[AArch32] Armv8.6-a Matrix Mult Assembly + Intrinsics

[LukeGeeson]

Summary

This patch upstreams support for the Armv8.6-a Matrix Multiplication
Extension. A summary of the features can be found here:

https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/arm-architecture-developments-armv8-6-a

This patch includes:

• Assembly support for AArch32
• Intrinsics Support for AArch32 Neon Intrinsics for Matrix Multiplication

Note: these extensions are optional in the 8.6a architecture and so have
to be enabled by default

No additional IR types or C Types are needed for this extension.

This is part of a patch series, starting with BFloat16 support and
the other components in the armv8.6a extension (in previous patches
linked in phabricator)

Based on work by:

• Luke Geeson
• Oliver Stannard
• Luke Cheeseman

[LukeGeeson]

Harbourmaster now biulds, and unit tests pass, errors related to linting

[miyuki]

clang/test/CodeGen/arm-v8.6a-neon-intrinsics.c

4

Can you try -sroa after -mem2reg? I think it should eliminate some more useless stores and loads.

llvm/lib/Target/ARM/ARMInstrNEON.td

4839

Why was this added?

[LukeGeeson]

• added -sroa to arm-v8.6a-neon-intrinsics test, updated test to remove redundant memory accesses
• made class vusdot for new vusdot instructions with hasNoSchedulinginfo for new instructions. Existing instructions retain scheduling via use of VDOT class

[LukeGeeson]

clang/test/CodeGen/arm-v8.6a-neon-intrinsics.c

4

added, test updated

llvm/lib/Target/ARM/ARMInstrNEON.td

4839

Added a vusdot class to handle this

[miyuki]

LGTM, but please wait a couple more days before committing to see if anyone wants to chime in (I guess one week since the upload date should be enough).

[miyuki]

This comment was removed by miyuki.

[dmgreen]

llvm/lib/Target/ARM/ARMInstrNEON.td

4846

I don't think that hasNoSchedulingInfo is necessarily the best way to handle this. That flag is intended for instructions that will never be scheduled, like Pseudo instructions.

If you are running into "Complete Schedule" problems, they might need HasMatMulInt8 added to the list of unsupported features instead.

[LukeGeeson]

llvm/lib/Target/ARM/ARMInstrNEON.td

4846

Since there are no 8.6a cpus in llvm that support this extension, the default behaviour is to use Cortex-A57 scheduling - this also has no notion of 8.6a matmul.

This falls back to SchedMachineModel in llvm/lib/Target/ARM/ARMScheduleA57.td and in particular UnsupportedFeatures would be a candidate place to put unsupported features like matmul. I took issue with putting all new extensions here because there should be a separation of concerns between a particular scheduling model, and supporting new behaviour (which could go in a generic catch all location that might be slightly more informative ).

Did you have something in particular in mind?

[dmgreen]

llvm/lib/Target/ARM/ARMInstrNEON.td

4846

The ARMSchedule A57schedule is marked with CompleteModel=1. I believe it's the only one ARM-side that does that, but that's why it's running into problems. I'm surprised it hasn't run into the same problems in the past.

On the AArch64 side we tend to mark all Neon instructions with WriteV, so they at least get basic scheduling info. We don't tend to do that for ARM though.

Marking the instruction as hasNoSchedulingInfo will stop _any_ schedule from setting information on them, which whilst technically OK for now would be cause problems in the long run. We should either be adding a Sched[] Write (but I'm not sure what we would add), marking A57 as not complete (which seems like a hack) or adding unsupported features. Or adding scheduling info for these instructions to A57 I guess, but that doesn't sound right for a CPU that doesn't support them!

I can put a patch together to clean it up pretty easily.

clang/lib/Basic/Targets/ARM.h

class LLVM_LIBRARY_VISIBILITY ARMTargetInfo : public TargetInfo {
   unsigned SoftFloat : 1;
   unsigned SoftFloatABI : 1;
 
   unsigned CRC : 1;
   unsigned Crypto : 1;
   unsigned DSP : 1;
   unsigned Unaligned : 1;
   unsigned DotProd : 1;
+  unsigned HasMatMul : 1;
 
   enum {
     LDREX_B = (1 << 0), /// byte (8-bit)
     LDREX_H = (1 << 1), /// half (16-bit)
     LDREX_W = (1 << 2), /// word (32-bit)
     LDREX_D = (1 << 3), /// double (64-bit)
   };
 

clang/lib/Basic/Targets/ARM.cpp

bool ARMTargetInfo::handleTargetFeatures(std::vector<std::string> &Features,
   CRC = 0;
   Crypto = 0;
   DSP = 0;
   Unaligned = 1;
   SoftFloat = false;
   // Note that SoftFloatABI is initialized in our constructor.
   HWDiv = 0;
   DotProd = 0;
+  HasMatMul = 0;
   HasFloat16 = true;
   ARMCDECoprocMask = 0;
 
