[llvm] 339b342 - [AVR] Respect the 'interrupt' function attribute
Dylan McKay via llvm-commits
llvm-commits at lists.llvm.org
Mon Mar 30 23:04:01 PDT 2020
Author: Dylan McKay
Date: 2020-03-31T19:00:18+13:00
New Revision: 339b34266c1b54a9b5ff2f83cfb1da9cd8c9d90a
URL: https://github.com/llvm/llvm-project/commit/339b34266c1b54a9b5ff2f83cfb1da9cd8c9d90a
DIFF: https://github.com/llvm/llvm-project/commit/339b34266c1b54a9b5ff2f83cfb1da9cd8c9d90a.diff
LOG: [AVR] Respect the 'interrupt' function attribute
In the past, AVR functions were only lowered with interrupt-specific
machine code if the function was defined with the "avr-interrupt" or
"avr-signal" calling conventions.
This patch modifies the backend so that if the function does not have a
special calling convention, but does have an "interrupt" attribute,
that function is interpreted as a function with interrupts.
This also extracts the "is this function an interrupt" logic from
several disparate places in the backend into one AVRMachineFunctionInfo
attribute.
Bug found by Wilhelm Meier.
Added:
Modified:
llvm/lib/Target/AVR/AVRFrameLowering.cpp
llvm/lib/Target/AVR/AVRISelLowering.cpp
llvm/lib/Target/AVR/AVRMachineFunctionInfo.h
llvm/lib/Target/AVR/AVRRegisterInfo.cpp
llvm/test/CodeGen/AVR/interrupts.ll
Removed:
################################################################################
diff --git a/llvm/lib/Target/AVR/AVRFrameLowering.cpp b/llvm/lib/Target/AVR/AVRFrameLowering.cpp
index 119bd21248bf..f327f9b68a81 100644
--- a/llvm/lib/Target/AVR/AVRFrameLowering.cpp
+++ b/llvm/lib/Target/AVR/AVRFrameLowering.cpp
@@ -56,10 +56,11 @@ void AVRFrameLowering::emitPrologue(MachineFunction &MF,
DebugLoc DL = (MBBI != MBB.end()) ? MBBI->getDebugLoc() : DebugLoc();
const AVRSubtarget &STI = MF.getSubtarget<AVRSubtarget>();
const AVRInstrInfo &TII = *STI.getInstrInfo();
+ const AVRMachineFunctionInfo *AFI = MF.getInfo<AVRMachineFunctionInfo>();
bool HasFP = hasFP(MF);
// Interrupt handlers re-enable interrupts in function entry.
- if (CallConv == CallingConv::AVR_INTR) {
+ if (AFI->isInterruptHandler() && CallConv != CallingConv::AVR_SIGNAL) {
BuildMI(MBB, MBBI, DL, TII.get(AVR::BSETs))
.addImm(0x07)
.setMIFlag(MachineInstr::FrameSetup);
@@ -74,8 +75,7 @@ void AVRFrameLowering::emitPrologue(MachineFunction &MF,
// Emit special prologue code to save R1, R0 and SREG in interrupt/signal
// handlers before saving any other registers.
- if (CallConv == CallingConv::AVR_INTR ||
- CallConv == CallingConv::AVR_SIGNAL) {
+ if (AFI->isInterruptHandler()) {
BuildMI(MBB, MBBI, DL, TII.get(AVR::PUSHWRr))
.addReg(AVR::R1R0, RegState::Kill)
.setMIFlag(MachineInstr::FrameSetup);
@@ -99,7 +99,6 @@ void AVRFrameLowering::emitPrologue(MachineFunction &MF,
}
const MachineFrameInfo &MFI = MF.getFrameInfo();
- const AVRMachineFunctionInfo *AFI = MF.getInfo<AVRMachineFunctionInfo>();
unsigned FrameSize = MFI.getStackSize() - AFI->getCalleeSavedFrameSize();
// Skip the callee-saved push instructions.
