From 2579c7c69f08330951d947c51f6f6938f0fdc737 Mon Sep 17 00:00:00 2001 From: Craig Topper Date: Fri, 12 May 2017 21:45:44 +0000 Subject: [PATCH] [APInt] In udivrem, remember the bit width in a local variable so we don't reread it from the LHS which might be aliased with Quotient or Remainder. This helped the compiler generate better code for the single word case. It was able to remember that the bit width was still a single word when it created the Remainder APInt and not create code for it possibly being multiword. llvm-svn: 302952 --- llvm/lib/Support/APInt.cpp | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/llvm/lib/Support/APInt.cpp b/llvm/lib/Support/APInt.cpp index f4aa627..25d3977 100644 --- a/llvm/lib/Support/APInt.cpp +++ b/llvm/lib/Support/APInt.cpp @@ -1648,14 +1648,15 @@ APInt APInt::srem(const APInt &RHS) const { void APInt::udivrem(const APInt &LHS, const APInt &RHS, APInt &Quotient, APInt &Remainder) { assert(LHS.BitWidth == RHS.BitWidth && "Bit widths must be the same"); + unsigned BitWidth = LHS.BitWidth; // First, deal with the easy case if (LHS.isSingleWord()) { assert(RHS.U.VAL != 0 && "Divide by zero?"); uint64_t QuotVal = LHS.U.VAL / RHS.U.VAL; uint64_t RemVal = LHS.U.VAL % RHS.U.VAL; - Quotient = APInt(LHS.BitWidth, QuotVal); - Remainder = APInt(LHS.BitWidth, RemVal); + Quotient = APInt(BitWidth, QuotVal); + Remainder = APInt(BitWidth, RemVal); return; } @@ -1688,8 +1689,8 @@ void APInt::udivrem(const APInt &LHS, const APInt &RHS, uint64_t lhsValue = LHS.U.pVal[0]; uint64_t rhsValue = RHS.U.pVal[0]; // Make sure there is enough space to hold the results. - Quotient.reallocate(LHS.BitWidth); - Remainder.reallocate(LHS.BitWidth); + Quotient.reallocate(BitWidth); + Remainder.reallocate(BitWidth); Quotient = lhsValue / rhsValue; Remainder = lhsValue % rhsValue; return; -- 2.7.4