Implement -disable-non-leaf-fp-elim which disable frame pointer elimination
optimization for non-leaf functions. This will be hooked up to gcc's
-momit-leaf-frame-pointer option. rdar://7886181
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101984 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/Target/TargetOptions.h b/include/llvm/Target/TargetOptions.h
index a01a67f..fb5698f 100644
--- a/include/llvm/Target/TargetOptions.h
+++ b/include/llvm/Target/TargetOptions.h
@@ -16,6 +16,8 @@
#define LLVM_TARGET_TARGETOPTIONS_H
namespace llvm {
+ class MachineFunction;
+
// Possible float ABI settings. Used with FloatABIType in TargetOptions.h.
namespace FloatABI {
enum ABIType {
@@ -35,6 +37,16 @@
/// elimination optimization, this option should disable it.
extern bool NoFramePointerElim;
+ /// NoFramePointerElimNonLeaf - This flag is enabled when the
+ /// -disable-non-leaf-fp-elim is specified on the command line. If the target
+ /// supports the frame pointer elimination optimization, this option should
+ /// disable it for non-leaf functions.
+ extern bool NoFramePointerElimNonLeaf;
+
+ /// DisableFramePointerElim - This returns true if frame pointer elimination
+ /// optimization should be disabled for the given machine function.
+ extern bool DisableFramePointerElim(const MachineFunction &MF);
+
/// LessPreciseFPMAD - This flag is enabled when the
/// -enable-fp-mad is specified on the command line. When this flag is off
/// (the default), the code generator is not allowed to generate mad
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 684a409..c31aec1 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -1251,7 +1251,7 @@
// DW_TAG_inlined_subroutine may refer to this DIE.
ModuleCU->insertDIE(SP.getNode(), SPDie);
- if (NoFramePointerElim == false)
+ if (!DisableFramePointerElim(*Asm->MF))
addUInt(SPDie, dwarf::DW_AT_APPLE_omit_frame_ptr, dwarf::DW_FORM_flag, 1);
return SPDie;
diff --git a/lib/Target/ARM/ARMBaseRegisterInfo.cpp b/lib/Target/ARM/ARMBaseRegisterInfo.cpp
index 46c50f9..2a4e1a8 100644
--- a/lib/Target/ARM/ARMBaseRegisterInfo.cpp
+++ b/lib/Target/ARM/ARMBaseRegisterInfo.cpp
@@ -481,7 +481,7 @@
///
bool ARMBaseRegisterInfo::hasFP(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
- return ((NoFramePointerElim && MFI->hasCalls())||
+ return ((DisableFramePointerElim(MF) && MFI->hasCalls())||
needsStackRealignment(MF) ||
MFI->hasVarSizedObjects() ||
MFI->isFrameAddressTaken());
@@ -509,7 +509,7 @@
bool ARMBaseRegisterInfo::
cannotEliminateFrame(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
- if (NoFramePointerElim && MFI->hasCalls())
+ if (DisableFramePointerElim(MF) && MFI->hasCalls())
return true;
return MFI->hasVarSizedObjects() || MFI->isFrameAddressTaken()
|| needsStackRealignment(MF);
diff --git a/lib/Target/Blackfin/BlackfinRegisterInfo.cpp b/lib/Target/Blackfin/BlackfinRegisterInfo.cpp
index 6fd610f..2512c9b 100644
--- a/lib/Target/Blackfin/BlackfinRegisterInfo.cpp
+++ b/lib/Target/Blackfin/BlackfinRegisterInfo.cpp
@@ -110,7 +110,8 @@
// if frame pointer elimination is disabled.
bool BlackfinRegisterInfo::hasFP(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
- return NoFramePointerElim || MFI->hasCalls() || MFI->hasVarSizedObjects();
+ return DisableFramePointerElim(MF) ||
+ MFI->hasCalls() || MFI->hasVarSizedObjects();
}
bool BlackfinRegisterInfo::
diff --git a/lib/Target/CellSPU/SPURegisterInfo.cpp b/lib/Target/CellSPU/SPURegisterInfo.cpp
index 9a9c9f7..fdbe10f 100644
--- a/lib/Target/CellSPU/SPURegisterInfo.cpp
+++ b/lib/Target/CellSPU/SPURegisterInfo.cpp
@@ -303,7 +303,7 @@
//
static bool needsFP(const MachineFunction &MF) {
const MachineFrameInfo *MFI = MF.getFrameInfo();
- return NoFramePointerElim || MFI->hasVarSizedObjects();
+ return DisableFramePointerElim(MF) || MFI->hasVarSizedObjects();
}
//--------------------------------------------------------------------------
diff --git a/lib/Target/MBlaze/MBlazeRegisterInfo.cpp b/lib/Target/MBlaze/MBlazeRegisterInfo.cpp
index a12310a..e15176e 100644
--- a/lib/Target/MBlaze/MBlazeRegisterInfo.cpp
+++ b/lib/Target/MBlaze/MBlazeRegisterInfo.cpp
@@ -243,7 +243,7 @@
// if frame pointer elimination is disabled.
