[llvm] [AArch64] Full reverse shuffles. (PR #119083)
David Green via llvm-commits
llvm-commits at lists.llvm.org
Sat Dec 7 09:15:33 PST 2024
https://github.com/davemgreen created https://github.com/llvm/llvm-project/pull/119083
A full shuffle reverse needs to use EXT+REV64. This adds handling for v8s16 and v16s8 types to match SDAG. Other types should be handled by perfect shuffles.
>From dda0d62ba9fea1f677c5a3269744fee0612d7af0 Mon Sep 17 00:00:00 2001
From: David Green <david.green at arm.com>
Date: Sat, 7 Dec 2024 17:02:36 +0000
Subject: [PATCH] [AArch64] Full reverse shuffles.
A full shuffle reverse needs to use EXT+REV64. This adds handling for v8s16 and
v16s8 types to match SDAG. Other types should be handled by perfect shuffles.
---
llvm/lib/Target/AArch64/AArch64Combine.td | 9 +++-
.../GISel/AArch64PostLegalizerLowering.cpp | 22 ++++++++
llvm/test/CodeGen/AArch64/aarch64-dup-ext.ll | 14 +++--
.../CodeGen/AArch64/neon-reverseshuffle.ll | 54 ++++++-------------
4 files changed, 51 insertions(+), 48 deletions(-)
diff --git a/llvm/lib/Target/AArch64/AArch64Combine.td b/llvm/lib/Target/AArch64/AArch64Combine.td
index 1b1d81fcd07a2b..3d2507fc1f25c4 100644
--- a/llvm/lib/Target/AArch64/AArch64Combine.td
+++ b/llvm/lib/Target/AArch64/AArch64Combine.td
@@ -131,6 +131,13 @@ def ext: GICombineRule <
(apply [{ applyEXT(*${root}, ${matchinfo}); }])
>;
+def fullrev: GICombineRule <
+ (defs root:$root, shuffle_matchdata:$matchinfo),
+ (match (G_SHUFFLE_VECTOR $src, $src1, $src2, $mask):$root,
+ [{ return matchFullRev(*${root}, MRI); }]),
+ (apply [{ applyFullRev(*${root}, MRI); }])
+>;
+
def insertelt_nonconst: GICombineRule <
(defs root:$root, shuffle_matchdata:$matchinfo),
(match (wip_match_opcode G_INSERT_VECTOR_ELT):$root,
@@ -163,7 +170,7 @@ def form_duplane : GICombineRule <
(apply [{ applyDupLane(*${root}, MRI, B, ${matchinfo}); }])
>;
-def shuffle_vector_lowering : GICombineGroup<[dup, rev, ext, zip, uzp, trn,
+def shuffle_vector_lowering : GICombineGroup<[dup, rev, ext, zip, uzp, trn, fullrev,
form_duplane, shuf_to_ins]>;
// Turn G_UNMERGE_VALUES -> G_EXTRACT_VECTOR_ELT's
diff --git a/llvm/lib/Target/AArch64/GISel/AArch64PostLegalizerLowering.cpp b/llvm/lib/Target/AArch64/GISel/AArch64PostLegalizerLowering.cpp
index 56d70ffdece713..244c0686750837 100644
--- a/llvm/lib/Target/AArch64/GISel/AArch64PostLegalizerLowering.cpp
+++ b/llvm/lib/Target/AArch64/GISel/AArch64PostLegalizerLowering.cpp
@@ -405,6 +405,28 @@ void applyEXT(MachineInstr &MI, ShuffleVectorPseudo &MatchInfo) {
MI.eraseFromParent();
}
+bool matchFullRev(MachineInstr &MI, MachineRegisterInfo &MRI) {
