[llvm-commits] [llvm] r108422 - in /llvm/trunk: lib/Transforms/InstCombine/InstCombineAndOrXor.cpp lib/Transforms/InstCombine/InstCombineSelect.cpp test/Transforms/InstCombine/bit-checks.ll

[Owen Anderson]

Author: resistor
Date: Thu Jul 15 10:00:23 2010
New Revision: 108422

URL: http://llvm.org/viewvc/llvm-project?rev=108422&view=rev
Log:
Reapply r108378, with bugfixes, testcase, and improved comment formatting.
This now passes LIT, nighty test, and llvm-gcc bootstrap on my machine.

Added:
    llvm/trunk/test/Transforms/InstCombine/bit-checks.ll
Modified:
    llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
    llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp?rev=108422&r1=108421&r2=108422&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp Thu Jul 15 10:00:23 2010
@@ -472,6 +472,25 @@
       Value *NewOr = Builder->CreateOr(Val, Val2);
       return Builder->CreateICmp(LHSCC, NewOr, LHSCst);
     }
+    
+    // (icmp ne (A & C1), 0) & (icmp ne (A & C2), 0) -->
+    // (icmp eq (A & (C1|C2)), (C1|C2))
+    if (LHSCC == ICmpInst::ICMP_NE && LHSCst->isZero()) {
+      Instruction *I1 = dyn_cast<Instruction>(Val);
+      Instruction *I2 = dyn_cast<Instruction>(Val2);
+      if (I1 && I1->getOpcode() == Instruction::And &&
+          I2 && I2->getOpcode() == Instruction::And &&
+          I1->getOperand(0) == I1->getOperand(0)) {
+        ConstantInt *CI1 = dyn_cast<ConstantInt>(I1->getOperand(1));
+        ConstantInt *CI2 = dyn_cast<ConstantInt>(I2->getOperand(1));
+        if (CI1 && !CI1->isZero() && CI2 && !CI2->isZero() &&
+            CI1->getValue().operator&(CI2->getValue()) == 0) {
+          Constant *ConstOr = ConstantExpr::getOr(CI1, CI2);
+          Value *NewAnd = Builder->CreateAnd(I1->getOperand(0), ConstOr);
+          return Builder->CreateICmp(ICmpInst::ICMP_EQ, NewAnd, ConstOr);
+        }
+      }
+    }
   }
   
   // From here on, we only handle:

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp?rev=108422&r1=108421&r2=108422&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp Thu Jul 15 10:00:23 2010
@@ -699,6 +699,34 @@
     SI.setOperand(2, TrueVal);
     return &SI;
   }
+  
+  // select (A == 0 | B == 0), T, F--> select (A != 0 & B != 0), F, T
+  // Note: This is a canonicalization rather than an optimization, and is used
+  // to expose opportunities to other instcombine transforms.
+  Instruction* CondInst = dyn_cast<Instruction>(CondVal);
+  if (CondInst && CondInst->hasOneUse() && 
+      CondInst->getOpcode() == Instruction::Or) {
+    ICmpInst *LHSCmp = dyn_cast<ICmpInst>(CondInst->getOperand(0));
+    ICmpInst *RHSCmp = dyn_cast<ICmpInst>(CondInst->getOperand(1));
+    if (LHSCmp && LHSCmp->hasOneUse() &&
+                  LHSCmp->getPredicate() == ICmpInst::ICMP_EQ &&
+        RHSCmp && RHSCmp->hasOneUse() &&
+                  RHSCmp->getPredicate() == ICmpInst::ICMP_EQ) {
+      ConstantInt* C1 = dyn_cast<ConstantInt>(LHSCmp->getOperand(1));
+      ConstantInt* C2 = dyn_cast<ConstantInt>(RHSCmp->getOperand(1));
+      if (C1 && C1->isZero() && C2 && C2->isZero()) {
+        LHSCmp->setPredicate(ICmpInst::ICMP_NE);
+        RHSCmp->setPredicate(ICmpInst::ICMP_NE);
+        Value *And =
+          InsertNewInstBefore(BinaryOperator::CreateAnd(LHSCmp, RHSCmp,
+                                             "and."+CondVal->getName()), SI);
+        SI.setOperand(0, And);
+        SI.setOperand(1, FalseVal);
+        SI.setOperand(2, TrueVal);
+        return &SI;
+      }
+    }
+  }
 
   return 0;
 }

Added: llvm/trunk/test/Transforms/InstCombine/bit-checks.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/bit-checks.ll?rev=108422&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/bit-checks.ll (added)
+++ llvm/trunk/test/Transforms/InstCombine/bit-checks.ll Thu Jul 15 10:00:23 2010
@@ -0,0 +1,15 @@
+; This test makes sure that these instructions are properly eliminated.
+;
+; RUN: opt < %s -instcombine -S | \
+; RUN:    not grep {tobool}
+; END.
+define i32 @main(i32 %argc, i8** %argv) nounwind ssp {
+entry:
+  %and = and i32 %argc, 1                         ; <i32> [#uses=1]
+  %tobool = icmp ne i32 %and, 0                   ; <i1> [#uses=1]
+  %and2 = and i32 %argc, 2                        ; <i32> [#uses=1]
+  %tobool3 = icmp ne i32 %and2, 0                 ; <i1> [#uses=1]
+  %or.cond = and i1 %tobool, %tobool3             ; <i1> [#uses=1]
+  %retval.0 = select i1 %or.cond, i32 2, i32 1    ; <i32> [#uses=1]
+  ret i32 %retval.0
+}