 26) - 1);
 
-  if (!Dis->tryAddingSymbolicOperand(Inst, imm << 2, Addr, true, 0, 4))
+  if (!Dis->tryAddingSymbolicOperand(Inst, imm * 4, Addr, true, 0, 4))
     Inst.addOperand(MCOperand::CreateImm(imm));
 
   return Success;
@@ -1548,7 +1548,7 @@ static DecodeStatus DecodeTestAndBranch(llvm::MCInst &Inst, uint32_t insn,
   else
     DecodeGPR64RegisterClass(Inst, Rt, Addr, Decoder);
   Inst.addOperand(MCOperand::CreateImm(bit));
-  if (!Dis->tryAddingSymbolicOperand(Inst, dst << 2, Addr, true, 0, 4))
+  if (!Dis->tryAddingSymbolicOperand(Inst, dst * 4, Addr, true, 0, 4))
     Inst.addOperand(MCOperand::CreateImm(dst));
 
   return Success;

diff --git a/lib/Target/AArch64/InstPrinter/AArch64InstPrinter.cpp b/lib/Target/AArch64/InstPrinter/AArch64InstPrinter.cpp
index 848153bf778b71c7059072a31f7fca9b1cc35dfa..0091ab354a07bf9b700cd67175eac5e1fb5e7043 100644 (file)
--- a/lib/Target/AArch64/InstPrinter/AArch64InstPrinter.cpp
+++ b/lib/Target/AArch64/InstPrinter/AArch64InstPrinter.cpp
@@ -1223,7 +1223,7 @@ void AArch64InstPrinter::printAlignedLabel(const MCInst *MI, unsigned OpNum,
   // If the label has already been resolved to an immediate offset (say, when
   // we're running the disassembler), just print the immediate.
   if (Op.isImm()) {
-    O << "#" << (Op.getImm() << 2);
+    O << "#" << (Op.getImm() * 4);
     return;
   }
 
@@ -1247,7 +1247,7 @@ void AArch64InstPrinter::printAdrpLabel(const MCInst *MI, unsigned OpNum,
   // If the label has already been resolved to an immediate offset (say, when
   // we're running the disassembler), just print the immediate.
   if (Op.isImm()) {
-    O << "#" << (Op.getImm() << 12);
+    O << "#" << (Op.getImm() * (1 << 12));
     return;
   }