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Commit 0c704176 by Manasij Mukherjee
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Selectively invert ICMP operands for better address optimization

Results in lower code size and more loads folded into cmp instructions. BUG=none R=eholk@chromium.org, jpp@chromium.org, stichnot@chromium.org Review URL: https://codereview.chromium.org/2124973005 .
parent 752e59fa
Showing with 132 additions and 70 deletions
src/IceInst.cpp
......@@ -65,9 +65,10 @@ const struct InstFcmpAttributes_ {
// Using non-anonymous struct so that array_lengthof works.
const struct InstIcmpAttributes_ {
const char *DisplayString;
InstIcmp::ICond Reverse;
} InstIcmpAttributes[] = {
#define X(tag, str) \
{ str } \
#define X(tag, reverse, str) \
{ str, InstIcmp::ICond::reverse } \
,
ICEINSTICMP_TABLE
#undef X
......@@ -1085,6 +1086,10 @@ void InstTarget::dump(const Cfg *Func) const {
InstBreakpoint::InstBreakpoint(Cfg *Func)
: InstHighLevel(Func, Inst::Breakpoint, 0, nullptr) {}
void InstIcmp::reverseConditionAndOperands() {
Condition = InstIcmpAttributes[Condition].Reverse;
std::swap(Srcs[0], Srcs[1]);
}
bool checkForRedundantAssign(const Variable *Dest, const Operand *Source) {
const auto *SrcVar = llvm::dyn_cast<const Variable>(Source);
if (!SrcVar)
......
src/IceInst.def
......@@ -31,74 +31,74 @@
// representable in the destination format. This standard does not
// specify which of the input NaNs will provide the payload."
#define ICEINSTARITHMETIC_TABLE \
/* enum value, printable string, commutative */ \
X(Add, "add", 1) \
X(Fadd, "fadd", 1) \
X(Sub, "sub", 0) \
X(Fsub, "fsub", 0) \
X(Mul, "mul", 1) \
X(Fmul, "fmul", 1) \
X(Udiv, "udiv", 0) \
X(Sdiv, "sdiv", 0) \
X(Fdiv, "fdiv", 0) \
X(Urem, "urem", 0) \
X(Srem, "srem", 0) \
X(Frem, "frem", 0) \
X(Shl, "shl", 0) \
X(Lshr, "lshr", 0) \
X(Ashr, "ashr", 0) \
X(And, "and", 1) \
X(Or, "or", 1) \
#define ICEINSTARITHMETIC_TABLE \
/* enum value, printable string, commutative */ \
X(Add, "add", 1) \
X(Fadd, "fadd", 1) \
X(Sub, "sub", 0) \
X(Fsub, "fsub", 0) \
X(Mul, "mul", 1) \
X(Fmul, "fmul", 1) \
X(Udiv, "udiv", 0) \
X(Sdiv, "sdiv", 0) \
X(Fdiv, "fdiv", 0) \
X(Urem, "urem", 0) \
X(Srem, "srem", 0) \
X(Frem, "frem", 0) \
X(Shl, "shl", 0) \
X(Lshr, "lshr", 0) \
X(Ashr, "ashr", 0) \
X(And, "and", 1) \
X(Or, "or", 1) \
X(Xor, "xor", 1)
//#define X(tag, str, commutative)
#define ICEINSTCAST_TABLE \
/* enum value, printable string */ \
X(Trunc, "trunc") \
X(Zext, "zext") \
X(Sext, "sext") \
X(Fptrunc, "fptrunc") \
X(Fpext, "fpext") \
X(Fptoui, "fptoui") \
X(Fptosi, "fptosi") \
X(Uitofp, "uitofp") \
X(Sitofp, "sitofp") \
#define ICEINSTCAST_TABLE \
/* enum value, printable string */ \
X(Trunc, "trunc") \
X(Zext, "zext") \
X(Sext, "sext") \
X(Fptrunc, "fptrunc") \
X(Fpext, "fpext") \
X(Fptoui, "fptoui") \
X(Fptosi, "fptosi") \
X(Uitofp, "uitofp") \
X(Sitofp, "sitofp") \
X(Bitcast, "bitcast")
//#define X(tag, str)
#define ICEINSTFCMP_TABLE \
/* enum value, printable string */ \
X(False, "false") \
X(Oeq, "oeq") \
X(Ogt, "ogt") \
X(Oge, "oge") \
X(Olt, "olt") \
X(Ole, "ole") \
X(One, "one") \
X(Ord, "ord") \
X(Ueq, "ueq") \
X(Ugt, "ugt") \
X(Uge, "uge") \
X(Ult, "ult") \
X(Ule, "ule") \
X(Une, "une") \
X(Uno, "uno") \
#define ICEINSTFCMP_TABLE \
