[PATCH] D91271: [AArch64] Attempt to sink mul operands

[Nicholas Guy via Phabricator via llvm-commits]

NickGuy created this revision.
NickGuy added reviewers: SjoerdMeijer, dmgreen, fhahn, efriedma.
NickGuy added a project: LLVM.
Herald added subscribers: danielkiss, hiraditya, kristof.beyls.
NickGuy requested review of this revision.

Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D91271

Files:
  llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
  llvm/test/CodeGen/AArch64/aarch64-matrix-smull.ll
  llvm/test/CodeGen/AArch64/aarch64-matrix-umull.ll


Index: llvm/test/CodeGen/AArch64/aarch64-matrix-umull.ll
===================================================================
--- llvm/test/CodeGen/AArch64/aarch64-matrix-umull.ll
+++ llvm/test/CodeGen/AArch64/aarch64-matrix-umull.ll
@@ -7,7 +7,7 @@
 ; CHECK-NEXT:    and w9, w3, #0xffff
 ; CHECK-NEXT:    // kill: def $w0 killed $w0 def $x0
 ; CHECK-NEXT:    and x8, x0, #0xfffffff8
-; CHECK-NEXT:    dup v0.4s, w9
+; CHECK-NEXT:    dup v0.4h, w9
 ; CHECK-NEXT:  .LBB0_1: // %vector.body
 ; CHECK-NEXT:    // =>This Inner Loop Header: Depth=1
 ; CHECK-NEXT:    add x9, x2, w0, uxtw #1
@@ -15,10 +15,8 @@
 ; CHECK-NEXT:    add x9, x1, w0, uxtw #2
 ; CHECK-NEXT:    subs x8, x8, #8 // =8
 ; CHECK-NEXT:    add w0, w0, #8 // =8
-; CHECK-NEXT:    ushll v1.4s, v1.4h, #0
-; CHECK-NEXT:    ushll v2.4s, v2.4h, #0
-; CHECK-NEXT:    mul v1.4s, v0.4s, v1.4s
-; CHECK-NEXT:    mul v2.4s, v0.4s, v2.4s
+; CHECK-NEXT:    umull v1.4s, v0.4h, v1.4h
+; CHECK-NEXT:    umull v2.4s, v0.4h, v2.4h
 ; CHECK-NEXT:    stp q1, q2, [x9]
 ; CHECK-NEXT:    b.ne .LBB0_1
 ; CHECK-NEXT:  // %bb.2: // %for.end12
Index: llvm/test/CodeGen/AArch64/aarch64-matrix-smull.ll
===================================================================
--- llvm/test/CodeGen/AArch64/aarch64-matrix-smull.ll
+++ llvm/test/CodeGen/AArch64/aarch64-matrix-smull.ll
@@ -4,10 +4,10 @@
 define void @matrix_mul_signed(i32 %N, i32* nocapture %C, i16* nocapture readonly %A, i16 %val) {
 ; CHECK-LABEL: matrix_mul_signed:
 ; CHECK:       // %bb.0: // %vector.header
-; CHECK-NEXT:    dup v0.4h, w3
+; CHECK-NEXT:    sxth w9, w3
 ; CHECK-NEXT:    // kill: def $w0 killed $w0 def $x0
-; CHECK-NEXT:    sshll v0.4s, v0.4h, #0
 ; CHECK-NEXT:    and x8, x0, #0xfffffff8
+; CHECK-NEXT:    dup v0.4h, w9
 ; CHECK-NEXT:  .LBB0_1: // %vector.body
 ; CHECK-NEXT:    // =>This Inner Loop Header: Depth=1
 ; CHECK-NEXT:    add x9, x2, w0, sxtw #1
@@ -15,10 +15,8 @@
 ; CHECK-NEXT:    add x9, x1, w0, sxtw #2
 ; CHECK-NEXT:    subs x8, x8, #8 // =8
 ; CHECK-NEXT:    add w0, w0, #8 // =8
-; CHECK-NEXT:    sshll v1.4s, v1.4h, #0
-; CHECK-NEXT:    sshll v2.4s, v2.4h, #0
-; CHECK-NEXT:    mul v1.4s, v0.4s, v1.4s
-; CHECK-NEXT:    mul v2.4s, v0.4s, v2.4s
+; CHECK-NEXT:    smull v1.4s, v0.4h, v1.4h
+; CHECK-NEXT:    smull v2.4s, v0.4h, v2.4h
 ; CHECK-NEXT:    stp q1, q2, [x9]
 ; CHECK-NEXT:    b.ne .LBB0_1
 ; CHECK-NEXT:  // %bb.2: // %for.end12
Index: llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
===================================================================
--- llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -10572,6 +10572,25 @@
 
     return true;
   }
+  case Instruction::Mul: {
+
+    for (auto &Op : I->operands()) {
+      // Make sure we are not already sinking this operand
+      if (any_of(Ops, [&](Use *U) { return U->get() == Op; }))
+        continue;
+
+      ShuffleVectorInst *Shuffle = dyn_cast<ShuffleVectorInst>(Op);
+      if (!Shuffle)
+        continue;
+
+      // TODO Why can this sometimes fail?
+      if (isa<Instruction>(&Shuffle->getOperandUse(0)))
+        Ops.push_back(&Shuffle->getOperandUse(0));
+      Ops.push_back(&Op);
+    }
+
+    return true;
+  }
   default:
     return false;
   }


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D91271.304528.patch
Type: text/x-patch
Size: 3232 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20201111/e0a0e1be/attachment.bin>