+ assert(MI.getOpcode() == TargetOpcode::G_SHUFFLE_VECTOR);
+ Register Dst = MI.getOperand(0).getReg();
+ LLT DstTy = MRI.getType(Dst);
+ Register V1 = MI.getOperand(1).getReg();
+ auto Mask = MI.getOperand(3).getShuffleMask();
+ return (DstTy == LLT::fixed_vector(16, 8) ||
+ DstTy == LLT::fixed_vector(8, 16)) &&
+ DstTy == MRI.getType(V1) &&
+ ShuffleVectorInst::isReverseMask(Mask, Mask.size());
+}
+
+void applyFullRev(MachineInstr &MI, MachineRegisterInfo &MRI) {
+ MachineIRBuilder MIRBuilder(MI);
+ Register Dst = MI.getOperand(0).getReg();
+ Register Src = MI.getOperand(1).getReg();
+ auto Cst = MIRBuilder.buildConstant(LLT::scalar(32), 8);
+ auto Rev = MIRBuilder.buildInstr(AArch64::G_REV64, {MRI.getType(Dst)}, {Src});
+ MIRBuilder.buildInstr(AArch64::G_EXT, {Dst}, {Rev, Rev, Cst});
+ MI.eraseFromParent();
+}
+
bool matchNonConstInsert(MachineInstr &MI, MachineRegisterInfo &MRI) {
assert(MI.getOpcode() == TargetOpcode::G_INSERT_VECTOR_ELT);
diff --git a/llvm/test/CodeGen/AArch64/aarch64-dup-ext.ll b/llvm/test/CodeGen/AArch64/aarch64-dup-ext.ll
index 0ce92a20fb3a17..a3bc2b58d708f3 100644
--- a/llvm/test/CodeGen/AArch64/aarch64-dup-ext.ll
+++ b/llvm/test/CodeGen/AArch64/aarch64-dup-ext.ll
@@ -407,11 +407,10 @@ define <8 x i16> @shufsext_v8i8_v8i16(<8 x i8> %src, <8 x i8> %b) {
;
; CHECK-GI-LABEL: shufsext_v8i8_v8i16:
; CHECK-GI: // %bb.0: // %entry
-; CHECK-GI-NEXT: adrp x8, .LCPI13_0
-; CHECK-GI-NEXT: sshll v2.8h, v0.8b, #0
+; CHECK-GI-NEXT: sshll v0.8h, v0.8b, #0
; CHECK-GI-NEXT: sshll v1.8h, v1.8b, #0
-; CHECK-GI-NEXT: ldr q0, [x8, :lo12:.LCPI13_0]
-; CHECK-GI-NEXT: tbl v0.16b, { v2.16b, v3.16b }, v0.16b
+; CHECK-GI-NEXT: rev64 v0.8h, v0.8h
+; CHECK-GI-NEXT: ext v0.16b, v0.16b, v0.16b, #8
; CHECK-GI-NEXT: mul v0.8h, v0.8h, v1.8h
; CHECK-GI-NEXT: ret
entry:
@@ -460,11 +459,10 @@ define <8 x i16> @shufzext_v8i8_v8i16(<8 x i8> %src, <8 x i8> %b) {
;
; CHECK-GI-LABEL: shufzext_v8i8_v8i16:
; CHECK-GI: // %bb.0: // %entry
-; CHECK-GI-NEXT: adrp x8, .LCPI15_0
-; CHECK-GI-NEXT: ushll v2.8h, v0.8b, #0
+; CHECK-GI-NEXT: ushll v0.8h, v0.8b, #0
; CHECK-GI-NEXT: ushll v1.8h, v1.8b, #0
-; CHECK-GI-NEXT: ldr q0, [x8, :lo12:.LCPI15_0]
-; CHECK-GI-NEXT: tbl v0.16b, { v2.16b, v3.16b }, v0.16b
+; CHECK-GI-NEXT: rev64 v0.8h, v0.8h
+; CHECK-GI-NEXT: ext v0.16b, v0.16b, v0.16b, #8
; CHECK-GI-NEXT: mul v0.8h, v0.8h, v1.8h
; CHECK-GI-NEXT: ret
entry:
diff --git a/llvm/test/CodeGen/AArch64/neon-reverseshuffle.ll b/llvm/test/CodeGen/AArch64/neon-reverseshuffle.ll
index 89838391956f29..7b0e0cfe04c010 100644
--- a/llvm/test/CodeGen/AArch64/neon-reverseshuffle.ll
