[llvm] r351523 - [AVR] Expand 8/16-bit multiplication to libcalls on MCUs that don't have hardware MUL
Dylan McKay via llvm-commits
llvm-commits at lists.llvm.org
Thu Jan 17 22:10:41 PST 2019
Author: dylanmckay
Date: Thu Jan 17 22:10:41 2019
New Revision: 351523
URL: http://llvm.org/viewvc/llvm-project?rev=351523&view=rev
Log:
[AVR] Expand 8/16-bit multiplication to libcalls on MCUs that don't have hardware MUL
This change modifies the LLVM ISel lowering settings so that
8-bit/16-bit multiplication is expanded to calls into the compiler
runtime library if the MCU being targeted does not support
multiplication in hardware.
Before this, MUL instructions would be generated on CPUs like the
ATtiny85, triggering a CPU reset due to an illegal instruction at
runtime.
First raised in https://github.com/avr-rust/rust/issues/124.
Added:
llvm/trunk/test/CodeGen/AVR/hardware-mul.ll
- copied, changed from r351297, llvm/trunk/test/CodeGen/AVR/mul.ll
llvm/trunk/test/CodeGen/AVR/software-mul.ll
Removed:
llvm/trunk/test/CodeGen/AVR/mul.ll
Modified:
llvm/trunk/lib/Target/AVR/AVRISelLowering.cpp
llvm/trunk/lib/Target/AVR/AVRISelLowering.h
llvm/trunk/lib/Target/AVR/AVRSubtarget.cpp
llvm/trunk/lib/Target/AVR/AVRSubtarget.h
llvm/trunk/test/CodeGen/AVR/smul-with-overflow.ll
llvm/trunk/test/CodeGen/AVR/umul-with-overflow.ll
Modified: llvm/trunk/lib/Target/AVR/AVRISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AVR/AVRISelLowering.cpp?rev=351523&r1=351522&r2=351523&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AVR/AVRISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/AVR/AVRISelLowering.cpp Thu Jan 17 22:10:41 2019
@@ -26,19 +26,21 @@
#include "AVR.h"
#include "AVRMachineFunctionInfo.h"
+#include "AVRSubtarget.h"
#include "AVRTargetMachine.h"
#include "MCTargetDesc/AVRMCTargetDesc.h"
namespace llvm {
-AVRTargetLowering::AVRTargetLowering(AVRTargetMachine &tm)
- : TargetLowering(tm) {
+AVRTargetLowering::AVRTargetLowering(const AVRTargetMachine &TM,
+ const AVRSubtarget &STI)
+ : TargetLowering(TM), Subtarget(STI) {
// Set up the register classes.
addRegisterClass(MVT::i8, &AVR::GPR8RegClass);
addRegisterClass(MVT::i16, &AVR::DREGSRegClass);
// Compute derived properties from the register classes.
- computeRegisterProperties(tm.getSubtargetImpl()->getRegisterInfo());
+ computeRegisterProperties(Subtarget.getRegisterInfo());
setBooleanContents(ZeroOrOneBooleanContent);
setBooleanVectorContents(ZeroOrOneBooleanContent);
@@ -163,6 +165,13 @@ AVRTargetLowering::AVRTargetLowering(AVR
setOperationAction(ISD::SMUL_LOHI, MVT::i16, Expand);
setOperationAction(ISD::UMUL_LOHI, MVT::i16, Expand);
+ // Expand multiplications to libcalls when there is
+ // no hardware MUL.
+ if (!Subtarget.supportsMultiplication()) {
+ setOperationAction(ISD::SMUL_LOHI, MVT::i8, Expand);
+ setOperationAction(ISD::UMUL_LOHI, MVT::i8, Expand);
+ }
+
for (MVT VT : MVT::integer_valuetypes()) {
setOperationAction(ISD::MULHS, VT, Expand);
setOperationAction(ISD::MULHU, VT, Expand);
@@ -1271,7 +1280,7 @@ SDValue AVRTargetLowering::LowerCall(Tar
// Add a register mask operand representing the call-preserved registers.
const AVRTargetMachine &TM = (const AVRTargetMachine &)getTargetMachine();
- const TargetRegisterInfo *TRI = TM.getSubtargetImpl()->getRegisterInfo();
+ const TargetRegisterInfo *TRI = Subtarget.getRegisterInfo();
const uint32_t *Mask =
TRI->getCallPreservedMask(DAG.getMachineFunction(), CallConv);
assert(Mask && "Missing call preserved mask for calling convention");
@@ -1434,7 +1443,7 @@ MachineBasicBlock *AVRTargetLowering::in
MachineFunction *F = BB->getParent();
MachineRegisterInfo &RI = F->getRegInfo();
const AVRTargetMachine &TM = (const AVRTargetMachine &)getTargetMachine();
- const TargetInstrInfo &TII = *TM.getSubtargetImpl()->getInstrInfo();
+ const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
DebugLoc dl = MI.getDebugLoc();
switch (MI.getOpcode()) {
@@ -1575,7 +1584,7 @@ static bool isCopyMulResult(MachineBasic
MachineBasicBlock *AVRTargetLowering::insertMul(MachineInstr &MI,
MachineBasicBlock *BB) const {
const AVRTargetMachine &TM = (const AVRTargetMachine &)getTargetMachine();
- const TargetInstrInfo &TII = *TM.getSubtargetImpl()->getInstrInfo();
+ const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
MachineBasicBlock::iterator I(MI);
++I; // in any case insert *after* the mul instruction
if (isCopyMulResult(I))
@@ -1838,9 +1847,6 @@ std::pair<unsigned, const TargetRegister
AVRTargetLowering::getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
StringRef Constraint,
MVT VT) const {
- auto STI = static_cast<const AVRTargetMachine &>(this->getTargetMachine())
- .getSubtargetImpl();
-
// We only support i8 and i16.