   // This does not diagnose illegal cases like having both
   // "+vfpv2" and "+vfpv3" or having "+neon" and "-fp64".
   for (const auto &Feature : Features) {
     if (Feature == "+soft-float") {
       SoftFloat = true;
if (Feature == "+soft-float") {
       DotProd = true;
     } else if (Feature == "+mve") {
       MVE |= MVE_INT;
     } else if (Feature == "+mve.fp") {
       HasLegalHalfType = true;
       FPU |= FPARMV8;
       MVE |= MVE_INT | MVE_FP;
       HW_FP |= HW_FP_SP | HW_FP_HP;
+    } else if (Feature == "+i8mm") {
+      HasMatMul = 1;
     } else if (Feature.size() == strlen("+cdecp0") && Feature >= "+cdecp0" &&
                Feature <= "+cdecp7") {
       unsigned Coproc = Feature.back() - '0';
       ARMCDECoprocMask |= (1U << Coproc);
     }
   }
 
   switch (ArchVersion) {
void ARMTargetInfo::getTargetDefines(const LangOptions &Opts,
   // Armv8.2-A FP16 scalar intrinsics
   if (HasLegalHalfType)
     Builder.defineMacro("__ARM_FEATURE_FP16_SCALAR_ARITHMETIC", "1");
 
   // Armv8.2-A dot product intrinsics
   if (DotProd)
     Builder.defineMacro("__ARM_FEATURE_DOTPROD", "1");
 
+  if (HasMatMul)
+    Builder.defineMacro("__ARM_FEATURE_MATMUL_INT8", "1");
+
   switch (ArchKind) {
   default:
     break;
   case llvm::ARM::ArchKind::ARMV8_1A:
     getTargetDefinesARMV81A(Opts, Builder);
     break;
   case llvm::ARM::ArchKind::ARMV8_2A:
     getTargetDefinesARMV82A(Opts, Builder);

clang/lib/CodeGen/CGBuiltin.cpp

static const ARMVectorIntrinsicInfo ARMSIMDIntrinsicMap [] = {
   NEONMAP2(vmax_v, arm_neon_vmaxu, arm_neon_vmaxs, Add1ArgType | UnsignedAlts),
   NEONMAP1(vmaxnm_v, arm_neon_vmaxnm, Add1ArgType),
   NEONMAP1(vmaxnmq_v, arm_neon_vmaxnm, Add1ArgType),
   NEONMAP2(vmaxq_v, arm_neon_vmaxu, arm_neon_vmaxs, Add1ArgType | UnsignedAlts),
   NEONMAP2(vmin_v, arm_neon_vminu, arm_neon_vmins, Add1ArgType | UnsignedAlts),
   NEONMAP1(vminnm_v, arm_neon_vminnm, Add1ArgType),
   NEONMAP1(vminnmq_v, arm_neon_vminnm, Add1ArgType),
   NEONMAP2(vminq_v, arm_neon_vminu, arm_neon_vmins, Add1ArgType | UnsignedAlts),
+  NEONMAP2(vmmlaq_v, arm_neon_ummla, arm_neon_smmla, 0),
   NEONMAP0(vmovl_v),
   NEONMAP0(vmovn_v),
   NEONMAP1(vmul_v, arm_neon_vmulp, Add1ArgType),
   NEONMAP0(vmull_v),
   NEONMAP1(vmulq_v, arm_neon_vmulp, Add1ArgType),
   NEONMAP2(vpadal_v, arm_neon_vpadalu, arm_neon_vpadals, UnsignedAlts),
   NEONMAP2(vpadalq_v, arm_neon_vpadalu, arm_neon_vpadals, UnsignedAlts),
   NEONMAP1(vpadd_v, arm_neon_vpadd, Add1ArgType),
static const ARMVectorIntrinsicInfo ARMSIMDIntrinsicMap [] = {
   NEONMAP1(vst4_v, arm_neon_vst4, 0),
   NEONMAP1(vst4q_lane_v, arm_neon_vst4lane, 0),
   NEONMAP1(vst4q_v, arm_neon_vst4, 0),
   NEONMAP0(vsubhn_v),
   NEONMAP0(vtrn_v),
   NEONMAP0(vtrnq_v),
   NEONMAP0(vtst_v),
   NEONMAP0(vtstq_v),
+  NEONMAP1(vusdot_v, arm_neon_usdot, 0),
+  NEONMAP1(vusdotq_v, arm_neon_usdot, 0),
+  NEONMAP1(vusmmlaq_v, arm_neon_usmmla, 0),
   NEONMAP0(vuzp_v),
   NEONMAP0(vuzpq_v),
   NEONMAP0(vzip_v),
   NEONMAP0(vzipq_v)
 };
 
 static const ARMVectorIntrinsicInfo AArch64SIMDIntrinsicMap[] = {
   NEONMAP0(splat_lane_v),

