[llvm] [AArch64] Use sve instructions for fixed-width smulh/umulh. (PR #166168)
David Green via llvm-commits
llvm-commits at lists.llvm.org
Mon Dec 8 06:00:49 PST 2025
https://github.com/davemgreen updated https://github.com/llvm/llvm-project/pull/166168
>From cd12b5b8e5bfb91e4145ca2ceca79f9ce155371b Mon Sep 17 00:00:00 2001
From: David Green <david.green at arm.com>
Date: Mon, 8 Dec 2025 12:27:32 +0000
Subject: [PATCH 1/2] [AArch64] Use sve instructions for fixed-width
smulh/umulh.
Like v2i64 mul and operations like divide, we should be able to use the SVE
umulh and smulh instructions with 128bit vectors, providing that we have
SVE/SVE2. There are a number of other instructions that look like they should
presumably be treated the same way.
---
.../Target/AArch64/AArch64ISelLowering.cpp | 6 +-
.../test/CodeGen/AArch64/sve-int-mulh-pred.ll | 140 ++++++++++--------
llvm/test/CodeGen/AArch64/sve2-int-mulh.ll | 124 ++++++++--------
3 files changed, 146 insertions(+), 124 deletions(-)
diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
index 7199319ccdd9f..3831b90ee68b4 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -1844,6 +1844,8 @@ AArch64TargetLowering::AArch64TargetLowering(const TargetMachine &TM,
MVT::v4i32, MVT::v1i64, MVT::v2i64}) {
setOperationAction(ISD::SDIV, VT, Custom);
setOperationAction(ISD::UDIV, VT, Custom);
+ setOperationAction(ISD::MULHS, VT, Custom);
+ setOperationAction(ISD::MULHU, VT, Custom);
}
// NEON doesn't support 64-bit vector integer muls, but SVE does.
@@ -1880,10 +1882,6 @@ AArch64TargetLowering::AArch64TargetLowering(const TargetMachine &TM,
setOperationAction(ISD::CTLZ, MVT::v1i64, Custom);
setOperationAction(ISD::CTLZ, MVT::v2i64, Custom);
setOperationAction(ISD::CTTZ, MVT::v1i64, Custom);
- setOperationAction(ISD::MULHS, MVT::v1i64, Custom);
- setOperationAction(ISD::MULHS, MVT::v2i64, Custom);
- setOperationAction(ISD::MULHU, MVT::v1i64, Custom);
- setOperationAction(ISD::MULHU, MVT::v2i64, Custom);
setOperationAction(ISD::SMAX, MVT::v1i64, Custom);
setOperationAction(ISD::SMAX, MVT::v2i64, Custom);
setOperationAction(ISD::SMIN, MVT::v1i64, Custom);
diff --git a/llvm/test/CodeGen/AArch64/sve-int-mulh-pred.ll b/llvm/test/CodeGen/AArch64/sve-int-mulh-pred.ll
index 146720febf486..3c817e5ddbd82 100644
--- a/llvm/test/CodeGen/AArch64/sve-int-mulh-pred.ll
+++ b/llvm/test/CodeGen/AArch64/sve-int-mulh-pred.ll
@@ -127,9 +127,11 @@ define <vscale x 2 x i64> @umulh_i64(<vscale x 2 x i64> %a, <vscale x 2 x i64> %
define <16 x i8> @smulh_v16i8(<16 x i8> %a, <16 x i8> %b) {
; CHECK-LABEL: smulh_v16i8:
; CHECK: // %bb.0:
-; CHECK-NEXT: smull2 v2.8h, v0.16b, v1.16b
-; CHECK-NEXT: smull v0.8h, v0.8b, v1.8b
-; CHECK-NEXT: uzp2 v0.16b, v0.16b, v2.16b
+; CHECK-NEXT: ptrue p0.b, vl16
+; CHECK-NEXT: // kill: def $q0 killed $q0 def $z0
+; CHECK-NEXT: // kill: def $q1 killed $q1 def $z1
+; CHECK-NEXT: smulh z0.b, p0/m, z0.b, z1.b
+; CHECK-NEXT: // kill: def $q0 killed $q0 killed $z0
; CHECK-NEXT: ret
%1 = sext <16 x i8> %a to <16 x i16>
