[PATCH] D36571: [DAGCombiner] combine vextract (v1iX extract_subvector(vNiX, Idx)) into vextract(vNiX, Idx).

[Elad Cohen via Phabricator via llvm-commits]

eladcohen updated this revision to Diff 110918.
eladcohen added a comment.

Fixed Simon's comments. Thanks for the review!


https://reviews.llvm.org/D36571

Files:
  lib/CodeGen/SelectionDAG/SelectionDAG.cpp
  test/CodeGen/X86/pr33349.ll


Index: test/CodeGen/X86/pr33349.ll
===================================================================
--- test/CodeGen/X86/pr33349.ll
+++ test/CodeGen/X86/pr33349.ll
@@ -43,34 +43,26 @@
 ; SKX-NEXT:    kshiftrw $2, %k0, %k1
 ; SKX-NEXT:    kshiftlw $15, %k1, %k2
 ; SKX-NEXT:    kshiftrw $15, %k2, %k2
-; SKX-NEXT:    kshiftlw $15, %k2, %k2
-; SKX-NEXT:    kshiftrw $15, %k2, %k2
 ; SKX-NEXT:    kmovd %k2, %eax
 ; SKX-NEXT:    testb $1, %al
 ; SKX-NEXT:    fld1
 ; SKX-NEXT:    fldz
 ; SKX-NEXT:    fld %st(0)
 ; SKX-NEXT:    fcmovne %st(2), %st(0)
 ; SKX-NEXT:    kshiftlw $14, %k1, %k1
 ; SKX-NEXT:    kshiftrw $15, %k1, %k1
-; SKX-NEXT:    kshiftlw $15, %k1, %k1
-; SKX-NEXT:    kshiftrw $15, %k1, %k1
 ; SKX-NEXT:    kmovd %k1, %eax
 ; SKX-NEXT:    testb $1, %al
 ; SKX-NEXT:    fld %st(1)
 ; SKX-NEXT:    fcmovne %st(3), %st(0)
 ; SKX-NEXT:    kshiftlw $15, %k0, %k1
 ; SKX-NEXT:    kshiftrw $15, %k1, %k1
-; SKX-NEXT:    kshiftlw $15, %k1, %k1
-; SKX-NEXT:    kshiftrw $15, %k1, %k1
 ; SKX-NEXT:    kmovd %k1, %eax
 ; SKX-NEXT:    testb $1, %al
 ; SKX-NEXT:    fld %st(2)
 ; SKX-NEXT:    fcmovne %st(4), %st(0)
 ; SKX-NEXT:    kshiftlw $14, %k0, %k0
 ; SKX-NEXT:    kshiftrw $15, %k0, %k0
-; SKX-NEXT:    kshiftlw $15, %k0, %k0
-; SKX-NEXT:    kshiftrw $15, %k0, %k0
 ; SKX-NEXT:    kmovd %k0, %eax
 ; SKX-NEXT:    testb $1, %al
 ; SKX-NEXT:    fxch %st(3)
Index: lib/CodeGen/SelectionDAG/SelectionDAG.cpp
===================================================================
--- lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -4373,6 +4373,15 @@
         return getNode(ISD::EXTRACT_VECTOR_ELT, DL, VT, N1.getOperand(0), N2);
       }
     }
+
+    // EXTRACT_VECTOR_ELT of v1iX EXTRACT_SUBVECTOR could be formed
+    // when vector types are scalarized and v1iX is legal.
+    // vextract (v1iX extract_subvector(vNiX, Idx)) -> vextract(vNiX,Idx)
+    if (N1.getOpcode() == ISD::EXTRACT_SUBVECTOR &&
+        N1.getValueType().getVectorNumElements() == 1) {
+      return getNode(ISD::EXTRACT_VECTOR_ELT, DL, VT, N1.getOperand(0),
+                     N1.getOperand(1));
+    }
     break;
   case ISD::EXTRACT_ELEMENT:
     assert(N2C && (unsigned)N2C->getZExtValue() < 2 && "Bad EXTRACT_ELEMENT!");


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D36571.110918.patch
Type: text/x-patch
Size: 2254 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20170814/311205ea/attachment.bin>