diff options
| -rw-r--r-- | lib/Transforms/Scalar/TailRecursionElimination.cpp | 9 | ||||
| -rw-r--r-- | lib/Transforms/Utils/InlineFunction.cpp | 9 | ||||
| -rw-r--r-- | test/Transforms/Inline/byval-tail-call.ll (renamed from test/Transforms/Inline/2010-05-31-ByvalTailcall.ll) | 21 | ||||
| -rw-r--r-- | test/Transforms/TailCallElim/basic.ll | 8 |
4 files changed, 35 insertions, 12 deletions
diff --git a/lib/Transforms/Scalar/TailRecursionElimination.cpp b/lib/Transforms/Scalar/TailRecursionElimination.cpp index 6d02777d09..2f77f9c404 100644 --- a/lib/Transforms/Scalar/TailRecursionElimination.cpp +++ b/lib/Transforms/Scalar/TailRecursionElimination.cpp @@ -204,6 +204,15 @@ bool TailCallElim::runOnFunction(Function &F) { } } + // If any byval or inalloca args are captured, exit. They are also allocated + // in our stack frame. + for (Argument &Arg : F.args()) { + if (Arg.hasByValOrInAllocaAttr()) + PointerMayBeCaptured(&Arg, &ACT); + if (ACT.Captured) + return false; + } + // Second pass, change any tail recursive calls to loops. // // FIXME: The code generator produces really bad code when an 'escaping diff --git a/lib/Transforms/Utils/InlineFunction.cpp b/lib/Transforms/Utils/InlineFunction.cpp index 5692d91c86..73d40f70b3 100644 --- a/lib/Transforms/Utils/InlineFunction.cpp +++ b/lib/Transforms/Utils/InlineFunction.cpp @@ -586,15 +586,8 @@ bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI, if (CS.isByValArgument(ArgNo)) { ActualArg = HandleByValArgument(ActualArg, TheCall, CalledFunc, IFI, CalledFunc->getParamAlignment(ArgNo+1)); - - // Calls that we inline may use the new alloca, so we need to clear - // their 'tail' flags if HandleByValArgument introduced a new alloca and - // the callee has calls. - if (ActualArg != *AI) { - MustClearTailCallFlags = true; + if (ActualArg != *AI) ByValInit.push_back(std::make_pair(ActualArg, (Value*) *AI)); - } - } VMap[I] = ActualArg; diff --git a/test/Transforms/Inline/2010-05-31-ByvalTailcall.ll b/test/Transforms/Inline/byval-tail-call.ll index 07ea5fc6cc..3a8906aa21 100644 --- a/test/Transforms/Inline/2010-05-31-ByvalTailcall.ll +++ b/test/Transforms/Inline/byval-tail-call.ll @@ -1,10 +1,8 @@ ; RUN: opt < %s -tailcallelim -inline -instcombine -dse -S | FileCheck %s ; PR7272 -; When inlining through a byval call site, the inliner creates allocas which may -; be used by inlined calls, so any inlined calls need to have their 'tail' flags -; cleared. If not then you can get nastiness like with this testcase, where the -; (inlined) call to 'ext' in 'foo' was being passed an uninitialized value. +; Calls that capture byval parameters cannot be marked as tail calls. Other +; tails that don't capture byval parameters can still be tail calls. target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32-n8:16:32" target triple = "i386-pc-linux-gnu" @@ -23,3 +21,18 @@ define void @foo(i32* %x) { call void @bar(i32* byval %x) ret void } + +define internal void @qux(i32* byval %x) { + call void @ext(i32* %x) + tail call void @ext(i32* null) + ret void +} +define void @frob(i32* %x) { +; CHECK-LABEL: define void @frob( +; CHECK: alloca i32 +; CHECK: {{^ *}}call void @ext( +; CHECK: tail call void @ext(i32* null) +; CHECK: ret void + tail call void @qux(i32* byval %x) + ret void +} diff --git a/test/Transforms/TailCallElim/basic.ll b/test/Transforms/TailCallElim/basic.ll index 35420ab08c..5582ee33ed 100644 --- a/test/Transforms/TailCallElim/basic.ll +++ b/test/Transforms/TailCallElim/basic.ll @@ -143,3 +143,11 @@ cond_false: call void @noarg() ret i32* null } + +; Don't tail call if a byval arg is captured. +define void @test9(i32* byval %a) { +; CHECK-LABEL: define void @test9( +; CHECK: {{^ *}}call void @use( + call void @use(i32* %a) + ret void +} |