Fix a README item by having InstructionSimplify do a mild form of value

numbering, in which it considers (for example) "%a = add i32 %x, %y" and
"%b = add i32 %x, %y" to be equal because the operands are equal and the
result of the instructions only depends on the values of the operands.
This has almost no effect (it removes 4 instructions from gcc-as-one-file),
and perhaps slows down compilation: I measured a 0.4% slowdown on the large
gcc-as-one-file testcase, but it wasn't statistically significant.

llvm-svn: 122654

1 files changed, 0 insertions, 11 deletions

diff --git a/llvm/lib/Target/README.txt b/llvm/lib/Target/README.txt
index ec5c412765f..c9561660b1c 100644
--- a/llvm/lib/Target/README.txt
+++ b/llvm/lib/Target/README.txt
@@ -2065,14 +2065,3 @@ entry:
 }
 
 //===---------------------------------------------------------------------===//
-
-This compare could fold to false:
-
-define i1 @g(i32 a) nounwind readnone {
-       %add = shl i32 %a, 1
-       %mul = shl i32 %a, 1
-       %cmp = icmp ugt i32 %add, %mul
-       ret i1 %cmp
-}
-
-//===---------------------------------------------------------------------===//