[llvm-commits] [llvm] r108136 - in /llvm/trunk: lib/Transforms/InstCombine/InstCombineAndOrXor.cpp test/Transforms/InstCombine/or.ll test/Transforms/InstCombine/xor2.ll

[Benjamin Kramer]

Author: d0k
Date: Mon Jul 12 06:54:45 2010
New Revision: 108136

URL: http://llvm.org/viewvc/llvm-project?rev=108136&view=rev
Log:
instcombine: fold (x & y) | (~x & z) and (x & y) ^ (~x & z) into ((y ^ z) & x) ^ z which is one instruction shorter. (PR6773)

before:
  %and = and i32 %y, %x
  %neg = xor i32 %x, -1
  %and4 = and i32 %z, %neg
  %xor = xor i32 %and4, %and

after:
  %xor1 = xor i32 %z, %y
  %and2 = and i32 %xor1, %x
  %xor = xor i32 %and2, %z

Modified:
    llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
    llvm/trunk/test/Transforms/InstCombine/or.ll
    llvm/trunk/test/Transforms/InstCombine/xor2.ll

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp?rev=108136&r1=108135&r2=108136&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp Mon Jul 12 06:54:45 2010
@@ -1584,6 +1584,14 @@
     if ((match(A, m_Not(m_Specific(B))) &&
          match(D, m_Not(m_Specific(C)))))
       return BinaryOperator::CreateXor(C, B);
+
+    // (A & ~C) | (B & C) -> ((B ^ A) & C) ^ A
+    if (Op0->hasOneUse() && Op1->hasOneUse() &&
+        match(C, m_Not(m_Specific(D)))) {
+      Value *Xor = Builder->CreateXor(B, A, "xor");
+      Value *And = Builder->CreateAnd(Xor, D, "and");
+      return BinaryOperator::CreateXor(And, A);
+    }
   }
   
   // (X >> Z) | (Y >> Z)  -> (X|Y) >> Z  for all shifts.
@@ -1920,6 +1928,15 @@
         return BinaryOperator::CreateAnd(NewOp, X);
       }
     }
+
+    // (A & ~C) ^ (B & C) -> ((B ^ A) & C) ^ A
+    if (Op0->hasOneUse() && Op1->hasOneUse() &&
+        match(Op0I, m_And(m_Value(A), m_Not(m_Value(D)))) &&
+        match(Op1I, m_And(m_Value(B), m_Value(D)))) {
+      Value *Xor = Builder->CreateXor(B, A, "xor");
+      Value *And = Builder->CreateAnd(Xor, D, "and");
+      return BinaryOperator::CreateXor(And, A);
+    }
   }
     
   // (icmp1 A, B) ^ (icmp2 A, B) --> (icmp3 A, B)

Modified: llvm/trunk/test/Transforms/InstCombine/or.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/or.ll?rev=108136&r1=108135&r2=108136&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/or.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/or.ll Mon Jul 12 06:54:45 2010
@@ -350,3 +350,17 @@
 ; CHECK: or <4 x i32> %and.i, %and.i129
 }
 
+; PR6773
+define i32 @test33(i32 %x, i32 %y, i32 %z) nounwind readnone {
+  %and = and i32 %y, %x
+  %not = xor i32 %x, -1
+  %and2 = and i32 %z, %not
+  %xor = xor i32 %and2, %and
+  ret i32 %xor
+; CHECK: @test33
+; CHECK: xor i32
+; CHECK: and i32
+; CHECK: xor i32
+; CHECK: ret i32
+}
+

Modified: llvm/trunk/test/Transforms/InstCombine/xor2.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/xor2.ll?rev=108136&r1=108135&r2=108136&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/xor2.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/xor2.ll Mon Jul 12 06:54:45 2010
@@ -51,3 +51,17 @@
 ; CHECK: %1 = ashr i32 %A, %B
 ; CHECK: ret i32 %1
 }
+
+; PR6773
+define i32 @test5(i32 %x, i32 %y, i32 %z) nounwind readnone {
+  %and = and i32 %y, %x
+  %not = xor i32 %x, -1
+  %and2 = and i32 %z, %not
+  %or = or i32 %and2, %and
+  ret i32 %or
+; CHECK: @test5
+; CHECK: xor i32
+; CHECK: and i32
+; CHECK: xor i32
+; CHECK: ret i32
+}