[llvm] r326044 - [TargetLowering] SimplifyDemandedVectorElts - pass demanded elts through ADD/SUB ops

[Simon Pilgrim via llvm-commits]

Author: rksimon
Date: Sat Feb 24 12:59:14 2018
New Revision: 326044

URL: http://llvm.org/viewvc/llvm-project?rev=326044&view=rev
Log:
[TargetLowering] SimplifyDemandedVectorElts - pass demanded elts through ADD/SUB ops

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp
    llvm/trunk/test/CodeGen/X86/widen_conv-1.ll

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp?rev=326044&r1=326043&r2=326044&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp Sat Feb 24 12:59:14 2018
@@ -1536,6 +1536,19 @@ bool TargetLowering::SimplifyDemandedVec
     }
     break;
   }
+  case ISD::ADD:
+  case ISD::SUB: {
+    APInt SrcUndef, SrcZero;
+    if (SimplifyDemandedVectorElts(Op.getOperand(1), DemandedElts, SrcUndef,
+                                   SrcZero, TLO, Depth + 1))
+      return true;
+    if (SimplifyDemandedVectorElts(Op.getOperand(0), DemandedElts, KnownUndef,
+                                   KnownZero, TLO, Depth + 1))
+      return true;
+    KnownZero &= SrcZero;
+    KnownUndef &= SrcUndef;
+    break;
+  }
   case ISD::TRUNCATE:
     if (SimplifyDemandedVectorElts(Op.getOperand(0), DemandedElts, KnownUndef,
                                    KnownZero, TLO, Depth + 1))

Modified: llvm/trunk/test/CodeGen/X86/widen_conv-1.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/widen_conv-1.ll?rev=326044&r1=326043&r2=326044&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/widen_conv-1.ll (original)
+++ llvm/trunk/test/CodeGen/X86/widen_conv-1.ll Sat Feb 24 12:59:14 2018
@@ -8,7 +8,8 @@ define void @convert_v2i64_to_v2i32(<2 x
 ; X86-LABEL: convert_v2i64_to_v2i32:
 ; X86:       # %bb.0: # %entry
 ; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
-; X86-NEXT:    paddd {{\.LCPI.*}}, %xmm0
+; X86-NEXT:    pcmpeqd %xmm1, %xmm1
+; X86-NEXT:    psubd %xmm1, %xmm0
 ; X86-NEXT:    pshufd {{.*#+}} xmm0 = xmm0[0,2,2,3]
 ; X86-NEXT:    movq %xmm0, (%eax)
 ; X86-NEXT:    retl