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Kill some now-dead code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23857 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Nate Begeman
parent
4d38567689
commit
0b2973aef2
@ -235,152 +235,6 @@ static bool factorize(int v[], int res[], int size, uint64_t c)
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}
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//Shamelessly adapted from PPC32
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// Structure used to return the necessary information to codegen an SDIV as
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// a multiply.
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struct ms {
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int64_t m; // magic number
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int64_t s; // shift amount
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};
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struct mu {
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uint64_t m; // magic number
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int64_t a; // add indicator
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int64_t s; // shift amount
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};
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/// magic - calculate the magic numbers required to codegen an integer sdiv as
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/// a sequence of multiply and shifts. Requires that the divisor not be 0, 1,
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/// or -1.
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static struct ms magic(int64_t d) {
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int64_t p;
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uint64_t ad, anc, delta, q1, r1, q2, r2, t;
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const uint64_t two63 = 9223372036854775808ULL; // 2^63
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struct ms mag;
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ad = llabs(d);
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t = two63 + ((uint64_t)d >> 63);
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anc = t - 1 - t%ad; // absolute value of nc
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p = 63; // initialize p
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q1 = two63/anc; // initialize q1 = 2p/abs(nc)
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r1 = two63 - q1*anc; // initialize r1 = rem(2p,abs(nc))
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q2 = two63/ad; // initialize q2 = 2p/abs(d)
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r2 = two63 - q2*ad; // initialize r2 = rem(2p,abs(d))
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do {
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p = p + 1;
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q1 = 2*q1; // update q1 = 2p/abs(nc)
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r1 = 2*r1; // update r1 = rem(2p/abs(nc))
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if (r1 >= anc) { // must be unsigned comparison
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q1 = q1 + 1;
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r1 = r1 - anc;
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}
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q2 = 2*q2; // update q2 = 2p/abs(d)
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r2 = 2*r2; // update r2 = rem(2p/abs(d))
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if (r2 >= ad) { // must be unsigned comparison
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q2 = q2 + 1;
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r2 = r2 - ad;
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}
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delta = ad - r2;
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} while (q1 < delta || (q1 == delta && r1 == 0));
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mag.m = q2 + 1;
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if (d < 0) mag.m = -mag.m; // resulting magic number
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mag.s = p - 64; // resulting shift
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return mag;
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}
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/// magicu - calculate the magic numbers required to codegen an integer udiv as
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/// a sequence of multiply, add and shifts. Requires that the divisor not be 0.
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static struct mu magicu(uint64_t d)
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{
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int64_t p;
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uint64_t nc, delta, q1, r1, q2, r2;
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struct mu magu;
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magu.a = 0; // initialize "add" indicator
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nc = - 1 - (-d)%d;
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p = 63; // initialize p
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q1 = 0x8000000000000000ull/nc; // initialize q1 = 2p/nc
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r1 = 0x8000000000000000ull - q1*nc; // initialize r1 = rem(2p,nc)
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q2 = 0x7FFFFFFFFFFFFFFFull/d; // initialize q2 = (2p-1)/d
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r2 = 0x7FFFFFFFFFFFFFFFull - q2*d; // initialize r2 = rem((2p-1),d)
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do {
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p = p + 1;
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if (r1 >= nc - r1 ) {
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q1 = 2*q1 + 1; // update q1
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r1 = 2*r1 - nc; // update r1
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}
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else {
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q1 = 2*q1; // update q1
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r1 = 2*r1; // update r1
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}
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if (r2 + 1 >= d - r2) {
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if (q2 >= 0x7FFFFFFFFFFFFFFFull) magu.a = 1;
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q2 = 2*q2 + 1; // update q2
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r2 = 2*r2 + 1 - d; // update r2
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}
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else {
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if (q2 >= 0x8000000000000000ull) magu.a = 1;
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q2 = 2*q2; // update q2
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r2 = 2*r2 + 1; // update r2
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}
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delta = d - 1 - r2;
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} while (p < 64 && (q1 < delta || (q1 == delta && r1 == 0)));
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magu.m = q2 + 1; // resulting magic number
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magu.s = p - 64; // resulting shift
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return magu;
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}
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/// BuildSDIVSequence - Given an ISD::SDIV node expressing a divide by constant,
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/// return a DAG expression to select that will generate the same value by
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/// multiplying by a magic number. See:
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/// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
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SDOperand AlphaISel::BuildSDIVSequence(SDOperand N) {
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int64_t d = (int64_t)cast<ConstantSDNode>(N.getOperand(1))->getSignExtended();
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ms magics = magic(d);
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// Multiply the numerator (operand 0) by the magic value
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SDOperand Q = ISelDAG->getNode(ISD::MULHS, MVT::i64, N.getOperand(0),
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ISelDAG->getConstant(magics.m, MVT::i64));
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// If d > 0 and m < 0, add the numerator
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if (d > 0 && magics.m < 0)
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Q = ISelDAG->getNode(ISD::ADD, MVT::i64, Q, N.getOperand(0));
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// If d < 0 and m > 0, subtract the numerator.
