diff --git a/llvm/lib/CodeGen/AggressiveAntiDepBreaker.cpp b/llvm/lib/CodeGen/AggressiveAntiDepBreaker.cpp index 845408f15f5c..4060db74a9b7 100644 --- a/llvm/lib/CodeGen/AggressiveAntiDepBreaker.cpp +++ b/llvm/lib/CodeGen/AggressiveAntiDepBreaker.cpp @@ -364,9 +364,11 @@ void AggressiveAntiDepBreaker::PrescanInstruction(MachineInstr *MI, // If MI's defs have a special allocation requirement, don't allow // any def registers to be changed. Also assume all registers - // defined in a call must not be changed (ABI). + // defined in a call must not be changed (ABI). Inline assembly may + // reference either system calls or the register directly. Skip it until we + // can tell user specified registers from compiler-specified. if (MI->isCall() || MI->hasExtraDefRegAllocReq() || - TII->isPredicated(MI)) { + TII->isPredicated(MI) || MI->isInlineAsm()) { DEBUG(if (State->GetGroup(Reg) != 0) dbgs() << "->g0(alloc-req)"); State->UnionGroups(Reg, 0); } @@ -428,6 +430,7 @@ void AggressiveAntiDepBreaker::ScanInstruction(MachineInstr *MI, // If MI's uses have special allocation requirement, don't allow // any use registers to be changed. Also assume all registers // used in a call must not be changed (ABI). + // Inline Assembly register uses also cannot be safely changed. // FIXME: The issue with predicated instruction is more complex. We are being // conservatively here because the kill markers cannot be trusted after // if-conversion: @@ -443,7 +446,7 @@ void AggressiveAntiDepBreaker::ScanInstruction(MachineInstr *MI, // changed. bool Special = MI->isCall() || MI->hasExtraSrcRegAllocReq() || - TII->isPredicated(MI); + TII->isPredicated(MI) || MI->isInlineAsm(); // Scan the register uses for this instruction and update // live-ranges, groups and RegRefs. diff --git a/llvm/test/CodeGen/PowerPC/aantidep-inline-asm-use.ll b/llvm/test/CodeGen/PowerPC/aantidep-inline-asm-use.ll new file mode 100644 index 000000000000..4e7e97750448 --- /dev/null +++ b/llvm/test/CodeGen/PowerPC/aantidep-inline-asm-use.ll @@ -0,0 +1,308 @@ +; RUN: llc -O2 < %s | FileCheck %s +; ModuleID = 'bugpoint-reduced-simplified.bc' +target datalayout = "e-m:e-i64:64-n32:64" +target triple = "powerpc64le-grtev4-linux-gnu" + +; Function Attrs: nounwind +define void @_ZN10SubProcess19ScrubbedForkAndExecEiPiS0_PNS_7ResultsE() #0 align 2 { +; CHECK: lis 3, 1234 +; CHECK-NOT: li 3 +; CHECK-NOT: ori 3 +; CHECK-NOT: addi 3 +; CHECK-NOT: addis 3 +; CHECK-NOT: lis 3 +; CHECK: sc + br i1 undef, label %1, label %2 + +;