[llvm] r292130 - [SelectionDAG] Add knownbits support for BITREVERSE

[Simon Pilgrim via llvm-commits]

Author: rksimon
Date: Mon Jan 16 08:49:26 2017
New Revision: 292130

URL: http://llvm.org/viewvc/llvm-project?rev=292130&view=rev
Log:
[SelectionDAG] Add knownbits support for BITREVERSE 

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
    llvm/trunk/test/CodeGen/X86/known-bits-vector.ll

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp?rev=292130&r1=292129&r2=292130&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp Mon Jan 16 08:49:26 2017
@@ -2673,6 +2673,13 @@ void SelectionDAG::computeKnownBits(SDVa
     }
     break;
   }
+  case ISD::BITREVERSE: {
+    computeKnownBits(Op.getOperand(0), KnownZero2, KnownOne2, DemandedElts,
+                     Depth + 1);
+    KnownZero = KnownZero2.reverseBits();
+    KnownOne = KnownOne2.reverseBits();
+    break;
+  }
   case ISD::BSWAP: {
     computeKnownBits(Op.getOperand(0), KnownZero2, KnownOne2, DemandedElts,
                      Depth + 1);

Modified: llvm/trunk/test/CodeGen/X86/known-bits-vector.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/known-bits-vector.ll?rev=292130&r1=292129&r2=292130&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/known-bits-vector.ll (original)
+++ llvm/trunk/test/CodeGen/X86/known-bits-vector.ll Mon Jan 16 08:49:26 2017
@@ -535,34 +535,12 @@ define <4 x float> @knownbits_mask_umax_
 define <4 x i32> @knownbits_mask_bitreverse_ashr(<4 x i32> %a0) {
 ; X32-LABEL: knownbits_mask_bitreverse_ashr:
 ; X32:       # BB#0:
-; X32-NEXT:    vpand {{\.LCPI.*}}, %xmm0, %xmm0
-; X32-NEXT:    vpshufb {{.*#+}} xmm0 = xmm0[3,2,1,0,7,6,5,4,11,10,9,8,15,14,13,12]
-; X32-NEXT:    vmovdqa {{.*#+}} xmm1 = [15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15]
-; X32-NEXT:    vpand %xmm1, %xmm0, %xmm2
-; X32-NEXT:    vmovdqa {{.*#+}} xmm3 = [0,128,64,192,32,160,96,224,16,144,80,208,48,176,112,240]
-; X32-NEXT:    vpshufb %xmm2, %xmm3, %xmm2
-; X32-NEXT:    vpsrlw $4, %xmm0, %xmm0
-; X32-NEXT:    vpand %xmm1, %xmm0, %xmm0
-; X32-NEXT:    vmovdqa {{.*#+}} xmm1 = [0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15]
-; X32-NEXT:    vpshufb %xmm0, %xmm1, %xmm0
-; X32-NEXT:    vpor %xmm0, %xmm2, %xmm0
-; X32-NEXT:    vpsrad $31, %xmm0, %xmm0
+; X32-NEXT:    vxorps %xmm0, %xmm0, %xmm0
 ; X32-NEXT:    retl
 ;
 ; X64-LABEL: knownbits_mask_bitreverse_ashr:
 ; X64:       # BB#0:
-; X64-NEXT:    vpand {{.*}}(%rip), %xmm0, %xmm0
-; X64-NEXT:    vpshufb {{.*#+}} xmm0 = xmm0[3,2,1,0,7,6,5,4,11,10,9,8,15,14,13,12]
-; X64-NEXT:    vmovdqa {{.*#+}} xmm1 = [15,15,15,15,15,15,15,15,15,15,15,15,15,15,15,15]
-; X64-NEXT:    vpand %xmm1, %xmm0, %xmm2
-; X64-NEXT:    vmovdqa {{.*#+}} xmm3 = [0,128,64,192,32,160,96,224,16,144,80,208,48,176,112,240]
-; X64-NEXT:    vpshufb %xmm2, %xmm3, %xmm2
-; X64-NEXT:    vpsrlw $4, %xmm0, %xmm0
-; X64-NEXT:    vpand %xmm1, %xmm0, %xmm0
-; X64-NEXT:    vmovdqa {{.*#+}} xmm1 = [0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15]
-; X64-NEXT:    vpshufb %xmm0, %xmm1, %xmm0
-; X64-NEXT:    vpor %xmm0, %xmm2, %xmm0
-; X64-NEXT:    vpsrad $31, %xmm0, %xmm0
+; X64-NEXT:    vxorps %xmm0, %xmm0, %xmm0
 ; X64-NEXT:    retq
   %1 = and <4 x i32> %a0, <i32 -2, i32 -2, i32 -2, i32 -2>
   %2 = call <4 x i32> @llvm.bitreverse.v4i32(<4 x i32> %1)