[llvm-branch-commits] [llvm] [GlobalISel][AArch64] Added support for sli intrinsic (PR #171448)

[Joshua Rodriguez via llvm-branch-commits]

https://github.com/JoshdRod updated https://github.com/llvm/llvm-project/pull/171448

>From 7854c9af0229e0da243ae75cc08aa3d65c1bdc8c Mon Sep 17 00:00:00 2001
From: Josh Rodriguez <josh.rodriguez at arm.com>
Date: Tue, 9 Dec 2025 14:27:56 +0000
Subject: [PATCH] [GlobalISel][AArch64] Added support for sli intrinsic

sli intrinsic now lowers correctly for all vector types.
---
 llvm/lib/Target/AArch64/AArch64InstrGISel.td           |  7 +++++++
 llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp |  9 ++++++++-
 .../Target/AArch64/GISel/AArch64RegisterBankInfo.cpp   |  2 ++
 llvm/test/CodeGen/AArch64/arm64-vshift.ll              | 10 ----------
 4 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/llvm/lib/Target/AArch64/AArch64InstrGISel.td b/llvm/lib/Target/AArch64/AArch64InstrGISel.td
index 75354e4098fb4..3002547eb2d79 100644
--- a/llvm/lib/Target/AArch64/AArch64InstrGISel.td
+++ b/llvm/lib/Target/AArch64/AArch64InstrGISel.td
@@ -270,6 +270,12 @@ def G_URSHR: AArch64GenericInstruction {
   let hasSideEffects = 0;
 }
 
+def G_VSLI: AArch64GenericInstruction {
+  let OutOperandList = (outs type0:$dst);
+  let InOperandList = (ins type0:$src1, type0:$src2, type0:$src3);
+  let hasSideEffects = 0;
+}
+
 // Generic instruction for the BSP pseudo. It is expanded into BSP, which
 // expands into BSL/BIT/BIF after register allocation.
 def G_BSP : AArch64GenericInstruction {
@@ -321,6 +327,7 @@ def : GINodeEquiv<G_USDOT, AArch64usdot>;
 def : GINodeEquiv<G_SQSHLU, AArch64sqshlui>;
 def : GINodeEquiv<G_SRSHR, AArch64srshri>;
 def : GINodeEquiv<G_URSHR, AArch64urshri>;
+def : GINodeEquiv<G_VSLI, AArch64vsli>;
 
 def : GINodeEquiv<G_EXTRACT_VECTOR_ELT, vector_extract>;
 
diff --git a/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp b/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp
index 8951ccfbd3352..642ddf4bc92c4 100644
--- a/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp
+++ b/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp
@@ -1949,6 +1949,13 @@ bool AArch64LegalizerInfo::legalizeIntrinsic(LegalizerHelper &Helper,
       return false;
     }
   }
+  case Intrinsic::aarch64_neon_vsli: {
+    MIB.buildInstr(
+        AArch64::G_VSLI, {MI.getOperand(0)},
+        {MI.getOperand(2), MI.getOperand(3), MI.getOperand(4).getImm()});
+    MI.eraseFromParent();
+    break;
+  }
   case Intrinsic::aarch64_neon_abs: {
     // Lower the intrinsic to G_ABS.
     MIB.buildInstr(TargetOpcode::G_ABS, {MI.getOperand(0)}, {MI.getOperand(2)});
@@ -2598,4 +2605,4 @@ bool AArch64LegalizerInfo::legalizeFptrunc(MachineInstr &MI,
   MRI.replaceRegWith(Dst, Fin);
   MI.eraseFromParent();
   return true;
-}
\ No newline at end of file
+}
diff --git a/llvm/lib/Target/AArch64/GISel/AArch64RegisterBankInfo.cpp b/llvm/lib/Target/AArch64/GISel/AArch64RegisterBankInfo.cpp
index 84bc3f1e14a7a..8cd7c73f157e3 100644
--- a/llvm/lib/Target/AArch64/GISel/AArch64RegisterBankInfo.cpp
+++ b/llvm/lib/Target/AArch64/GISel/AArch64RegisterBankInfo.cpp
@@ -575,6 +575,7 @@ bool AArch64RegisterBankInfo::onlyUsesFP(const MachineInstr &MI,
   case TargetOpcode::G_LROUND:
   case TargetOpcode::G_LLROUND:
   case AArch64::G_PMULL:
+  case AArch64::G_VSLI:
     return true;
   case TargetOpcode::G_INTRINSIC:
     switch (cast<GIntrinsic>(MI).getIntrinsicID()) {
@@ -613,6 +614,7 @@ bool AArch64RegisterBankInfo::onlyDefinesFP(const MachineInstr &MI,
   case TargetOpcode::G_INSERT_VECTOR_ELT:
   case TargetOpcode::G_BUILD_VECTOR:
   case TargetOpcode::G_BUILD_VECTOR_TRUNC:
+  case AArch64::G_VSLI:
     return true;
   case TargetOpcode::G_INTRINSIC_W_SIDE_EFFECTS:
     switch (cast<GIntrinsic>(MI).getIntrinsicID()) {
diff --git a/llvm/test/CodeGen/AArch64/arm64-vshift.ll b/llvm/test/CodeGen/AArch64/arm64-vshift.ll
index a316a4bc543b5..05ddb4b5a7c64 100644
--- a/llvm/test/CodeGen/AArch64/arm64-vshift.ll
+++ b/llvm/test/CodeGen/AArch64/arm64-vshift.ll
@@ -2,16 +2,6 @@
 ; RUN: llc < %s -mtriple=arm64-eabi -global-isel=0 | FileCheck %s --check-prefixes=CHECK,CHECK-SD
 ; RUN: llc < %s -mtriple=arm64-eabi -global-isel=1 -global-isel-abort=2 2>&1 | FileCheck %s --check-prefixes=CHECK,CHECK-GI
 
-; CHECK-GI:    warning: Instruction selection used fallback path for sli8b
-; CHECK-GI NEXT:    warning: Instruction selection used fallback path for sli4h
-; CHECK-GI NEXT:    warning: Instruction selection used fallback path for sli2s
-; CHECK-GI NEXT:    warning: Instruction selection used fallback path for sli1d
-; CHECK-GI NEXT:    warning: Instruction selection used fallback path for sli1d_imm0
-; CHECK-GI NEXT:    warning: Instruction selection used fallback path for sli16b
-; CHECK-GI NEXT:    warning: Instruction selection used fallback path for sli8h
-; CHECK-GI NEXT:    warning: Instruction selection used fallback path for sli4s
-; CHECK-GI NEXT:    warning: Instruction selection used fallback path for sli2d
-
 define <8 x i8> @sqshl8b(ptr %A, ptr %B) nounwind {
 ; CHECK-LABEL: sqshl8b:
 ; CHECK:       // %bb.0: