Add -ftrapv support, patch from David Chisnall; well all except the

clang option code that is and two bug fixes.

llvm-svn: 68240
This commit is contained in:
Mike Stump 2009-04-01 20:28:16 +00:00
parent 807a0f207d
commit 0c61b7322a
4 changed files with 130 additions and 2 deletions

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@ -59,6 +59,9 @@ public:
unsigned MathErrno : 1; // Math functions must respect errno
// (modulo the platform support).
unsigned OverflowChecking : 1; // Extension to call a handler function when
// integer arithmetic overflows.
unsigned HeinousExtensions : 1; // Extensions that we really don't like and
// may be ripped out at any time.
private:
@ -87,6 +90,8 @@ public:
EmitAllDecls = 0;
MathErrno = 1;
OverflowChecking = 0;
InstantiationDepth = 99;
}

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@ -448,6 +448,7 @@ OPTION("-ftemplate-depth-", ftemplate_depth_, Joined, f_Group, INVALID, "", 0, 0
OPTION("-fterminated-vtables", fterminated_vtables, Flag, f_Group, INVALID, "", 0, 0, 0)
OPTION("-ftime-report", ftime_report, Flag, clang_f_Group, INVALID, "", 0, 0, 0)
OPTION("-ftraditional", ftraditional, Flag, f_Group, INVALID, "", 0, 0, 0)
OPTION("-ftrapv", ftrapv, Flag, clang_f_Group, INVALID, "", 0, 0, 0)
OPTION("-funwind-tables", funwind_tables, Flag, f_Group, INVALID, "", 0, 0, 0)
OPTION("-fverbose-asm", fverbose_asm, Flag, f_Group, INVALID, "", 0, 0, 0)
OPTION("-fwritable-strings", fwritable_strings, Flag, clang_f_Group, INVALID, "", 0, 0, 0)

