Sanjay Patel 712b7c2463 [InstCombine] fold negate disguised as select+mul ...

Name: negate if true
  %sel = select i1 %cond, i32 -1, i32 1
  %r = mul i32 %sel, %x
  =>
  %m = sub i32 0, %x
  %r = select i1 %cond, i32 %m, i32 %x

  Name: negate if false
  %sel = select i1 %cond, i32 1, i32 -1
  %r = mul i32 %sel, %x
  =>
  %m = sub i32 0, %x
  %r = select i1 %cond, i32 %x, i32 %m

https://rise4fun.com/Alive/Nlh

llvm-svn: 373230

2019-09-30 17:02:26 +00:00

53 KiB

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