[llvm-commits] CVS: llvm/lib/Target/Alpha/AlphaISelPattern.cpp
Nate Begeman
natebegeman at mac.com
Thu Oct 20 18:52:31 PDT 2005
Changes in directory llvm/lib/Target/Alpha:
AlphaISelPattern.cpp updated: 1.174 -> 1.175
---
Log message:
Kill some now-dead code.
---
Diffs of the changes: (+0 -159)
AlphaISelPattern.cpp | 159 ---------------------------------------------------
1 files changed, 159 deletions(-)
Index: llvm/lib/Target/Alpha/AlphaISelPattern.cpp
diff -u llvm/lib/Target/Alpha/AlphaISelPattern.cpp:1.174 llvm/lib/Target/Alpha/AlphaISelPattern.cpp:1.175
--- llvm/lib/Target/Alpha/AlphaISelPattern.cpp:1.174 Thu Oct 20 14:39:24 2005
+++ llvm/lib/Target/Alpha/AlphaISelPattern.cpp Thu Oct 20 20:52:20 2005
@@ -235,152 +235,6 @@
}
-//Shamelessly adapted from PPC32
-// Structure used to return the necessary information to codegen an SDIV as
-// a multiply.
-struct ms {
- int64_t m; // magic number
- int64_t s; // shift amount
-};
-
-struct mu {
- uint64_t m; // magic number
- int64_t a; // add indicator
- int64_t s; // shift amount
-};
-
-/// magic - calculate the magic numbers required to codegen an integer sdiv as
-/// a sequence of multiply and shifts. Requires that the divisor not be 0, 1,
-/// or -1.
-static struct ms magic(int64_t d) {
- int64_t p;
- uint64_t ad, anc, delta, q1, r1, q2, r2, t;
- const uint64_t two63 = 9223372036854775808ULL; // 2^63
- struct ms mag;
-
- ad = llabs(d);
- t = two63 + ((uint64_t)d >> 63);
- anc = t - 1 - t%ad; // absolute value of nc
- p = 63; // initialize p
- q1 = two63/anc; // initialize q1 = 2p/abs(nc)
- r1 = two63 - q1*anc; // initialize r1 = rem(2p,abs(nc))
- q2 = two63/ad; // initialize q2 = 2p/abs(d)
- r2 = two63 - q2*ad; // initialize r2 = rem(2p,abs(d))
- do {
- p = p + 1;
- q1 = 2*q1; // update q1 = 2p/abs(nc)
- r1 = 2*r1; // update r1 = rem(2p/abs(nc))
- if (r1 >= anc) { // must be unsigned comparison
- q1 = q1 + 1;
- r1 = r1 - anc;
- }
- q2 = 2*q2; // update q2 = 2p/abs(d)
- r2 = 2*r2; // update r2 = rem(2p/abs(d))
- if (r2 >= ad) { // must be unsigned comparison
- q2 = q2 + 1;
- r2 = r2 - ad;
- }
- delta = ad - r2;
- } while (q1 < delta || (q1 == delta && r1 == 0));
-
- mag.m = q2 + 1;
- if (d < 0) mag.m = -mag.m; // resulting magic number
- mag.s = p - 64; // resulting shift
- return mag;
-}
-
-/// magicu - calculate the magic numbers required to codegen an integer udiv as
-/// a sequence of multiply, add and shifts. Requires that the divisor not be 0.