clang/test/CodeGen/arm-v8.6a-neon-intrinsics.c

+// RUN: %clang_cc1 -triple armv8.6a-arm-none-eabi -target-feature +neon -target-feature +fullfp16 -target-feature +i8mm \
+// RUN: -fallow-half-arguments-and-returns -S -disable-O0-optnone -emit-llvm -o - %s \
+// RUN: | opt -S -mem2reg -sroa \
+// RUN: | FileCheck %s
+
+// REQUIRES: arm-registered-target
+
+#include <arm_neon.h>
+
+// CHECK-LABEL: test_vmmlaq_s32
+// CHECK: [[VAL:%.*]] = call <4 x i32> @llvm.arm.neon.smmla.v4i32.v16i8(<4 x i32> %r, <16 x i8> %a, <16 x i8> %b)
+// CHECK: ret <4 x i32> [[VAL]]
+int32x4_t test_vmmlaq_s32(int32x4_t r, int8x16_t a, int8x16_t b) {
+  return vmmlaq_s32(r, a, b);
+}
+
+// CHECK-LABEL: test_vmmlaq_u32
+// CHECK: [[VAL:%.*]] = call <4 x i32> @llvm.arm.neon.ummla.v4i32.v16i8(<4 x i32> %r, <16 x i8> %a, <16 x i8> %b)
+// CHECK: ret <4 x i32> [[VAL]]
+uint32x4_t test_vmmlaq_u32(uint32x4_t r, uint8x16_t a, uint8x16_t b) {
+  return vmmlaq_u32(r, a, b);
+}
+
+// CHECK-LABEL: test_vusmmlaq_s32
+// CHECK: [[VAL:%.*]] = call <4 x i32> @llvm.arm.neon.usmmla.v4i32.v16i8(<4 x i32> %r, <16 x i8> %a, <16 x i8> %b)
+// CHECK: ret <4 x i32> [[VAL]]
+int32x4_t test_vusmmlaq_s32(int32x4_t r, uint8x16_t a, int8x16_t b) {
+  return vusmmlaq_s32(r, a, b);
+}
+
+// CHECK-LABEL: test_vusdot_s32
+// CHECK: [[VAL:%.*]] = call <2 x i32> @llvm.arm.neon.usdot.v2i32.v8i8(<2 x i32> %r, <8 x i8> %a, <8 x i8> %b)
+// CHECK: ret <2 x i32> [[VAL]]
+int32x2_t test_vusdot_s32(int32x2_t r, uint8x8_t a, int8x8_t b) {
+  return vusdot_s32(r, a, b);
+}
+
+// CHECK-LABEL: test_vusdot_lane_s32
+// CHECK: [[TMP0:%.*]] = bitcast <8 x i8> %b to <2 x i32>
+// CHECK: [[TMP1:%.*]] = bitcast <2 x i32> [[TMP0]] to <8 x i8>
+// CHECK: [[TMP2:%.*]] = bitcast <8 x i8> [[TMP1]] to <2 x i32>
+// CHECK: [[LANE:%.*]] = shufflevector <2 x i32> [[TMP2]], <2 x i32> [[TMP2]], <2 x i32> zeroinitializer
+// CHECK: [[TMP3:%.*]] = bitcast <2 x i32> [[LANE]] to <8 x i8>
+// CHECK: [[TMP4:%.*]] = bitcast <2 x i32> %r to <8 x i8>
+// CHECK: [[OP:%.*]] = call <2 x i32> @llvm.arm.neon.usdot.v2i32.v8i8(<2 x i32> %r, <8 x i8> %a, <8 x i8> [[TMP3]])
+// CHECK: ret <2 x i32> [[OP]]
+int32x2_t test_vusdot_lane_s32(int32x2_t r, uint8x8_t a, int8x8_t b) {
+  return vusdot_lane_s32(r, a, b, 0);
+}
+
+// CHECK-LABEL: test_vsudot_lane_s32
+// CHECK: [[TMP0:%.*]] = bitcast <8 x i8> %b to <2 x i32>
+// CHECK: [[TMP1:%.*]] = bitcast <2 x i32> [[TMP0]] to <8 x i8>
+// CHECK: [[TMP2:%.*]] = bitcast <8 x i8> [[TMP1]] to <2 x i32>
+// CHECK: [[LANE:%.*]] = shufflevector <2 x i32> [[TMP2]], <2 x i32> [[TMP2]], <2 x i32> zeroinitializer
+// CHECK: [[TMP3:%.*]] = bitcast <2 x i32> [[LANE]] to <8 x i8>
+// CHECK: [[TMP4:%.*]] = bitcast <2 x i32> %r to <8 x i8>
+// CHECK: [[OP:%.*]] = call <2 x i32> @llvm.arm.neon.usdot.v2i32.v8i8(<2 x i32> %r, <8 x i8> [[TMP3]], <8 x i8> %a)
+// CHECK: ret <2 x i32> [[OP]]
+int32x2_t test_vsudot_lane_s32(int32x2_t r, int8x8_t a, uint8x8_t b) {
+  return vsudot_lane_s32(r, a, b, 0);
+}
+
+// CHECK-LABEL: test_vusdotq_lane_s32
+// CHECK: [[TMP0:%.*]] = bitcast <8 x i8> %b to <2 x i32>
+// CHECK: [[TMP1:%.*]] = bitcast <2 x i32> [[TMP0]] to <8 x i8>
+// CHECK: [[TMP2:%.*]] = bitcast <8 x i8> [[TMP1]] to <2 x i32>
+// CHECK: [[LANE:%.*]] = shufflevector <2 x i32> [[TMP2]], <2 x i32> [[TMP2]], <4 x i32> zeroinitializer
+// CHECK: [[TMP4:%.*]] = bitcast <4 x i32> [[LANE]] to <16 x i8>
+// CHECK: [[TMP5:%.*]] = bitcast <4 x i32> %r to <16 x i8>
+// CHECK: [[OP:%.*]] = call <4 x i32> @llvm.arm.neon.usdot.v4i32.v16i8(<4 x i32> %r, <16 x i8> %a, <16 x i8> [[TMP4]])
+// CHECK: ret <4 x i32> [[OP]]
+int32x4_t test_vusdotq_lane_s32(int32x4_t r, uint8x16_t a, int8x8_t b) {
+  return vusdotq_lane_s32(r, a, b, 0);
+}
+
+// CHECK-LABEL: test_vsudotq_lane_s32
+// CHECK: [[TMP0:%.*]] = bitcast <8 x i8> %b to <2 x i32>
+// CHECK: [[TMP1:%.*]] = bitcast <2 x i32> [[TMP0]] to <8 x i8>
+// CHECK: [[TMP2:%.*]] = bitcast <8 x i8> [[TMP1]] to <2 x i32>
+// CHECK: [[LANE:%.*]] = shufflevector <2 x i32> [[TMP2]], <2 x i32> [[TMP2]], <4 x i32> zeroinitializer
+// CHECK: [[TMP4:%.*]] = bitcast <4 x i32> %r to <16 x i8>
+// CHECK: [[OP:%.*]] = call <4 x i32> @llvm.arm.neon.usdot.v4i32.v16i8(<4 x i32> %r, <16 x i8> %3, <16 x i8> %a)
+// CHECK: ret <4 x i32> [[OP]]
+int32x4_t test_vsudotq_lane_s32(int32x4_t r, int8x16_t a, uint8x8_t b) {
+  return vsudotq_lane_s32(r, a, b, 0);
+}

