[llvm] b092dc0 - [AArch64ISelLowering] Avoid duplane in some cases when sve enabled

[via llvm-commits]

Author: guopeilin
Date: 2021-10-15T15:33:24+08:00
New Revision: b092dc0bb9e454720e37c562b2044c31b68f42f5

URL: https://github.com/llvm/llvm-project/commit/b092dc0bb9e454720e37c562b2044c31b68f42f5
DIFF: https://github.com/llvm/llvm-project/commit/b092dc0bb9e454720e37c562b2044c31b68f42f5.diff

LOG: [AArch64ISelLowering] Avoid duplane in some cases when sve enabled

Reviewed By: david-arm, sdesmalen

Differential Revision: https://reviews.llvm.org/D110524

Added: 
    llvm/test/CodeGen/AArch64/sve-fixed-length-limit-duplane.ll

Modified: 
    llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

Removed: 
    


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diff  --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
index c7082bcc08e23..49f13e7bdb414 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -9515,8 +9515,11 @@ static SDValue constructDup(SDValue V, int Lane, SDLoc dl, EVT VT,
   } else if (V.getOpcode() == ISD::EXTRACT_SUBVECTOR) {
     // The lane is incremented by the index of the extract.
     // Example: dup v2f32 (extract v4f32 X, 2), 1 --> dup v4f32 X, 3
-    Lane += V.getConstantOperandVal(1);
-    V = V.getOperand(0);
+    auto VecVT = V.getOperand(0).getValueType();
+    if (VecVT.isFixedLengthVector() && VecVT.getFixedSizeInBits() <= 128) {
+      Lane += V.getConstantOperandVal(1);
+      V = V.getOperand(0);
+    }
   } else if (V.getOpcode() == ISD::CONCAT_VECTORS) {
     // The lane is decremented if we are splatting from the 2nd operand.
     // Example: dup v4i32 (concat v2i32 X, v2i32 Y), 3 --> dup v4i32 Y, 1

diff  --git a/llvm/test/CodeGen/AArch64/sve-fixed-length-limit-duplane.ll b/llvm/test/CodeGen/AArch64/sve-fixed-length-limit-duplane.ll
new file mode 100644
index 0000000000000..c4a25349a1c24
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/sve-fixed-length-limit-duplane.ll
@@ -0,0 +1,28 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mattr=+sve -aarch64-sve-vector-bits-min=256 < %s | FileCheck %s
+target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
+target triple = "aarch64-unknown-linux-gnu"
+
+define <4 x i32> @test(<16 x i32>* %arg1, <16 x i32>* %arg2) {
+; CHECK-LABEL: test:
+; CHECK:       // %bb.0: // %entry
+; CHECK-NEXT:    mov x8, #8
+; CHECK-NEXT:    ptrue p0.s, vl8
+; CHECK-NEXT:    ld1w { z1.s }, p0/z, [x0, x8, lsl #2]
+; CHECK-NEXT:    ld1w { z2.s }, p0/z, [x0]
+; CHECK-NEXT:    mov z0.d, z1.d
+; CHECK-NEXT:    add z2.s, p0/m, z2.s, z2.s
+; CHECK-NEXT:    ext z0.b, z0.b, z1.b, #16
+; CHECK-NEXT:    add z1.s, p0/m, z1.s, z1.s
+; CHECK-NEXT:    dup v0.4s, v0.s[2]
+; CHECK-NEXT:    st1w { z1.s }, p0, [x0, x8, lsl #2]
+; CHECK-NEXT:    st1w { z2.s }, p0, [x0]
+; CHECK-NEXT:    ret
+entry:
+  %0 = load <16 x i32>, <16 x i32>* %arg1, align 256
+  %1 = load <16 x i32>, <16 x i32>* %arg2, align 256
+  %shvec = shufflevector <16 x i32> %0, <16 x i32> %1, <4 x i32> <i32 14, i32 14, i32 14, i32 14>
+  %2 = add <16 x i32> %0, %0
+  store <16 x i32> %2, <16 x i32>* %arg1, align 256
+  ret <4 x i32> %shvec
+}