//
//:FIXME: remove this assert for now since it gets sometimes executed
@@ -1884,8 +1890,8 @@ AVRTargetLowering::getRegForInlineAsmCon
}
}
- return TargetLowering::getRegForInlineAsmConstraint(STI->getRegisterInfo(),
- Constraint, VT);
+ return TargetLowering::getRegForInlineAsmConstraint(
+ Subtarget.getRegisterInfo(), Constraint, VT);
}
void AVRTargetLowering::LowerAsmOperandForConstraint(SDValue Op,
Modified: llvm/trunk/lib/Target/AVR/AVRISelLowering.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AVR/AVRISelLowering.h?rev=351523&r1=351522&r2=351523&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AVR/AVRISelLowering.h (original)
+++ llvm/trunk/lib/Target/AVR/AVRISelLowering.h Thu Jan 17 22:10:41 2019
@@ -64,12 +64,14 @@ enum NodeType {
} // end of namespace AVRISD
+class AVRSubtarget;
class AVRTargetMachine;
/// Performs target lowering for the AVR.
class AVRTargetLowering : public TargetLowering {
public:
- explicit AVRTargetLowering(AVRTargetMachine &TM);
+ explicit AVRTargetLowering(const AVRTargetMachine &TM,
+ const AVRSubtarget &STI);
public:
MVT getScalarShiftAmountTy(const DataLayout &, EVT LHSTy) const override {
@@ -164,6 +166,10 @@ private:
const SDLoc &dl, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals) const;
+protected:
+
+ const AVRSubtarget &Subtarget;
+
private:
MachineBasicBlock *insertShift(MachineInstr &MI, MachineBasicBlock *BB) const;
MachineBasicBlock *insertMul(MachineInstr &MI, MachineBasicBlock *BB) const;
Modified: llvm/trunk/lib/Target/AVR/AVRSubtarget.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AVR/AVRSubtarget.cpp?rev=351523&r1=351522&r2=351523&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AVR/AVRSubtarget.cpp (original)
+++ llvm/trunk/lib/Target/AVR/AVRSubtarget.cpp Thu Jan 17 22:10:41 2019
@@ -29,9 +29,9 @@
namespace llvm {
AVRSubtarget::AVRSubtarget(const Triple &TT, const std::string &CPU,
- const std::string &FS, AVRTargetMachine &TM)
+ const std::string &FS, const AVRTargetMachine &TM)
: AVRGenSubtargetInfo(TT, CPU, FS), InstrInfo(), FrameLowering(),
- TLInfo(TM), TSInfo(),
+ TLInfo(TM, initializeSubtargetDependencies(CPU, FS, TM)), TSInfo(),
// Subtarget features
m_hasSRAM(false), m_hasJMPCALL(false), m_hasIJMPCALL(false),
@@ -44,4 +44,12 @@ AVRSubtarget::AVRSubtarget(const Triple
ParseSubtargetFeatures(CPU, FS);
}
+AVRSubtarget &
+AVRSubtarget::initializeSubtargetDependencies(StringRef CPU, StringRef FS,
+ const TargetMachine &TM) {
+ // Parse features string.
+ ParseSubtargetFeatures(CPU, FS);
+ return *this;
+}
+
} // end of namespace llvm
Modified: llvm/trunk/lib/Target/AVR/AVRSubtarget.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AVR/AVRSubtarget.h?rev=351523&r1=351522&r2=351523&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AVR/AVRSubtarget.h (original)
+++ llvm/trunk/lib/Target/AVR/AVRSubtarget.h Thu Jan 17 22:10:41 2019
@@ -37,7 +37,7 @@ public:
//! \param FS The feature string.
//! \param TM The target machine.
AVRSubtarget(const Triple &TT, const std::string &CPU, const std::string &FS,
- AVRTargetMachine &TM);
+ const AVRTargetMachine &TM);
const AVRInstrInfo *getInstrInfo() const override { return &InstrInfo; }
const TargetFrameLowering *getFrameLowering() const override { return &FrameLowering; }
@@ -49,6 +49,9 @@ public:
/// \note Definition of function is auto generated by `tblgen`.
void ParseSubtargetFeatures(StringRef CPU, StringRef FS);
+ AVRSubtarget &initializeSubtargetDependencies(StringRef CPU, StringRef FS,
+ const TargetMachine &TM);
+
// Subtarget feature getters.