/* enum value, printable string */ \
X(False, "false") \
X(Oeq, "oeq") \
X(Ogt, "ogt") \
X(Oge, "oge") \
X(Olt, "olt") \
X(Ole, "ole") \
X(One, "one") \
X(Ord, "ord") \
X(Ueq, "ueq") \
X(Ugt, "ugt") \
X(Uge, "uge") \
X(Ult, "ult") \
X(Ule, "ule") \
X(Une, "une") \
X(Uno, "uno") \
X(True, "true")
//#define X(tag, str)
#define ICEINSTICMP_TABLE \
/* enum value, printable string */ \
X(Eq, "eq") \
X(Ne, "ne") \
X(Ugt, "ugt") \
X(Uge, "uge") \
X(Ult, "ult") \
X(Ule, "ule") \
X(Sgt, "sgt") \
X(Sge, "sge") \
X(Slt, "slt") \
X(Sle, "sle")
//#define X(tag, str)
#define ICEINSTICMP_TABLE \
/* enum value, reverse, printable string */ \
X(Eq, Eq, "eq") \
X(Ne, Ne, "ne") \
X(Ugt, Ult, "ugt") \
X(Uge, Ule, "uge") \
X(Ult, Ugt, "ult") \
X(Ule, Uge, "ule") \
X(Sgt, Slt, "sgt") \
X(Sge, Sle, "sge") \
X(Slt, Sgt, "slt") \
X(Sle, Sge, "sle")
//#define X(tag, reverse, str)
#endif // SUBZERO_SRC_ICEINST_DEF
src/IceInst.h
......@@ -538,7 +538,7 @@ class InstIcmp : public InstHighLevel {
public:
enum ICond {
#define X(tag, str) tag,
#define X(tag, inverse, str) tag,
ICEINSTICMP_TABLE
#undef X
_num
......@@ -550,6 +550,7 @@ public:
InstIcmp(Func, Condition, Dest, Source1, Source2);
}
ICond getCondition() const { return Condition; }
void reverseConditionAndOperands();
bool isMemoryWrite() const override { return false; }
void dump(const Cfg *Func) const override;
static bool classof(const Inst *Instr) { return Instr->getKind() == Icmp; }
......@@ -558,7 +559,7 @@ private:
InstIcmp(Cfg *Func, ICond Condition, Variable *Dest, Operand *Source1,
Operand *Source2);
const ICond Condition;
ICond Condition;
};
/// InsertElement instruction.
......
src/IceTargetLowering.cpp
......@@ -344,6 +344,7 @@ void TargetLowering::genTargetHelperCalls() {
}
void TargetLowering::doAddressOpt() {
doAddressOptOther();
if (llvm::isa<InstLoad>(*Context.getCur()))
doAddressOptLoad();
else if (llvm::isa<InstStore>(*Context.getCur()))
......
src/IceTargetLowering.h
......@@ -396,6 +396,8 @@ protected:
virtual void genTargetHelperCallFor(Inst *Instr) = 0;
virtual uint32_t getCallStackArgumentsSizeBytes(const InstCall *Instr) = 0;
/// Opportunity to modify other instructions to help Address Optimization
virtual void doAddressOptOther() {}
virtual void doAddressOptLoad() {}
virtual void doAddressOptStore() {}
virtual void doMockBoundsCheck(Operand *) {}
......
src/IceTargetLoweringARM32.cpp
......@@ -170,7 +170,8 @@ enum _icmp_ll_enum {
_num
};
// Define a set of constants based on high-level table entries.
#define X(tag, str) static constexpr int _icmp_hl_##tag = InstIcmp::tag;
#define X(tag, reverse, str) \
static constexpr int _icmp_hl_##tag = InstIcmp::tag;
ICEINSTICMP_TABLE
#undef X
// Define a set of constants based on low-level table entries, and ensure the
......@@ -183,7 +184,7 @@ ICMPARM32_TABLE
#undef X
// Repeat the static asserts with respect to the high-level table entries in
// case the high-level table has extra entries.
#define X(tag, str) \
#define X(tag, reverse, str) \
static_assert( \
_icmp_hl_##tag == _icmp_ll_##tag, \
"Inconsistency between ICMPARM32_TABLE and ICEINSTICMP_TABLE: " #tag);
......
src/IceTargetLoweringX8632.cpp
......@@ -436,7 +436,7 @@ enum _tmp_enum {
_num
};
// Define a set of constants based on high-level table entries.
