[llvm] r362483 - [SelectionDAG] Add fpto[us]i(undef) --> undef constant fold

[Simon Pilgrim via llvm-commits]

Author: rksimon
Date: Tue Jun  4 03:04:55 2019
New Revision: 362483

URL: http://llvm.org/viewvc/llvm-project?rev=362483&view=rev
Log:
[SelectionDAG] Add fpto[us]i(undef) --> undef constant fold

Follow up to D62807.

Differential Revision: https://reviews.llvm.org/D62811

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
    llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
    llvm/trunk/test/CodeGen/X86/vec_fp_to_int-widen.ll
    llvm/trunk/test/CodeGen/X86/vec_fp_to_int.ll

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=362483&r1=362482&r2=362483&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Tue Jun  4 03:04:55 2019
@@ -12770,6 +12770,10 @@ SDValue DAGCombiner::visitFP_TO_SINT(SDN
   SDValue N0 = N->getOperand(0);
   EVT VT = N->getValueType(0);
 
+  // fold (fp_to_sint undef) -> undef
+  if (N0.isUndef())
+    return DAG.getUNDEF(VT);
+
   // fold (fp_to_sint c1fp) -> c1
   if (isConstantFPBuildVectorOrConstantFP(N0))
     return DAG.getNode(ISD::FP_TO_SINT, SDLoc(N), VT, N0);
@@ -12781,6 +12785,10 @@ SDValue DAGCombiner::visitFP_TO_UINT(SDN
   SDValue N0 = N->getOperand(0);
   EVT VT = N->getValueType(0);
 
+  // fold (fp_to_uint undef) -> undef
+  if (N0.isUndef())
+    return DAG.getUNDEF(VT);
+
   // fold (fp_to_uint c1fp) -> c1
   if (isConstantFPBuildVectorOrConstantFP(N0))
     return DAG.getNode(ISD::FP_TO_UINT, SDLoc(N), VT, N0);

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp?rev=362483&r1=362482&r2=362483&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp Tue Jun  4 03:04:55 2019
@@ -4440,6 +4440,11 @@ SDValue SelectionDAG::getNode(unsigned O
     if (Operand.isUndef())
       return getUNDEF(VT);
     break;
+  case ISD::FP_TO_SINT:
+  case ISD::FP_TO_UINT:
+    if (Operand.isUndef())
+      return getUNDEF(VT);
+    break;
   case ISD::SINT_TO_FP:
   case ISD::UINT_TO_FP:
     // [us]itofp(undef) = 0, because the result value is bounded.

Modified: llvm/trunk/test/CodeGen/X86/vec_fp_to_int-widen.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/vec_fp_to_int-widen.ll?rev=362483&r1=362482&r2=362483&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/vec_fp_to_int-widen.ll (original)
+++ llvm/trunk/test/CodeGen/X86/vec_fp_to_int-widen.ll Tue Jun  4 03:04:55 2019
@@ -106,9 +106,7 @@ define <2 x i32> @fptosi_2f64_to_2i32(<2
 define <4 x i32> @fptosi_4f64_to_2i32(<2 x double> %a) {
 ; SSE-LABEL: fptosi_4f64_to_2i32:
 ; SSE:       # %bb.0:
-; SSE-NEXT:    cvttpd2dq %xmm0, %xmm1
 ; SSE-NEXT:    cvttpd2dq %xmm0, %xmm0
-; SSE-NEXT:    unpcklpd {{.*#+}} xmm0 = xmm0[0],xmm1[0]
 ; SSE-NEXT:    retq
 ;
 ; AVX-LABEL: fptosi_4f64_to_2i32:

Modified: llvm/trunk/test/CodeGen/X86/vec_fp_to_int.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/vec_fp_to_int.ll?rev=362483&r1=362482&r2=362483&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/vec_fp_to_int.ll (original)
+++ llvm/trunk/test/CodeGen/X86/vec_fp_to_int.ll Tue Jun  4 03:04:55 2019
@@ -108,9 +108,7 @@ define <2 x i32> @fptosi_2f64_to_2i32(<2
 define <4 x i32> @fptosi_4f64_to_2i32(<2 x double> %a) {
 ; SSE-LABEL: fptosi_4f64_to_2i32:
 ; SSE:       # %bb.0:
-; SSE-NEXT:    cvttpd2dq %xmm0, %xmm1
 ; SSE-NEXT:    cvttpd2dq %xmm0, %xmm0
-; SSE-NEXT:    unpcklpd {{.*#+}} xmm0 = xmm0[0],xmm1[0]
 ; SSE-NEXT:    retq
 ;
 ; AVX-LABEL: fptosi_4f64_to_2i32: