Fix two-address pass's aggressive instruction commuting heuristics. It's meant

to catch cases like:
 %reg1024<def> = MOV r1
 %reg1025<def> = MOV r0
 %reg1026<def> = ADD %reg1024, %reg1025
 r0            = MOV %reg1026

By commuting ADD, it let coalescer eliminate all of the copies. However, there
was a bug in the heuristics where it ended up commuting the ADD in:

 %reg1024<def> = MOV r0
 %reg1025<def> = MOV 0
 %reg1026<def> = ADD %reg1024, %reg1025
 r0            = MOV %reg1026

That did no benefit but rather ensure the last MOV would not be coalesced.

rdar://11355268


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156048 91177308-0d34-0410-b5e6-96231b3b80d8

test/CodeGen/X86/4char-promote.ll

@@ -1,11 +1,12 @@
 ; A test for checking PR 9623
-;RUN: llc -march=x86-64 -mcpu=corei7 -promote-elements < %s | FileCheck %s
+; RUN: llc -march=x86-64 -mcpu=corei7 -promote-elements < %s | FileCheck %s
 
 target triple = "x86_64-apple-darwin"
 
 ; CHECK:  pmulld 
 ; CHECK:  paddd  
-; CHECK:  movdqa 
+; CHECK-NOT:  movdqa 
+; CHECK:  ret
 
 define <4 x i8> @foo(<4 x i8> %x, <4 x i8> %y) {
 entry:

test/CodeGen/X86/jump_sign.ll

@@ -22,6 +22,7 @@ declare i32 @bar(...)
 declare i32 @baz(...)
 
 ; rdar://10633221
+; rdar://11355268
 define i32 @g(i32 %a, i32 %b) nounwind {
 entry:
 ; CHECK: g:
@@ -39,6 +40,8 @@ entry:
 ; CHECK: h:
 ; CHECK-NOT: cmp
 ; CHECK: cmov
+; CHECK-NOT: movl
+; CHECK: ret
   %cmp = icmp slt i32 %b, %a
   %sub = sub nsw i32 %a, %b
   %cond = select i1 %cmp, i32 %sub, i32 0
@@ -49,6 +52,8 @@ entry:
 ; CHECK: i:
 ; CHECK-NOT: cmp
 ; CHECK: cmov
+; CHECK-NOT: movl
+; CHECK: ret
   %cmp = icmp sgt i32 %a, %b
   %sub = sub nsw i32 %a, %b
   %cond = select i1 %cmp, i32 %sub, i32 0
@@ -59,6 +64,8 @@ entry:
 ; CHECK: j:
 ; CHECK-NOT: cmp
 ; CHECK: cmov
+; CHECK-NOT: movl
+; CHECK: ret
   %cmp = icmp ugt i32 %a, %b
   %sub = sub i32 %a, %b
   %cond = select i1 %cmp, i32 %sub, i32 0
@@ -69,6 +76,8 @@ entry:
 ; CHECK: k:
 ; CHECK-NOT: cmp
 ; CHECK: cmov
+; CHECK-NOT: movl
+; CHECK: ret
   %cmp = icmp ult i32 %b, %a
   %sub = sub i32 %a, %b
   %cond = select i1 %cmp, i32 %sub, i32 0