[llvm] Revert "[AArch64] Convert concat(uhadd(a,b), uhadd(c,d)) to uhadd(concat(a,c), concat(b,d))" (PR #80157)

via llvm-commits llvm-commits at lists.llvm.org
Wed Jan 31 08:35:03 PST 2024 

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-aarch64

Author: Rin Dobrescu (Rin18)

<details>
<summary>Changes</summary>

Reverts llvm/llvm-project#<!-- -->79464 while figuring out why the tests are failing.

---
Full diff: https://github.com/llvm/llvm-project/pull/80157.diff


3 Files Affected:

- (modified) llvm/lib/Target/AArch64/AArch64ISelLowering.cpp (+38-8) 
- (modified) llvm/test/CodeGen/AArch64/avoid-pre-trunc.ll (+66-27) 
- (removed) llvm/test/CodeGen/AArch64/concat-vector-add-combine.ll (-120) 


``````````diff
diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
index 242a2d35b93f3..823d181efc4f0 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -18242,11 +18242,18 @@ static SDValue performConcatVectorsCombine(SDNode *N,
   if (DCI.isBeforeLegalizeOps())
     return SDValue();
 
-  // Optimise concat_vectors of two [us]avgceils or [us]avgfloors with a 128-bit
-  // destination size, combine into an avg of two contacts of the source
-  // vectors. eg: concat(uhadd(a,b), uhadd(c, d)) -> uhadd(concat(a, c),
-  // concat(b, d))
-  if (N->getNumOperands() == 2 && N0Opc == N1Opc && VT.is128BitVector() &&
+  // Optimise concat_vectors of two [us]avgceils or [us]avgfloors that use
+  // extracted subvectors from the same original vectors. Combine these into a
+  // single avg that operates on the two original vectors.
+  // avgceil is the target independant name for rhadd, avgfloor is a hadd.
+  // Example:
+  //  (concat_vectors (v8i8 (avgceils (extract_subvector (v16i8 OpA, <0>),
+  //                                   extract_subvector (v16i8 OpB, <0>))),
+  //                  (v8i8 (avgceils (extract_subvector (v16i8 OpA, <8>),
+  //                                   extract_subvector (v16i8 OpB, <8>)))))
+  // ->
+  //  (v16i8(avgceils(v16i8 OpA, v16i8 OpB)))
+  if (N->getNumOperands() == 2 && N0Opc == N1Opc &&
       (N0Opc == ISD::AVGCEILU || N0Opc == ISD::AVGCEILS ||
        N0Opc == ISD::AVGFLOORU || N0Opc == ISD::AVGFLOORS)) {
     SDValue N00 = N0->getOperand(0);
@@ -18254,9 +18261,32 @@ static SDValue performConcatVectorsCombine(SDNode *N,
     SDValue N10 = N1->getOperand(0);
     SDValue N11 = N1->getOperand(1);
 
-    SDValue Concat0 = DAG.getNode(ISD::CONCAT_VECTORS, dl, VT, N00, N10);
-    SDValue Concat1 = DAG.getNode(ISD::CONCAT_VECTORS, dl, VT, N01, N11);
-    return DAG.getNode(N0Opc, dl, VT, Concat0, Concat1);
