From 8148ae8847f849e2e1f7d9278b67e7fc9cae6eac Mon Sep 17 00:00:00 2001 From: Evan Cheng Date: Wed, 3 Feb 2010 21:40:40 +0000 Subject: [PATCH] Speculatively disable x86 automatic tail call optimization while we track down a self-hosting issue. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95259 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/X86/X86ISelLowering.cpp | 3 +++ test/CodeGen/X86/tailcall2.ll | 1 + 2 files changed, 4 insertions(+) diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp index 9d6b5a39b2a..2b5ff3ca1a9 100644 --- a/lib/Target/X86/X86ISelLowering.cpp +++ b/lib/Target/X86/X86ISelLowering.cpp @@ -52,6 +52,7 @@ using namespace llvm; STATISTIC(NumTailCalls, "Number of tail calls"); +static cl::opt TailCallLimit("tailcall-limit", cl::init(0)); static cl::opt DisableMMX("disable-mmx", cl::Hidden, cl::desc("Disable use of MMX")); @@ -2271,6 +2272,8 @@ X86TargetLowering::IsEligibleForTailCallOptimization(SDValue Callee, // Look for obvious safe cases to perform tail call optimization that does not // requite ABI changes. This is what gcc calls sibcall. + if (NumTailCalls >= TailCallLimit) + return false; // Do not tail call optimize vararg calls for now. if (isVarArg) diff --git a/test/CodeGen/X86/tailcall2.ll b/test/CodeGen/X86/tailcall2.ll index 3cd8b26f608..b35fc4b5a58 100644 --- a/test/CodeGen/X86/tailcall2.ll +++ b/test/CodeGen/X86/tailcall2.ll @@ -1,5 +1,6 @@ ; RUN: llc < %s -march=x86 -asm-verbose=false | FileCheck %s -check-prefix=32 ; RUN: llc < %s -march=x86-64 -asm-verbose=false | FileCheck %s -check-prefix=64 +; XFAIL: * define void @t1(i32 %x) nounwind ssp { entry: