From 320174f009f2d32067398326c17b8437a2e35df6 Mon Sep 17 00:00:00 2001 From: Andrew Lenharth Date: Thu, 7 Apr 2005 17:19:16 +0000 Subject: [PATCH] fixup magic constant making code. tested by thousands of random divisions.... by 10000. ok, so random divisors would be good too, but this at least fixes some things git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21140 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/Alpha/AlphaISelPattern.cpp | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/lib/Target/Alpha/AlphaISelPattern.cpp b/lib/Target/Alpha/AlphaISelPattern.cpp index 5df40ca154d..cfd58757317 100644 --- a/lib/Target/Alpha/AlphaISelPattern.cpp +++ b/lib/Target/Alpha/AlphaISelPattern.cpp @@ -413,7 +413,7 @@ static struct ms magic(int64_t d) { ad = abs(d); t = two63 + ((uint64_t)d >> 63); anc = t - 1 - t%ad; // absolute value of nc - p = 31; // initialize p + 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) @@ -450,11 +450,11 @@ static struct mu magicu(uint64_t d) struct mu magu; magu.a = 0; // initialize "add" indicator nc = - 1 - (-d)%d; - p = 31; // initialize p - q1 = 0x8000000000000000ll/nc; // initialize q1 = 2p/nc - r1 = 0x8000000000000000ll - q1*nc; // initialize r1 = rem(2p,nc) - q2 = 0x7FFFFFFFFFFFFFFFll/d; // initialize q2 = (2p-1)/d - r2 = 0x7FFFFFFFFFFFFFFFll - q2*d; // initialize r2 = rem((2p-1),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 ) { @@ -466,19 +466,19 @@ static struct mu magicu(uint64_t d) r1 = 2*r1; // update r1 } if (r2 + 1 >= d - r2) { - if (q2 >= 0x7FFFFFFFFFFFFFFFll) magu.a = 1; + if (q2 >= 0x7FFFFFFFFFFFFFFFull) magu.a = 1; q2 = 2*q2 + 1; // update q2 r2 = 2*r2 + 1 - d; // update r2 } else { - if (q2 >= 0x8000000000000000ll) magu.a = 1; + 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 - 32; // resulting shift + magu.s = p - 64; // resulting shift return magu; } @@ -487,7 +487,7 @@ static struct mu magicu(uint64_t d) /// multiplying by a magic number. See: /// SDOperand ISel::BuildSDIVSequence(SDOperand N) { - int d = (int)cast(N.getOperand(1))->getSignExtended(); + int64_t d = (int64_t)cast(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), -- 2.34.1