llvm/include/llvm/IR/IntrinsicsARM.td

 class Neon_Dot_Intrinsic
   : Intrinsic<[llvm_anyvector_ty],
               [LLVMMatchType<0>, llvm_anyvector_ty,
                LLVMMatchType<1>],
               [IntrNoMem]>;
 def int_arm_neon_udot : Neon_Dot_Intrinsic;
 def int_arm_neon_sdot : Neon_Dot_Intrinsic;
 
+// v8.6-A Matrix Multiply Intrinsics
+class Neon_MatMul_Intrinsic
+  : Intrinsic<[llvm_anyvector_ty],
+              [LLVMMatchType<0>, llvm_anyvector_ty,
+               LLVMMatchType<1>],
+              [IntrNoMem]>;
+def int_arm_neon_ummla  : Neon_MatMul_Intrinsic;
+def int_arm_neon_smmla  : Neon_MatMul_Intrinsic;
+def int_arm_neon_usmmla : Neon_MatMul_Intrinsic;
+def int_arm_neon_usdot  : Neon_Dot_Intrinsic;
+
+// v8.6-A Bfloat Intrinsics
+
 def int_arm_cls: Intrinsic<[llvm_i32_ty], [llvm_i32_ty], [IntrNoMem]>;
 def int_arm_cls64: Intrinsic<[llvm_i32_ty], [llvm_i64_ty], [IntrNoMem]>;
 
 def int_arm_mve_vctp8  : Intrinsic<[llvm_v16i1_ty], [llvm_i32_ty], [IntrNoMem]>;
 def int_arm_mve_vctp16 : Intrinsic<[llvm_v8i1_ty], [llvm_i32_ty], [IntrNoMem]>;
 def int_arm_mve_vctp32 : Intrinsic<[llvm_v4i1_ty], [llvm_i32_ty], [IntrNoMem]>;
 // vctp64 takes v4i1, to work around v2i1 not being a legal MVE type
 def int_arm_mve_vctp64 : Intrinsic<[llvm_v4i1_ty], [llvm_i32_ty], [IntrNoMem]>;

llvm/lib/Target/ARM/ARM.td

 
 def FeatureSB       : SubtargetFeature<"sb", "HasSB", "true",
   "Enable v8.5a Speculation Barrier" >;
 
 // Armv8.6-A extensions
 def FeatureBF16     : SubtargetFeature<"bf16", "HasBF16", "true",
   "Enable support for BFloat16 instructions",  [FeatureNEON]>;
 
+def FeatureMatMulInt8 : SubtargetFeature<"i8mm", "HasMatMulInt8",
+    "true", "Enable Matrix Multiply Int8 Extension", [FeatureNEON]>;
+
 // Armv8.1-M extensions
 
 def FeatureLOB            : SubtargetFeature<"lob", "HasLOB", "true",
                                              "Enable Low Overhead Branch "
                                              "extensions">;
 