bool MBlazeRegisterInfo::hasFP(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
- return NoFramePointerElim || MFI->hasVarSizedObjects();
+ return DisableFramePointerElim(MF) || MFI->hasVarSizedObjects();
}
// This function eliminate ADJCALLSTACKDOWN,
diff --git a/lib/Target/MSP430/MSP430RegisterInfo.cpp b/lib/Target/MSP430/MSP430RegisterInfo.cpp
index d91783a..0cae267 100644
--- a/lib/Target/MSP430/MSP430RegisterInfo.cpp
+++ b/lib/Target/MSP430/MSP430RegisterInfo.cpp
@@ -138,7 +138,7 @@
bool MSP430RegisterInfo::hasFP(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
- return (NoFramePointerElim ||
+ return (DisableFramePointerElim(MF) ||
MF.getFrameInfo()->hasVarSizedObjects() ||
MFI->isFrameAddressTaken());
}
diff --git a/lib/Target/Mips/MipsRegisterInfo.cpp b/lib/Target/Mips/MipsRegisterInfo.cpp
index f43e69b..478da84 100644
--- a/lib/Target/Mips/MipsRegisterInfo.cpp
+++ b/lib/Target/Mips/MipsRegisterInfo.cpp
@@ -338,7 +338,7 @@
bool MipsRegisterInfo::
hasFP(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
- return NoFramePointerElim || MFI->hasVarSizedObjects();
+ return DisableFramePointerElim(MF) || MFI->hasVarSizedObjects();
}
// This function eliminate ADJCALLSTACKDOWN,
diff --git a/lib/Target/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp
index 894436c..b825d64 100644
--- a/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -5531,7 +5531,7 @@
MachineFunction &MF = DAG.getMachineFunction();
MachineFrameInfo *MFI = MF.getFrameInfo();
- bool is31 = (NoFramePointerElim || MFI->hasVarSizedObjects())
+ bool is31 = (DisableFramePointerElim(MF) || MFI->hasVarSizedObjects())
&& MFI->getStackSize();
if (isPPC64)
diff --git a/lib/Target/PowerPC/PPCRegisterInfo.cpp b/lib/Target/PowerPC/PPCRegisterInfo.cpp
index 889acde..8048df2 100644
--- a/lib/Target/PowerPC/PPCRegisterInfo.cpp
+++ b/lib/Target/PowerPC/PPCRegisterInfo.cpp
@@ -409,7 +409,7 @@
//
static bool needsFP(const MachineFunction &MF) {
const MachineFrameInfo *MFI = MF.getFrameInfo();
- return NoFramePointerElim || MFI->hasVarSizedObjects() ||
+ return DisableFramePointerElim(MF) || MFI->hasVarSizedObjects() ||
(GuaranteedTailCallOpt && MF.getInfo<PPCFunctionInfo>()->hasFastCall());
}
diff --git a/lib/Target/SystemZ/SystemZRegisterInfo.cpp b/lib/Target/SystemZ/SystemZRegisterInfo.cpp
index 5e325c0..638fd17 100644
--- a/lib/Target/SystemZ/SystemZRegisterInfo.cpp
+++ b/lib/Target/SystemZ/SystemZRegisterInfo.cpp
@@ -77,7 +77,7 @@
/// allocas or if frame pointer elimination is disabled.
bool SystemZRegisterInfo::hasFP(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
- return NoFramePointerElim || MFI->hasVarSizedObjects();
+ return DisableFramePointerElim(MF) || MFI->hasVarSizedObjects();
}
void SystemZRegisterInfo::
diff --git a/lib/Target/TargetMachine.cpp b/lib/Target/TargetMachine.cpp
index 871b148..d90755a 100644
--- a/lib/Target/TargetMachine.cpp
+++ b/lib/Target/TargetMachine.cpp
@@ -11,6 +11,8 @@
//
//===----------------------------------------------------------------------===//
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
@@ -25,6 +27,7 @@
bool LessPreciseFPMADOption;
bool PrintMachineCode;
bool NoFramePointerElim;
+ bool NoFramePointerElimNonLeaf;
bool NoExcessFPPrecision;
bool UnsafeFPMath;
bool FiniteOnlyFPMathOption;
@@ -58,6 +61,11 @@
cl::location(NoFramePointerElim),
cl::init(false));
static cl::opt<bool, true>
+DisableFPElimNonLeaf("disable-non-leaf-fp-elim",
+ cl::desc("Disable frame pointer elimination optimization for non-leaf funcs"),
+ cl::location(NoFramePointerElimNonLeaf),
+ cl::init(false));
+static cl::opt<bool, true>
DisableExcessPrecision("disable-excess-fp-precision",
cl::desc("Disable optimizations that may increase FP precision"),
cl::location(NoExcessFPPrecision),
@@ -268,6 +276,18 @@
}
namespace llvm {
+ /// DisableFramePointerElim - This returns true if frame pointer elimination
+ /// optimization should be disabled for the given machine function.