+    EVT N00VT = N00.getValueType();
+    EVT N10VT = N10.getValueType();
+
+    if (N00->getOpcode() == ISD::EXTRACT_SUBVECTOR &&
+        N01->getOpcode() == ISD::EXTRACT_SUBVECTOR &&
+        N10->getOpcode() == ISD::EXTRACT_SUBVECTOR &&
+        N11->getOpcode() == ISD::EXTRACT_SUBVECTOR && N00VT == N10VT) {
+      SDValue N00Source = N00->getOperand(0);
+      SDValue N01Source = N01->getOperand(0);
+      SDValue N10Source = N10->getOperand(0);
+      SDValue N11Source = N11->getOperand(0);
+
+      if (N00Source == N10Source && N01Source == N11Source &&
+          N00Source.getValueType() == VT && N01Source.getValueType() == VT) {
+        assert(N0.getValueType() == N1.getValueType());
+
+        uint64_t N00Index = N00.getConstantOperandVal(1);
+        uint64_t N01Index = N01.getConstantOperandVal(1);
+        uint64_t N10Index = N10.getConstantOperandVal(1);
+        uint64_t N11Index = N11.getConstantOperandVal(1);
+
+        if (N00Index == N01Index && N10Index == N11Index && N00Index == 0 &&
+            N10Index == N00VT.getVectorNumElements())
+          return DAG.getNode(N0Opc, dl, VT, N00Source, N01Source);
+      }
+    }
   }
 
   auto IsRSHRN = [](SDValue Shr) {
diff --git a/llvm/test/CodeGen/AArch64/avoid-pre-trunc.ll b/llvm/test/CodeGen/AArch64/avoid-pre-trunc.ll
index c4de177176e33..24cce9a2b26b5 100644
--- a/llvm/test/CodeGen/AArch64/avoid-pre-trunc.ll
+++ b/llvm/test/CodeGen/AArch64/avoid-pre-trunc.ll
@@ -1,36 +1,75 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 4
 ; RUN: llc -mtriple=aarch64 < %s | FileCheck %s
 
+define i32 @lower_lshr(<4 x i32> %a, <4 x i32> %b, <4 x i32> %c, <4 x i32> %d, <4 x i32> %e, <4 x i32> %f, <4 x i32> %g, <4 x i32> %h) {
+; CHECK-LABEL: lower_lshr:
+; CHECK:       // %bb.0:
+; CHECK-NEXT:    addv s0, v0.4s
+; CHECK-NEXT:    addv s1, v1.4s
+; CHECK-NEXT:    addv s4, v4.4s
+; CHECK-NEXT:    addv s5, v5.4s
+; CHECK-NEXT:    addv s2, v2.4s
+; CHECK-NEXT:    addv s6, v6.4s
+; CHECK-NEXT:    mov v0.s[1], v1.s[0]
+; CHECK-NEXT:    addv s1, v3.4s
+; CHECK-NEXT:    addv s3, v7.4s
+; CHECK-NEXT:    mov v4.s[1], v5.s[0]
+; CHECK-NEXT:    mov v0.s[2], v2.s[0]
+; CHECK-NEXT:    mov v4.s[2], v6.s[0]
+; CHECK-NEXT:    mov v0.s[3], v1.s[0]
+; CHECK-NEXT:    mov v4.s[3], v3.s[0]
+; CHECK-NEXT:    xtn v1.4h, v0.4s
+; CHECK-NEXT:    shrn v0.4h, v0.4s, #16
+; CHECK-NEXT:    xtn v2.4h, v4.4s
+; CHECK-NEXT:    shrn v3.4h, v4.4s, #16
+; CHECK-NEXT:    uhadd v0.4h, v1.4h, v0.4h
+; CHECK-NEXT:    uhadd v1.4h, v2.4h, v3.4h
+; CHECK-NEXT:    mov v0.d[1], v1.d[0]
