Reimplement (part of) the or -> add optimization. Matching 'or' into 'add'
is general goodness because it allows ORs to be converted to LEA to avoid
inserting copies. However, this is bad because it makes the generated .s
file less obvious and gives valgrind heartburn (tons of false positives in
bitfield code).
While the general fix should be in valgrind, we can at least try to avoid
emitting ADD instructions that *don't* get promoted to LEA. This is more
work because it requires introducing pseudo instructions to represents
"add that knows the bits are disjoint", but hey, people really love valgrind.
This fixes this testcase:
https://bugs.kde.org/show_bug.cgi?id=242137#c20
the add r/i cases are coming next.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116007 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86InstrInfo.cpp b/lib/Target/X86/X86InstrInfo.cpp
index 67b5ab0..a231850 100644
--- a/lib/Target/X86/X86InstrInfo.cpp
+++ b/lib/Target/X86/X86InstrInfo.cpp
@@ -55,6 +55,11 @@
X86InstrInfo::X86InstrInfo(X86TargetMachine &tm)
: TargetInstrInfoImpl(X86Insts, array_lengthof(X86Insts)),
TM(tm), RI(tm, *this) {
+ enum {
+ TB_NOT_REVERSABLE = 1U << 31,
+ TB_FLAGS = TB_NOT_REVERSABLE
+ };
+
static const unsigned OpTbl2Addr[][2] = {
{ X86::ADC32ri, X86::ADC32mi },
{ X86::ADC32ri8, X86::ADC32mi8 },
@@ -65,12 +70,15 @@
{ X86::ADD16ri, X86::ADD16mi },
{ X86::ADD16ri8, X86::ADD16mi8 },
{ X86::ADD16rr, X86::ADD16mr },
+ { X86::ADD16rr_DB, X86::ADD16mr | TB_NOT_REVERSABLE },
{ X86::ADD32ri, X86::ADD32mi },
{ X86::ADD32ri8, X86::ADD32mi8 },
{ X86::ADD32rr, X86::ADD32mr },
+ { X86::ADD32rr_DB, X86::ADD32mr | TB_NOT_REVERSABLE },
{ X86::ADD64ri32, X86::ADD64mi32 },
{ X86::ADD64ri8, X86::ADD64mi8 },
{ X86::ADD64rr, X86::ADD64mr },
+ { X86::ADD64rr_DB, X86::ADD64mr | TB_NOT_REVERSABLE },
{ X86::ADD8ri, X86::ADD8mi },
{ X86::ADD8rr, X86::ADD8mr },
{ X86::AND16ri, X86::AND16mi },
@@ -215,16 +223,21 @@
for (unsigned i = 0, e = array_lengthof(OpTbl2Addr); i != e; ++i) {
unsigned RegOp = OpTbl2Addr[i][0];
- unsigned MemOp = OpTbl2Addr[i][1];
- if (!RegOp2MemOpTable2Addr.insert(std::make_pair(RegOp,
- std::make_pair(MemOp,0))).second)
- assert(false && "Duplicated entries?");
+ unsigned MemOp = OpTbl2Addr[i][1] & ~TB_FLAGS;
+ assert(!RegOp2MemOpTable2Addr.count(RegOp) && "Duplicated entries?");
+ RegOp2MemOpTable2Addr[RegOp] = std::make_pair(MemOp, 0U);
+
+ // If this is not a reversable operation (because there is a many->one)
+ // mapping, don't insert the reverse of the operation into MemOp2RegOpTable.
+ if (OpTbl2Addr[i][1] & TB_NOT_REVERSABLE)
+ continue;
+
// Index 0, folded load and store, no alignment requirement.
unsigned AuxInfo = 0 | (1 << 4) | (1 << 5);
- if (!MemOp2RegOpTable.insert(std::make_pair(MemOp,
- std::make_pair(RegOp,
- AuxInfo))).second)
- assert(false && "Duplicated entries in unfolding maps?");
+
+ assert(!MemOp2RegOpTable.count(MemOp) &&
+ "Duplicated entries in unfolding maps?");
+ MemOp2RegOpTable[MemOp] = std::make_pair(RegOp, AuxInfo);
}
// If the third value is 1, then it's folding either a load or a store.
