From fa946233b4e1ad857ecc4b14cec1f31c40eb94fa Mon Sep 17 00:00:00 2001 From: JF Bastien Date: Thu, 10 Sep 2015 18:08:35 +0000 Subject: [PATCH] [MergeFuncs] Fix callsite attributes in thunk generation This change correctly sets the attributes on the callsites generated in thunks. This makes sure things such as sret, sext, etc. are correctly set, so that the call can be a proper tailcall. Also, the transfer of attributes in the replaceDirectCallers function appears to be unnecessary, but until this is confirmed it will remain. Author: jrkoenig Reviewers: dschuff, jfb Subscribers: llvm-commits, nlewycky Differential revision: http://reviews.llvm.org/D12581 llvm-svn: 247313 --- llvm/lib/Transforms/IPO/MergeFunctions.cpp | 10 +++++++++- llvm/test/Transforms/MergeFunc/apply_function_attributes.ll | 7 +++++++ llvm/test/Transforms/MergeFunc/inttoptr-address-space.ll | 2 +- llvm/test/Transforms/MergeFunc/inttoptr.ll | 2 +- 4 files changed, 18 insertions(+), 3 deletions(-) diff --git a/llvm/lib/Transforms/IPO/MergeFunctions.cpp b/llvm/lib/Transforms/IPO/MergeFunctions.cpp index fa6c4ea..a8a85982 100644 --- a/llvm/lib/Transforms/IPO/MergeFunctions.cpp +++ b/llvm/lib/Transforms/IPO/MergeFunctions.cpp @@ -1559,9 +1559,16 @@ void MergeFunctions::replaceDirectCallers(Function *Old, Function *New) { CallSite CS(U->getUser()); if (CS && CS.isCallee(U)) { // Transfer the called function's attributes to the call site. Due to the - // bitcast we will 'loose' ABI changing attributes because the 'called + // bitcast we will 'lose' ABI changing attributes because the 'called // function' is no longer a Function* but the bitcast. Code that looks up // the attributes from the called function will fail. + + // FIXME: This is not actually true, at least not anymore. The callsite + // will always have the same ABI affecting attributes as the callee, + // because otherwise the original input has UB. Note that Old and New + // always have matching ABI, so no attributes need to be changed. + // Transferring other attributes may help other optimizations, but that + // should be done uniformly and not in this ad-hoc way. auto &Context = New->getContext(); auto NewFuncAttrs = New->getAttributes(); auto CallSiteAttrs = CS.getAttributes(); @@ -1656,6 +1663,7 @@ void MergeFunctions::writeThunk(Function *F, Function *G) { CallInst *CI = Builder.CreateCall(F, Args); CI->setTailCall(); CI->setCallingConv(F->getCallingConv()); + CI->setAttributes(F->getAttributes()); if (NewG->getReturnType()->isVoidTy()) { Builder.CreateRetVoid(); } else { diff --git a/llvm/test/Transforms/MergeFunc/apply_function_attributes.ll b/llvm/test/Transforms/MergeFunc/apply_function_attributes.ll index fa7f052..e9ede45 100644 --- a/llvm/test/Transforms/MergeFunc/apply_function_attributes.ll +++ b/llvm/test/Transforms/MergeFunc/apply_function_attributes.ll @@ -38,3 +38,10 @@ define void @A(%Opaque_type* sret %a, %D2i* %b, i32* %xp, i32* %yp) { ; CHECK: tail call void bitcast (void (%Opaque_type*, %D2i*, i32*, i32*)* @A to void (%Opaque_type*, %S2i*, i32*, i32*)*)(%Opaque_type* sret %0, %S2i* %1, i32* %2, i32* %3) ; CHECK: ret void + +; Make sure we transfer the parameter attributes to the call site. +; CHECK-LABEL: define void @B(%Opaque_type* sret +; CHECK: %5 = bitcast +; CHECK: tail call void @A(%Opaque_type* sret %0, %D2i* %5, i32* %2, i32* %3) +; CHECK: ret void + diff --git a/llvm/test/Transforms/MergeFunc/inttoptr-address-space.ll b/llvm/test/Transforms/MergeFunc/inttoptr-address-space.ll index 5f672de..86deb2c 100644 --- a/llvm/test/Transforms/MergeFunc/inttoptr-address-space.ll +++ b/llvm/test/Transforms/MergeFunc/inttoptr-address-space.ll @@ -21,7 +21,7 @@ define internal i8* @func35(%.qux.2585 addrspace(1)* nocapture %this) align 2 { bb: ; CHECK-LABEL: @func35( ; CHECK: %[[V2:.+]] = bitcast %.qux.2585 addrspace(1)* %{{.*}} to %.qux.2496 addrspace(1)* -; CHECK: %[[V3:.+]] = tail call i32 @func10(%.qux.2496 addrspace(1)* %[[V2]]) +; CHECK: %[[V3:.+]] = tail call i32 @func10(%.qux.2496 addrspace(1)* nocapture %[[V2]]) ; CHECK: %{{.*}} = inttoptr i32 %[[V3]] to i8* %tmp = getelementptr inbounds %.qux.2585, %.qux.2585 addrspace(1)* %this, i32 0, i32 2 %tmp1 = load i8*, i8* addrspace(1)* %tmp, align 4 diff --git a/llvm/test/Transforms/MergeFunc/inttoptr.ll b/llvm/test/Transforms/MergeFunc/inttoptr.ll index 0abbf62..05ae766 100644 --- a/llvm/test/Transforms/MergeFunc/inttoptr.ll +++ b/llvm/test/Transforms/MergeFunc/inttoptr.ll @@ -48,7 +48,7 @@ define internal i8* @func35(%.qux.2585* nocapture %this) align 2 { bb: ; CHECK-LABEL: @func35( ; CHECK: %[[V2:.+]] = bitcast %.qux.2585* %{{.*}} to %.qux.2496* -; CHECK: %[[V3:.+]] = tail call i32 @func10(%.qux.2496* %[[V2]]) +; CHECK: %[[V3:.+]] = tail call i32 @func10(%.qux.2496* nocapture %[[V2]]) ; CHECK: %{{.*}} = inttoptr i32 %[[V3]] to i8* %tmp = getelementptr inbounds %.qux.2585, %.qux.2585* %this, i32 0, i32 2 %tmp1 = load i8*, i8** %tmp, align 4 -- 2.7.4