 //===----------------------------------------------------------------------===//
 // ARM architecture class
def HasV8_4aOps   : SubtargetFeature<"v8.4a", "HasV8_4aOps", "true",
                                    [HasV8_3aOps, FeatureDotProd]>;
 
 def HasV8_5aOps   : SubtargetFeature<"v8.5a", "HasV8_5aOps", "true",
                                    "Support ARM v8.5a instructions",
                                    [HasV8_4aOps, FeatureSB]>;
 
 def HasV8_6aOps   : SubtargetFeature<"v8.6a", "HasV8_6aOps", "true",
                                    "Support ARM v8.6a instructions",
-                                   [HasV8_5aOps, FeatureBF16]>;
+                                   [HasV8_5aOps, FeatureBF16,
+                                    FeatureMatMulInt8]>;
 
 def HasV8_1MMainlineOps : SubtargetFeature<
                "v8.1m.main", "HasV8_1MMainlineOps", "true",
                "Support ARM v8-1M Mainline instructions",
                [HasV8MMainlineOps]>;
 def HasMVEIntegerOps : SubtargetFeature<
                "mve", "HasMVEIntegerOps", "true",
                "Support M-Class Vector Extension with integer ops",

llvm/lib/Target/ARM/ARMInstrNEON.td

 def : Pat<(v4f32 (fma (fneg QPR:$Vn), QPR:$Vm, QPR:$src1)),
           (VFMSfq QPR:$src1, QPR:$Vn, QPR:$Vm)>,
       Requires<[HasNEON,HasVFP4]>;
 
 // ARMv8.2a dot product instructions.
 // We put them in the VFPV8 decoder namespace because the ARM and Thumb
 // encodings are the same and thus no further bit twiddling is necessary
 // in the disassembler.
-class VDOT<bit op6, bit op4, RegisterClass RegTy, string Asm, string AsmTy,
-           ValueType AccumTy, ValueType InputTy,
+class VDOT<bit op6, bit op4, bit op23, RegisterClass RegTy, string Asm,
+           string AsmTy, ValueType AccumTy, ValueType InputTy,
            SDPatternOperator OpNode> :
-      N3Vnp<0b11000, 0b10, 0b1101, op6, op4, (outs RegTy:$dst),
+      N3Vnp<{0b1100, op23}, 0b10, 0b1101, op6, op4, (outs RegTy:$dst),
             (ins RegTy:$Vd, RegTy:$Vn, RegTy:$Vm), N3RegFrm, IIC_VDOTPROD,
             Asm, AsmTy,
             [(set (AccumTy RegTy:$dst),
                   (OpNode (AccumTy RegTy:$Vd),
                           (InputTy RegTy:$Vn),
                           (InputTy RegTy:$Vm)))]> {
   let Predicates = [HasDotProd];
   let DecoderNamespace = "VFPV8";
   let Constraints = "$dst = $Vd";
 }
 
-def VUDOTD : VDOT<0, 1, DPR, "vudot", "u8", v2i32, v8i8,  int_arm_neon_udot>;
-def VSDOTD : VDOT<0, 0, DPR, "vsdot", "s8", v2i32, v8i8,  int_arm_neon_sdot>;
-def VUDOTQ : VDOT<1, 1, QPR, "vudot", "u8", v4i32, v16i8, int_arm_neon_udot>;
-def VSDOTQ : VDOT<1, 0, QPR, "vsdot", "s8", v4i32, v16i8, int_arm_neon_sdot>;
+
+class VUSDOT<bit op6, bit op4, bit op23, RegisterClass RegTy, string Asm,
+           string AsmTy, ValueType AccumTy, ValueType InputTy,
+           SDPatternOperator OpNode> :
+      VDOT<op6, op4, op23, RegTy, Asm, AsmTy, AccumTy, InputTy, OpNode> {
+  let hasNoSchedulingInfo = 1;
+
+}
+
+def VUDOTD : VDOT<0, 1, 0, DPR, "vudot", "u8", v2i32, v8i8,  int_arm_neon_udot>;
+def VSDOTD : VDOT<0, 0, 0, DPR, "vsdot", "s8", v2i32, v8i8,  int_arm_neon_sdot>;
+def VUDOTQ : VDOT<1, 1, 0, QPR, "vudot", "u8", v4i32, v16i8, int_arm_neon_udot>;
+def VSDOTQ : VDOT<1, 0, 0, QPR, "vsdot", "s8", v4i32, v16i8, int_arm_neon_sdot>;
 
 // Indexed dot product instructions:
 multiclass DOTI<string opc, string dt, bit Q, bit U, RegisterClass Ty,
            ValueType AccumType, ValueType InputType, SDPatternOperator OpNode,
            dag RHS> {
   def "" : N3Vnp<0b11100, 0b10, 0b1101, Q, U, (outs Ty:$dst),
                  (ins Ty:$Vd, Ty:$Vn, DPR_VFP2:$Vm, VectorIndex32:$lane),
                  N3RegFrm, IIC_VDOTPROD, opc, dt, []> {
defm VUDOTDI : DOTI<"vudot", "u8", 0b0, 0b1, DPR, v2i32, v8i8,
                     int_arm_neon_udot, (v2i32 DPR_VFP2:$Vm)>;
 defm VSDOTDI : DOTI<"vsdot", "s8", 0b0, 0b0, DPR, v2i32, v8i8,
                     int_arm_neon_sdot, (v2i32 DPR_VFP2:$Vm)>;
 defm VUDOTQI : DOTI<"vudot", "u8", 0b1, 0b1, QPR, v4i32, v16i8,
                     int_arm_neon_udot, (EXTRACT_SUBREG QPR:$Vm, dsub_0)>;
 defm VSDOTQI : DOTI<"vsdot", "s8", 0b1, 0b0, QPR, v4i32, v16i8,
                     int_arm_neon_sdot, (EXTRACT_SUBREG QPR:$Vm, dsub_0)>;
 
