From: Quentin Colombet <qcolombet@apple.com>
Date: Thu, 2 Apr 2015 18:54:23 +0000 (+0000)
Subject: [AArch64] Add a comment to make it explicit why we increased the complexity.
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=fa8f2103a5878b63296b4d521aa68ea7f4d6aed9;p=oota-llvm.git

[AArch64] Add a comment to make it explicit why we increased the complexity.
Follow-up of r233653.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233936 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/AArch64/AArch64InstrFormats.td b/lib/Target/AArch64/AArch64InstrFormats.td
index 555b5006eba..0e457329f73 100644
--- a/lib/Target/AArch64/AArch64InstrFormats.td
+++ b/lib/Target/AArch64/AArch64InstrFormats.td
@@ -1637,6 +1637,10 @@ multiclass AddSub<bit isSub, string mnemonic,
                   SDPatternOperator OpNode = null_frag> {
   let hasSideEffects = 0, isReMaterializable = 1, isAsCheapAsAMove = 1 in {
   // Add/Subtract immediate
+  // Increase the weight of the immediate variant to try to match it before
+  // the extended register variant.
+  // We used to match the register variant before the immediate when the
+  // register argument could be implicitly zero-extended.
   let AddedComplexity = 6 in
   def Wri  : BaseAddSubImm<isSub, 0, GPR32sp, GPR32sp, addsub_shifted_imm32,
                            mnemonic, OpNode> {