// See AVR.td for details.
bool hasSRAM() const { return m_hasSRAM; }
Copied: llvm/trunk/test/CodeGen/AVR/hardware-mul.ll (from r351297, llvm/trunk/test/CodeGen/AVR/mul.ll)
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AVR/hardware-mul.ll?p2=llvm/trunk/test/CodeGen/AVR/hardware-mul.ll&p1=llvm/trunk/test/CodeGen/AVR/mul.ll&r1=351297&r2=351523&rev=351523&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AVR/mul.ll (original)
+++ llvm/trunk/test/CodeGen/AVR/hardware-mul.ll Thu Jan 17 22:10:41 2019
@@ -1,5 +1,7 @@
; RUN: llc -mattr=mul,movw < %s -march=avr | FileCheck %s
+; Tests lowering of multiplication to hardware instructions.
+
define i8 @mult8(i8 %a, i8 %b) {
; CHECK-LABEL: mult8:
; CHECK: muls r22, r24
Removed: llvm/trunk/test/CodeGen/AVR/mul.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AVR/mul.ll?rev=351522&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/AVR/mul.ll (original)
+++ llvm/trunk/test/CodeGen/AVR/mul.ll (removed)
@@ -1,28 +0,0 @@
-; RUN: llc -mattr=mul,movw < %s -march=avr | FileCheck %s
-
-define i8 @mult8(i8 %a, i8 %b) {
-; CHECK-LABEL: mult8:
-; CHECK: muls r22, r24
-; CHECK: clr r1
-; CHECK: mov r24, r0
- %mul = mul i8 %b, %a
- ret i8 %mul
-}
-
-define i16 @mult16(i16 %a, i16 %b) {
-; CHECK-LABEL: mult16:
-; CHECK: muls r22, r25
-; CHECK: mov r18, r0
-; CHECK: mul r22, r24
-; CHECK: mov r19, r0
-; CHECK: mov r20, r1
-; CHECK: clr r1
-; CHECK: add r20, r18
-; CHECK: muls r23, r24
-; CHECK: clr r1
-; CHECK: mov r22, r0
-; CHECK: add r22, r20
-; :TODO: finish after reworking shift instructions
- %mul = mul nsw i16 %b, %a
- ret i16 %mul
-}
Modified: llvm/trunk/test/CodeGen/AVR/smul-with-overflow.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AVR/smul-with-overflow.ll?rev=351523&r1=351522&r2=351523&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AVR/smul-with-overflow.ll (original)
+++ llvm/trunk/test/CodeGen/AVR/smul-with-overflow.ll Thu Jan 17 22:10:41 2019
@@ -1,4 +1,4 @@
-; RUN: llc < %s -march=avr | FileCheck %s
+; RUN: llc -mattr=avr6 < %s -march=avr | FileCheck %s
define i1 @signed_multiplication_did_overflow(i8, i8) unnamed_addr {
; CHECK-LABEL: signed_multiplication_did_overflow:
Added: llvm/trunk/test/CodeGen/AVR/software-mul.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AVR/software-mul.ll?rev=351523&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/AVR/software-mul.ll (added)
+++ llvm/trunk/test/CodeGen/AVR/software-mul.ll Thu Jan 17 22:10:41 2019
@@ -0,0 +1,28 @@
+; RUN: llc -mattr=avr6,-mul < %s -march=avr | FileCheck %s
+; RUN: llc -mcpu=attiny85 < %s -march=avr | FileCheck %s
+; RUN: llc -mcpu=ata5272 < %s -march=avr | FileCheck %s
+; RUN: llc -mcpu=attiny861a < %s -march=avr | FileCheck %s
+; RUN: llc -mcpu=at90usb82 < %s -march=avr | FileCheck %s
+
+; Tests lowering of multiplication to compiler support routines.
+
+; CHECK-LABEL: mul8:
+define i8 @mul8(i8 %a, i8 %b) {
+; CHECK: mov r25, r24
+; CHECK: mov r24, r22
+; CHECK: mov r22, r25
+; CHECK: call __mulqi3
+ %mul = mul i8 %b, %a
+ ret i8 %mul
+}
+
+; CHECK-LABEL: mul16:
+define i16 @mul16(i16 %a, i16 %b) {
+; CHECK: movw r18, r24
+; CHECK: movw r24, r22
+; CHECK: movw r22, r18
+; CHECK: call __mulhi3
+ %mul = mul nsw i16 %b, %a
+ ret i16 %mul
+}
+
Modified: llvm/trunk/test/CodeGen/AVR/umul-with-overflow.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AVR/umul-with-overflow.ll?rev=351523&r1=351522&r2=351523&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AVR/umul-with-overflow.ll (original)
+++ llvm/trunk/test/CodeGen/AVR/umul-with-overflow.ll Thu Jan 17 22:10:41 2019
@@ -1,4 +1,4 @@
-; RUN: llc < %s -march=avr | FileCheck %s
+; RUN: llc -mattr=avr6 < %s -march=avr | FileCheck %s
define i1 @unsigned_multiplication_did_overflow(i8, i8) unnamed_addr {
; CHECK-LABEL: unsigned_multiplication_did_overflow:
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