-static struct mu magicu(uint64_t d)
-{
- int64_t p;
- uint64_t nc, delta, q1, r1, q2, r2;
- struct mu magu;
- magu.a = 0; // initialize "add" indicator
- nc = - 1 - (-d)%d;
- p = 63; // initialize p
- q1 = 0x8000000000000000ull/nc; // initialize q1 = 2p/nc
- r1 = 0x8000000000000000ull - q1*nc; // initialize r1 = rem(2p,nc)
- q2 = 0x7FFFFFFFFFFFFFFFull/d; // initialize q2 = (2p-1)/d
- r2 = 0x7FFFFFFFFFFFFFFFull - q2*d; // initialize r2 = rem((2p-1),d)
- do {
- p = p + 1;
- if (r1 >= nc - r1 ) {
- q1 = 2*q1 + 1; // update q1
- r1 = 2*r1 - nc; // update r1
- }
- else {
- q1 = 2*q1; // update q1
- r1 = 2*r1; // update r1
- }
- if (r2 + 1 >= d - r2) {
- if (q2 >= 0x7FFFFFFFFFFFFFFFull) magu.a = 1;
- q2 = 2*q2 + 1; // update q2
- r2 = 2*r2 + 1 - d; // update r2
- }
- else {
- if (q2 >= 0x8000000000000000ull) magu.a = 1;
- q2 = 2*q2; // update q2
- r2 = 2*r2 + 1; // update r2
- }
- delta = d - 1 - r2;
- } while (p < 64 && (q1 < delta || (q1 == delta && r1 == 0)));
- magu.m = q2 + 1; // resulting magic number
- magu.s = p - 64; // resulting shift
- return magu;
-}
-
-/// BuildSDIVSequence - Given an ISD::SDIV node expressing a divide by constant,
-/// return a DAG expression to select that will generate the same value by
-/// multiplying by a magic number. See:
-/// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
-SDOperand AlphaISel::BuildSDIVSequence(SDOperand N) {
- int64_t d = (int64_t)cast<ConstantSDNode>(N.getOperand(1))->getSignExtended();
- ms magics = magic(d);
- // Multiply the numerator (operand 0) by the magic value
- SDOperand Q = ISelDAG->getNode(ISD::MULHS, MVT::i64, N.getOperand(0),
- ISelDAG->getConstant(magics.m, MVT::i64));
- // If d > 0 and m < 0, add the numerator
- if (d > 0 && magics.m < 0)
- Q = ISelDAG->getNode(ISD::ADD, MVT::i64, Q, N.getOperand(0));
- // If d < 0 and m > 0, subtract the numerator.
- if (d < 0 && magics.m > 0)
- Q = ISelDAG->getNode(ISD::SUB, MVT::i64, Q, N.getOperand(0));
- // Shift right algebraic if shift value is nonzero
- if (magics.s > 0)
- Q = ISelDAG->getNode(ISD::SRA, MVT::i64, Q,
- ISelDAG->getConstant(magics.s, MVT::i64));
- // Extract the sign bit and add it to the quotient
- SDOperand T =
- ISelDAG->getNode(ISD::SRL, MVT::i64, Q, ISelDAG->getConstant(63, MVT::i64));
- return ISelDAG->getNode(ISD::ADD, MVT::i64, Q, T);
-}
-
-/// BuildUDIVSequence - Given an ISD::UDIV node expressing a divide by constant,
-/// return a DAG expression to select that will generate the same value by
-/// multiplying by a magic number. See:
-/// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
-SDOperand AlphaISel::BuildUDIVSequence(SDOperand N) {
- unsigned d =
- (unsigned)cast<ConstantSDNode>(N.getOperand(1))->getSignExtended();
- mu magics = magicu(d);
- // Multiply the numerator (operand 0) by the magic value
- SDOperand Q = ISelDAG->getNode(ISD::MULHU, MVT::i64, N.getOperand(0),
- ISelDAG->getConstant(magics.m, MVT::i64));
- if (magics.a == 0) {
- Q = ISelDAG->getNode(ISD::SRL, MVT::i64, Q,
- ISelDAG->getConstant(magics.s, MVT::i64));
- } else {
- SDOperand NPQ = ISelDAG->getNode(ISD::SUB, MVT::i64, N.getOperand(0), Q);
- NPQ = ISelDAG->getNode(ISD::SRL, MVT::i64, NPQ,
- ISelDAG->getConstant(1, MVT::i64));
- NPQ = ISelDAG->getNode(ISD::ADD, MVT::i64, NPQ, Q);
- Q = ISelDAG->getNode(ISD::SRL, MVT::i64, NPQ,
- ISelDAG->getConstant(magics.s-1, MVT::i64));
- }
- return Q;
-}
-
//These describe LDAx
static const int IMM_LOW = -32768;
static const int IMM_HIGH = 32767;
@@ -1390,20 +1244,7 @@
}
}
//Else fall through
-
case ISD::UDIV:
- {
- if (isSIntImmediate(N.getOperand(1), SImm) && (SImm >= 2 || SImm <= -2))
- {
- // If this is a divide by constant, we can emit code using some magic
- // constants to implement it as a multiply instead.
- ExprMap.erase(N);
- if (opcode == ISD::SDIV)
- return SelectExpr(BuildSDIVSequence(N));
- else
- return SelectExpr(BuildUDIVSequence(N));
- }
- }
//else fall though
case ISD::UREM:
case ISD::SREM: {
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