[llvm] 7c3b807 - [X86] Add DAG combine to turn (v2i64 (scalar_to_vector (i64 (bitconvert (mmx))))) to MOVQ2DQ. Remove unneeded isel patterns.

[Craig Topper via llvm-commits]

Author: Craig Topper
Date: 2020-05-30T19:47:08-07:00
New Revision: 7c3b8077cc3feed2de3de6f3efb0627d619d1434

URL: https://github.com/llvm/llvm-project/commit/7c3b8077cc3feed2de3de6f3efb0627d619d1434
DIFF: https://github.com/llvm/llvm-project/commit/7c3b8077cc3feed2de3de6f3efb0627d619d1434.diff

LOG: [X86] Add DAG combine to turn (v2i64 (scalar_to_vector (i64 (bitconvert (mmx))))) to MOVQ2DQ. Remove unneeded isel patterns.

We already had a DAG combine for (mmx (bitconvert (i64 (extractelement v2i64))))
to MOVDQ2Q.

Remove patterns for MMX_MOVQ2DQrr/MMX_MOVDQ2Qrr that use
scalar_to_vector/extractelement involving i64 scalar type with
v2i64 and x86mmx.

Added: 
    

Modified: 
    llvm/lib/Target/X86/X86ISelLowering.cpp
    llvm/lib/Target/X86/X86InstrMMX.td

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index fa1b194afc1a..5eba9f3875a9 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -47463,6 +47463,11 @@ static SDValue combineScalarToVector(SDNode *N, SelectionDAG &DAG) {
         VT, DAG.getNode(ISD::SCALAR_TO_VECTOR, DL, MVT::v4i32,
                         DAG.getAnyExtOrTrunc(Src.getOperand(0), DL, MVT::i32)));
 
+  // Combine (v2i64 (scalar_to_vector (i64 (bitconvert (mmx))))) to MOVQ2DQ.
+  if (VT == MVT::v2i64 && Src.getOpcode() == ISD::BITCAST &&
+      Src.getOperand(0).getValueType() == MVT::x86mmx)
+    return DAG.getNode(X86ISD::MOVQ2DQ, DL, VT, Src.getOperand(0));
+
   return SDValue();
 }
 

diff  --git a/llvm/lib/Target/X86/X86InstrMMX.td b/llvm/lib/Target/X86/X86InstrMMX.td
index 415e0389145a..92c3561ac21a 100644
--- a/llvm/lib/Target/X86/X86InstrMMX.td
+++ b/llvm/lib/Target/X86/X86InstrMMX.td
@@ -232,20 +232,21 @@ def MMX_MOVQ64mr : MMXI<0x7F, MRMDestMem, (outs), (ins i64mem:$dst, VR64:$src),
                         "movq\t{$src, $dst|$dst, $src}",
                         [(store (x86mmx VR64:$src), addr:$dst)]>;
 
+def MMX_X86movdq2q : SDNode<"X86ISD::MOVDQ2Q", SDTypeProfile<1, 1,
+                            [SDTCisVT<0, x86mmx>, SDTCisVT<1, v2i64>]>>;
+def MMX_X86movq2dq : SDNode<"X86ISD::MOVQ2DQ", SDTypeProfile<1, 1,
+                            [SDTCisVT<0, v2i64>, SDTCisVT<1, x86mmx>]>>;
+
 let SchedRW = [SchedWriteVecMoveLS.XMM.RR] in {
 def MMX_MOVDQ2Qrr : MMXSDIi8<0xD6, MRMSrcReg, (outs VR64:$dst),
                              (ins VR128:$src), "movdq2q\t{$src, $dst|$dst, $src}",
                              [(set VR64:$dst,
-                               (x86mmx (bitconvert
-                               (i64 (extractelt (v2i64 VR128:$src),
-                                     (iPTR 0))))))]>;
+                               (x86mmx (MMX_X86movdq2q VR128:$src)))]>;
 
 def MMX_MOVQ2DQrr : MMXS2SIi8<0xD6, MRMSrcReg, (outs VR128:$dst),
                               (ins VR64:$src), "movq2dq\t{$src, $dst|$dst, $src}",
                               [(set VR128:$dst,
-                                (v2i64
-                                  (scalar_to_vector
-                                    (i64 (bitconvert (x86mmx VR64:$src))))))]>;
+                                (v2i64 (MMX_X86movq2dq VR64:$src)))]>;
 
 let isCodeGenOnly = 1, hasSideEffects = 1 in {
 def MMX_MOVQ2FR64rr: MMXS2SIi8<0xD6, MRMSrcReg, (outs FR64:$dst),
@@ -550,24 +551,6 @@ def MMX_PMOVMSKBrr : MMXI<0xD7, MRMSrcReg, (outs GR32orGR64:$dst),
                                 (int_x86_mmx_pmovmskb VR64:$src))]>,
                           Sched<[WriteMMXMOVMSK]>;
 
-// MMX to XMM for vector types
-def MMX_X86movq2dq : SDNode<"X86ISD::MOVQ2DQ", SDTypeProfile<1, 1,
-                            [SDTCisVT<0, v2i64>, SDTCisVT<1, x86mmx>]>>;
-
-def : Pat<(v2i64 (MMX_X86movq2dq VR64:$src)),
-          (v2i64 (MMX_MOVQ2DQrr VR64:$src))>;
-
-// Low word of XMM to MMX.
-def MMX_X86movdq2q : SDNode<"X86ISD::MOVDQ2Q", SDTypeProfile<1, 1,
-                            [SDTCisVT<0, x86mmx>, SDTCisVT<1, v2i64>]>>;
-
-def : Pat<(x86mmx (MMX_X86movdq2q VR128:$src)),
-          (x86mmx (MMX_MOVDQ2Qrr VR128:$src))>;
-
-def : Pat<(v2i64 (X86vzmovl (scalar_to_vector
-                             (i64 (bitconvert (x86mmx VR64:$src)))))),
-          (MMX_MOVQ2DQrr VR64:$src)>;
-
 // Misc.
 let SchedRW = [SchedWriteShuffle.MMX] in {
 let Uses = [EDI], Predicates = [HasMMX, HasSSE1,Not64BitMode] in