@@ -142,13 +141,11 @@ void AVRFrameLowering::emitPrologue(MachineFunction &MF,
void AVRFrameLowering::emitEpilogue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
- CallingConv::ID CallConv = MF.getFunction().getCallingConv();
- bool isHandler = (CallConv == CallingConv::AVR_INTR ||
- CallConv == CallingConv::AVR_SIGNAL);
+ const AVRMachineFunctionInfo *AFI = MF.getInfo<AVRMachineFunctionInfo>();
// Early exit if the frame pointer is not needed in this function except for
// signal/interrupt handlers where special code generation is required.
- if (!hasFP(MF) && !isHandler) {
+ if (!hasFP(MF) && !AFI->isInterruptHandler()) {
return;
}
@@ -158,14 +155,13 @@ void AVRFrameLowering::emitEpilogue(MachineFunction &MF,
DebugLoc DL = MBBI->getDebugLoc();
const MachineFrameInfo &MFI = MF.getFrameInfo();
- const AVRMachineFunctionInfo *AFI = MF.getInfo<AVRMachineFunctionInfo>();
unsigned FrameSize = MFI.getStackSize() - AFI->getCalleeSavedFrameSize();
const AVRSubtarget &STI = MF.getSubtarget<AVRSubtarget>();
const AVRInstrInfo &TII = *STI.getInstrInfo();
// Emit special epilogue code to restore R1, R0 and SREG in interrupt/signal
// handlers at the very end of the function, just before reti.
- if (isHandler) {
+ if (AFI->isInterruptHandler()) {
BuildMI(MBB, MBBI, DL, TII.get(AVR::POPRd), AVR::R0);
BuildMI(MBB, MBBI, DL, TII.get(AVR::OUTARr))
.addImm(0x3f)
diff --git a/llvm/lib/Target/AVR/AVRISelLowering.cpp b/llvm/lib/Target/AVR/AVRISelLowering.cpp
index 1c77b68a9012..159a3ca19200 100644
--- a/llvm/lib/Target/AVR/AVRISelLowering.cpp
+++ b/llvm/lib/Target/AVR/AVRISelLowering.cpp
@@ -1429,10 +1429,12 @@ AVRTargetLowering::LowerReturn(SDValue Chain, CallingConv::ID CallConv,
return Chain;
}
+ const AVRMachineFunctionInfo *AFI = MF.getInfo<AVRMachineFunctionInfo>();
+
unsigned RetOpc =
- (CallConv == CallingConv::AVR_INTR || CallConv == CallingConv::AVR_SIGNAL)
- ? AVRISD::RETI_FLAG
- : AVRISD::RET_FLAG;
+ AFI->isInterruptHandler()
+ ? AVRISD::RETI_FLAG
+ : AVRISD::RET_FLAG;
RetOps[0] = Chain; // Update chain.
diff --git a/llvm/lib/Target/AVR/AVRMachineFunctionInfo.h b/llvm/lib/Target/AVR/AVRMachineFunctionInfo.h
index 5226e30491c3..5fa6bb513348 100644
--- a/llvm/lib/Target/AVR/AVRMachineFunctionInfo.h
+++ b/llvm/lib/Target/AVR/AVRMachineFunctionInfo.h
@@ -31,6 +31,9 @@ class AVRMachineFunctionInfo : public MachineFunctionInfo {
/// used inside the function.
bool HasStackArgs;
+ /// Whether or not the function is an interrupt handler.
+ bool IsInterruptHandler;
+
/// Size of the callee-saved register portion of the
/// stack frame in bytes.