%2 = sext <16 x i8> %b to <16 x i16>
@@ -142,9 +144,11 @@ define <16 x i8> @smulh_v16i8(<16 x i8> %a, <16 x i8> %b) {
define <8 x i16> @smulh_v8i16(<8 x i16> %a, <8 x i16> %b) {
; CHECK-LABEL: smulh_v8i16:
; CHECK: // %bb.0:
-; CHECK-NEXT: smull2 v2.4s, v0.8h, v1.8h
-; CHECK-NEXT: smull v0.4s, v0.4h, v1.4h
-; CHECK-NEXT: uzp2 v0.8h, v0.8h, v2.8h
+; CHECK-NEXT: ptrue p0.h, vl8
+; CHECK-NEXT: // kill: def $q0 killed $q0 def $z0
+; CHECK-NEXT: // kill: def $q1 killed $q1 def $z1
+; CHECK-NEXT: smulh z0.h, p0/m, z0.h, z1.h
+; CHECK-NEXT: // kill: def $q0 killed $q0 killed $z0
; CHECK-NEXT: ret
%1 = sext <8 x i16> %a to <8 x i32>
%2 = sext <8 x i16> %b to <8 x i32>
@@ -157,9 +161,11 @@ define <8 x i16> @smulh_v8i16(<8 x i16> %a, <8 x i16> %b) {
define <4 x i32> @smulh_v4i32(<4 x i32> %a, <4 x i32> %b) {
; CHECK-LABEL: smulh_v4i32:
; CHECK: // %bb.0:
-; CHECK-NEXT: smull2 v2.2d, v0.4s, v1.4s
-; CHECK-NEXT: smull v0.2d, v0.2s, v1.2s
-; CHECK-NEXT: uzp2 v0.4s, v0.4s, v2.4s
+; CHECK-NEXT: ptrue p0.s, vl4
+; CHECK-NEXT: // kill: def $q0 killed $q0 def $z0
+; CHECK-NEXT: // kill: def $q1 killed $q1 def $z1
+; CHECK-NEXT: smulh z0.s, p0/m, z0.s, z1.s
+; CHECK-NEXT: // kill: def $q0 killed $q0 killed $z0
; CHECK-NEXT: ret
%1 = sext <4 x i32> %a to <4 x i64>
%2 = sext <4 x i32> %b to <4 x i64>
@@ -172,15 +178,11 @@ define <4 x i32> @smulh_v4i32(<4 x i32> %a, <4 x i32> %b) {
define <2 x i64> @smulh_v2i64(<2 x i64> %a, <2 x i64> %b) {
; CHECK-LABEL: smulh_v2i64:
; CHECK: // %bb.0:
-; CHECK-NEXT: mov x8, v0.d[1]
-; CHECK-NEXT: mov x9, v1.d[1]
-; CHECK-NEXT: fmov x10, d0
-; CHECK-NEXT: fmov x11, d1
-; CHECK-NEXT: smulh x10, x10, x11
-; CHECK-NEXT: smulh x8, x8, x9
-; CHECK-NEXT: fmov d0, x10
-; CHECK-NEXT: fmov d1, x8
-; CHECK-NEXT: mov v0.d[1], v1.d[0]
+; CHECK-NEXT: ptrue p0.d, vl2
+; CHECK-NEXT: // kill: def $q0 killed $q0 def $z0
+; CHECK-NEXT: // kill: def $q1 killed $q1 def $z1
+; CHECK-NEXT: smulh z0.d, p0/m, z0.d, z1.d
+; CHECK-NEXT: // kill: def $q0 killed $q0 killed $z0
; CHECK-NEXT: ret
%1 = sext <2 x i64> %a to <2 x i128>
%2 = sext <2 x i64> %b to <2 x i128>
@@ -193,9 +195,11 @@ define <2 x i64> @smulh_v2i64(<2 x i64> %a, <2 x i64> %b) {
define <16 x i8> @umulh_v16i8(<16 x i8> %a, <16 x i8> %b) {
; CHECK-LABEL: umulh_v16i8:
; CHECK: // %bb.0:
-; CHECK-NEXT: umull2 v2.8h, v0.16b, v1.16b
-; CHECK-NEXT: umull v0.8h, v0.8b, v1.8b
-; CHECK-NEXT: uzp2 v0.16b, v0.16b, v2.16b
+; CHECK-NEXT: ptrue p0.b, vl16
+; CHECK-NEXT: // kill: def $q0 killed $q0 def $z0
+; CHECK-NEXT: // kill: def $q1 killed $q1 def $z1
+; CHECK-NEXT: umulh z0.b, p0/m, z0.b, z1.b
+; CHECK-NEXT: // kill: def $q0 killed $q0 killed $z0
; CHECK-NEXT: ret
%1 = zext <16 x i8> %a to <16 x i16>
%2 = zext <16 x i8> %b to <16 x i16>
@@ -208,9 +212,11 @@ define <16 x i8> @umulh_v16i8(<16 x i8> %a, <16 x i8> %b) {
define <8 x i16> @umulh_v8i16(<8 x i16> %a, <8 x i16> %b) {
; CHECK-LABEL: umulh_v8i16:
; CHECK: // %bb.0:
-; CHECK-NEXT: umull2 v2.4s, v0.8h, v1.8h
-; CHECK-NEXT: umull v0.4s, v0.4h, v1.4h
-; CHECK-NEXT: uzp2 v0.8h, v0.8h, v2.8h
