[llvm-commits] [llvm] r112962 - in /llvm/trunk: lib/Target/ARM/ARMBaseRegisterInfo.cpp lib/Target/ARM/ARMBaseRegisterInfo.h lib/Target/ARM/Thumb1RegisterInfo.cpp test/CodeGen/Thumb/dyn-stackalloc.ll test/CodeGen/Thumb2/2010-04-15-DynAllocBug.ll
Daniel Dunbar
daniel at zuster.org
Fri Sep 3 08:26:42 PDT 2010
Author: ddunbar
Date: Fri Sep 3 10:26:42 2010
New Revision: 112962
URL: http://llvm.org/viewvc/llvm-project?rev=112962&view=rev
Log:
Revert "For ARM stack frames that utilize variable sized objects and have either", it is breaking oggenc with Clang for ARMv6.
This reverts commit 8d6e29cfda270be483abf638850311670829ee65.
Modified:
llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.cpp
llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.h
llvm/trunk/lib/Target/ARM/Thumb1RegisterInfo.cpp
llvm/trunk/test/CodeGen/Thumb/dyn-stackalloc.ll
llvm/trunk/test/CodeGen/Thumb2/2010-04-15-DynAllocBug.ll
Modified: llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.cpp?rev=112962&r1=112961&r2=112962&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.cpp (original)
+++ llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.cpp Fri Sep 3 10:26:42 2010
@@ -50,10 +50,6 @@
using namespace llvm;
-static cl::opt<bool>
-EnableBasePointer("arm-use-base-pointer", cl::Hidden, cl::init(true),
- cl::desc("Enable use of a base pointer for complex stack frames"));
-
unsigned ARMBaseRegisterInfo::getRegisterNumbering(unsigned RegEnum,
bool *isSPVFP) {
if (isSPVFP)
@@ -150,8 +146,7 @@
const ARMSubtarget &sti)
: ARMGenRegisterInfo(ARM::ADJCALLSTACKDOWN, ARM::ADJCALLSTACKUP),
TII(tii), STI(sti),
- FramePtr((STI.isTargetDarwin() || STI.isThumb()) ? ARM::R7 : ARM::R11),
- BasePtr(ARM::R6) {
+ FramePtr((STI.isTargetDarwin() || STI.isThumb()) ? ARM::R7 : ARM::R11) {
}
const unsigned*
@@ -187,8 +182,6 @@
Reserved.set(ARM::FPSCR);
if (hasFP(MF))
Reserved.set(FramePtr);
- if (hasBasePointer(MF))
- Reserved.set(BasePtr);
// Some targets reserve R9.
if (STI.isR9Reserved())
Reserved.set(ARM::R9);
@@ -202,10 +195,6 @@
case ARM::SP:
case ARM::PC:
return true;
- case ARM::R6:
- if (hasBasePointer(MF))
- return true;
- break;
case ARM::R7:
case ARM::R11:
if (FramePtr == Reg && hasFP(MF))
@@ -636,49 +625,35 @@
MFI->isFrameAddressTaken());
}
-bool ARMBaseRegisterInfo::hasBasePointer(const MachineFunction &MF) const {
- const MachineFrameInfo *MFI = MF.getFrameInfo();
- const ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
-
- if (!EnableBasePointer)
- return false;
-
- if (needsStackRealignment(MF) && MFI->hasVarSizedObjects())
- return true;
-
- // Thumb has trouble with negative offsets from the FP. Thumb2 has a limited
- // negative range for ldr/str (255), and thumb1 is positive offsets only.
- // It's going to be better to use the SP or Base Pointer instead. When there
- // are variable sized objects, we can't reference off of the SP, so we
- // reserve a Base Pointer.
- if (AFI->isThumbFunction() && MFI->hasVarSizedObjects()) {
- // Conservatively estimate whether the negative offset from the frame
- // pointer will be sufficient to reach. If a function has a smallish
- // frame, it's less likely to have lots of spills and callee saved
- // space, so it's all more likely to be within range of the frame pointer.
- // If it's wrong, the scavenger will still enable access to work, it just
- // won't be optimal.
- if (AFI->isThumb2Function() && MFI->getLocalFrameSize() < 128)
- return false;
- return true;
- }
-
- return false;
-}
-
bool ARMBaseRegisterInfo::canRealignStack(const MachineFunction &MF) const {
+ const MachineFrameInfo *MFI = MF.getFrameInfo();
const ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- return (RealignStack && !AFI->isThumb1OnlyFunction());
+ return (RealignStack &&
+ !AFI->isThumb1OnlyFunction() &&
+ !MFI->hasVarSizedObjects());
}
bool ARMBaseRegisterInfo::
needsStackRealignment(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
const Function *F = MF.getFunction();
+ const ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
unsigned StackAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
bool requiresRealignment = ((MFI->getMaxAlignment() > StackAlign) ||
F->hasFnAttr(Attribute::StackAlignment));
+ // FIXME: Currently we don't support stack realignment for functions with
+ // variable-sized allocas.
