Displaying 3 results from an estimated 3 matches for "createicmpult".
2019 Jul 03
3
optimisation issue in an llvm IR pass
Hi Craig,
On 03.07.19 17:33, Craig Topper wrote:
> Don't the CreateICmp calls return a Value* with an i1 type? But then
> they are added to an i8 type? Not sure that works.
I had that initially:
auto cf = IRB.CreateICmpULT(Incr, ConstantInt::get(Int8Ty, 1));
auto carry = IRB.CreateZExt(cf, Int8Ty);
Incr = IRB.CreateAdd(Incr, carry);
it makes no difference to the generated assembly
> Have you tried using the llvm.uadd.with.overflow.i8 intrinsic?
we have tried this:
CallInst *AddOv =
IRB.CreateBinaryIntrinsic...
2019 Jul 03
2
optimisation issue in an llvm IR pass
...dl instead
adc dl,0x1
mov BYTE PTR [rsi+rdi*1],dl
Far below are both variants with the full code around it, however the
difference in both variants is this:
//variant1
auto cf = IRB.CreateICmpEQ(Incr, ConstantInt::get(Int8Ty, 0));
Incr = IRB.CreateAdd(Incr, cf);
//variant2
auto cf = IRB.CreateICmpULT(Incr, ConstantInt::get(Int8Ty, 1));
Incr = IRB.CreateAdd(Incr, cf);
//interestingly this totally different approach creates the same
instructions as variant2
CallInst *AddOv = IRB.CreateBinaryIntrinsic(Intrinsic::uadd_with_over
flow, Counter, ConstantInt::get(Int8Ty, 1));
AddOv->setMetadata(M.g...
2011 Aug 31
2
[LLVMdev] How to place call(s) to functions found in other llvm modules ???
...",
gcd);
IRBuilder<> builder(entry);
Value* xEqualsY = builder.CreateICmpEQ(x, y, "tmp");
builder.CreateCondBr(xEqualsY, ret, cond_false);
builder.SetInsertPoint(ret);
builder.CreateRet(x);
builder.SetInsertPoint(cond_false);
Value* xLessThanY = builder.CreateICmpULT(x, y, "tmp");
builder.CreateCondBr(xLessThanY, cond_true, cond_false_2);
builder.SetInsertPoint(cond_true);
Value* yMinusX = builder.CreateSub(y, x, "tmp");
std::vector<Value*> args1;
args1.push_back(x);
args1.push_back(yMinusX);
Value* recur_1 = buil...