+; CHECK-NEXT:    uaddlv s0, v0.8h
+; CHECK-NEXT:    fmov w0, s0
+; CHECK-NEXT:    ret
+  %l87  = tail call i32 @llvm.vector.reduce.add.v4i32(<4 x i32> %a)
+  %l174 = tail call i32 @llvm.vector.reduce.add.v4i32(<4 x i32> %b)
+  %l257 = tail call i32 @llvm.vector.reduce.add.v4i32(<4 x i32> %c)
+  %l340 = tail call i32 @llvm.vector.reduce.add.v4i32(<4 x i32> %d)
+  %l427 = tail call i32 @llvm.vector.reduce.add.v4i32(<4 x i32> %e)
+  %l514 = tail call i32 @llvm.vector.reduce.add.v4i32(<4 x i32> %f)
+  %l597 = tail call i32 @llvm.vector.reduce.add.v4i32(<4 x i32> %g)
+  %l680 = tail call i32 @llvm.vector.reduce.add.v4i32(<4 x i32> %h)
+  %l681 = insertelement <8 x i32> poison, i32 %l87, i32 0
+  %l682 = insertelement <8 x i32> %l681, i32 %l174, i32 1
+  %l683 = insertelement <8 x i32> %l682, i32 %l257, i32 2
+  %l684 = insertelement <8 x i32> %l683, i32 %l340, i32 3
+  %l685 = insertelement <8 x i32> %l684, i32 %l427, i32 4
+  %l686 = insertelement <8 x i32> %l685, i32 %l514, i32 5
+  %l687 = insertelement <8 x i32> %l686, i32 %l597, i32 6
+  %l688 = insertelement <8 x i32> %l687, i32 %l680, i32 7
+  %l689 = and <8 x i32> %l688, <i32 65535, i32 65535, i32 65535, i32 65535, i32 65535, i32 65535, i32 65535, i32 65535>
+  %l690 = lshr <8 x i32> %l688, <i32 16, i32 16, i32 16, i32 16, i32 16, i32 16, i32 16, i32 16>
+  %l691 = add nuw nsw <8 x i32> %l689, %l690
+  %l692 = lshr <8 x i32> %l691, <i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1>
+  %l693 = call i32 @llvm.vector.reduce.add.v8i32(<8 x i32> %l692)
+  ret i32 %l693
+}
+declare i32 @llvm.vector.reduce.add.v4i32(<4 x i32>)
+declare i32 @llvm.vector.reduce.add.v8i32(<8 x i32>)
+
 define <16 x i8> @lower_trunc_16xi8(i16 %a, i16 %b, i16 %c, i16 %d, i16 %e, i16 %f, i16 %g, i16 %h, i16 %i, i16 %j, i16 %k, i16 %l, i16 %m, i16 %n, i16 %o, i16 %p) {
 ; CHECK-LABEL: lower_trunc_16xi8:
 ; CHECK:       // %bb.0:
 ; CHECK-NEXT:    fmov s0, w0
-; CHECK-NEXT:    ldr h1, [sp]
-; CHECK-NEXT:    add x8, sp, #8
-; CHECK-NEXT:    ld1 { v1.h }[1], [x8]
-; CHECK-NEXT:    add x8, sp, #16
+; CHECK-NEXT:    add x8, sp, #56
+; CHECK-NEXT:    ld1r { v1.8h }, [x8]
 ; CHECK-NEXT:    mov v0.h[1], w1
-; CHECK-NEXT:    ld1 { v1.h }[2], [x8]
-; CHECK-NEXT:    add x8, sp, #24
+; CHECK-NEXT:    add v3.8h, v1.8h, v1.8h
 ; CHECK-NEXT:    mov v0.h[2], w2
-; CHECK-NEXT:    ld1 { v1.h }[3], [x8]
-; CHECK-NEXT:    add x8, sp, #32
 ; CHECK-NEXT:    mov v0.h[3], w3
-; CHECK-NEXT:    ld1 { v1.h }[4], [x8]
-; CHECK-NEXT:    add x8, sp, #40
-; CHECK-NEXT:    ld1 { v1.h }[5], [x8]
-; CHECK-NEXT:    add x8, sp, #48