+; CHECK-NEXT: ptrue p0.h, vl8
+; CHECK-NEXT: // kill: def $q0 killed $q0 def $z0
+; CHECK-NEXT: // kill: def $q1 killed $q1 def $z1
+; CHECK-NEXT: umulh z0.h, p0/m, z0.h, z1.h
+; CHECK-NEXT: // kill: def $q0 killed $q0 killed $z0
; CHECK-NEXT: ret
%1 = zext <8 x i16> %a to <8 x i32>
%2 = zext <8 x i16> %b to <8 x i32>
@@ -223,9 +229,11 @@ define <8 x i16> @umulh_v8i16(<8 x i16> %a, <8 x i16> %b) {
define <4 x i32> @umulh_v4i32(<4 x i32> %a, <4 x i32> %b) {
; CHECK-LABEL: umulh_v4i32:
; CHECK: // %bb.0:
-; CHECK-NEXT: umull2 v2.2d, v0.4s, v1.4s
-; CHECK-NEXT: umull v0.2d, v0.2s, v1.2s
-; CHECK-NEXT: uzp2 v0.4s, v0.4s, v2.4s
+; CHECK-NEXT: ptrue p0.s, vl4
+; CHECK-NEXT: // kill: def $q0 killed $q0 def $z0
+; CHECK-NEXT: // kill: def $q1 killed $q1 def $z1
+; CHECK-NEXT: umulh z0.s, p0/m, z0.s, z1.s
+; CHECK-NEXT: // kill: def $q0 killed $q0 killed $z0
; CHECK-NEXT: ret
%1 = zext <4 x i32> %a to <4 x i64>
%2 = zext <4 x i32> %b to <4 x i64>
@@ -238,15 +246,11 @@ define <4 x i32> @umulh_v4i32(<4 x i32> %a, <4 x i32> %b) {
define <2 x i64> @umulh_v2i64(<2 x i64> %a, <2 x i64> %b) {
; CHECK-LABEL: umulh_v2i64:
; CHECK: // %bb.0:
-; CHECK-NEXT: mov x8, v0.d[1]
-; CHECK-NEXT: mov x9, v1.d[1]
-; CHECK-NEXT: fmov x10, d0
-; CHECK-NEXT: fmov x11, d1
-; CHECK-NEXT: umulh x10, x10, x11
-; CHECK-NEXT: umulh x8, x8, x9
-; CHECK-NEXT: fmov d0, x10
-; CHECK-NEXT: fmov d1, x8
-; CHECK-NEXT: mov v0.d[1], v1.d[0]
+; CHECK-NEXT: ptrue p0.d, vl2
+; CHECK-NEXT: // kill: def $q0 killed $q0 def $z0
+; CHECK-NEXT: // kill: def $q1 killed $q1 def $z1
+; CHECK-NEXT: umulh z0.d, p0/m, z0.d, z1.d
+; CHECK-NEXT: // kill: def $q0 killed $q0 killed $z0
; CHECK-NEXT: ret
%1 = zext <2 x i64> %a to <2 x i128>
%2 = zext <2 x i64> %b to <2 x i128>
@@ -263,8 +267,11 @@ define <2 x i64> @umulh_v2i64(<2 x i64> %a, <2 x i64> %b) {
define <8 x i8> @smulh_v8i8(<8 x i8> %a, <8 x i8> %b) {
; CHECK-LABEL: smulh_v8i8:
; CHECK: // %bb.0:
-; CHECK-NEXT: smull v0.8h, v0.8b, v1.8b
-; CHECK-NEXT: shrn v0.8b, v0.8h, #8
+; CHECK-NEXT: ptrue p0.b, vl8
+; CHECK-NEXT: // kill: def $d0 killed $d0 def $z0
+; CHECK-NEXT: // kill: def $d1 killed $d1 def $z1
+; CHECK-NEXT: smulh z0.b, p0/m, z0.b, z1.b
+; CHECK-NEXT: // kill: def $d0 killed $d0 killed $z0
; CHECK-NEXT: ret
%1 = sext <8 x i8> %a to <8 x i16>
%2 = sext <8 x i8> %b to <8 x i16>
@@ -277,8 +284,11 @@ define <8 x i8> @smulh_v8i8(<8 x i8> %a, <8 x i8> %b) {
define <4 x i16> @smulh_v4i16(<4 x i16> %a, <4 x i16> %b) {
; CHECK-LABEL: smulh_v4i16:
; CHECK: // %bb.0:
-; CHECK-NEXT: smull v0.4s, v0.4h, v1.4h
-; CHECK-NEXT: shrn v0.4h, v0.4s, #16
+; CHECK-NEXT: ptrue p0.h, vl4
+; CHECK-NEXT: // kill: def $d0 killed $d0 def $z0
+; CHECK-NEXT: // kill: def $d1 killed $d1 def $z1
+; CHECK-NEXT: smulh z0.h, p0/m, z0.h, z1.h
+; CHECK-NEXT: // kill: def $d0 killed $d0 killed $z0
; CHECK-NEXT: ret
%1 = sext <4 x i16> %a to <4 x i32>
%2 = sext <4 x i16> %b to <4 x i32>
@@ -291,8 +301,11 @@ define <4 x i16> @smulh_v4i16(<4 x i16> %a, <4 x i16> %b) {
