From 7cf85e74e3885005ca8e5fdb155fa5351e255b85 Mon Sep 17 00:00:00 2001 From: Duncan Sands Date: Sat, 1 Jan 2011 16:12:09 +0000 Subject: 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. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122654 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/README.txt | 11 ----------- 1 file changed, 11 deletions(-) (limited to 'lib/Target/README.txt') diff --git a/lib/Target/README.txt b/lib/Target/README.txt index ec5c412765..c9561660b1 100644 --- a/lib/Target/README.txt +++ b/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 -} - -//===---------------------------------------------------------------------===// -- cgit v1.2.3