mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2026-04-27 04:18:42 +00:00
Evan Cheng
79590b8edf
%shr = lshr i64 %key, 3 %0 = load i64* %val, align 8 %sub = add i64 %0, -1 %and = and i64 %sub, %shr ret i64 %and to: %shr = lshr i64 %key, 3 %0 = load i64* %val, align 8 %sub = add i64 %0, 2305843009213693951 %and = and i64 %sub, %shr ret i64 %and The demanded bit optimization is actually a pessimization because add -1 would be codegen'ed as a sub 1. Teach the demanded constant shrinking optimization to check for negated constant to make sure it is actually reducing the width of the constant. rdar://11793464 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160101 91177308-0d34-0410-b5e6-96231b3b80d8
Low Level Virtual Machine (LLVM) ================================ This directory and its subdirectories contain source code for the Low Level Virtual Machine, a toolkit for the construction of highly optimized compilers, optimizers, and runtime environments. LLVM is open source software. You may freely distribute it under the terms of the license agreement found in LICENSE.txt. Please see the HTML documentation provided in docs/index.html for further assistance with LLVM. If you're writing a package for LLVM, see docs/Packaging.html for our suggestions.