+ // FIXME: It's more complicated than this...
+ if (0 && requiresRealignment && MFI->hasVarSizedObjects())
+ report_fatal_error(
+ "Stack realignment in presense of dynamic allocas is not supported");
+
+ // FIXME: This probably isn't the right place for this.
+ if (0 && requiresRealignment && AFI->isThumb1OnlyFunction())
+ report_fatal_error(
+ "Stack realignment in thumb1 functions is not supported");
+
return requiresRealignment && canRealignStack(MF);
}
@@ -801,10 +776,6 @@
if (AFI->isThumb1OnlyFunction() && AFI->getVarArgsRegSaveSize() > 0)
MF.getRegInfo().setPhysRegUsed(ARM::LR);
- // Spill the BasePtr if it's used.
- if (hasBasePointer(MF))
- MF.getRegInfo().setPhysRegUsed(BasePtr);
-
// Don't spill FP if the frame can be eliminated. This is determined
// by scanning the callee-save registers to see if any is used.
const unsigned *CSRegs = getCalleeSavedRegs();
@@ -1051,14 +1022,13 @@
return Offset - AFI->getDPRCalleeSavedAreaOffset();
// When dynamically realigning the stack, use the frame pointer for
- // parameters, and the stack/base pointer for locals.
+ // parameters, and the stack pointer for locals.
if (needsStackRealignment(MF)) {
assert (hasFP(MF) && "dynamic stack realignment without a FP!");
if (isFixed) {
FrameReg = getFrameRegister(MF);
Offset = FPOffset;
- } else if (MFI->hasVarSizedObjects())
- FrameReg = BasePtr;
+ }
return Offset;
}
@@ -1066,13 +1036,9 @@
if (hasFP(MF) && AFI->hasStackFrame()) {
// Use frame pointer to reference fixed objects. Use it for locals if
// there are VLAs (and thus the SP isn't reliable as a base).
- if (isFixed || (MFI->hasVarSizedObjects() && !hasBasePointer(MF))) {
+ if (isFixed || MFI->hasVarSizedObjects()) {
FrameReg = getFrameRegister(MF);
Offset = FPOffset;
- } else if (MFI->hasVarSizedObjects()) {
- assert(hasBasePointer(MF) && "missing base pointer!");
- // Use the base register since we have it.
- FrameReg = BasePtr;
} else if (AFI->isThumb2Function()) {
// In Thumb2 mode, the negative offset is very limited. Try to avoid
// out of range references.
@@ -1086,9 +1052,6 @@
Offset = FPOffset;
}
}
- // Use the base pointer if we have one.
- if (hasBasePointer(MF))
- FrameReg = BasePtr;
return Offset;
}
@@ -1126,8 +1089,7 @@
case ARM::R5:
return ARM::R4;
case ARM::R7:
- return (isReservedReg(MF, ARM::R7) || isReservedReg(MF, ARM::R6))
- ? 0 : ARM::R6;
+ return isReservedReg(MF, ARM::R7) ? 0 : ARM::R6;
case ARM::R9:
return isReservedReg(MF, ARM::R9) ? 0 :ARM::R8;
case ARM::R11:
@@ -1216,8 +1178,7 @@
case ARM::R4:
return ARM::R5;
case ARM::R6:
- return (isReservedReg(MF, ARM::R7) || isReservedReg(MF, ARM::R6))
- ? 0 : ARM::R7;
+ return isReservedReg(MF, ARM::R7) ? 0 : ARM::R7;
case ARM::R8:
return isReservedReg(MF, ARM::R9) ? 0 :ARM::R9;
case ARM::R10:
@@ -1917,20 +1878,6 @@
AFI->setShouldRestoreSPFromFP(true);
}
- // If we need a base pointer, set it up here. It's whatever the value
- // of the stack pointer is at this point. Any variable size objects
- // will be allocated after this, so we can still use the base pointer
- // to reference locals.
- if (hasBasePointer(MF)) {
- if (isARM)
- BuildMI(MBB, MBBI, dl, TII.get(ARM::MOVr), BasePtr)
- .addReg(ARM::SP)
- .addImm((unsigned)ARMCC::AL).addReg(0).addReg(0);
- else
- BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVgpr2gpr), BasePtr)
- .addReg(ARM::SP);
- }
-
// If the frame has variable sized objects then the epilogue must restore
// the sp from fp.
if (!AFI->shouldRestoreSPFromFP() && MFI->hasVarSizedObjects())
Modified: llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.h?rev=112962&r1=112961&r2=112962&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.h (original)
+++ llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.h Fri Sep 3 10:26:42 2010
@@ -52,11 +52,6 @@
/// FramePtr - ARM physical register used as frame ptr.
unsigned FramePtr;
- /// BasePtr - ARM physical register used as a base ptr in complex stack
- /// frames. I.e., when we need a 3rd base, not just SP and FP, due to
- /// variable size stack objects.
