diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp index ed29f134637..7777e23f85e 100644 --- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp +++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp @@ -2224,7 +2224,7 @@ bool TargetLowering::isLegalAddressingMode(const AddrMode &AM, struct mu { APInt m; // magic number bool a; // add indicator - uint32_t s; // shift amount + unsigned s; // shift amount }; /// magicu - calculate the magic numbers required to codegen an integer udiv as @@ -2273,89 +2273,50 @@ static mu magicu(const APInt& d) { } // Magic for divide replacement -// FIXME: This should be APInt'ified struct ms { - int64_t m; // magic number - int64_t s; // shift amount + APInt m; // magic number + unsigned 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 ms magic32(int32_t d) { - int32_t p; - uint32_t ad, anc, delta, q1, r1, q2, r2, t; - const uint32_t two31 = 0x80000000U; +static ms magic(const APInt& d) { + unsigned p; + APInt ad, anc, delta, q1, r1, q2, r2, t; + APInt allOnes = APInt::getAllOnesValue(d.getBitWidth()); + APInt signedMin = APInt::getSignedMinValue(d.getBitWidth()); + APInt signedMax = APInt::getSignedMaxValue(d.getBitWidth()); struct ms mag; - ad = abs(d); - t = two31 + ((uint32_t)d >> 31); - anc = t - 1 - t%ad; // absolute value of nc - p = 31; // initialize p - q1 = two31/anc; // initialize q1 = 2p/abs(nc) - r1 = two31 - q1*anc; // initialize r1 = rem(2p,abs(nc)) - q2 = two31/ad; // initialize q2 = 2p/abs(d) - r2 = two31 - q2*ad; // initialize r2 = rem(2p,abs(d)) + ad = d.abs(); + t = signedMin + (d.lshr(d.getBitWidth() - 1)); + anc = t - 1 - t.urem(ad); // absolute value of nc + p = d.getBitWidth() - 1; // initialize p + q1 = signedMin.udiv(anc); // initialize q1 = 2p/abs(nc) + r1 = signedMin - q1*anc; // initialize r1 = rem(2p,abs(nc)) + q2 = signedMin.udiv(ad); // initialize q2 = 2p/abs(d) + r2 = signedMin - 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; // update q1 = 2p/abs(nc) + r1 = r1<<1; // update r1 = rem(2p/abs(nc)) + if (r1.uge(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; // update q2 = 2p/abs(d) + r2 = r2<<1; // update r2 = rem(2p/abs(d)) + if (r2.uge(ad)) { // must be unsigned comparison q2 = q2 + 1; r2 = r2 - ad; } delta = ad - r2; - } while (q1 < delta || (q1 == delta && r1 == 0)); - - mag.m = (int32_t)(q2 + 1); // make sure to sign extend - if (d < 0) mag.m = -mag.m; // resulting magic number - mag.s = p - 32; // resulting shift - return mag; -} - -/// 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 ms magic64(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 = d >= 0 ? d : -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)); + } while (q1.ule(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 + if (d.isNegative()) mag.m = -mag.m; // resulting magic number + mag.s = p - d.getBitWidth(); // resulting shift return mag; } @@ -2368,13 +2329,15 @@ SDValue TargetLowering::BuildSDIV(SDNode *N, SelectionDAG &DAG, MVT VT = N->getValueType(0); // Check to see if we can do this. - if (!isTypeLegal(VT) || (VT != MVT::i32 && VT != MVT::i64)) - return SDValue(); // BuildSDIV only operates on i32 or i64 + // FIXME: We should be more aggressive here. + if (!isTypeLegal(VT)) + return SDValue(); - int64_t d = cast(N->getOperand(1))->getSExtValue(); - ms magics = (VT == MVT::i32) ? magic32(d) : magic64(d); + APInt d = cast(N->getOperand(1))->getAPIntValue(); + ms magics = magic(d); // Multiply the numerator (operand 0) by the magic value + // FIXME: We should support doing a MUL in a wider type SDValue Q; if (isOperationLegal(ISD::MULHS, VT)) Q = DAG.getNode(ISD::MULHS, VT, N->getOperand(0), @@ -2386,13 +2349,13 @@ SDValue TargetLowering::BuildSDIV(SDNode *N, SelectionDAG &DAG, else return SDValue(); // No mulhs or equvialent // If d > 0 and m < 0, add the numerator - if (d > 0 && magics.m < 0) { + if (d.isStrictlyPositive() && magics.m.isNegative()) { Q = DAG.getNode(ISD::ADD, VT, Q, N->getOperand(0)); if (Created) Created->push_back(Q.getNode()); } // If d < 0 and m > 0, subtract the numerator. - if (d < 0 && magics.m > 0) { + if (d.isNegative() && magics.m.isStrictlyPositive()) { Q = DAG.getNode(ISD::SUB, VT, Q, N->getOperand(0)); if (Created) Created->push_back(Q.getNode()); diff --git a/test/CodeGen/X86/2008-11-29-DivideConstant16bitSigned.ll b/test/CodeGen/X86/2008-11-29-DivideConstant16bitSigned.ll new file mode 100644 index 00000000000..faf7cd4b220 --- /dev/null +++ b/test/CodeGen/X86/2008-11-29-DivideConstant16bitSigned.ll @@ -0,0 +1,10 @@ +; RUN: llvm-as < %s | llc -mtriple=i686-pc-linux-gnu | grep 63551 +; ModuleID = '' +target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32" +target triple = "i686-pc-linux-gnu" + +define signext i16 @a(i16 signext %x) nounwind { +entry: + %div = sdiv i16 %x, 33 ; [#uses=1] + ret i16 %div +}