define <2 x i32> @smulh_v2i32(<2 x i32> %a, <2 x i32> %b) {
; CHECK-LABEL: smulh_v2i32:
; CHECK: // %bb.0:
-; CHECK-NEXT: smull v0.2d, v0.2s, v1.2s
-; CHECK-NEXT: shrn v0.2s, v0.2d, #32
+; CHECK-NEXT: ptrue p0.s, vl2
+; CHECK-NEXT: // kill: def $d0 killed $d0 def $z0
+; CHECK-NEXT: // kill: def $d1 killed $d1 def $z1
+; CHECK-NEXT: smulh z0.s, p0/m, z0.s, z1.s
+; CHECK-NEXT: // kill: def $d0 killed $d0 killed $z0
; CHECK-NEXT: ret
%1 = sext <2 x i32> %a to <2 x i64>
%2 = sext <2 x i32> %b to <2 x i64>
@@ -305,12 +318,11 @@ define <2 x i32> @smulh_v2i32(<2 x i32> %a, <2 x i32> %b) {
define <1 x i64> @smulh_v1i64(<1 x i64> %a, <1 x i64> %b) {
; CHECK-LABEL: smulh_v1i64:
; CHECK: // %bb.0:
-; CHECK-NEXT: // kill: def $d1 killed $d1 def $q1
-; CHECK-NEXT: // kill: def $d0 killed $d0 def $q0
-; CHECK-NEXT: fmov x8, d0
-; CHECK-NEXT: fmov x9, d1
-; CHECK-NEXT: smulh x8, x8, x9
-; CHECK-NEXT: fmov d0, x8
+; CHECK-NEXT: ptrue p0.d, vl1
+; CHECK-NEXT: // kill: def $d0 killed $d0 def $z0
+; CHECK-NEXT: // kill: def $d1 killed $d1 def $z1
+; CHECK-NEXT: smulh z0.d, p0/m, z0.d, z1.d
+; CHECK-NEXT: // kill: def $d0 killed $d0 killed $z0
; CHECK-NEXT: ret
%1 = sext <1 x i64> %a to <1 x i128>
%2 = sext <1 x i64> %b to <1 x i128>
@@ -323,8 +335,11 @@ define <1 x i64> @smulh_v1i64(<1 x i64> %a, <1 x i64> %b) {
define <8 x i8> @umulh_v8i8(<8 x i8> %a, <8 x i8> %b) {
; CHECK-LABEL: umulh_v8i8:
; CHECK: // %bb.0:
-; CHECK-NEXT: umull v0.8h, v0.8b, v1.8b
-; CHECK-NEXT: shrn v0.8b, v0.8h, #8
+; CHECK-NEXT: ptrue p0.b, vl8
+; CHECK-NEXT: // kill: def $d0 killed $d0 def $z0
+; CHECK-NEXT: // kill: def $d1 killed $d1 def $z1
+; CHECK-NEXT: umulh z0.b, p0/m, z0.b, z1.b
+; CHECK-NEXT: // kill: def $d0 killed $d0 killed $z0
; CHECK-NEXT: ret
%1 = zext <8 x i8> %a to <8 x i16>
%2 = zext <8 x i8> %b to <8 x i16>
@@ -337,8 +352,11 @@ define <8 x i8> @umulh_v8i8(<8 x i8> %a, <8 x i8> %b) {
define <4 x i16> @umulh_v4i16(<4 x i16> %a, <4 x i16> %b) {
; CHECK-LABEL: umulh_v4i16:
; CHECK: // %bb.0:
-; CHECK-NEXT: umull v0.4s, v0.4h, v1.4h
-; CHECK-NEXT: shrn v0.4h, v0.4s, #16
+; CHECK-NEXT: ptrue p0.h, vl4
+; CHECK-NEXT: // kill: def $d0 killed $d0 def $z0
+; CHECK-NEXT: // kill: def $d1 killed $d1 def $z1
+; CHECK-NEXT: umulh z0.h, p0/m, z0.h, z1.h
+; CHECK-NEXT: // kill: def $d0 killed $d0 killed $z0
; CHECK-NEXT: ret
%1 = zext <4 x i16> %a to <4 x i32>
%2 = zext <4 x i16> %b to <4 x i32>
@@ -351,8 +369,11 @@ define <4 x i16> @umulh_v4i16(<4 x i16> %a, <4 x i16> %b) {
define <2 x i32> @umulh_v2i32(<2 x i32> %a, <2 x i32> %b) {
; CHECK-LABEL: umulh_v2i32:
; CHECK: // %bb.0:
-; CHECK-NEXT: umull v0.2d, v0.2s, v1.2s
-; CHECK-NEXT: shrn v0.2s, v0.2d, #32
+; CHECK-NEXT: ptrue p0.s, vl2
+; CHECK-NEXT: // kill: def $d0 killed $d0 def $z0
+; CHECK-NEXT: // kill: def $d1 killed $d1 def $z1
+; CHECK-NEXT: umulh z0.s, p0/m, z0.s, z1.s
+; CHECK-NEXT: // kill: def $d0 killed $d0 killed $z0
; CHECK-NEXT: ret
%1 = zext <2 x i32> %a to <2 x i64>
%2 = zext <2 x i32> %b to <2 x i64>
@@ -365,12 +386,11 @@ define <2 x i32> @umulh_v2i32(<2 x i32> %a, <2 x i32> %b) {