+ bool DisableFramePointerElim(const MachineFunction &MF) {
+ if (NoFramePointerElim)
+ return true;
+ if (NoFramePointerElimNonLeaf) {
+ const MachineFrameInfo *MFI = MF.getFrameInfo();
+ return MFI->hasCalls();
+ }
+ return false;
+ }
+
/// LessPreciseFPMAD - This flag return true when -enable-fp-mad option
/// is specified on the command line. When this flag is off(default), the
/// code generator is not allowed to generate mad (multiply add) if the
diff --git a/lib/Target/X86/X86RegisterInfo.cpp b/lib/Target/X86/X86RegisterInfo.cpp
index abb9aca..6bf9be5 100644
--- a/lib/Target/X86/X86RegisterInfo.cpp
+++ b/lib/Target/X86/X86RegisterInfo.cpp
@@ -439,7 +439,7 @@
const MachineFrameInfo *MFI = MF.getFrameInfo();
const MachineModuleInfo &MMI = MF.getMMI();
- return (NoFramePointerElim ||
+ return (DisableFramePointerElim(MF) ||
needsStackRealignment(MF) ||
MFI->hasVarSizedObjects() ||
MFI->isFrameAddressTaken() ||
diff --git a/lib/Target/XCore/XCoreRegisterInfo.cpp b/lib/Target/XCore/XCoreRegisterInfo.cpp
index 0db867f..0cfb358 100644
--- a/lib/Target/XCore/XCoreRegisterInfo.cpp
+++ b/lib/Target/XCore/XCoreRegisterInfo.cpp
@@ -113,7 +113,7 @@
}
bool XCoreRegisterInfo::hasFP(const MachineFunction &MF) const {
- return NoFramePointerElim || MF.getFrameInfo()->hasVarSizedObjects();
+ return DisableFramePointerElim(MF) || MF.getFrameInfo()->hasVarSizedObjects();
}
// This function eliminates ADJCALLSTACKDOWN,
diff --git a/test/CodeGen/X86/fp-elim.ll b/test/CodeGen/X86/fp-elim.ll
new file mode 100644
index 0000000..60892a2
--- /dev/null
+++ b/test/CodeGen/X86/fp-elim.ll
@@ -0,0 +1,44 @@
+; RUN: llc < %s -march=x86 -asm-verbose=false | FileCheck %s -check-prefix=FP-ELIM
+; RUN: llc < %s -march=x86 -asm-verbose=false -disable-fp-elim | FileCheck %s -check-prefix=NO-ELIM
+; RUN: llc < %s -march=x86 -asm-verbose=false -disable-non-leaf-fp-elim | FileCheck %s -check-prefix=NON-LEAF
+
+; Implement -momit-leaf-frame-pointer
+; rdar://7886181
+
+define i32 @t1() nounwind readnone {
+entry:
+; FP-ELIM: t1:
+; FP-ELIM-NEXT: movl
+; FP-ELIM-NEXT: ret
+
+; NO-ELIM: t1:
+; NO-ELIM-NEXT: pushl %ebp
+; NO-ELIM: popl %ebp
+; NO-ELIM-NEXT: ret
+
+; NON-LEAF: t1:
+; NON-LEAF-NEXT: movl
+; NON-LEAF-NEXT: ret
+ ret i32 10
+}
+
+define void @t2() nounwind {
+entry:
+; FP-ELIM: t2:
+; FP-ELIM-NOT: pushl %ebp
+; FP-ELIM: ret
+
+; NO-ELIM: t2:
+; NO-ELIM-NEXT: pushl %ebp
+; NO-ELIM: popl %ebp
+; NO-ELIM-NEXT: ret
+
+; NON-LEAF: t2:
+; NON-LEAF-NEXT: pushl %ebp
+; NON-LEAF: popl %ebp
+; NON-LEAF-NEXT: ret
+ tail call void @foo(i32 0) nounwind
+ ret void
+}
+
+declare void @foo(i32)