[llvm-commits] [llvm] r170495 - in /llvm/trunk: lib/CodeGen/SelectionDAG/TargetLowering.cpp test/CodeGen/X86/cmp.ll

[Craig Topper]

Author: ctopper
Date: Wed Dec 19 00:12:28 2012
New Revision: 170495

URL: http://llvm.org/viewvc/llvm-project?rev=170495&view=rev
Log:
Teach SimplifySetCC that comparing AssertZext i1 against a constant 1 can be rewritten as a compare against a constant 0 with the opposite condition.

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp
    llvm/trunk/test/CodeGen/X86/cmp.ll

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp?rev=170495&r1=170494&r2=170495&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp Wed Dec 19 00:12:28 2012
@@ -2206,9 +2206,10 @@
           Cond = (Cond == ISD::SETEQ) ? ISD::SETNE : ISD::SETEQ;
           return DAG.getSetCC(dl, VT, Op0.getOperand(0), Op0.getOperand(1),
                               Cond);
-        } else if (Op0.getOpcode() == ISD::AND &&
-                isa<ConstantSDNode>(Op0.getOperand(1)) &&
-                cast<ConstantSDNode>(Op0.getOperand(1))->getAPIntValue() == 1) {
+        }
+        if (Op0.getOpcode() == ISD::AND &&
+            isa<ConstantSDNode>(Op0.getOperand(1)) &&
+            cast<ConstantSDNode>(Op0.getOperand(1))->getAPIntValue() == 1) {
           // If this is (X&1) == / != 1, normalize it to (X&1) != / == 0.
           if (Op0.getValueType().bitsGT(VT))
             Op0 = DAG.getNode(ISD::AND, dl, VT,
@@ -2223,6 +2224,11 @@
                               DAG.getConstant(0, Op0.getValueType()),
                               Cond == ISD::SETEQ ? ISD::SETNE : ISD::SETEQ);
         }
+        if (Op0.getOpcode() == ISD::AssertZext &&
+            cast<VTSDNode>(Op0.getOperand(1))->getVT() == MVT::i1)
+          return DAG.getSetCC(dl, VT, Op0,
+                              DAG.getConstant(0, Op0.getValueType()),
+                              Cond == ISD::SETEQ ? ISD::SETNE : ISD::SETEQ);
       }
     }
 

Modified: llvm/trunk/test/CodeGen/X86/cmp.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/cmp.ll?rev=170495&r1=170494&r2=170495&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/cmp.ll (original)
+++ llvm/trunk/test/CodeGen/X86/cmp.ll Wed Dec 19 00:12:28 2012
@@ -151,3 +151,18 @@
   %conv = zext i1 %cmp to i32
   ret i32 %conv
 }
+
+define i32 @test12() uwtable ssp {
+; CHECK: test12:
+; CHECK: testb
+  %1 = call zeroext i1 @test12b()
+  br i1 %1, label %2, label %3
+
+; <label>:2                                       ; preds = %0
+  ret i32 1
+
+; <label>:3                                       ; preds = %0
+  ret i32 2
+}
+
+declare zeroext i1 @test12b()