 ; CHECK-NEXT:    mov v0.h[4], w4
-; CHECK-NEXT:    ld1 { v1.h }[6], [x8]
-; CHECK-NEXT:    add x8, sp, #56
 ; CHECK-NEXT:    mov v0.h[5], w5
-; CHECK-NEXT:    ld1 { v1.h }[7], [x8]
 ; CHECK-NEXT:    mov v0.h[6], w6
-; CHECK-NEXT:    add v2.8h, v1.8h, v1.8h
-; CHECK-NEXT:    mov v0.h[7], w7
-; CHECK-NEXT:    add v3.8h, v0.8h, v0.8h
+; CHECK-NEXT:    add v2.8h, v0.8h, v0.8h
 ; CHECK-NEXT:    uzp1 v0.16b, v0.16b, v1.16b
-; CHECK-NEXT:    uzp1 v1.16b, v3.16b, v2.16b
+; CHECK-NEXT:    uzp1 v1.16b, v2.16b, v3.16b
 ; CHECK-NEXT:    eor v0.16b, v0.16b, v1.16b
 ; CHECK-NEXT:    ret
   %a1 = insertelement <16 x i16> poison, i16 %a, i16 0
@@ -41,14 +80,14 @@ define <16 x i8> @lower_trunc_16xi8(i16 %a, i16 %b, i16 %c, i16 %d, i16 %e, i16
   %f1 = insertelement <16 x i16> %e1, i16 %f, i16 5
   %g1 = insertelement <16 x i16> %f1, i16 %g, i16 6
   %h1 = insertelement <16 x i16> %g1, i16 %h, i16 7
-  %i1 = insertelement <16 x i16> %h1, i16 %i, i16 8
-  %j1 = insertelement <16 x i16> %i1, i16 %j, i16 9
-  %k1 = insertelement <16 x i16> %j1, i16 %k, i16 10
-  %l1 = insertelement <16 x i16> %k1, i16 %l, i16 11
-  %m1 = insertelement <16 x i16> %l1, i16 %m, i16 12
-  %n1 = insertelement <16 x i16> %m1, i16 %n, i16 13
-  %o1 = insertelement <16 x i16> %n1, i16 %o, i16 14
-  %p1 = insertelement <16 x i16> %o1, i16 %p, i16 15
+  %i1 = insertelement <16 x i16> %f1, i16 %i, i16 8
+  %j1 = insertelement <16 x i16> %g1, i16 %j, i16 9
+  %k1 = insertelement <16 x i16> %f1, i16 %k, i16 10
+  %l1 = insertelement <16 x i16> %g1, i16 %l, i16 11
+  %m1 = insertelement <16 x i16> %f1, i16 %m, i16 12
+  %n1 = insertelement <16 x i16> %g1, i16 %n, i16 13
+  %o1 = insertelement <16 x i16> %f1, i16 %o, i16 14
+  %p1 = insertelement <16 x i16> %g1, i16 %p, i16 15
   %t = trunc <16 x i16> %p1 to <16 x i8>
   %s = add <16 x i16> %p1, %p1
   %t2 = trunc <16 x i16> %s to <16 x i8>
diff --git a/llvm/test/CodeGen/AArch64/concat-vector-add-combine.ll b/llvm/test/CodeGen/AArch64/concat-vector-add-combine.ll
deleted file mode 100644
index 58d610764f4a9..0000000000000
--- a/llvm/test/CodeGen/AArch64/concat-vector-add-combine.ll
+++ /dev/null
@@ -1,120 +0,0 @@
-; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 4
-; RUN: llc -mtriple=aarch64 < %s | FileCheck %s
-
-define i16 @combine_add_16xi16(i16 %a, i16 %b, i16 %c, i16 %d, i16 %e, i16 %f, i16 %g, i16 %h, i16 %i, i16 %j, i16 %k, i16 %l, i16 %m, i16 %n, i16 %o, i16 %p) {
-; CHECK-LABEL: combine_add_16xi16:
-; CHECK:       // %bb.0:
-; CHECK-NEXT:    fmov s0, w0
-; CHECK-NEXT:    ldr h1, [sp]
