[FastISel][AArch64] Fold mul into add/sub and logical operations.

Try to fold the multiply into the add/sub or logical operations (when
possible).

This is related to rdar://problem/18369687.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217978 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Juergen Ributzka 2014-09-17 19:51:38 +00:00
parent 5461af97bc
commit 46d6fd2908
2 changed files with 117 additions and 19 deletions

View File

@ -949,8 +949,13 @@ unsigned AArch64FastISel::emitAddSub(bool UseAdd, MVT RetVT, const Value *LHS,
if (UseAdd && isa<ConstantInt>(LHS) && !isa<ConstantInt>(RHS))
std::swap(LHS, RHS);
// Canonicalize mul by power of 2 to the RHS.
if (UseAdd && LHS->hasOneUse() && isValueAvailable(LHS))
if (isMulPowOf2(LHS))
std::swap(LHS, RHS);
// Canonicalize shift immediate to the RHS.
if (UseAdd && isValueAvailable(LHS))
if (UseAdd && LHS->hasOneUse() && isValueAvailable(LHS))
if (const auto *SI = dyn_cast<BinaryOperator>(LHS))
if (isa<ConstantInt>(SI->getOperand(1)))
if (SI->getOpcode() == Instruction::Shl ||
@ -980,7 +985,8 @@ unsigned AArch64FastISel::emitAddSub(bool UseAdd, MVT RetVT, const Value *LHS,
return ResultReg;
// Only extend the RHS within the instruction if there is a valid extend type.
if (ExtendType != AArch64_AM::InvalidShiftExtend && isValueAvailable(RHS)) {
if (ExtendType != AArch64_AM::InvalidShiftExtend && RHS->hasOneUse() &&
isValueAvailable(RHS)) {
if (const auto *SI = dyn_cast<BinaryOperator>(RHS))
if (const auto *C = dyn_cast<ConstantInt>(SI->getOperand(1)))
if ((SI->getOpcode() == Instruction::Shl) && (C->getZExtValue() < 4)) {
@ -1000,8 +1006,28 @@ unsigned AArch64FastISel::emitAddSub(bool UseAdd, MVT RetVT, const Value *LHS,
ExtendType, 0, SetFlags, WantResult);
}
// Check if the mul can be folded into the instruction.
if (RHS->hasOneUse() && isValueAvailable(RHS))
if (isMulPowOf2(RHS)) {
const Value *MulLHS = cast<MulOperator>(RHS)->getOperand(0);
const Value *MulRHS = cast<MulOperator>(RHS)->getOperand(1);
if (const auto *C = dyn_cast<ConstantInt>(MulLHS))
if (C->getValue().isPowerOf2())
std::swap(MulLHS, MulRHS);
assert(isa<ConstantInt>(MulRHS) && "Expected a ConstantInt.");
uint64_t ShiftVal = cast<ConstantInt>(MulRHS)->getValue().logBase2();
unsigned RHSReg = getRegForValue(MulLHS);
if (!RHSReg)
return 0;
bool RHSIsKill = hasTrivialKill(MulLHS);
return emitAddSub_rs(UseAdd, RetVT, LHSReg, LHSIsKill, RHSReg, RHSIsKill,
AArch64_AM::LSL, ShiftVal, SetFlags, WantResult);
}
// Check if the shift can be folded into the instruction.
if (isValueAvailable(RHS))
if (RHS->hasOneUse() && isValueAvailable(RHS))
if (const auto *SI = dyn_cast<BinaryOperator>(RHS)) {
if (const auto *C = dyn_cast<ConstantInt>(SI->getOperand(1))) {
AArch64_AM::ShiftExtendType ShiftType = AArch64_AM::InvalidShiftExtend;
@ -1296,12 +1322,16 @@ unsigned AArch64FastISel::emitLogicalOp(unsigned ISDOpc, MVT RetVT,
if (isa<ConstantInt>(LHS) && !isa<ConstantInt>(RHS))
std::swap(LHS, RHS);
// Canonicalize mul by power-of-2 to the RHS.
if (LHS->hasOneUse() && isValueAvailable(LHS))
if (isMulPowOf2(LHS))
std::swap(LHS, RHS);
// Canonicalize shift immediate to the RHS.
if (isValueAvailable(LHS))
if (const auto *SI = dyn_cast<BinaryOperator>(LHS))
if (LHS->hasOneUse() && isValueAvailable(LHS))
if (const auto *SI = dyn_cast<ShlOperator>(LHS))
if (isa<ConstantInt>(SI->getOperand(1)))
if (SI->getOpcode() == Instruction::Shl)
std::swap(LHS, RHS);
std::swap(LHS, RHS);
unsigned LHSReg = getRegForValue(LHS);
if (!LHSReg)
@ -1316,19 +1346,39 @@ unsigned AArch64FastISel::emitLogicalOp(unsigned ISDOpc, MVT RetVT,
if (ResultReg)
return ResultReg;
// Check if the mul can be folded into the instruction.
if (RHS->hasOneUse() && isValueAvailable(RHS))
if (isMulPowOf2(RHS)) {
const Value *MulLHS = cast<MulOperator>(RHS)->getOperand(0);
const Value *MulRHS = cast<MulOperator>(RHS)->getOperand(1);
if (const auto *C = dyn_cast<ConstantInt>(MulLHS))
if (C->getValue().isPowerOf2())
std::swap(MulLHS, MulRHS);
assert(isa<ConstantInt>(MulRHS) && "Expected a ConstantInt.");
uint64_t ShiftVal = cast<ConstantInt>(MulRHS)->getValue().logBase2();
unsigned RHSReg = getRegForValue(MulLHS);
if (!RHSReg)
return 0;
bool RHSIsKill = hasTrivialKill(MulLHS);
return emitLogicalOp_rs(ISDOpc, RetVT, LHSReg, LHSIsKill, RHSReg,
RHSIsKill, ShiftVal);
}
// Check if the shift can be folded into the instruction.
if (isValueAvailable(RHS))
if (const auto *SI = dyn_cast<BinaryOperator>(RHS))
if (const auto *C = dyn_cast<ConstantInt>(SI->getOperand(1)))
if (SI->getOpcode() == Instruction::Shl) {
uint64_t ShiftVal = C->getZExtValue();
unsigned RHSReg = getRegForValue(SI->getOperand(0));
if (!RHSReg)
return 0;
bool RHSIsKill = hasTrivialKill(SI->getOperand(0));
return emitLogicalOp_rs(ISDOpc, RetVT, LHSReg, LHSIsKill, RHSReg,
RHSIsKill, ShiftVal);
}
if (RHS->hasOneUse() && isValueAvailable(RHS))
if (const auto *SI = dyn_cast<ShlOperator>(RHS))
if (const auto *C = dyn_cast<ConstantInt>(SI->getOperand(1))) {
uint64_t ShiftVal = C->getZExtValue();
unsigned RHSReg = getRegForValue(SI->getOperand(0));
if (!RHSReg)
return 0;
bool RHSIsKill = hasTrivialKill(SI->getOperand(0));
return emitLogicalOp_rs(ISDOpc, RetVT, LHSReg, LHSIsKill, RHSReg,
RHSIsKill, ShiftVal);
}
unsigned RHSReg = getRegForValue(RHS);
if (!RHSReg)