#define X(tag, str) static const int _table1_##tag = InstIcmp::tag;
#define X(tag, reverse, str) static const int _table1_##tag = InstIcmp::tag;
ICEINSTICMP_TABLE
#undef X
// Define a set of constants based on low-level table entries, and ensure the
......@@ -450,7 +450,7 @@ ICMPX8632_TABLE
#undef X
// Repeat the static asserts with respect to the high-level table entries in
// case the high-level table has extra entries.
#define X(tag, str) \
#define X(tag, reverse, str) \
static_assert( \
_table1_##tag == _table2_##tag, \
"Inconsistency between ICMPX8632_TABLE and ICEINSTICMP_TABLE");
......
src/IceTargetLoweringX8664.cpp
......@@ -775,7 +775,7 @@ enum _tmp_enum {
_num
};
// Define a set of constants based on high-level table entries.
#define X(tag, str) static const int _table1_##tag = InstIcmp::tag;
#define X(tag, reverse, str) static const int _table1_##tag = InstIcmp::tag;
ICEINSTICMP_TABLE
#undef X
// Define a set of constants based on low-level table entries, and ensure the
......@@ -789,7 +789,7 @@ ICMPX8664_TABLE
#undef X
// Repeat the static asserts with respect to the high-level table entries in
// case the high-level table has extra entries.
#define X(tag, str) \
#define X(tag, reverse, str) \
static_assert( \
_table1_##tag == _table2_##tag, \
"Inconsistency between ICMPX8664_TABLE and ICEINSTICMP_TABLE");
......
src/IceTargetLoweringX86Base.h
......@@ -289,6 +289,7 @@ protected:
// <Relocatable + Offset>(Base, Index, Shift)
X86OperandMem *computeAddressOpt(const Inst *Instr, Type MemType,
Operand *Addr);
void doAddressOptOther() override;
void doAddressOptLoad() override;
void doAddressOptStore() override;
void doMockBoundsCheck(Operand *Opnd) override;
......
src/IceTargetLoweringX86BaseImpl.h
......@@ -5658,6 +5658,39 @@ void TargetX86Base<TraitsType>::lowerLoad(const InstLoad *Load) {
}
template <typename TraitsType>
void TargetX86Base<TraitsType>::doAddressOptOther() {
// Inverts some Icmp instructions which helps doAddressOptLoad later.
// TODO(manasijm): Refactor to unify the conditions for Var0 and Var1
Inst *Instr = Context.getCur();
auto *VMetadata = Func->getVMetadata();
if (auto *Icmp = llvm::dyn_cast<InstIcmp>(Instr)) {
if (llvm::isa<Constant>(Icmp->getSrc(0)) ||
llvm::isa<Constant>(Icmp->getSrc(1)))
return;
auto *Var0 = llvm::dyn_cast<Variable>(Icmp->getSrc(0));
if (Var0 == nullptr)
return;
if (!VMetadata->isTracked(Var0))
return;
auto *Op0Def = VMetadata->getFirstDefinitionSingleBlock(Var0);
if (Op0Def == nullptr || !llvm::isa<InstLoad>(Op0Def))
return;
if (VMetadata->getLocalUseNode(Var0) != Context.getNode())
return;
auto *Var1 = llvm::dyn_cast<Variable>(Icmp->getSrc(1));
if (Var1 != nullptr && VMetadata->isTracked(Var1)) {
auto *Op1Def = VMetadata->getFirstDefinitionSingleBlock(Var1);
if (Op1Def != nullptr && !VMetadata->isMultiBlock(Var1) &&
llvm::isa<InstLoad>(Op1Def)) {
return; // Both are loads
}
}
Icmp->reverseConditionAndOperands();
}
}
template <typename TraitsType>
void TargetX86Base<TraitsType>::doAddressOptLoad() {
Inst *Instr = Context.getCur();
Operand *Addr = Instr->getSrc(0);
......
tests_lit/llvm2ice_tests/address-mode-opt.ll
......@@ -187,3 +187,20 @@ entry:
; CHECK: or
; CHECK-NOT: movss xmm{{[0-9]+}},DWORD PTR [{{e..}}*4+0xFFFF]
}
define internal void @invert_icmp(i32* %arg1, i32* %arg2) {
entry:
%addr.other = load i32, i32* %arg2, align 1
br label %next
next:
%addr.load = load i32, i32* %arg1, align 1
%cond = icmp slt i32 %addr.load, %addr.other
br i1 %cond, label %if.then, label %if.else
if.then:
ret void
if.else:
ret void
; CHECK-LABEL: invert_icmp
; CHECK: cmp {{e..}},DWORD PTR [{{e..}}]
; CHECK: jle
}
\ No newline at end of file
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