Thumb2 size reduction fix for tied operands of tMUL.

The tied source operand of tMUL is the second source operand, not the
first like every other two-address thumb instruction. Special case it
in the size reduction pass to make sure we create the tMUL instruction
properly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151315 91177308-0d34-0410-b5e6-96231b3b80d8

test/CodeGen/ARM/avoid-cpsr-rmw.ll

@@ -6,9 +6,9 @@
 define i32 @t1(i32 %a, i32 %b, i32 %c, i32 %d) nounwind readnone {
  entry:
 ; CHECK: t1:
-; CHECK: muls [[REG:(r[0-9]+)]], r2, r3
-; CHECK-NEXT: mul  [[REG2:(r[0-9]+)]], r0, r1
-; CHECK-NEXT: muls r0, [[REG2]], [[REG]]
+; CHECK: muls [[REG:(r[0-9]+)]], r3, r2
+; CHECK-NEXT: mul  [[REG2:(r[0-9]+)]], r1, r0
+; CHECK-NEXT: muls r0, [[REG]], [[REG2]]
   %0 = mul nsw i32 %a, %b
   %1 = mul nsw i32 %c, %d
   %2 = mul nsw i32 %0, %1

test/CodeGen/Thumb2/thumb2-mls.ll

@@ -15,5 +15,5 @@ define i32 @f2(i32 %a, i32 %b, i32 %c) {
     ret i32 %tmp2
 }
 ; CHECK: f2:
-; CHECK: 	muls	r0, r0, r1
+; CHECK: 	muls	r0, r1, r0
 

test/CodeGen/Thumb2/thumb2-mul.ll

@@ -2,7 +2,7 @@
 
 define i32 @f1(i32 %a, i32 %b, i32 %c) {
 ; CHECK: f1:
-; CHECK: muls r0, r0, r1
+; CHECK: muls r0, r1, r0
     %tmp = mul i32 %a, %b
     ret i32 %tmp
 }