define <1 x i64> @umulh_v1i64(<1 x i64> %a, <1 x i64> %b) {
; CHECK-LABEL: umulh_v1i64:
; CHECK: // %bb.0:
-; CHECK-NEXT: // kill: def $d1 killed $d1 def $q1
-; CHECK-NEXT: // kill: def $d0 killed $d0 def $q0
-; CHECK-NEXT: fmov x8, d0
-; CHECK-NEXT: fmov x9, d1
-; CHECK-NEXT: umulh x8, x8, x9
-; CHECK-NEXT: fmov d0, x8
+; CHECK-NEXT: ptrue p0.d, vl1
+; CHECK-NEXT: // kill: def $d0 killed $d0 def $z0
+; CHECK-NEXT: // kill: def $d1 killed $d1 def $z1
+; CHECK-NEXT: umulh z0.d, p0/m, z0.d, z1.d
+; CHECK-NEXT: // kill: def $d0 killed $d0 killed $z0
; CHECK-NEXT: ret
%1 = zext <1 x i64> %a to <1 x i128>
%2 = zext <1 x i64> %b to <1 x i128>
diff --git a/llvm/test/CodeGen/AArch64/sve2-int-mulh.ll b/llvm/test/CodeGen/AArch64/sve2-int-mulh.ll
index d7534712b53a0..917d8e6ec22ef 100644
--- a/llvm/test/CodeGen/AArch64/sve2-int-mulh.ll
+++ b/llvm/test/CodeGen/AArch64/sve2-int-mulh.ll
@@ -119,9 +119,10 @@ define <vscale x 2 x i64> @umulh_i64(<vscale x 2 x i64> %a, <vscale x 2 x i64> %
define <16 x i8> @smulh_v16i8(<16 x i8> %a, <16 x i8> %b) {
; CHECK-LABEL: smulh_v16i8:
; CHECK: // %bb.0:
-; CHECK-NEXT: smull2 v2.8h, v0.16b, v1.16b
-; CHECK-NEXT: smull v0.8h, v0.8b, v1.8b
-; CHECK-NEXT: uzp2 v0.16b, v0.16b, v2.16b
+; CHECK-NEXT: // kill: def $q0 killed $q0 def $z0
+; CHECK-NEXT: // kill: def $q1 killed $q1 def $z1
+; CHECK-NEXT: smulh z0.b, z0.b, z1.b
+; CHECK-NEXT: // kill: def $q0 killed $q0 killed $z0
; CHECK-NEXT: ret
%1 = sext <16 x i8> %a to <16 x i16>
%2 = sext <16 x i8> %b to <16 x i16>
@@ -134,9 +135,10 @@ define <16 x i8> @smulh_v16i8(<16 x i8> %a, <16 x i8> %b) {
define <8 x i16> @smulh_v8i16(<8 x i16> %a, <8 x i16> %b) {
; CHECK-LABEL: smulh_v8i16:
; CHECK: // %bb.0:
-; CHECK-NEXT: smull2 v2.4s, v0.8h, v1.8h
-; CHECK-NEXT: smull v0.4s, v0.4h, v1.4h
-; CHECK-NEXT: uzp2 v0.8h, v0.8h, v2.8h
+; CHECK-NEXT: // kill: def $q0 killed $q0 def $z0
+; CHECK-NEXT: // kill: def $q1 killed $q1 def $z1
+; CHECK-NEXT: smulh z0.h, z0.h, z1.h
+; CHECK-NEXT: // kill: def $q0 killed $q0 killed $z0
; CHECK-NEXT: ret
%1 = sext <8 x i16> %a to <8 x i32>
%2 = sext <8 x i16> %b to <8 x i32>
@@ -149,9 +151,10 @@ define <8 x i16> @smulh_v8i16(<8 x i16> %a, <8 x i16> %b) {
define <4 x i32> @smulh_v4i32(<4 x i32> %a, <4 x i32> %b) {
; CHECK-LABEL: smulh_v4i32:
; CHECK: // %bb.0:
-; CHECK-NEXT: smull2 v2.2d, v0.4s, v1.4s
-; CHECK-NEXT: smull v0.2d, v0.2s, v1.2s
-; CHECK-NEXT: uzp2 v0.4s, v0.4s, v2.4s
+; CHECK-NEXT: // kill: def $q0 killed $q0 def $z0
+; CHECK-NEXT: // kill: def $q1 killed $q1 def $z1
+; CHECK-NEXT: smulh z0.s, z0.s, z1.s
+; CHECK-NEXT: // kill: def $q0 killed $q0 killed $z0
; CHECK-NEXT: ret
%1 = sext <4 x i32> %a to <4 x i64>
%2 = sext <4 x i32> %b to <4 x i64>
@@ -164,15 +167,10 @@ define <4 x i32> @smulh_v4i32(<4 x i32> %a, <4 x i32> %b) {
define <2 x i64> @smulh_v2i64(<2 x i64> %a, <2 x i64> %b) {
; CHECK-LABEL: smulh_v2i64:
; CHECK: // %bb.0:
-; CHECK-NEXT: mov x8, v0.d[1]
-; CHECK-NEXT: mov x9, v1.d[1]
-; CHECK-NEXT: fmov x10, d0
