llvm-6502/test/Transforms/InstCombine/2010-11-23-Distributed.ll at 2ff28e4b9e151831890c2086cf2aed2ec9b94eb0 - llvm-6502 - Applefritter: Git

6502/llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-11-03 14:21:30 +00:00

Files

Duncan Sands 5057f38141 Exploit distributive laws (eg: And distributes over Or, Mul over Add, etc) in a

fairly systematic way in instcombine.  Some of these cases were already dealt
with, in which case I removed the existing code.  The case of Add has a bunch of
funky logic which covers some of this plus a few variants (considers shifts to be
a form of multiplication), which I didn't touch.  The simplification performed is:
A*B+A*C -> A*(B+C).  The improvement is to do this in cases that were not already
handled [such as A*B-A*C -> A*(B-C), which was reported on the mailing list], and
also to do it more often by not checking for "only one use" if "B+C" simplifies.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120024 91177308-0d34-0410-b5e6-96231b3b80d8

2010-11-23 14:23:47 +00:00

12 lines

285 B

LLVM

Raw Blame History

 ; RUN: opt < %s -instcombine -S | FileCheck %s
 define i32 @foo(i32 %x, i32 %y) {
 ; CHECK: @foo
   %add = add nsw i32 %y, %x
   %mul = mul nsw i32 %add, %y
   %square = mul nsw i32 %y, %y
   %res = sub i32 %mul, %square
 ; CHECK: %res = mul i32 %x, %y
   ret i32 %res
 ; CHECK: ret i32 %res
 }