+// v8.6A matrix multiplication extension
+let Predicates = [HasMatMulInt8] in {
+  class N3VMatMul<bit B, bit U, string Asm, string AsmTy,
+                  SDPatternOperator OpNode>
+        : N3Vnp<{0b1100, B}, 0b10, 0b1100, 1, U, (outs QPR:$dst),
+                (ins QPR:$Vd, QPR:$Vn, QPR:$Vm), N3RegFrm, NoItinerary,
+                Asm, AsmTy,
+                [(set (v4i32 QPR:$dst), (OpNode (v4i32 QPR:$Vd),
+                                                (v16i8 QPR:$Vn),
+                                                (v16i8 QPR:$Vm)))]> {
+    let DecoderNamespace = "VFPV8";
+    let Constraints = "$dst = $Vd";
+    let hasNoSchedulingInfo = 1;
+  }
+
+  multiclass N3VMixedDotLane<bit Q, bit U, string Asm, string AsmTy, RegisterClass RegTy,
+                        ValueType AccumTy, ValueType InputTy, SDPatternOperator OpNode,
+                        dag RHS> {
+
+    def "" : N3Vnp<0b11101, 0b00, 0b1101, Q, U, (outs RegTy:$dst),
+                (ins RegTy:$Vd, RegTy:$Vn, DPR_VFP2:$Vm, VectorIndex32:$lane), N3RegFrm,
+                 NoItinerary, Asm, AsmTy, []> {
+      bit lane;
+      let hasNoSchedulingInfo = 1;
+      let Inst{5} = lane;
+      let AsmString = !strconcat(Asm, ".", AsmTy, "\t$Vd, $Vn, $Vm$lane");
+      let DecoderNamespace = "VFPV8";
+      let Constraints = "$dst = $Vd";
+    }
+
+    def : Pat<
+      (AccumTy (OpNode (AccumTy RegTy:$Vd),
+                       (InputTy RegTy:$Vn),
+                       (InputTy (bitconvert (AccumTy
+                                (ARMvduplane (AccumTy RegTy:$Vm),
+                                              VectorIndex32:$lane)))))),
+      (!cast<Instruction>(NAME) RegTy:$Vd, RegTy:$Vn, RHS, VectorIndex32:$lane)>;
+
+  }
+
+  multiclass SUDOTLane<bit Q, RegisterClass RegTy, ValueType AccumTy, ValueType InputTy, dag RHS>
+        : N3VMixedDotLane<Q, 1, "vsudot", "u8", RegTy, AccumTy, InputTy, null_frag, null_frag> {
+    def : Pat<
+      (AccumTy (int_arm_neon_usdot (AccumTy RegTy:$Vd),
+                                   (InputTy (bitconvert (AccumTy
+                                            (ARMvduplane (AccumTy RegTy:$Vm),
+                                                          VectorIndex32:$lane)))),
+                                   (InputTy RegTy:$Vn))),
+      (!cast<Instruction>(NAME) RegTy:$Vd, RegTy:$Vn, RHS, VectorIndex32:$lane)>;
+  }
+
+  def VSMMLA  : N3VMatMul<0, 0, "vsmmla",  "s8", int_arm_neon_smmla>;
+  def VUMMLA  : N3VMatMul<0, 1, "vummla",  "u8", int_arm_neon_ummla>;
+  def VUSMMLA : N3VMatMul<1, 0, "vusmmla", "s8", int_arm_neon_usmmla>;
+  def VUSDOTD : VUSDOT<0, 0, 1, DPR, "vusdot", "s8", v2i32, v8i8,  int_arm_neon_usdot>;
+  def VUSDOTQ : VUSDOT<1, 0, 1, QPR, "vusdot", "s8", v4i32, v16i8, int_arm_neon_usdot>;
+
+  defm VUSDOTDI : N3VMixedDotLane<0, 0, "vusdot", "s8", DPR, v2i32, v8i8,
+                                  int_arm_neon_usdot, (v2i32 DPR_VFP2:$Vm)>;
+  defm VUSDOTQI : N3VMixedDotLane<1, 0, "vusdot", "s8", QPR, v4i32, v16i8,
+                                  int_arm_neon_usdot, (EXTRACT_SUBREG QPR:$Vm, dsub_0)>;
+  defm VSUDOTDI : SUDOTLane<0, DPR, v2i32, v8i8, (v2i32 DPR_VFP2:$Vm)>;
+  defm VSUDOTQI : SUDOTLane<1, QPR, v4i32, v16i8, (EXTRACT_SUBREG QPR:$Vm, dsub_0)>;
+}
 