-; CHECK-NEXT: fmov x11, d1
-; CHECK-NEXT: smulh x10, x10, x11
-; CHECK-NEXT: smulh x8, x8, x9
-; CHECK-NEXT: fmov d0, x10
-; CHECK-NEXT: fmov d1, x8
-; CHECK-NEXT: mov v0.d[1], v1.d[0]
+; CHECK-NEXT: // kill: def $q0 killed $q0 def $z0
+; CHECK-NEXT: // kill: def $q1 killed $q1 def $z1
+; CHECK-NEXT: smulh z0.d, z0.d, z1.d
+; CHECK-NEXT: // kill: def $q0 killed $q0 killed $z0
; CHECK-NEXT: ret
%1 = sext <2 x i64> %a to <2 x i128>
%2 = sext <2 x i64> %b to <2 x i128>
@@ -185,9 +183,10 @@ define <2 x i64> @smulh_v2i64(<2 x i64> %a, <2 x i64> %b) {
define <16 x i8> @umulh_v16i8(<16 x i8> %a, <16 x i8> %b) {
; CHECK-LABEL: umulh_v16i8:
; CHECK: // %bb.0:
-; CHECK-NEXT: umull2 v2.8h, v0.16b, v1.16b
-; CHECK-NEXT: umull v0.8h, v0.8b, v1.8b
-; CHECK-NEXT: uzp2 v0.16b, v0.16b, v2.16b
+; CHECK-NEXT: // kill: def $q0 killed $q0 def $z0
+; CHECK-NEXT: // kill: def $q1 killed $q1 def $z1
+; CHECK-NEXT: umulh z0.b, z0.b, z1.b
+; CHECK-NEXT: // kill: def $q0 killed $q0 killed $z0
; CHECK-NEXT: ret
%1 = zext <16 x i8> %a to <16 x i16>
%2 = zext <16 x i8> %b to <16 x i16>
@@ -200,9 +199,10 @@ define <16 x i8> @umulh_v16i8(<16 x i8> %a, <16 x i8> %b) {
define <8 x i16> @umulh_v8i16(<8 x i16> %a, <8 x i16> %b) {
; CHECK-LABEL: umulh_v8i16:
; CHECK: // %bb.0:
-; CHECK-NEXT: umull2 v2.4s, v0.8h, v1.8h
-; CHECK-NEXT: umull v0.4s, v0.4h, v1.4h
-; CHECK-NEXT: uzp2 v0.8h, v0.8h, v2.8h
+; CHECK-NEXT: // kill: def $q0 killed $q0 def $z0
+; CHECK-NEXT: // kill: def $q1 killed $q1 def $z1
+; CHECK-NEXT: umulh z0.h, z0.h, z1.h
+; CHECK-NEXT: // kill: def $q0 killed $q0 killed $z0
; CHECK-NEXT: ret
%1 = zext <8 x i16> %a to <8 x i32>
%2 = zext <8 x i16> %b to <8 x i32>
@@ -215,9 +215,10 @@ define <8 x i16> @umulh_v8i16(<8 x i16> %a, <8 x i16> %b) {
define <4 x i32> @umulh_v4i32(<4 x i32> %a, <4 x i32> %b) {
; CHECK-LABEL: umulh_v4i32:
; CHECK: // %bb.0:
-; CHECK-NEXT: umull2 v2.2d, v0.4s, v1.4s
-; CHECK-NEXT: umull v0.2d, v0.2s, v1.2s
-; CHECK-NEXT: uzp2 v0.4s, v0.4s, v2.4s
+; CHECK-NEXT: // kill: def $q0 killed $q0 def $z0
+; CHECK-NEXT: // kill: def $q1 killed $q1 def $z1
+; CHECK-NEXT: umulh z0.s, z0.s, z1.s
+; CHECK-NEXT: // kill: def $q0 killed $q0 killed $z0
; CHECK-NEXT: ret
%1 = zext <4 x i32> %a to <4 x i64>
%2 = zext <4 x i32> %b to <4 x i64>
@@ -230,15 +231,10 @@ define <4 x i32> @umulh_v4i32(<4 x i32> %a, <4 x i32> %b) {
define <2 x i64> @umulh_v2i64(<2 x i64> %a, <2 x i64> %b) {
; CHECK-LABEL: umulh_v2i64:
; CHECK: // %bb.0:
-; CHECK-NEXT: mov x8, v0.d[1]
-; CHECK-NEXT: mov x9, v1.d[1]
-; CHECK-NEXT: fmov x10, d0
-; CHECK-NEXT: fmov x11, d1
-; CHECK-NEXT: umulh x10, x10, x11
-; CHECK-NEXT: umulh x8, x8, x9
-; CHECK-NEXT: fmov d0, x10
-; CHECK-NEXT: fmov d1, x8
-; CHECK-NEXT: mov v0.d[1], v1.d[0]
+; CHECK-NEXT: // kill: def $q0 killed $q0 def $z0
+; CHECK-NEXT: // kill: def $q1 killed $q1 def $z1
+; CHECK-NEXT: umulh z0.d, z0.d, z1.d
+; CHECK-NEXT: // kill: def $q0 killed $q0 killed $z0
; CHECK-NEXT: ret
%1 = zext <2 x i64> %a to <2 x i128>
%2 = zext <2 x i64> %b to <2 x i128>
