Dpdk Backend: Enable header stack dynamic index elimination

backends/dpdk/midend.cpp

@@ -44,6 +44,7 @@ limitations under the License.
 #include "midend/fillEnumMap.h"
 #include "midend/flattenHeaders.h"
 #include "midend/flattenInterfaceStructs.h"
+#include "midend/hsIndexSimplify.h"
 #include "midend/local_copyprop.h"
 #include "midend/midEndLast.h"
 #include "midend/nestedStructs.h"
@@ -205,10 +206,9 @@ DpdkMidEnd::DpdkMidEnd(CompilerOptions &options,
             new P4::FlattenHeaders(&refMap, &typeMap),
             new P4::FlattenInterfaceStructs(&refMap, &typeMap),
             new P4::SimplifyControlFlow(&refMap, &typeMap),
+            new P4::HSIndexSimplifier(&refMap, &typeMap),
             new P4::ParsersUnroll(true, &refMap, &typeMap),
             new P4::ReplaceSelectRange(&refMap, &typeMap),
-            // DPDK architecture does not currently support predicated instructions
-            // new P4::Predication(&refMap),
             new P4::MoveDeclarations(),  // more may have been introduced
             new P4::ConstantFolding(&refMap, &typeMap),
             new P4::LocalCopyPropagation(&refMap, &typeMap, nullptr, policy),

testdata/p4_16_samples/pna-example-varIndex-1.p4

@@ -0,0 +1,140 @@
+/*
+Copyright 2022 Intel Corporation
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+#include <core.p4>
+#include "pna.p4"
+
+#define MAX_LAYERS 2
+typedef bit<48>  EthernetAddress;
+
+enum bit<16> ether_type_t {
+    TPID = 0x8100,
+    IPV4 = 0x0800,
+    IPV6 = 0x86DD
+}
+
+header ethernet_t {
+    EthernetAddress dstAddr;
+    EthernetAddress srcAddr;
+    bit<16>         etherType;
+}
+
+header vlan_tag_h {
+    bit<3>        pcp;
+    bit<1>        cfi;
+    bit<12>       vid;
+    ether_type_t  ether_type;
+}
+
+struct headers_t {
+    ethernet_t ethernet;
+    vlan_tag_h[MAX_LAYERS]      vlan_tag;
+}
+
+struct main_metadata_t {
+    bit<2> depth;
+    bit<16> ethType;
+}
+
+control PreControlImpl(
+    in    headers_t  hdrs,
+    inout main_metadata_t meta,
+    in    pna_pre_input_metadata_t  istd,
+    inout pna_pre_output_metadata_t ostd)
+{
+    apply {
+    }
+}
+
+parser MainParserImpl(
+    packet_in pkt,
+    out   headers_t       hdrs,
+    inout main_metadata_t meta,
+    in    pna_main_parser_input_metadata_t istd)
+{
+    state start {
+        meta.depth = MAX_LAYERS - 1;
+        pkt.extract(hdrs.ethernet);
+        transition select(hdrs.ethernet.etherType) {
+            ether_type_t.TPID :  parse_vlan_tag;
+            default: accept;
+        }
+    }
+    state parse_vlan_tag {
+        pkt.extract(hdrs.vlan_tag.next);
+        meta.depth = meta.depth - 1;
+        transition select(hdrs.vlan_tag.last.ether_type) {
+            ether_type_t.TPID :  parse_vlan_tag;
+            default: accept;
+        }
+    }
+
+}
+
+control MainControlImpl(
+    inout headers_t       hdrs,           // from main parser
+    inout main_metadata_t meta,     // from main parser, to "next block"
+    in    pna_main_input_metadata_t  istd,
+    inout pna_main_output_metadata_t ostd)
+{
+    action execute() {
+        hdrs.vlan_tag[meta.depth].vid = hdrs.vlan_tag[meta.depth-1].vid;
+    }
+    action execute_1() {
+         drop_packet();
+    }
+
+    table stub {
+        key = {
+              hdrs.vlan_tag[meta.depth].vid : exact;
+        }
+
+        actions = {
+		execute;
+        }
+	const default_action = execute;
+        size=1000000;
+    }
+
+    apply {
+        stub.apply();
+    }
+}
+
+control MainDeparserImpl(
+    packet_out pkt,
+    in    headers_t hdr,                // from main control
+    in    main_metadata_t user_meta,    // from main control
+    in    pna_main_output_metadata_t ostd)
+{
+    apply {
+        pkt.emit(hdr.ethernet);
+        pkt.emit(hdr.vlan_tag[0]);
+        pkt.emit(hdr.vlan_tag[1]);
+    }
+}
+
+// BEGIN:Package_Instantiation_Example
+PNA_NIC(
+    MainParserImpl(),
+    PreControlImpl(),
+    MainControlImpl(),
+    MainDeparserImpl()
+    // Hoping to make this optional parameter later, but not supported
+    // by p4c yet.
+    //, PreParserImpl()
+    ) main;
+// END:Package_Instantiation_Example