+++ b/llvm/test/CodeGen/AArch64/neon-reverseshuffle.ll
@@ -60,19 +60,11 @@ entry:
}
define <8 x i16> @v8i16(<8 x i16> %a) {
-; CHECK-SD-LABEL: v8i16:
-; CHECK-SD: // %bb.0: // %entry
-; CHECK-SD-NEXT: rev64 v0.8h, v0.8h
-; CHECK-SD-NEXT: ext v0.16b, v0.16b, v0.16b, #8
-; CHECK-SD-NEXT: ret
-;
-; CHECK-GI-LABEL: v8i16:
-; CHECK-GI: // %bb.0: // %entry
-; CHECK-GI-NEXT: adrp x8, .LCPI4_0
-; CHECK-GI-NEXT: // kill: def $q0 killed $q0 def $q0_q1
-; CHECK-GI-NEXT: ldr q2, [x8, :lo12:.LCPI4_0]
-; CHECK-GI-NEXT: tbl v0.16b, { v0.16b, v1.16b }, v2.16b
-; CHECK-GI-NEXT: ret
+; CHECK-LABEL: v8i16:
+; CHECK: // %bb.0: // %entry
+; CHECK-NEXT: rev64 v0.8h, v0.8h
+; CHECK-NEXT: ext v0.16b, v0.16b, v0.16b, #8
+; CHECK-NEXT: ret
entry:
%V128 = shufflevector <8 x i16> %a, <8 x i16> undef, <8 x i32> <i32 7, i32 6, i32 5, i32 4, i32 3, i32 2, i32 1, i32 0>
ret <8 x i16> %V128
@@ -112,19 +104,11 @@ entry:
}
define <16 x i8> @v16i8(<16 x i8> %a) {
-; CHECK-SD-LABEL: v16i8:
-; CHECK-SD: // %bb.0: // %entry
-; CHECK-SD-NEXT: rev64 v0.16b, v0.16b
-; CHECK-SD-NEXT: ext v0.16b, v0.16b, v0.16b, #8
-; CHECK-SD-NEXT: ret
-;
-; CHECK-GI-LABEL: v16i8:
-; CHECK-GI: // %bb.0: // %entry
-; CHECK-GI-NEXT: adrp x8, .LCPI7_0
-; CHECK-GI-NEXT: // kill: def $q0 killed $q0 def $q0_q1
-; CHECK-GI-NEXT: ldr q2, [x8, :lo12:.LCPI7_0]
-; CHECK-GI-NEXT: tbl v0.16b, { v0.16b, v1.16b }, v2.16b
-; CHECK-GI-NEXT: ret
+; CHECK-LABEL: v16i8:
+; CHECK: // %bb.0: // %entry
+; CHECK-NEXT: rev64 v0.16b, v0.16b
+; CHECK-NEXT: ext v0.16b, v0.16b, v0.16b, #8
+; CHECK-NEXT: ret
entry:
%V128 = shufflevector <16 x i8> %a, <16 x i8> undef, <16 x i32> <i32 15, i32 14, i32 13, i32 12, i32 11, i32 10, i32 9, i32 8, i32 7, i32 6, i32 5, i32 4, i32 3, i32 2, i32 1, i32 0>
ret <16 x i8> %V128
@@ -203,19 +187,11 @@ entry:
}
define <8 x half> @v8f16(<8 x half> %a) {
-; CHECK-SD-LABEL: v8f16:
-; CHECK-SD: // %bb.0: // %entry
-; CHECK-SD-NEXT: rev64 v0.8h, v0.8h
-; CHECK-SD-NEXT: ext v0.16b, v0.16b, v0.16b, #8
-; CHECK-SD-NEXT: ret
-;
-; CHECK-GI-LABEL: v8f16:
-; CHECK-GI: // %bb.0: // %entry
-; CHECK-GI-NEXT: adrp x8, .LCPI13_0
-; CHECK-GI-NEXT: // kill: def $q0 killed $q0 def $q0_q1
-; CHECK-GI-NEXT: ldr q2, [x8, :lo12:.LCPI13_0]
-; CHECK-GI-NEXT: tbl v0.16b, { v0.16b, v1.16b }, v2.16b
-; CHECK-GI-NEXT: ret
+; CHECK-LABEL: v8f16:
+; CHECK: // %bb.0: // %entry
+; CHECK-NEXT: rev64 v0.8h, v0.8h
+; CHECK-NEXT: ext v0.16b, v0.16b, v0.16b, #8
+; CHECK-NEXT: ret
entry:
%V128 = shufflevector <8 x half> %a, <8 x half> undef, <8 x i32> <i32 7, i32 6, i32 5, i32 4, i32 3, i32 2, i32 1, i32 0>
ret <8 x half> %V128
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