@@ -455,8 +468,11 @@
{ X86::ADC32rr, X86::ADC32rm, 0 },
{ X86::ADC64rr, X86::ADC64rm, 0 },
{ X86::ADD16rr, X86::ADD16rm, 0 },
+ { X86::ADD16rr_DB, X86::ADD16rm | TB_NOT_REVERSABLE, 0 },
{ X86::ADD32rr, X86::ADD32rm, 0 },
+ { X86::ADD32rr_DB, X86::ADD32rm | TB_NOT_REVERSABLE, 0 },
{ X86::ADD64rr, X86::ADD64rm, 0 },
+ { X86::ADD64rr_DB, X86::ADD64rm | TB_NOT_REVERSABLE, 0 },
{ X86::ADD8rr, X86::ADD8rm, 0 },
{ X86::ADDPDrr, X86::ADDPDrm, 16 },
{ X86::ADDPSrr, X86::ADDPSrm, 16 },
@@ -651,16 +667,23 @@
for (unsigned i = 0, e = array_lengthof(OpTbl2); i != e; ++i) {
unsigned RegOp = OpTbl2[i][0];
- unsigned MemOp = OpTbl2[i][1];
+ unsigned MemOp = OpTbl2[i][1] & ~TB_FLAGS;
unsigned Align = OpTbl2[i][2];
- if (!RegOp2MemOpTable2.insert(std::make_pair(RegOp,
- std::make_pair(MemOp,Align))).second)
- assert(false && "Duplicated entries?");
+
+ assert(!RegOp2MemOpTable2.count(RegOp) && "Duplicate entry!");
+ RegOp2MemOpTable2[RegOp] = std::make_pair(MemOp, Align);
+
+
+ // If this is not a reversable operation (because there is a many->one)
+ // mapping, don't insert the reverse of the operation into MemOp2RegOpTable.
+ if (OpTbl2[i][1] & TB_NOT_REVERSABLE)
+ continue;
+
// Index 2, folded load
unsigned AuxInfo = 2 | (1 << 4);
- if (!MemOp2RegOpTable.insert(std::make_pair(MemOp,
- std::make_pair(RegOp, AuxInfo))).second)
- assert(false && "Duplicated entries in unfolding maps?");
+ assert(!MemOp2RegOpTable.count(MemOp) &&
+ "Duplicated entries in unfolding maps?");
+ MemOp2RegOpTable[MemOp] = std::make_pair(RegOp, AuxInfo);
}
}
@@ -1135,7 +1158,8 @@
case X86::ADD16ri8:
addRegOffset(MIB, leaInReg, true, MI->getOperand(2).getImm());
break;
- case X86::ADD16rr: {
+ case X86::ADD16rr:
+ case X86::ADD16rr_DB: {
unsigned Src2 = MI->getOperand(2).getReg();
bool isKill2 = MI->getOperand(2).isKill();
unsigned leaInReg2 = 0;
@@ -1348,18 +1372,27 @@
Src, isKill, -1);
break;
case X86::ADD64rr:
- case X86::ADD32rr: {
+ case X86::ADD64rr_DB:
+ case X86::ADD32rr:
+ case X86::ADD32rr_DB: {
assert(MI->getNumOperands() >= 3 && "Unknown add instruction!");
- unsigned Opc = MIOpc == X86::ADD64rr ? X86::LEA64r
- : (is64Bit ? X86::LEA64_32r : X86::LEA32r);
+ unsigned Opc;
+ TargetRegisterClass *RC;
+ if (MIOpc == X86::ADD64rr || MIOpc == X86::ADD64rr_DB) {
+ Opc = X86::LEA64r;
+ RC = X86::GR64_NOSPRegisterClass;
+ } else {
+ Opc = is64Bit ? X86::LEA64_32r : X86::LEA32r;
+ RC = X86::GR32_NOSPRegisterClass;
+ }
+
+
unsigned Src2 = MI->getOperand(2).getReg();
bool isKill2 = MI->getOperand(2).isKill();
// LEA can't handle RSP.
if (TargetRegisterInfo::isVirtualRegister(Src2) &&
- !MF.getRegInfo().constrainRegClass(Src2,
- MIOpc == X86::ADD64rr ? X86::GR64_NOSPRegisterClass :
- X86::GR32_NOSPRegisterClass))
+ !MF.getRegInfo().constrainRegClass(Src2, RC))
return 0;
NewMI = addRegReg(BuildMI(MF, MI->getDebugLoc(), get(Opc))
@@ -1370,7 +1403,8 @@
LV->replaceKillInstruction(Src2, MI, NewMI);
break;
}
- case X86::ADD16rr: {
+ case X86::ADD16rr:
+ case X86::ADD16rr_DB: {
if (DisableLEA16)
return is64Bit ? convertToThreeAddressWithLEA(MIOpc, MFI, MBBI, LV) : 0;
assert(MI->getNumOperands() >= 3 && "Unknown add instruction!");
@@ -2598,13 +2632,8 @@
OpcodeTablePtr = &RegOp2MemOpTable2;
}
- if (OpcodeTablePtr) {
- // Find the Opcode to fuse
- DenseMap<unsigned, std::pair<unsigned,unsigned> >::const_iterator I =
- OpcodeTablePtr->find(Opc);
- if (I != OpcodeTablePtr->end())
- return true;
- }
+ if (OpcodeTablePtr && OpcodeTablePtr->count(Opc))
+ return true;
return TargetInstrInfoImpl::canFoldMemoryOperand(MI, Ops);
}