testdata/p4_16_samples/pna-example-varIndex-2.p4

@@ -0,0 +1,155 @@
+/*
+Copyright 2022 Intel Corporation
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+#include <core.p4>
+#include "pna.p4"
+
+#define MAX_LAYERS 2
+typedef bit<48>  EthernetAddress;
+
+enum bit<16> ether_type_t {
+    TPID = 0x8100,
+    IPV4 = 0x0800,
+    IPV6 = 0x86DD
+}
+
+header ethernet_t {
+    EthernetAddress dstAddr;
+    EthernetAddress srcAddr;
+    bit<16>         etherType;
+}
+
+header vlan_tag_h {
+    bit<3>        pcp;
+    bit<1>        cfi;
+    bit<12>       vid;
+    ether_type_t  ether_type;
+}
+
+struct headers_t {
+    ethernet_t ethernet;
+    vlan_tag_h[MAX_LAYERS]      vlan_tag;
+}
+
+struct main_metadata_t {
+    bit<2> depth;
+    bit<16> ethType;
+}
+
+control PreControlImpl(
+    in    headers_t  hdrs,
+    inout main_metadata_t meta,
+    in    pna_pre_input_metadata_t  istd,
+    inout pna_pre_output_metadata_t ostd)
+{
+    apply {
+    }
+}
+
+parser MainParserImpl(
+    packet_in pkt,
+    out   headers_t       hdrs,
+    inout main_metadata_t meta,
+    in    pna_main_parser_input_metadata_t istd)
+{
+    state start {
+        meta.depth = MAX_LAYERS - 1;
+        pkt.extract(hdrs.ethernet);
+        transition select(hdrs.ethernet.etherType) {
+            ether_type_t.TPID :  parse_vlan_tag;
+            default: accept;
+        }
+    }
+    state parse_vlan_tag {
+        pkt.extract(hdrs.vlan_tag.next);
+        meta.depth = meta.depth - 1;
+        transition select(hdrs.vlan_tag.last.ether_type) {
+            ether_type_t.TPID :  parse_vlan_tag;
+            default: accept;
+        }
+    }
+
+}
+
+control MainControlImpl(
+    inout headers_t       hdrs,           // from main parser
+    inout main_metadata_t meta,     // from main parser, to "next block"
+    in    pna_main_input_metadata_t  istd,
+    inout pna_main_output_metadata_t ostd)
+{
+    action execute() {
+        hdrs.vlan_tag[meta.depth].vid = hdrs.vlan_tag[0].vid;
+    }
+    action execute_1() {
+         drop_packet();
+    }
+
+    table stub {
+        key = {
+              hdrs.vlan_tag[meta.depth].vid : exact;
+        }
+
+        actions = {
+		execute;
+        }
+	const default_action = execute;
+        size=1000000;
+    }
+
+    table stub1 {
+        key = {
+              hdrs.ethernet.etherType : exact;
+        }
+
+        actions = {
+		execute_1;
+        }
+	const default_action = execute_1;
+        size=1000000;
+    }
+
+    apply {
+        switch (hdrs.vlan_tag[meta.depth].vid) {
+            12w1: { stub.apply();}
+            12w2: { stub1.apply();}
+        }
+    }
+}
+
+control MainDeparserImpl(
+    packet_out pkt,
+    in    headers_t hdr,                // from main control
+    in    main_metadata_t user_meta,    // from main control
+    in    pna_main_output_metadata_t ostd)
+{
+    apply {
+        pkt.emit(hdr.ethernet);
+        pkt.emit(hdr.vlan_tag[0]);
+        pkt.emit(hdr.vlan_tag[1]);
+    }
+}
+
+// BEGIN:Package_Instantiation_Example
+PNA_NIC(
+    MainParserImpl(),
+    PreControlImpl(),
+    MainControlImpl(),
+    MainDeparserImpl()
+    // Hoping to make this optional parameter later, but not supported
+    // by p4c yet.
+    //, PreParserImpl()
+    ) main;
+// END:Package_Instantiation_Example