From 66571bbb0a8676d62cff739a7e715a307f4140e4 Mon Sep 17 00:00:00 2001 From: Craig Topper Date: Wed, 10 May 2017 18:15:24 +0000 Subject: [PATCH] [APInt] Make toString use udivrem instead of calling the divide helper method directly. Do a better job of reusing allocations while looping. NFCI This lets toString take advantage of the degenerate case checks in udivrem and is just generally cleaner. One minor downside of this is that the divisor APInt now needs to be the same size as Tmp which requires an additional allocation. But we were doing a poor job of reusing allocations before so the new code should still be an improvement. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@302704 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Support/APInt.cpp | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/lib/Support/APInt.cpp b/lib/Support/APInt.cpp index 90aba5b3624..227cfbd2e2e 100644 --- a/lib/Support/APInt.cpp +++ b/lib/Support/APInt.cpp @@ -1948,22 +1948,23 @@ void APInt::toString(SmallVectorImpl &Str, unsigned Radix, unsigned ShiftAmt = (Radix == 16 ? 4 : (Radix == 8 ? 3 : 1)); unsigned MaskAmt = Radix - 1; - while (Tmp != 0) { + while (Tmp.getBoolValue()) { unsigned Digit = unsigned(Tmp.getRawData()[0]) & MaskAmt; Str.push_back(Digits[Digit]); Tmp.lshrInPlace(ShiftAmt); } } else { - APInt divisor(Radix == 10? 4 : 8, Radix); - while (Tmp != 0) { - APInt APdigit(1, 0); - APInt tmp2(Tmp.getBitWidth(), 0); - divide(Tmp, Tmp.getNumWords(), divisor, divisor.getNumWords(), &tmp2, - &APdigit); + APInt divisor(Tmp.getBitWidth(), Radix); + APInt APdigit; + APInt tmp2(Tmp.getBitWidth(), 0); + while (Tmp.getBoolValue()) { + udivrem(Tmp, divisor, tmp2, APdigit); unsigned Digit = (unsigned)APdigit.getZExtValue(); assert(Digit < Radix && "divide failed"); Str.push_back(Digits[Digit]); - Tmp = tmp2; + // Move the quotient into Tmp and move the old allocation of Tmp into + // tmp2 to be used on the next loop iteration. + std::swap(Tmp, tmp2); } } -- 2.50.1