-; CHECK-NEXT:    add x8, sp, #8
-; CHECK-NEXT:    ld1 { v1.h }[1], [x8]
-; CHECK-NEXT:    add x8, sp, #16
-; CHECK-NEXT:    mov v0.h[1], w1
-; CHECK-NEXT:    ld1 { v1.h }[2], [x8]
-; CHECK-NEXT:    add x8, sp, #24
-; CHECK-NEXT:    mov v0.h[2], w2
-; CHECK-NEXT:    ld1 { v1.h }[3], [x8]
-; CHECK-NEXT:    add x8, sp, #32
-; CHECK-NEXT:    mov v0.h[3], w3
-; CHECK-NEXT:    ld1 { v1.h }[4], [x8]
-; CHECK-NEXT:    add x8, sp, #40
-; CHECK-NEXT:    ld1 { v1.h }[5], [x8]
-; CHECK-NEXT:    add x8, sp, #48
-; CHECK-NEXT:    mov v0.h[4], w4
-; CHECK-NEXT:    ld1 { v1.h }[6], [x8]
-; CHECK-NEXT:    add x8, sp, #56
-; CHECK-NEXT:    mov v0.h[5], w5
-; CHECK-NEXT:    ld1 { v1.h }[7], [x8]
-; CHECK-NEXT:    mov v0.h[6], w6
-; CHECK-NEXT:    mov v0.h[7], w7
-; CHECK-NEXT:    uzp2 v2.16b, v0.16b, v1.16b
-; CHECK-NEXT:    uzp1 v0.16b, v0.16b, v1.16b
-; CHECK-NEXT:    uhadd v0.16b, v0.16b, v2.16b
-; CHECK-NEXT:    uaddlv h0, v0.16b
-; CHECK-NEXT:    umov w0, v0.h[0]
-; CHECK-NEXT:    ret
-  %a1 = insertelement <16 x i16> poison, i16 %a, i16 0
-  %b1 = insertelement <16 x i16> %a1, i16 %b, i16 1
-  %c1 = insertelement <16 x i16> %b1, i16 %c, i16 2
-  %d1 = insertelement <16 x i16> %c1, i16 %d, i16 3
-  %e1 = insertelement <16 x i16> %d1, i16 %e, i16 4
-  %f1 = insertelement <16 x i16> %e1, i16 %f, i16 5
-  %g1 = insertelement <16 x i16> %f1, i16 %g, i16 6
-  %h1 = insertelement <16 x i16> %g1, i16 %h, i16 7
-  %i1 = insertelement <16 x i16> %h1, i16 %i, i16 8
-  %j1 = insertelement <16 x i16> %i1, i16 %j, i16 9
-  %k1 = insertelement <16 x i16> %j1, i16 %k, i16 10
-  %l1 = insertelement <16 x i16> %k1, i16 %l, i16 11
-  %m1 = insertelement <16 x i16> %l1, i16 %m, i16 12
-  %n1 = insertelement <16 x i16> %m1, i16 %n, i16 13
-  %o1 = insertelement <16 x i16> %n1, i16 %o, i16 14
-  %p1 = insertelement <16 x i16> %o1, i16 %p, i16 15
-  %x = and <16 x i16> %p1, <i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255>
-  %sh1 = lshr <16 x i16> %p1, <i16 8, i16 8, i16 8, i16 8, i16 8, i16 8, i16 8, i16 8, i16 8, i16 8, i16 8, i16 8, i16 8, i16 8, i16 8, i16 8>
-  %s = add nuw nsw <16 x i16> %x, %sh1
-  %sh2 = lshr <16 x i16> %s, <i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1>
-  %res = call i16 @llvm.vector.reduce.add.v16i16(<16 x i16> %sh2)
-  ret i16 %res
-}
-
-define i32 @combine_add_8xi32(i32 %a, i32 %b, i32 %c, i32 %d, i32 %e, i32 %f, i32 %g, i32 %h) local_unnamed_addr #0 {
-; CHECK-LABEL: combine_add_8xi32:
-; CHECK:       // %bb.0:
-; CHECK-NEXT:    fmov s0, w4
-; CHECK-NEXT:    fmov s1, w0
-; CHECK-NEXT:    mov v0.s[1], w5
