[llvm] intrinsic to generate a ubfx instruction (PR #80103)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-ir

Author: Rama Malladi (RamaMalladiAWS)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/80103.diff


4 Files Affected:

- (modified) llvm/include/llvm/IR/IntrinsicsAArch64.td (+3) 
- (modified) llvm/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp (+13) 
- (modified) llvm/lib/Target/AArch64/AArch64InstrInfo.td (+6) 
- (added) llvm/test/CodeGen/AArch64/ubfx-64-intrinsic.ll (+36) 


``````````diff
diff --git a/llvm/include/llvm/IR/IntrinsicsAArch64.td b/llvm/include/llvm/IR/IntrinsicsAArch64.td
index 921e5b95ae03e..868265dcd1192 100644
--- a/llvm/include/llvm/IR/IntrinsicsAArch64.td
+++ b/llvm/include/llvm/IR/IntrinsicsAArch64.td
@@ -855,6 +855,9 @@ def int_aarch64_crc32x  : DefaultAttrsIntrinsic<[llvm_i32_ty], [llvm_i32_ty, llv
     [IntrNoMem]>;
 def int_aarch64_crc32cx : DefaultAttrsIntrinsic<[llvm_i32_ty], [llvm_i32_ty, llvm_i64_ty],
     [IntrNoMem]>;
+def int_aarch64_ubfx : DefaultAttrsIntrinsic<
+    [llvm_anyint_ty], [llvm_anyint_ty, llvm_anyint_ty, llvm_anyint_ty],
+    [IntrNoMem, ImmArg<ArgIndex<1>>, ImmArg<ArgIndex<2>>]>;
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/llvm/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp b/llvm/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp
index 163ed520a8a67..acdc9f70cb14c 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp
@@ -5230,6 +5230,19 @@ void AArch64DAGToDAGISel::Select(SDNode *Node) {
     switch (IntNo) {
     default:
       break;
+    case Intrinsic::aarch64_ubfx: {
+      SDLoc DL(Node);
+      auto lsb = cast<ConstantSDNode>(Node->getOperand(2))->getZExtValue();
+      auto width = cast<ConstantSDNode>(Node->getOperand(3))->getZExtValue();
+      auto ImmR = (VT.getSizeInBits() - lsb) % VT.getSizeInBits();
+      auto ImmS = width - 1;
+      SDValue Ops[] = {Node->getOperand(1),
+                       CurDAG->getTargetConstant(ImmR, DL, VT),
+                       CurDAG->getTargetConstant(ImmS, DL, VT)};
+      unsigned Opc = (VT == MVT::i32) ? AArch64::UBFMWri : AArch64::UBFMXri;
+      CurDAG->SelectNodeTo(Node, Opc, VT, Ops);
+      return;
+    }
     case Intrinsic::aarch64_tagp:
       SelectTagP(Node);
       return;
diff --git a/llvm/lib/Target/AArch64/AArch64InstrInfo.td b/llvm/lib/Target/AArch64/AArch64InstrInfo.td
index 03baa7497615e..cc2d094cb0755 100644
--- a/llvm/lib/Target/AArch64/AArch64InstrInfo.td
+++ b/llvm/lib/Target/AArch64/AArch64InstrInfo.td
@@ -2558,6 +2558,12 @@ def : Pat<(rotr GPR32:$Rn, (i64 imm0_31:$imm)),
 def : Pat<(rotr GPR64:$Rn, (i64 imm0_63:$imm)),
           (EXTRXrri GPR64:$Rn, GPR64:$Rn, imm0_63:$imm)>;
 
+def SDT_AArch64UBFX_32bit : SDTypeProfile<1, 1, [SDTCisVT<0, i32>, SDTCisVT<1, i32>]>;
+def SDT_AArch64UBFX_64bit : SDTypeProfile<1, 1, [SDTCisVT<0, i64>, SDTCisVT<1, i64>]>;
+
+def aarch64_ubfxw  : SDNode<"AArch64::UBFMWri",  SDT_AArch64UBFX_32bit>;
+def aarch64_ubfxx  : SDNode<"AArch64::UBFMXri",  SDT_AArch64UBFX_64bit>;
+
 //===----------------------------------------------------------------------===//
 // Other bitfield immediate instructions.
 //===----------------------------------------------------------------------===//
diff --git a/llvm/test/CodeGen/AArch64/ubfx-64-intrinsic.ll b/llvm/test/CodeGen/AArch64/ubfx-64-intrinsic.ll
new file mode 100644
index 0000000000000..a98cd99f3a16c
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/ubfx-64-intrinsic.ll
@@ -0,0 +1,36 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=aarch64-none-linux-gnu %s -o - 2>&1 | FileCheck %s --check-prefixes=CHECK,CHECK-GI
+
+define i32 @f32(i32 %A) nounwind {
+; CHECK-LABEL: f32:
+; CHECK-GI:      // %bb.0:
+; CHECK-GI-NEXT: ubfiz w0, w0, #3, #3
+; CHECK-GI-NEXT: ret
+entry:
+  %tmp = call i32 @llvm.aarch64.ubfx.i32(i32 %A, i32 3, i32 3)
+  ret i32 %tmp
+}
+
+define i64 @f64(i64 %A) nounwind {
+; CHECK-LABEL: f64:
+; CHECK-GI:      // %bb.0:
+; CHECK-GI-NEXT: ubfiz x0, x0, #38, #4
+; CHECK-GI-NEXT: ret
+entry:
+  %tmp = call i64 @llvm.aarch64.ubfx.i64(i64 %A, i64 38, i64 4)
+  ret i64 %tmp
+}
+
+define i64 @f64_1(i64 %A) nounwind {
+; CHECK-LABEL: f64_1:
+; CHECK-GI:      // %bb.0:
+; CHECK-GI-NEXT: ubfx x0, x0, #50, #3
+; CHECK-GI-NEXT: ret
+entry:
+  %tmp = call i64 @llvm.aarch64.ubfx.i64(i64 %A, i64 14, i64 53)
+  ret i64 %tmp
+}
+
+declare i32 @llvm.aarch64.ubfx.i32(i32, i32, i32)
+declare i64 @llvm.aarch64.ubfx.i64(i64, i64, i64)
+

``````````

</details>


https://github.com/llvm/llvm-project/pull/80103