[llvm-commits] [llvm] r146357 - in /llvm/trunk: include/llvm/Intrinsics.td lib/Analysis/ConstantFolding.cpp lib/Transforms/Scalar/SimplifyLibCalls.cpp lib/VMCore/AutoUpgrade.cpp
Chandler Carruth
chandlerc at gmail.com
Sun Dec 11 20:26:04 PST 2011
Author: chandlerc
Date: Sun Dec 11 22:26:04 2011
New Revision: 146357
URL: http://llvm.org/viewvc/llvm-project?rev=146357&view=rev
Log:
Switch llvm.cttz and llvm.ctlz to accept a second i1 parameter which
indicates whether the intrinsic has a defined result for a first
argument equal to zero. This will eventually allow these intrinsics to
accurately model the semantics of GCC's __builtin_ctz and __builtin_clz
and the X86 instructions (prior to AVX) which implement them.
This patch merely sets the stage by extending the signature of these
intrinsics and establishing auto-upgrade logic so that the old spelling
still works both in IR and in bitcode. The upgrade logic preserves the
existing (inefficient) semantics. This patch should not change any
behavior. CodeGen isn't updated because it can use the existing
semantics regardless of the flag's value.
Note that this will be followed by API updates to Clang and DragonEgg.
Reviewed by Nick Lewycky!
Modified:
llvm/trunk/include/llvm/Intrinsics.td
llvm/trunk/lib/Analysis/ConstantFolding.cpp
llvm/trunk/lib/Transforms/Scalar/SimplifyLibCalls.cpp
llvm/trunk/lib/VMCore/AutoUpgrade.cpp
Modified: llvm/trunk/include/llvm/Intrinsics.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Intrinsics.td?rev=146357&r1=146356&r2=146357&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Intrinsics.td (original)
+++ llvm/trunk/include/llvm/Intrinsics.td Sun Dec 11 22:26:04 2011
@@ -284,8 +284,8 @@
let Properties = [IntrNoMem] in {
def int_bswap: Intrinsic<[llvm_anyint_ty], [LLVMMatchType<0>]>;
def int_ctpop: Intrinsic<[llvm_anyint_ty], [LLVMMatchType<0>]>;
- def int_ctlz : Intrinsic<[llvm_anyint_ty], [LLVMMatchType<0>]>;
- def int_cttz : Intrinsic<[llvm_anyint_ty], [LLVMMatchType<0>]>;
+ def int_ctlz : Intrinsic<[llvm_anyint_ty], [LLVMMatchType<0>, llvm_i1_ty]>;
+ def int_cttz : Intrinsic<[llvm_anyint_ty], [LLVMMatchType<0>, llvm_i1_ty]>;
}
//===------------------------ Debugger Intrinsics -------------------------===//
Modified: llvm/trunk/lib/Analysis/ConstantFolding.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ConstantFolding.cpp?rev=146357&r1=146356&r2=146357&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ConstantFolding.cpp (original)
+++ llvm/trunk/lib/Analysis/ConstantFolding.cpp Sun Dec 11 22:26:04 2011
@@ -1290,10 +1290,6 @@
return ConstantInt::get(F->getContext(), Op->getValue().byteSwap());
case Intrinsic::ctpop:
return ConstantInt::get(Ty, Op->getValue().countPopulation());
- case Intrinsic::cttz:
- return ConstantInt::get(Ty, Op->getValue().countTrailingZeros());
- case Intrinsic::ctlz:
- return ConstantInt::get(Ty, Op->getValue().countLeadingZeros());
case Intrinsic::convert_from_fp16: {
APFloat Val(Op->getValue());
@@ -1418,6 +1414,14 @@
};
return ConstantStruct::get(cast<StructType>(F->getReturnType()), Ops);
}
+ case Intrinsic::cttz:
+ // FIXME: This should check for Op2 == 1, and become unreachable if
+ // Op1 == 0.
+ return ConstantInt::get(Ty, Op1->getValue().countTrailingZeros());
+ case Intrinsic::ctlz:
+ // FIXME: This should check for Op2 == 1, and become unreachable if
+ // Op1 == 0.
+ return ConstantInt::get(Ty, Op1->getValue().countLeadingZeros());
}
}
Modified: llvm/trunk/lib/Transforms/Scalar/SimplifyLibCalls.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/SimplifyLibCalls.cpp?rev=146357&r1=146356&r2=146357&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/SimplifyLibCalls.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/SimplifyLibCalls.cpp Sun Dec 11 22:26:04 2011
@@ -999,7 +999,7 @@
Type *ArgType = Op->getType();
Value *F = Intrinsic::getDeclaration(Callee->getParent(),
Intrinsic::cttz, ArgType);
- Value *V = B.CreateCall(F, Op, "cttz");
+ Value *V = B.CreateCall2(F, Op, B.getFalse(), "cttz");
V = B.CreateAdd(V, ConstantInt::get(V->getType(), 1));
V = B.CreateIntCast(V, B.getInt32Ty(), false);
Modified: llvm/trunk/lib/VMCore/AutoUpgrade.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/VMCore/AutoUpgrade.cpp?rev=146357&r1=146356&r2=146357&view=diff
==============================================================================
--- llvm/trunk/lib/VMCore/AutoUpgrade.cpp (original)
+++ llvm/trunk/lib/VMCore/AutoUpgrade.cpp Sun Dec 11 22:26:04 2011
@@ -40,7 +40,20 @@
switch (Name[0]) {
default: break;
- // SOMEDAY: Add some.
+ case 'c': {
+ Type *Tys[] = { F->arg_begin()->getType() };
+ if (Name.startswith("ctlz.") && F->arg_size() == 1) {
+ F->setName(Name + ".old");
+ NewFn = Intrinsic::getDeclaration(F->getParent(), Intrinsic::ctlz, Tys);
+ return true;
+ }
+ if (Name.startswith("cttz.") && F->arg_size() == 1) {
+ F->setName(Name + ".old");
+ NewFn = Intrinsic::getDeclaration(F->getParent(), Intrinsic::cttz, Tys);
+ return true;
+ }
+ break;
+ }
}
// This may not belong here. This function is effectively being overloaded
@@ -72,15 +85,29 @@
// order to seamlessly integrate with existing context.
void llvm::UpgradeIntrinsicCall(CallInst *CI, Function *NewFn) {
Function *F = CI->getCalledFunction();
+ LLVMContext &C = CI->getContext();
assert(F && "CallInst has no function associated with it.");
- if (NewFn) return;
-
- if (F->getName() == "llvm.something eventually") {
- // UPGRADE HERE.
- } else {
+ if (!NewFn) return;
+
+ IRBuilder<> Builder(C);
+ Builder.SetInsertPoint(CI->getParent(), CI);
+
+ switch (NewFn->getIntrinsicID()) {
+ default:
llvm_unreachable("Unknown function for CallInst upgrade.");
+
+ case Intrinsic::ctlz:
+ case Intrinsic::cttz:
+ assert(CI->getNumArgOperands() == 1 &&
+ "Mismatch between function args and call args");
+ StringRef Name = CI->getName();
+ CI->setName(Name + ".old");
+ CI->replaceAllUsesWith(Builder.CreateCall2(NewFn, CI->getArgOperand(0),
+ Builder.getFalse(), Name));
+ CI->eraseFromParent();
+ return;
}
}
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