For PR950:
This patch converts the old SHR instruction into two instructions,
AShr (Arithmetic) and LShr (Logical). The Shr instructions now are not
dependent on the sign of their operands.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31542 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/CBackend/Writer.cpp b/lib/Target/CBackend/Writer.cpp
index c820fca..4b6ee91 100644
--- a/lib/Target/CBackend/Writer.cpp
+++ b/lib/Target/CBackend/Writer.cpp
@@ -606,7 +606,8 @@
case Instruction::SetGT:
case Instruction::SetGE:
case Instruction::Shl:
- case Instruction::Shr:
+ case Instruction::LShr:
+ case Instruction::AShr:
{
Out << '(';
bool NeedsClosingParens = printConstExprCast(CE);
@@ -631,7 +632,8 @@
case Instruction::SetGT: Out << " > "; break;
case Instruction::SetGE: Out << " >= "; break;
case Instruction::Shl: Out << " << "; break;
- case Instruction::Shr: Out << " >> "; break;
+ case Instruction::LShr:
+ case Instruction::AShr: Out << " >> "; break;
default: assert(0 && "Illegal opcode here!");
}
printConstantWithCast(CE->getOperand(1), CE->getOpcode());
@@ -826,23 +828,23 @@
// because their operands were casted to the expected type. This function takes
// care of detecting that case and printing the cast for the ConstantExpr.
bool CWriter::printConstExprCast(const ConstantExpr* CE) {
- bool Result = false;
+ bool NeedsExplicitCast = false;
const Type* Ty = CE->getOperand(0)->getType();
switch (CE->getOpcode()) {
- case Instruction::UDiv:
+ case Instruction::LShr:
case Instruction::URem:
- Result = Ty->isSigned(); break;
- case Instruction::SDiv:
+ case Instruction::UDiv: NeedsExplicitCast = Ty->isSigned(); break;
+ case Instruction::AShr:
case Instruction::SRem:
- Result = Ty->isUnsigned(); break;
+ case Instruction::SDiv: NeedsExplicitCast = Ty->isUnsigned(); break;
default: break;
}
- if (Result) {
+ if (NeedsExplicitCast) {
Out << "((";
printType(Out, Ty);
Out << ")(";
}
- return Result;
+ return NeedsExplicitCast;
}
// Print a constant assuming that it is the operand for a given Opcode. The
@@ -863,6 +865,7 @@
default:
// for most instructions, it doesn't matter
break;
+ case Instruction::LShr:
case Instruction::UDiv:
case Instruction::URem:
// For UDiv/URem get correct type
@@ -871,6 +874,7 @@
shouldCast = true;
}
break;
+ case Instruction::AShr:
case Instruction::SDiv:
case Instruction::SRem:
// For SDiv/SRem get correct type
@@ -927,23 +931,23 @@
// This function takes care of detecting that case and printing the cast
// for the Instruction.
bool CWriter::writeInstructionCast(const Instruction &I) {
- bool Result = false;
+ bool NeedsExplicitCast = false;
const Type* Ty = I.getOperand(0)->getType();
switch (I.getOpcode()) {
- case Instruction::UDiv:
+ case Instruction::LShr:
case Instruction::URem:
- Result = Ty->isSigned(); break;
- case Instruction::SDiv:
+ case Instruction::UDiv: NeedsExplicitCast = Ty->isSigned(); break;
+ case Instruction::AShr:
case Instruction::SRem:
- Result = Ty->isUnsigned(); break;
+ case Instruction::SDiv: NeedsExplicitCast = Ty->isUnsigned(); break;
default: break;
}
- if (Result) {
+ if (NeedsExplicitCast) {
Out << "((";
printType(Out, Ty);
Out << ")(";
}
- return Result;
+ return NeedsExplicitCast;
}
// Write the operand with a cast to another type based on the Opcode being used.
@@ -964,6 +968,7 @@
default:
// for most instructions, it doesn't matter
break;
+ case Instruction::LShr:
case Instruction::UDiv:
case Instruction::URem:
// For UDiv to have unsigned operands
@@ -972,6 +977,7 @@
shouldCast = true;
}
break;
+ case Instruction::AShr:
case Instruction::SDiv:
case Instruction::SRem:
if (OpTy->isUnsigned()) {
@@ -1832,7 +1838,8 @@
case Instruction::SetLT: Out << " < "; break;
case Instruction::SetGT: Out << " > "; break;
case Instruction::Shl : Out << " << "; break;
- case Instruction::Shr : Out << " >> "; break;
+ case Instruction::LShr:
+ case Instruction::AShr: Out << " >> "; break;
default: std::cerr << "Invalid operator type!" << I; abort();
}