[llvm] r292881 - [X86] Don't split v8i32 all ones values if only AVX1 is available. Keep it intact and split it at isel.

[Craig Topper via llvm-commits]

Author: ctopper
Date: Mon Jan 23 22:33:03 2017
New Revision: 292881

URL: http://llvm.org/viewvc/llvm-project?rev=292881&view=rev
Log:
[X86] Don't split v8i32 all ones values if only AVX1 is available. Keep it intact and split it at isel.

This allows us to remove the check in ANDN combining that had to look through the extraction.

Modified:
    llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
    llvm/trunk/lib/Target/X86/X86InstrSSE.td

Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=292881&r1=292880&r2=292881&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Mon Jan 23 22:33:03 2017
@@ -5090,8 +5090,7 @@ static SDValue concat256BitVectors(SDVal
 }
 
 /// Returns a vector of specified type with all bits set.
-/// Always build ones vectors as <4 x i32> or <8 x i32>. For 256-bit types with
-/// no AVX2 support, use two <4 x i32> inserted in a <8 x i32> appropriately.
+/// Always build ones vectors as <4 x i32>, <8 x i32> or <16 x i32>.
 /// Then bitcast to their original type, ensuring they get CSE'd.
 static SDValue getOnesVector(EVT VT, const X86Subtarget &Subtarget,
                              SelectionDAG &DAG, const SDLoc &dl) {
@@ -5100,13 +5099,7 @@ static SDValue getOnesVector(EVT VT, con
 
   APInt Ones = APInt::getAllOnesValue(32);
   unsigned NumElts = VT.getSizeInBits() / 32;
-  SDValue Vec;
-  if (!Subtarget.hasInt256() && NumElts == 8) {
-    Vec = DAG.getConstant(Ones, dl, MVT::v4i32);
-    Vec = concat128BitVectors(Vec, Vec, MVT::v8i32, 8, DAG, dl);
-  } else {
-    Vec = DAG.getConstant(Ones, dl, MVT::getVectorVT(MVT::i32, NumElts));
-  }
+  SDValue Vec = DAG.getConstant(Ones, dl, MVT::getVectorVT(MVT::i32, NumElts));
   return DAG.getBitcast(VT, Vec);
 }
 
@@ -30633,20 +30626,9 @@ static SDValue combineANDXORWithAllOnesI
 
   N01 = peekThroughBitcasts(N01);
 
-  // Either match a direct AllOnes for 128, 256, and 512-bit vectors, or an
-  // insert_subvector building a 256-bit AllOnes vector.
-  if (!ISD::isBuildVectorAllOnes(N01.getNode())) {
-    if (!VT.is256BitVector() || N01->getOpcode() != ISD::INSERT_SUBVECTOR)
-      return SDValue();
+  if (!ISD::isBuildVectorAllOnes(N01.getNode()))
+    return SDValue();
 
-    SDValue V1 = N01->getOperand(0);
-    SDValue V2 = N01->getOperand(1);
-    if (V1.getOpcode() != ISD::INSERT_SUBVECTOR ||
-        !V1.getOperand(0).isUndef() ||
-        !ISD::isBuildVectorAllOnes(V1.getOperand(1).getNode()) ||
-        !ISD::isBuildVectorAllOnes(V2.getNode()))
-      return SDValue();
-  }
   return DAG.getNode(X86ISD::ANDNP, DL, VT, N00, N1);
 }
 

Modified: llvm/trunk/lib/Target/X86/X86InstrSSE.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86InstrSSE.td?rev=292881&r1=292880&r2=292881&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86InstrSSE.td (original)
+++ llvm/trunk/lib/Target/X86/X86InstrSSE.td Mon Jan 23 22:33:03 2017
@@ -491,7 +491,6 @@ let isReMaterializable = 1, isAsCheapAsA
                           [(set VR256:$dst, (v8i32 immAllOnesV))]>;
 }
 
-
 //===----------------------------------------------------------------------===//
 // SSE 1 & 2 - Move FP Scalar Instructions
 //
@@ -7862,6 +7861,15 @@ def VINSERTF128rm : AVXAIi8<0x18, MRMSrc
           []>, Sched<[WriteFShuffleLd, ReadAfterLd]>, VEX_4V, VEX_L;
 }
 
+
+// Without AVX2 we need to concat two v4i32 V_SETALLONES to create a 256-bit
+// all ones value.
+let Predicates = [HasAVX1Only] in
+def : Pat<(v8i32 immAllOnesV),
+          (VINSERTF128rr
+           (INSERT_SUBREG (v8i32 (IMPLICIT_DEF)), (V_SETALLONES), sub_xmm),
+           (V_SETALLONES), 1)>;
+
 multiclass vinsert_lowering<string InstrStr, ValueType From, ValueType To,
                             PatFrag memop_frag> {
   def : Pat<(vinsert128_insert:$ins (To VR256:$src1), (From VR128:$src2),