diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp index 1a634744806..937d51023bd 100644 --- a/lib/Target/X86/X86ISelLowering.cpp +++ b/lib/Target/X86/X86ISelLowering.cpp @@ -2458,17 +2458,23 @@ X86TargetLowering::IsEligibleForTailCallOptimization(SDValue Callee, // If the tailcall address may be in a register, then make sure it's // possible to register allocate for it. In 32-bit, the call address can // only target EAX, EDX, or ECX since the tail call must be scheduled after - // callee-saved registers are restored. In 64-bit, it's RAX, RCX, RDX, RSI, - // RDI, R8, R9, R11. - if (!isa(Callee) && + // callee-saved registers are restored. These happen to be the same + // registers used to pass 'inreg' arguments so watch out for those. + if (!Subtarget->is64Bit() && + !isa(Callee) && !isa(Callee)) { - unsigned Limit = Subtarget->is64Bit() ? 8 : 3; unsigned NumInRegs = 0; for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) { CCValAssign &VA = ArgLocs[i]; - if (VA.isRegLoc()) { - if (++NumInRegs == Limit) + if (!VA.isRegLoc()) + continue; + unsigned Reg = VA.getLocReg(); + switch (Reg) { + default: break; + case X86::EAX: case X86::EDX: case X86::ECX: + if (++NumInRegs == 3) return false; + break; } } } diff --git a/test/CodeGen/X86/sibcall-4.ll b/test/CodeGen/X86/sibcall-4.ll new file mode 100644 index 00000000000..1499e668802 --- /dev/null +++ b/test/CodeGen/X86/sibcall-4.ll @@ -0,0 +1,13 @@ +; RUN: llc < %s -mtriple=i386-pc-linux-gnu | FileCheck %s +; pr7610 + +define cc10 void @t(i32* %Base_Arg, i32* %Sp_Arg, i32* %Hp_Arg, i32 %R1_Arg) nounwind { +cm1: +; CHECK: t: +; CHECK: jmpl *%eax + %nm3 = getelementptr i32* %Sp_Arg, i32 1 + %nm9 = load i32* %Sp_Arg + %nma = inttoptr i32 %nm9 to void (i32*, i32*, i32*, i32)* + tail call cc10 void %nma(i32* %Base_Arg, i32* %nm3, i32* %Hp_Arg, i32 %R1_Arg) nounwind + ret void +}