 // ARMv8.3 complex operations
 class BaseN3VCP8ComplexTied<bit op21, bit op4, bit s, bit q,
                             InstrItinClass itin, dag oops, dag iops,
                             string opc, string dt, list<dag> pattern>
   : N3VCP8<{?,?}, {op21,s}, q, op4, oops,
            iops, itin, opc, dt, "$Vd, $Vn, $Vm, $rot", "$src1 = $Vd", pattern>{
   bits<2> rot;

llvm/lib/Target/ARM/ARMPredicates.td

 def HasFP16          : Predicate<"Subtarget->hasFP16()">,
                                  AssemblerPredicate<(all_of FeatureFP16),"half-float conversions">;
 def HasFullFP16      : Predicate<"Subtarget->hasFullFP16()">,
                                  AssemblerPredicate<(all_of FeatureFullFP16),"full half-float">;
 def HasFP16FML       : Predicate<"Subtarget->hasFP16FML()">,
                                  AssemblerPredicate<(all_of FeatureFP16FML),"full half-float fml">;
 def HasBF16          : Predicate<"Subtarget->hasBF16()">,
                                  AssemblerPredicate<(all_of FeatureBF16),"BFloat16 floating point extension">;
+def HasMatMulInt8    : Predicate<"Subtarget->hasMatMulInt8()">,
+                                 AssemblerPredicate<(all_of FeatureMatMulInt8),"8-bit integer matrix multiply">;
 def HasDivideInThumb : Predicate<"Subtarget->hasDivideInThumbMode()">,
                                  AssemblerPredicate<(all_of FeatureHWDivThumb), "divide in THUMB">;
 def HasDivideInARM   : Predicate<"Subtarget->hasDivideInARMMode()">,
                                  AssemblerPredicate<(all_of FeatureHWDivARM), "divide in ARM">;
 def HasDSP           : Predicate<"Subtarget->hasDSP()">,
                                  AssemblerPredicate<(all_of FeatureDSP), "dsp">;
 def HasDB            : Predicate<"Subtarget->hasDataBarrier()">,
                                  AssemblerPredicate<(all_of FeatureDB),

llvm/lib/Target/ARM/ARMSubtarget.h

protected:
   bool HasFullFP16 = false;
 
   /// HasFP16FML - True if subtarget supports half-precision FP fml operations
   bool HasFP16FML = false;
 
   /// HasBF16 - True if subtarget supports BFloat16 floating point operations
   bool HasBF16 = false;
 
+  /// HasMatMulInt8 - True if subtarget supports 8-bit integer matrix multiply
+  bool HasMatMulInt8 = false;
+
   /// HasD32 - True if subtarget has the full 32 double precision
   /// FP registers for VFPv3.
   bool HasD32 = false;
 
   /// HasHardwareDivide - True if subtarget supports [su]div in Thumb mode
   bool HasHardwareDivideInThumb = false;
 
   /// HasHardwareDivideInARM - True if subtarget supports [su]div in ARM mode
public:
   bool hasFullFP16() const { return HasFullFP16; }
   bool hasFP16FML() const { return HasFP16FML; }
 
   bool hasFuseAES() const { return HasFuseAES; }
   bool hasFuseLiterals() const { return HasFuseLiterals; }
   /// Return true if the CPU supports any kind of instruction fusion.
   bool hasFusion() const { return hasFuseAES() || hasFuseLiterals(); }
 
+  bool hasMatMulInt8() const { return HasMatMulInt8; }
+
   const Triple &getTargetTriple() const { return TargetTriple; }
 
   bool isTargetDarwin() const { return TargetTriple.isOSDarwin(); }
   bool isTargetIOS() const { return TargetTriple.isiOS(); }
   bool isTargetWatchOS() const { return TargetTriple.isWatchOS(); }
   bool isTargetWatchABI() const { return TargetTriple.isWatchABI(); }
   bool isTargetLinux() const { return TargetTriple.isOSLinux(); }
   bool isTargetNaCl() const { return TargetTriple.isOSNaCl(); }