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if (d < 0 && magics.m > 0)
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Q = ISelDAG->getNode(ISD::SUB, MVT::i64, Q, N.getOperand(0));
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// Shift right algebraic if shift value is nonzero
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if (magics.s > 0)
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Q = ISelDAG->getNode(ISD::SRA, MVT::i64, Q,
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ISelDAG->getConstant(magics.s, MVT::i64));
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// Extract the sign bit and add it to the quotient
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SDOperand T =
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ISelDAG->getNode(ISD::SRL, MVT::i64, Q, ISelDAG->getConstant(63, MVT::i64));
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return ISelDAG->getNode(ISD::ADD, MVT::i64, Q, T);
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}
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/// BuildUDIVSequence - Given an ISD::UDIV node expressing a divide by constant,
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/// return a DAG expression to select that will generate the same value by
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/// multiplying by a magic number. See:
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/// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
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SDOperand AlphaISel::BuildUDIVSequence(SDOperand N) {
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unsigned d =
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(unsigned)cast<ConstantSDNode>(N.getOperand(1))->getSignExtended();
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mu magics = magicu(d);
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// Multiply the numerator (operand 0) by the magic value
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SDOperand Q = ISelDAG->getNode(ISD::MULHU, MVT::i64, N.getOperand(0),
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ISelDAG->getConstant(magics.m, MVT::i64));
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if (magics.a == 0) {
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Q = ISelDAG->getNode(ISD::SRL, MVT::i64, Q,
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ISelDAG->getConstant(magics.s, MVT::i64));
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} else {
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SDOperand NPQ = ISelDAG->getNode(ISD::SUB, MVT::i64, N.getOperand(0), Q);
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NPQ = ISelDAG->getNode(ISD::SRL, MVT::i64, NPQ,
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ISelDAG->getConstant(1, MVT::i64));
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NPQ = ISelDAG->getNode(ISD::ADD, MVT::i64, NPQ, Q);
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Q = ISelDAG->getNode(ISD::SRL, MVT::i64, NPQ,
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ISelDAG->getConstant(magics.s-1, MVT::i64));
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}
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return Q;
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}
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//These describe LDAx
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static const int IMM_LOW = -32768;
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static const int IMM_HIGH = 32767;
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@ -1390,20 +1244,7 @@ unsigned AlphaISel::SelectExpr(SDOperand N) {
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}
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}
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//Else fall through
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case ISD::UDIV:
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{
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if (isSIntImmediate(N.getOperand(1), SImm) && (SImm >= 2 || SImm <= -2))
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{
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// If this is a divide by constant, we can emit code using some magic
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// constants to implement it as a multiply instead.
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ExprMap.erase(N);
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if (opcode == ISD::SDIV)
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return SelectExpr(BuildSDIVSequence(N));
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else
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return SelectExpr(BuildUDIVSequence(N));
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}
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}
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//else fall though
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case ISD::UREM:
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case ISD::SREM: {
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