-; CHECK-NEXT:    mov v1.s[1], w1
-; CHECK-NEXT:    mov v0.s[2], w6
-; CHECK-NEXT:    mov v1.s[2], w2
-; CHECK-NEXT:    mov v0.s[3], w7
-; CHECK-NEXT:    mov v1.s[3], w3
-; CHECK-NEXT:    uzp2 v2.8h, v1.8h, v0.8h
-; CHECK-NEXT:    uzp1 v0.8h, v1.8h, v0.8h
-; CHECK-NEXT:    uhadd v0.8h, v0.8h, v2.8h
-; CHECK-NEXT:    uaddlv s0, v0.8h
-; CHECK-NEXT:    fmov w0, s0
-; CHECK-NEXT:    ret
-  %a1 = insertelement <8 x i32> poison, i32 %a, i32 0
-  %b1 = insertelement <8 x i32> %a1, i32 %b, i32 1
-  %c1 = insertelement <8 x i32> %b1, i32 %c, i32 2
-  %d1 = insertelement <8 x i32> %c1, i32 %d, i32 3
-  %e1 = insertelement <8 x i32> %d1, i32 %e, i32 4
-  %f1 = insertelement <8 x i32> %e1, i32 %f, i32 5
-  %g1 = insertelement <8 x i32> %f1, i32 %g, i32 6
-  %h1 = insertelement <8 x i32> %g1, i32 %h, i32 7
-  %x = and <8 x i32> %h1, <i32 65535, i32 65535, i32 65535, i32 65535, i32 65535, i32 65535, i32 65535, i32 65535>
-  %sh1 = lshr <8 x i32> %h1, <i32 16, i32 16, i32 16, i32 16, i32 16, i32 16, i32 16, i32 16>
-  %s = add nuw nsw <8 x i32> %x, %sh1
-  %sh2 = lshr <8 x i32> %s, <i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1>
-  %res = call i32 @llvm.vector.reduce.add.v8i32(<8 x i32> %sh2)
-  ret i32 %res
-}
-
-define i64 @combine_add_4xi64(i64 %a, i64 %b, i64 %c, i64 %d) local_unnamed_addr #0 {
-; CHECK-LABEL: combine_add_4xi64:
-; CHECK:       // %bb.0:
-; CHECK-NEXT:    fmov d0, x2
-; CHECK-NEXT:    fmov d1, x0
-; CHECK-NEXT:    mov v0.d[1], x3
-; CHECK-NEXT:    mov v1.d[1], x1
-; CHECK-NEXT:    uzp2 v2.4s, v1.4s, v0.4s
-; CHECK-NEXT:    uzp1 v0.4s, v1.4s, v0.4s
-; CHECK-NEXT:    uhadd v0.4s, v0.4s, v2.4s
-; CHECK-NEXT:    uaddlv d0, v0.4s
-; CHECK-NEXT:    fmov x0, d0
-; CHECK-NEXT:    ret
-  %a1 = insertelement <4 x i64> poison, i64 %a, i64 0
-  %b1 = insertelement <4 x i64> %a1, i64 %b, i64 1
-  %c1 = insertelement <4 x i64> %b1, i64 %c, i64 2
-  %d1 = insertelement <4 x i64> %c1, i64 %d, i64 3
-  %x = and <4 x i64> %d1, <i64 4294967295, i64 4294967295, i64 4294967295, i64 4294967295>
-  %sh1 = lshr <4 x i64> %d1, <i64 32, i64 32, i64 32, i64 32>
-  %s = add nuw nsw <4 x i64> %x, %sh1
-  %sh2 = lshr <4 x i64> %s, <i64 1, i64 1, i64 1, i64 1>
-  %res = call i64 @llvm.vector.reduce.add.v4i64(<4 x i64> %sh2)
-  ret i64 %res
-}
-
-declare i16 @llvm.vector.reduce.add.v16i16(<16 x i16>)
-declare i32 @llvm.vector.reduce.add.v8i32(<8 x i32>)
-declare i64 @llvm.vector.reduce.add.v4i64(<4 x i64>)

``````````

</details>


https://github.com/llvm/llvm-project/pull/80157

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