@@ -255,8 +251,10 @@ define <2 x i64> @umulh_v2i64(<2 x i64> %a, <2 x i64> %b) {
define <8 x i8> @smulh_v8i8(<8 x i8> %a, <8 x i8> %b) {
; CHECK-LABEL: smulh_v8i8:
; CHECK: // %bb.0:
-; CHECK-NEXT: smull v0.8h, v0.8b, v1.8b
-; CHECK-NEXT: shrn v0.8b, v0.8h, #8
+; CHECK-NEXT: // kill: def $d0 killed $d0 def $z0
+; CHECK-NEXT: // kill: def $d1 killed $d1 def $z1
+; CHECK-NEXT: smulh z0.b, z0.b, z1.b
+; CHECK-NEXT: // kill: def $d0 killed $d0 killed $z0
; CHECK-NEXT: ret
%1 = sext <8 x i8> %a to <8 x i16>
%2 = sext <8 x i8> %b to <8 x i16>
@@ -269,8 +267,10 @@ define <8 x i8> @smulh_v8i8(<8 x i8> %a, <8 x i8> %b) {
define <4 x i16> @smulh_v4i16(<4 x i16> %a, <4 x i16> %b) {
; CHECK-LABEL: smulh_v4i16:
; CHECK: // %bb.0:
-; CHECK-NEXT: smull v0.4s, v0.4h, v1.4h
-; CHECK-NEXT: shrn v0.4h, v0.4s, #16
+; CHECK-NEXT: // kill: def $d0 killed $d0 def $z0
+; CHECK-NEXT: // kill: def $d1 killed $d1 def $z1
+; CHECK-NEXT: smulh z0.h, z0.h, z1.h
+; CHECK-NEXT: // kill: def $d0 killed $d0 killed $z0
; CHECK-NEXT: ret
%1 = sext <4 x i16> %a to <4 x i32>
%2 = sext <4 x i16> %b to <4 x i32>
@@ -283,8 +283,10 @@ define <4 x i16> @smulh_v4i16(<4 x i16> %a, <4 x i16> %b) {
define <2 x i32> @smulh_v2i32(<2 x i32> %a, <2 x i32> %b) {
; CHECK-LABEL: smulh_v2i32:
; CHECK: // %bb.0:
-; CHECK-NEXT: smull v0.2d, v0.2s, v1.2s
-; CHECK-NEXT: shrn v0.2s, v0.2d, #32
+; CHECK-NEXT: // kill: def $d0 killed $d0 def $z0
+; CHECK-NEXT: // kill: def $d1 killed $d1 def $z1
+; CHECK-NEXT: smulh z0.s, z0.s, z1.s
+; CHECK-NEXT: // kill: def $d0 killed $d0 killed $z0
; CHECK-NEXT: ret
%1 = sext <2 x i32> %a to <2 x i64>
%2 = sext <2 x i32> %b to <2 x i64>
@@ -297,12 +299,10 @@ define <2 x i32> @smulh_v2i32(<2 x i32> %a, <2 x i32> %b) {
define <1 x i64> @smulh_v1i64(<1 x i64> %a, <1 x i64> %b) {
; CHECK-LABEL: smulh_v1i64:
; CHECK: // %bb.0:
-; CHECK-NEXT: // kill: def $d1 killed $d1 def $q1
-; CHECK-NEXT: // kill: def $d0 killed $d0 def $q0
-; CHECK-NEXT: fmov x8, d0
-; CHECK-NEXT: fmov x9, d1
-; CHECK-NEXT: smulh x8, x8, x9
-; CHECK-NEXT: fmov d0, x8
+; CHECK-NEXT: // kill: def $d0 killed $d0 def $z0
+; CHECK-NEXT: // kill: def $d1 killed $d1 def $z1
+; CHECK-NEXT: smulh z0.d, z0.d, z1.d
+; CHECK-NEXT: // kill: def $d0 killed $d0 killed $z0
; CHECK-NEXT: ret
%1 = sext <1 x i64> %a to <1 x i128>
%2 = sext <1 x i64> %b to <1 x i128>
@@ -315,8 +315,10 @@ define <1 x i64> @smulh_v1i64(<1 x i64> %a, <1 x i64> %b) {
define <8 x i8> @umulh_v8i8(<8 x i8> %a, <8 x i8> %b) {
; CHECK-LABEL: umulh_v8i8:
; CHECK: // %bb.0:
-; CHECK-NEXT: umull v0.8h, v0.8b, v1.8b
-; CHECK-NEXT: shrn v0.8b, v0.8h, #8
+; CHECK-NEXT: // kill: def $d0 killed $d0 def $z0
+; CHECK-NEXT: // kill: def $d1 killed $d1 def $z1
+; CHECK-NEXT: umulh z0.b, z0.b, z1.b
+; CHECK-NEXT: // kill: def $d0 killed $d0 killed $z0
; CHECK-NEXT: ret
%1 = zext <8 x i8> %a to <8 x i16>
%2 = zext <8 x i8> %b to <8 x i16>
@@ -329,8 +331,10 @@ define <8 x i8> @umulh_v8i8(<8 x i8> %a, <8 x i8> %b) {
define <4 x i16> @umulh_v4i16(<4 x i16> %a, <4 x i16> %b) {
