From 3769fe149bb47dfdaa8ac39b7a4c26cf98ec503e Mon Sep 17 00:00:00 2001 From: Nuno Lopes Date: Mon, 25 Jun 2012 17:11:47 +0000 Subject: [PATCH] improve optimization of invoke instructions: - simplifycfg: invoke undef/null -> unreachable - instcombine: invoke new -> invoke expect(0, 0) (an arbitrary NOOP intrinsic; only done if the allocated memory is unused, of course) - verifier: allow invoke of intrinsics (to make the previous step work) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159146 91177308-0d34-0410-b5e6-96231b3b80d8 --- .../InstCombine/InstructionCombining.cpp | 9 +++- lib/Transforms/Scalar/SimplifyCFGPass.cpp | 9 +++- lib/VMCore/Verifier.cpp | 3 +- test/Transforms/InstCombine/objsize-64.ll | 2 +- test/Transforms/SimplifyCFG/invoke.ll | 45 +++++++++++++++++++ 5 files changed, 63 insertions(+), 5 deletions(-) create mode 100644 test/Transforms/SimplifyCFG/invoke.ll diff --git a/lib/Transforms/InstCombine/InstructionCombining.cpp b/lib/Transforms/InstCombine/InstructionCombining.cpp index 269ea1516ff..07793ac6b5f 100644 --- a/lib/Transforms/InstCombine/InstructionCombining.cpp +++ b/lib/Transforms/InstCombine/InstructionCombining.cpp @@ -1169,7 +1169,14 @@ Instruction *InstCombiner::visitMalloc(Instruction &MI) { } if (InvokeInst *II = dyn_cast(&MI)) { - BranchInst::Create(II->getNormalDest(), II->getParent()); + // Replace invoke with a NOOP intrinsic to maintain the original CFG + Module *M = II->getParent()->getParent()->getParent(); + IntegerType *Ty = IntegerType::get(II->getContext(), 8); + ConstantInt *CI = ConstantInt::get(Ty, 0); + Value *Args[] = {CI, CI}; + Function *F = Intrinsic::getDeclaration(M, Intrinsic::expect, Ty); + InvokeInst::Create(F, II->getNormalDest(), II->getUnwindDest(), Args, + "dummy", II->getParent()); } return EraseInstFromFunction(MI); } diff --git a/lib/Transforms/Scalar/SimplifyCFGPass.cpp b/lib/Transforms/Scalar/SimplifyCFGPass.cpp index a66b3e38258..594369780ac 100644 --- a/lib/Transforms/Scalar/SimplifyCFGPass.cpp +++ b/lib/Transforms/Scalar/SimplifyCFGPass.cpp @@ -157,11 +157,16 @@ static bool MarkAliveBlocks(BasicBlock *BB, } // Turn invokes that call 'nounwind' functions into ordinary calls. - if (InvokeInst *II = dyn_cast(BB->getTerminator())) - if (II->doesNotThrow()) { + if (InvokeInst *II = dyn_cast(BB->getTerminator())) { + Value *Callee = II->getCalledValue(); + if (isa(Callee) || isa(Callee)) { + ChangeToUnreachable(II, true); + Changed = true; + } else if (II->doesNotThrow()) { ChangeToCall(II); Changed = true; } + } Changed |= ConstantFoldTerminator(BB, true); for (succ_iterator SI = succ_begin(BB), SE = succ_end(BB); SI != SE; ++SI) diff --git a/lib/VMCore/Verifier.cpp b/lib/VMCore/Verifier.cpp index 477b81dc67f..9a9b0b7e0b3 100644 --- a/lib/VMCore/Verifier.cpp +++ b/lib/VMCore/Verifier.cpp @@ -1636,7 +1636,8 @@ void Verifier::visitInstruction(Instruction &I) { if (Function *F = dyn_cast(I.getOperand(i))) { // Check to make sure that the "address of" an intrinsic function is never // taken. - Assert1(!F->isIntrinsic() || (i + 1 == e && isa(I)), + CallSite CS(&I); + Assert1(!F->isIntrinsic() || (CS && i == (CS.isCall() ? e-1 : 2)), "Cannot take the address of an intrinsic!", &I); Assert1(F->getParent() == Mod, "Referencing function in another module!", &I); diff --git a/test/Transforms/InstCombine/objsize-64.ll b/test/Transforms/InstCombine/objsize-64.ll index 77b43ecd235..7a39f461948 100644 --- a/test/Transforms/InstCombine/objsize-64.ll +++ b/test/Transforms/InstCombine/objsize-64.ll @@ -19,7 +19,7 @@ define i64 @f1() { ; CHECK: @f2 define i64 @f2() nounwind uwtable ssp { entry: -; CHECK: br label +; CHECK: invoke i8 @llvm.expect.i8(i8 0, i8 0) %call = invoke noalias i8* @_Znwm(i64 13) to label %invoke.cont unwind label %lpad diff --git a/test/Transforms/SimplifyCFG/invoke.ll b/test/Transforms/SimplifyCFG/invoke.ll new file mode 100644 index 00000000000..c9169d41fff --- /dev/null +++ b/test/Transforms/SimplifyCFG/invoke.ll @@ -0,0 +1,45 @@ +; RUN: opt < %s -simplifycfg -S | FileCheck %s +target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128" + +declare i32 @__gxx_personality_v0(...) +declare void @__cxa_call_unexpected(i8*) +declare i64 @llvm.objectsize.i64(i8*, i1) nounwind readonly + + +; CHECK: @f1 +define i8* @f1() nounwind uwtable ssp { +entry: +; CHECK: call void @llvm.trap() +; CHECK: unreachable + %call = invoke noalias i8* undef() + to label %invoke.cont unwind label %lpad + +invoke.cont: + ret i8* %call + +lpad: + %0 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) + filter [0 x i8*] zeroinitializer + %1 = extractvalue { i8*, i32 } %0, 0 + tail call void @__cxa_call_unexpected(i8* %1) noreturn nounwind + unreachable +} + +; CHECK: @f2 +define i8* @f2() nounwind uwtable ssp { +entry: +; CHECK: call void @llvm.trap() +; CHECK: unreachable + %call = invoke noalias i8* null() + to label %invoke.cont unwind label %lpad + +invoke.cont: + ret i8* %call + +lpad: + %0 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) + filter [0 x i8*] zeroinitializer + %1 = extractvalue { i8*, i32 } %0, 0 + tail call void @__cxa_call_unexpected(i8* %1) noreturn nounwind + unreachable +}