- unsigned BasePtr;
-
// Can be only subclassed.
explicit ARMBaseRegisterInfo(const ARMBaseInstrInfo &tii,
const ARMSubtarget &STI);
@@ -107,7 +102,6 @@
MachineFunction &MF) const;
bool hasFP(const MachineFunction &MF) const;
- bool hasBasePointer(const MachineFunction &MF) const;
bool canRealignStack(const MachineFunction &MF) const;
bool needsStackRealignment(const MachineFunction &MF) const;
Modified: llvm/trunk/lib/Target/ARM/Thumb1RegisterInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/Thumb1RegisterInfo.cpp?rev=112962&r1=112961&r2=112962&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/Thumb1RegisterInfo.cpp (original)
+++ llvm/trunk/lib/Target/ARM/Thumb1RegisterInfo.cpp Fri Sep 3 10:26:42 2010
@@ -604,12 +604,9 @@
else if (MF.getFrameInfo()->hasVarSizedObjects()) {
assert(SPAdj == 0 && hasFP(MF) && "Unexpected");
// There are alloca()'s in this function, must reference off the frame
- // pointer or base pointer instead.
- if (!hasBasePointer(MF)) {
- FrameReg = getFrameRegister(MF);
- Offset -= AFI->getFramePtrSpillOffset();
- } else
- FrameReg = BasePtr;
+ // pointer instead.
+ FrameReg = getFrameRegister(MF);
+ Offset -= AFI->getFramePtrSpillOffset();
}
// Special handling of dbg_value instructions.
@@ -790,13 +787,6 @@
AFI->setGPRCalleeSavedArea1Size(GPRCS1Size);
AFI->setGPRCalleeSavedArea2Size(GPRCS2Size);
AFI->setDPRCalleeSavedAreaSize(DPRCSSize);
-
- // If we need a base pointer, set it up here. It's whatever the value
- // of the stack pointer is at this point. Any variable size objects
- // will be allocated after this, so we can still use the base pointer
- // to reference locals.
- if (hasBasePointer(MF))
- BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVgpr2gpr), BasePtr).addReg(ARM::SP);
}
static bool isCalleeSavedRegister(unsigned Reg, const unsigned *CSRegs) {
Modified: llvm/trunk/test/CodeGen/Thumb/dyn-stackalloc.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/Thumb/dyn-stackalloc.ll?rev=112962&r1=112961&r2=112962&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/Thumb/dyn-stackalloc.ll (original)
+++ llvm/trunk/test/CodeGen/Thumb/dyn-stackalloc.ll Fri Sep 3 10:26:42 2010
@@ -1,7 +1,7 @@
; RUN: llc < %s -march=thumb | not grep {ldr sp}
; RUN: llc < %s -mtriple=thumb-apple-darwin | \
; RUN: not grep {sub.*r7}
-; RUN: llc < %s -march=thumb | grep {mov.*r6, sp}
+; RUN: llc < %s -march=thumb | grep 4294967280
%struct.state = type { i32, %struct.info*, float**, i32, i32, i32, i32, i32, i32, i32, i32, i32, i64, i64, i64, i64, i64, i64, i8* }
%struct.info = type { i32, i32, i32, i32, i32, i32, i32, i8* }
Modified: llvm/trunk/test/CodeGen/Thumb2/2010-04-15-DynAllocBug.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/Thumb2/2010-04-15-DynAllocBug.ll?rev=112962&r1=112961&r2=112962&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/Thumb2/2010-04-15-DynAllocBug.ll (original)
+++ llvm/trunk/test/CodeGen/Thumb2/2010-04-15-DynAllocBug.ll Fri Sep 3 10:26:42 2010
@@ -7,12 +7,19 @@
define void @t() nounwind ssp {
entry:
; CHECK: t:
- %size = mul i32 8, 2
+; CHECK: push {r4, r7}
+; CHECK: mov r0, sp
+; CHECK: add r7, sp, #4
+; CHECK: bic r0, r0, #7
; CHECK: subs r0, #16
; CHECK: mov sp, r0
- %vla_a = alloca i8, i32 %size, align 8
+; CHECK: mov r0, sp
+; CHECK: bic r0, r0, #7
; CHECK: subs r0, #16
; CHECK: mov sp, r0
+
+ %size = mul i32 8, 2
+ %vla_a = alloca i8, i32 %size, align 8
%vla_b = alloca i8, i32 %size, align 8
unreachable
}
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