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@ -22,6 +22,7 @@
#include "llvm/Function.h"
#include "llvm/GlobalVariable.h"
#include "llvm/Intrinsics.h"
#include "llvm/Module.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/CFG.h"
#include "llvm/Target/TargetData.h"
@ -261,8 +262,13 @@ public:
// Binary Operators.
Value *EmitMul(const BinOpInfo &Ops) {
if (CGF.getContext().getLangOptions().OverflowChecking)
return EmitOverflowCheckedBinOp(Ops);
return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul");
}
/// Create a binary op that checks for overflow.
/// Currently only supports +, - and *.
Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops);
Value *EmitDiv(const BinOpInfo &Ops);
Value *EmitRem(const BinOpInfo &Ops);
Value *EmitAdd(const BinOpInfo &Ops);
@ -825,10 +831,114 @@ Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) {
return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem");
}
Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) {
unsigned IID;
unsigned OpID = 0;
if (Ops.Ty->isSignedIntegerType()) {
switch (Ops.E->getOpcode()) {
case BinaryOperator::Add:
OpID = 1;
IID = llvm::Intrinsic::sadd_with_overflow;
break;
case BinaryOperator::Sub:
OpID = 2;
IID = llvm::Intrinsic::ssub_with_overflow;
break;
case BinaryOperator::Mul:
OpID = 3;
IID = llvm::Intrinsic::smul_with_overflow;
break;
default:
assert(false && "Unsupported operation for overflow detection");
}
OpID <<= 1;
OpID |= 1;
}
else {
assert(Ops.Ty->isUnsignedIntegerType() &&
"Must be either a signed or unsigned integer op");
switch (Ops.E->getOpcode()) {
case BinaryOperator::Add:
OpID = 1;
IID = llvm::Intrinsic::uadd_with_overflow;
break;
case BinaryOperator::Sub:
OpID = 2;
IID = llvm::Intrinsic::usub_with_overflow;
break;
case BinaryOperator::Mul:
OpID = 3;
IID = llvm::Intrinsic::umul_with_overflow;
break;
default:
assert(false && "Unsupported operation for overflow detection");
}
OpID <<= 1;
}
const llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty);
llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, &opTy, 1);
Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS);
Value *result = Builder.CreateExtractValue(resultAndOverflow, 0);
Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1);
// Branch in case of overflow.
llvm::BasicBlock *initialBB = Builder.GetInsertBlock();
llvm::BasicBlock *overflowBB =
CGF.createBasicBlock("overflow", CGF.CurFn);
llvm::BasicBlock *continueBB =
CGF.createBasicBlock("overflow.continue", CGF.CurFn);
Builder.CreateCondBr(overflow, overflowBB, continueBB);
// Handle overflow
Builder.SetInsertPoint(overflowBB);
// Handler is:
// long long *__overflow_handler)(long long a, long long b, char op,
// char width)
std::vector<const llvm::Type*> handerArgTypes;
handerArgTypes.push_back(llvm::Type::Int64Ty);
handerArgTypes.push_back(llvm::Type::Int64Ty);
handerArgTypes.push_back(llvm::Type::Int8Ty);
handerArgTypes.push_back(llvm::Type::Int8Ty);
llvm::FunctionType *handlerTy = llvm::FunctionType::get(llvm::Type::Int64Ty,
handerArgTypes, false);
llvm::Value *handlerFunction =
CGF.CGM.getModule().getOrInsertGlobal("__overflow_handler",
llvm::PointerType::getUnqual(handlerTy));
handlerFunction = Builder.CreateLoad(handlerFunction);
llvm::Value *handlerResult = Builder.CreateCall4(handlerFunction,
Builder.CreateSExt(Ops.LHS, llvm::Type::Int64Ty),
Builder.CreateSExt(Ops.RHS, llvm::Type::Int64Ty),
llvm::ConstantInt::get(llvm::Type::Int8Ty, OpID),
llvm::ConstantInt::get(llvm::Type::Int8Ty,
cast<llvm::IntegerType>(opTy)->getBitWidth()));
handlerResult = Builder.CreateTrunc(handlerResult, opTy);
Builder.CreateBr(continueBB);
// Set up the continuation
Builder.SetInsertPoint(continueBB);
// Get the correct result
llvm::PHINode *phi = Builder.CreatePHI(opTy);
phi->reserveOperandSpace(2);
phi->addIncoming(result, initialBB);
phi->addIncoming(handlerResult, overflowBB);
return phi;
}
Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) {
if (!Ops.Ty->isPointerType())
if (!Ops.Ty->isPointerType()) {
if (CGF.getContext().getLangOptions().OverflowChecking)
return EmitOverflowCheckedBinOp(Ops);
return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add");
}
if (Ops.Ty->getAsPointerType()->isVariableArrayType()) {
// The amount of the addition needs to account for the VLA size
@ -875,8 +985,11 @@ Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) {
}
Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) {
if (!isa<llvm::PointerType>(Ops.LHS->getType()))
if (!isa<llvm::PointerType>(Ops.LHS->getType())) {
if (CGF.getContext().getLangOptions().OverflowChecking)
return EmitOverflowCheckedBinOp(Ops);
return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub");
}
if (Ops.E->getLHS()->getType()->getAsPointerType()->isVariableArrayType()) {
// The amount of the addition needs to account for the VLA size for

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@ -675,6 +675,14 @@ void InitializeGCMode(LangOptions &Options) {
Options.setGCMode(LangOptions::HybridGC);
}
static llvm::cl::opt<bool>
OverflowChecking("ftrapv",
llvm::cl::desc("Trap on integer overflow"),
llvm::cl::init(false));
void InitializeOverflowChecking(LangOptions &Options) {
Options.OverflowChecking = OverflowChecking;
}
//===----------------------------------------------------------------------===//
// Target Triple Processing.
//===----------------------------------------------------------------------===//
@ -1626,6 +1634,7 @@ int main(int argc, char **argv) {
LangKind LK = GetLanguage(InFile);
InitializeLangOptions(LangInfo, LK);
InitializeGCMode(LangInfo);
InitializeOverflowChecking(LangInfo);
InitializeLanguageStandard(LangInfo, LK, Target.get());
// Process the -I options and set them in the HeaderInfo.