[PATCH] Added InstCombine Transform for ((B | C) & A) | B -> B | (A & C)

[sonam kumari]

Hi David,

Thanks for your valuable comments.
I have changed the second "if" condition as you mentioned.
For handling ( ( B | C ) & A ) | C -> C | ( A & B) :
I passed the following test case using reassociate before instcombine 

define i32 @test19(i32 %x, i32 %y, i32 %z) {
  %or = or i32 %y, %z
  %and = and i32 %x, %or
  %or1 = or i32 %and, %z
  ret i32 %or1
}

 The output I got was :

define i32 @test19(i32 %x, i32 %y, i32 %z) {
  %1 = and i32 %x, %y
  %or1 = or i32 %1, %z
  ret i32 %or1
}

So, I guess we need not handle this case.
Please help in reviewing the same.

Thanks,
Sonam.

http://reviews.llvm.org/D4865

Files:
  lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
  test/Transforms/InstCombine/or.ll

Index: lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
===================================================================
--- lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -2124,6 +2124,11 @@
       if (Op0->hasOneUse() || cast<BinaryOperator>(Op0)->hasOneUse())
         return BinaryOperator::CreateOr(Op1, C);
 
+  // ((B | C) & A) | B -> B | (A & C)
+  if (match(Op0, m_And(m_Or(m_Value(B), m_Value(C)), m_Value(A))))
+    if (Op1 == B)
+      return BinaryOperator::CreateOr(B, Builder->CreateAnd(A, C));
+
   // (X >> Z) | (Y >> Z)  -> (X|Y) >> Z  for all shifts.
   if (BinaryOperator *SI1 = dyn_cast<BinaryOperator>(Op1)) {
     if (BinaryOperator *SI0 = dyn_cast<BinaryOperator>(Op0))
Index: test/Transforms/InstCombine/or.ll
===================================================================
--- test/Transforms/InstCombine/or.ll
+++ test/Transforms/InstCombine/or.ll
@@ -469,3 +469,14 @@
  %or = or i32 %xor, %and
  ret i32 %or
 }
+
+define i32 @test45(i32 %x, i32 %y, i32 %z) {
+; CHECK-LABEL: test45(
+; CHECK-NEXT: %1 = and i32 %x, %z
+; CHECK-NEXT: %or1 = or i32 %1, %y
+; CHECK-NEXT: ret i32 %or1
+  %or = or i32 %y, %z
+  %and = and i32 %x, %or
+  %or1 = or i32 %and, %y
+  ret i32 %or1
+}
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