; CHECK-LABEL: umulh_v4i16:
; CHECK: // %bb.0:
-; CHECK-NEXT: umull v0.4s, v0.4h, v1.4h
-; CHECK-NEXT: shrn v0.4h, v0.4s, #16
+; CHECK-NEXT: // kill: def $d0 killed $d0 def $z0
+; CHECK-NEXT: // kill: def $d1 killed $d1 def $z1
+; CHECK-NEXT: umulh z0.h, z0.h, z1.h
+; CHECK-NEXT: // kill: def $d0 killed $d0 killed $z0
; CHECK-NEXT: ret
%1 = zext <4 x i16> %a to <4 x i32>
%2 = zext <4 x i16> %b to <4 x i32>
@@ -343,8 +347,10 @@ define <4 x i16> @umulh_v4i16(<4 x i16> %a, <4 x i16> %b) {
define <2 x i32> @umulh_v2i32(<2 x i32> %a, <2 x i32> %b) {
; CHECK-LABEL: umulh_v2i32:
; CHECK: // %bb.0:
-; CHECK-NEXT: umull v0.2d, v0.2s, v1.2s
-; CHECK-NEXT: shrn v0.2s, v0.2d, #32
+; CHECK-NEXT: // kill: def $d0 killed $d0 def $z0
+; CHECK-NEXT: // kill: def $d1 killed $d1 def $z1
+; CHECK-NEXT: umulh z0.s, z0.s, z1.s
+; CHECK-NEXT: // kill: def $d0 killed $d0 killed $z0
; CHECK-NEXT: ret
%1 = zext <2 x i32> %a to <2 x i64>
%2 = zext <2 x i32> %b to <2 x i64>
@@ -357,12 +363,10 @@ define <2 x i32> @umulh_v2i32(<2 x i32> %a, <2 x i32> %b) {
define <1 x i64> @umulh_v1i64(<1 x i64> %a, <1 x i64> %b) {
; CHECK-LABEL: umulh_v1i64:
; CHECK: // %bb.0:
-; CHECK-NEXT: // kill: def $d1 killed $d1 def $q1
-; CHECK-NEXT: // kill: def $d0 killed $d0 def $q0
-; CHECK-NEXT: fmov x8, d0
-; CHECK-NEXT: fmov x9, d1
-; CHECK-NEXT: umulh x8, x8, x9
-; CHECK-NEXT: fmov d0, x8
+; CHECK-NEXT: // kill: def $d0 killed $d0 def $z0
+; CHECK-NEXT: // kill: def $d1 killed $d1 def $z1
+; CHECK-NEXT: umulh z0.d, z0.d, z1.d
+; CHECK-NEXT: // kill: def $d0 killed $d0 killed $z0
; CHECK-NEXT: ret
%1 = zext <1 x i64> %a to <1 x i128>
%2 = zext <1 x i64> %b to <1 x i128>
>From 600adef41d8927ce3322aa1acc5b3394e2c34dfb Mon Sep 17 00:00:00 2001
From: David Green <david.green at arm.com>
Date: Mon, 8 Dec 2025 13:59:05 +0000
Subject: [PATCH 2/2] Address comments
---
llvm/lib/Target/AArch64/AArch64ISelLowering.cpp | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
index 3831b90ee68b4..d4dc1f0690b7b 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -1839,7 +1839,8 @@ AArch64TargetLowering::AArch64TargetLowering(const TargetMachine &TM,
setOperationAction(ISD::INTRINSIC_WO_CHAIN, MVT::i8, Custom);
setOperationAction(ISD::INTRINSIC_WO_CHAIN, MVT::i16, Custom);
- // NEON doesn't support integer divides, but SVE does
+ // A number of operations like MULH and integer divides are not supported by
+ // NEON but are available in SVE.
for (auto VT : {MVT::v8i8, MVT::v16i8, MVT::v4i16, MVT::v8i16, MVT::v2i32,
MVT::v4i32, MVT::v1i64, MVT::v2i64}) {
setOperationAction(ISD::SDIV, VT, Custom);
@@ -1903,8 +1904,6 @@ AArch64TargetLowering::AArch64TargetLowering(const TargetMachine &TM,
setOperationAction(ISD::VECREDUCE_AND, VT, Custom);
setOperationAction(ISD::VECREDUCE_OR, VT, Custom);
setOperationAction(ISD::VECREDUCE_XOR, VT, Custom);
- setOperationAction(ISD::MULHS, VT, Custom);
- setOperationAction(ISD::MULHU, VT, Custom);
}
// Use SVE for vectors with more than 2 elements.
More information about the llvm-commits
mailing list