llvm/test/CodeGen/ARM/arm-matmul.ll

+; RUN: llc -mtriple=arm-none-linux-gnu -mattr=+neon,+i8mm -float-abi=hard < %s -o -| FileCheck %s
+
+define <4 x i32> @smmla.v4i32.v16i8(<4 x i32> %r, <16 x i8> %a, <16 x i8> %b) {
+entry:
+; CHECK-LABEL: smmla.v4i32.v16i8
+; CHECK:        vsmmla.s8       q0, q1, q2
+  %vmmla1.i = tail call <4 x i32> @llvm.arm.neon.smmla.v4i32.v16i8(<4 x i32> %r, <16 x i8> %a, <16 x i8> %b) #3
+  ret <4 x i32> %vmmla1.i
+}
+
+define <4 x i32> @ummla.v4i32.v16i8(<4 x i32> %r, <16 x i8> %a, <16 x i8> %b) {
+entry:
+; CHECK-LABEL: ummla.v4i32.v16i8
+; CHECK:        vummla.u8       q0, q1, q2
+  %vmmla1.i = tail call <4 x i32> @llvm.arm.neon.ummla.v4i32.v16i8(<4 x i32> %r, <16 x i8> %a, <16 x i8> %b) #3
+  ret <4 x i32> %vmmla1.i
+}
+
+define <4 x i32> @usmmla.v4i32.v16i8(<4 x i32> %r, <16 x i8> %a, <16 x i8> %b) {
+entry:
+; CHECK-LABEL: usmmla.v4i32.v16i8
+; CHECK:        vusmmla.s8       q0, q1, q2
+  %vusmmla1.i = tail call <4 x i32> @llvm.arm.neon.usmmla.v4i32.v16i8(<4 x i32> %r, <16 x i8> %a, <16 x i8> %b) #3
+  ret <4 x i32> %vusmmla1.i
+}
+
+define <2 x i32> @usdot.v2i32.v8i8(<2 x i32> %r, <8 x i8> %a, <8 x i8> %b) {
+entry:
+; CHECK-LABEL: usdot.v2i32.v8i8
+; CHECK:        vusdot.s8       d0, d1, d2
+  %vusdot1.i = tail call <2 x i32> @llvm.arm.neon.usdot.v2i32.v8i8(<2 x i32> %r, <8 x i8> %a, <8 x i8> %b) #3
+  ret <2 x i32> %vusdot1.i
+}
+
+define <2 x i32> @usdot_lane.v2i32.v8i8(<2 x i32> %r, <8 x i8> %a, <8 x i8> %b) {
+entry:
+; CHECK-LABEL: usdot_lane.v2i32.v8i8
+; CHECK:        vusdot.s8       d0, d1, d2[0]
+  %0 = bitcast <8 x i8> %b to <2 x i32>
+  %shuffle = shufflevector <2 x i32> %0, <2 x i32> undef, <2 x i32> zeroinitializer
+  %1 = bitcast <2 x i32> %shuffle to <8 x i8>
+  %vusdot1.i = tail call <2 x i32> @llvm.arm.neon.usdot.v2i32.v8i8(<2 x i32> %r, <8 x i8> %a, <8 x i8> %1) #3
+  ret <2 x i32> %vusdot1.i
+}
+
+define <2 x i32> @sudot_lane.v2i32.v8i8(<2 x i32> %r, <8 x i8> %a, <8 x i8> %b) {
+entry:
+; CHECK-LABEL: sudot_lane.v2i32.v8i8
+; CHECK:        vsudot.u8       d0, d1, d2[0]
+  %0 = bitcast <8 x i8> %b to <2 x i32>
+  %shuffle = shufflevector <2 x i32> %0, <2 x i32> undef, <2 x i32> zeroinitializer
+  %1 = bitcast <2 x i32> %shuffle to <8 x i8>
+  %vusdot1.i = tail call <2 x i32> @llvm.arm.neon.usdot.v2i32.v8i8(<2 x i32> %r, <8 x i8> %1, <8 x i8> %a) #3
+  ret <2 x i32> %vusdot1.i
+}
+
+define <4 x i32> @usdotq_lane.v4i32.v16i8(<4 x i32> %r, <16 x i8> %a, <8 x i8> %b) {
+entry:
+; CHECK-LABEL: usdotq_lane.v4i32.v16i8
+; CHECK:        vusdot.s8       q0, q1, d4[0]
+  %0 = bitcast <8 x i8> %b to <2 x i32>
+  %shuffle = shufflevector <2 x i32> %0, <2 x i32> undef, <4 x i32> zeroinitializer
+  %1 = bitcast <4 x i32> %shuffle to <16 x i8>
+  %vusdot1.i = tail call <4 x i32> @llvm.arm.neon.usdot.v4i32.v16i8(<4 x i32> %r, <16 x i8> %a, <16 x i8> %1) #3
+  ret <4 x i32> %vusdot1.i
+}
+
+define <4 x i32> @sudotq_lane.v4i32.v16i8(<4 x i32> %r, <16 x i8> %a, <8 x i8> %b) {
+entry:
+; CHECK-LABEL: sudotq_lane.v4i32.v16i8
+; CHECK:        vsudot.u8       q0, q1, d4[0]
+  %0 = bitcast <8 x i8> %b to <2 x i32>
+  %shuffle = shufflevector <2 x i32> %0, <2 x i32> undef, <4 x i32> zeroinitializer
+  %1 = bitcast <4 x i32> %shuffle to <16 x i8>
+  %vusdot1.i = tail call <4 x i32> @llvm.arm.neon.usdot.v4i32.v16i8(<4 x i32> %r, <16 x i8> %1, <16 x i8> %a) #3
+  ret <4 x i32> %vusdot1.i
+}
+
+declare <4 x i32> @llvm.arm.neon.smmla.v4i32.v16i8(<4 x i32>, <16 x i8>, <16 x i8>) #2
+declare <4 x i32> @llvm.arm.neon.ummla.v4i32.v16i8(<4 x i32>, <16 x i8>, <16 x i8>) #2
+declare <4 x i32> @llvm.arm.neon.usmmla.v4i32.v16i8(<4 x i32>, <16 x i8>, <16 x i8>) #2
+declare <2 x i32> @llvm.arm.neon.usdot.v2i32.v8i8(<2 x i32>, <8 x i8>, <8 x i8>) #2
+declare <4 x i32> @llvm.arm.neon.usdot.v4i32.v16i8(<4 x i32>, <16 x i8>, <16 x i8>) #2