unsigned CalleeSavedFrameSize;
@@ -41,11 +44,19 @@ class AVRMachineFunctionInfo : public MachineFunctionInfo {
public:
AVRMachineFunctionInfo()
: HasSpills(false), HasAllocas(false), HasStackArgs(false),
- CalleeSavedFrameSize(0), VarArgsFrameIndex(0) {}
+ IsInterruptHandler(false), CalleeSavedFrameSize(0),
+ VarArgsFrameIndex(0) {}
explicit AVRMachineFunctionInfo(MachineFunction &MF)
: HasSpills(false), HasAllocas(false), HasStackArgs(false),
- CalleeSavedFrameSize(0), VarArgsFrameIndex(0) {}
+ CalleeSavedFrameSize(0), VarArgsFrameIndex(0) {
+ unsigned CallConv = MF.getFunction().getCallingConv();
+
+ this->IsInterruptHandler =
+ CallConv == CallingConv::AVR_INTR ||
+ CallConv == CallingConv::AVR_SIGNAL ||
+ MF.getFunction().hasFnAttribute("interrupt");
+ }
bool getHasSpills() const { return HasSpills; }
void setHasSpills(bool B) { HasSpills = B; }
@@ -56,6 +67,8 @@ class AVRMachineFunctionInfo : public MachineFunctionInfo {
bool getHasStackArgs() const { return HasStackArgs; }
void setHasStackArgs(bool B) { HasStackArgs = B; }
+ bool isInterruptHandler() const { return IsInterruptHandler; }
+
unsigned getCalleeSavedFrameSize() const { return CalleeSavedFrameSize; }
void setCalleeSavedFrameSize(unsigned Bytes) { CalleeSavedFrameSize = Bytes; }
diff --git a/llvm/lib/Target/AVR/AVRRegisterInfo.cpp b/llvm/lib/Target/AVR/AVRRegisterInfo.cpp
index 601510da56e8..6caa460eb6d3 100644
--- a/llvm/lib/Target/AVR/AVRRegisterInfo.cpp
+++ b/llvm/lib/Target/AVR/AVRRegisterInfo.cpp
@@ -22,6 +22,7 @@
#include "AVR.h"
#include "AVRInstrInfo.h"
+#include "AVRMachineFunctionInfo.h"
#include "AVRTargetMachine.h"
#include "MCTargetDesc/AVRMCTargetDesc.h"
@@ -34,19 +35,21 @@ AVRRegisterInfo::AVRRegisterInfo() : AVRGenRegisterInfo(0) {}
const uint16_t *
AVRRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
- CallingConv::ID CC = MF->getFunction().getCallingConv();
+ const AVRMachineFunctionInfo *AFI = MF->getInfo<AVRMachineFunctionInfo>();
- return ((CC == CallingConv::AVR_INTR || CC == CallingConv::AVR_SIGNAL)
+ return AFI->isInterruptHandler()
? CSR_Interrupts_SaveList
- : CSR_Normal_SaveList);
+ : CSR_Normal_SaveList;
}
const uint32_t *
AVRRegisterInfo::getCallPreservedMask(const MachineFunction &MF,
CallingConv::ID CC) const {
- return ((CC == CallingConv::AVR_INTR || CC == CallingConv::AVR_SIGNAL)
+ const AVRMachineFunctionInfo *AFI = MF.getInfo<AVRMachineFunctionInfo>();
+
+ return AFI->isInterruptHandler()
? CSR_Interrupts_RegMask
- : CSR_Normal_RegMask);
+ : CSR_Normal_RegMask;
}
BitVector AVRRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
diff --git a/llvm/test/CodeGen/AVR/interrupts.ll b/llvm/test/CodeGen/AVR/interrupts.ll
index 5dddf0ea7018..da8a5ce46f46 100644
--- a/llvm/test/CodeGen/AVR/interrupts.ll
+++ b/llvm/test/CodeGen/AVR/interrupts.ll
@@ -16,6 +16,22 @@ define avr_intrcc void @interrupt_handler() {
ret void
}
+define void @interrupt_handler_via_ir_attribute() #0 {
+; CHECK-LABEL: interrupt_handler_via_ir_attribute:
+; CHECK: sei
+; CHECK-NEXT: push r0
+; CHECK-NEXT: push r1
+; CHECK-NEXT: in r0, 63
+; CHECK-NEXT: push r0
+; CHECK: clr r0
+; CHECK: pop r0
+; CHECK-NEXT: out 63, r0
+; CHECK-NEXT: pop r1
+; CHECK-NEXT: pop r0
+; CHECK-NEXT: reti
+ ret void
+}
+
define avr_signalcc void @signal_handler() {
; CHECK-LABEL: signal_handler:
; CHECK-NOT: sei
@@ -31,3 +47,6 @@ define avr_signalcc void @signal_handler() {
; CHECK-NEXT: reti
ret void
}
+
+attributes #0 = { "interrupt" }
+attributes #1 = { "signal" }
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