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@ -108,6 +108,22 @@ define i64 @and_rs_i64(i64 %a, i64 %b) {
ret i64 %2
}
define i32 @and_mul_i32(i32 %a, i32 %b) {
; CHECK-LABEL: and_mul_i32
; CHECK: and w0, w0, w1, lsl #2
%1 = mul i32 %b, 4
%2 = and i32 %a, %1
ret i32 %2
}
define i64 @and_mul_i64(i64 %a, i64 %b) {
; CHECK-LABEL: and_mul_i64
; CHECK: and x0, x0, x1, lsl #2
%1 = mul i64 %b, 4
%2 = and i64 %a, %1
ret i64 %2
}
; OR
define zeroext i1 @or_rr_i1(i1 signext %a, i1 signext %b) {
; CHECK-LABEL: or_rr_i1
@ -210,6 +226,22 @@ define i64 @or_rs_i64(i64 %a, i64 %b) {
ret i64 %2
}
define i32 @or_mul_i32(i32 %a, i32 %b) {
; CHECK-LABEL: or_mul_i32
; CHECK: orr w0, w0, w1, lsl #2
%1 = mul i32 %b, 4
%2 = or i32 %a, %1
ret i32 %2
}
define i64 @or_mul_i64(i64 %a, i64 %b) {
; CHECK-LABEL: or_mul_i64
; CHECK: orr x0, x0, x1, lsl #2
%1 = mul i64 %b, 4
%2 = or i64 %a, %1
ret i64 %2
}
; XOR
define zeroext i1 @xor_rr_i1(i1 signext %a, i1 signext %b) {
; CHECK-LABEL: xor_rr_i1
@ -312,3 +344,19 @@ define i64 @xor_rs_i64(i64 %a, i64 %b) {
ret i64 %2
}
define i32 @xor_mul_i32(i32 %a, i32 %b) {
; CHECK-LABEL: xor_mul_i32
; CHECK: eor w0, w0, w1, lsl #2
%1 = mul i32 %b, 4
%2 = xor i32 %a, %1
ret i32 %2
}
define i64 @xor_mul_i64(i64 %a, i64 %b) {
; CHECK-LABEL: xor_mul_i64
; CHECK: eor x0, x0, x1, lsl #2
%1 = mul i64 %b, 4
%2 = xor i64 %a, %1
ret i64 %2
}