Addressed comments

Signed-off-by: Komal, Jain <[email protected]>
p4lang · Oct 24, 2024 · 1aa85c6 · 1aa85c6
1 parent e7cf274
commit 1aa85c6
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Showing 4 changed files with 9 additions and 4 deletions.
diff --git a/backends/tc/ebpfCodeGen.h b/backends/tc/ebpfCodeGen.h
@@ -293,7 +293,6 @@ class EBPFControlPNA : public EBPF::EBPFControlPSA {
     }
     EBPFHashPNA *getHash(cstring name) const {
         auto result = ::P4::get(pna_hashes, name);
-        BUG_CHECK(result != nullptr, "No hash named %1%", name);
         return result;
     }
     void emitExternDefinition(EBPF::CodeBuilder *builder) {

diff --git a/backends/tc/tcExterns.cpp b/backends/tc/tcExterns.cpp
@@ -481,7 +481,11 @@ void EBPFHashPNA::calculateHash(EBPF::CodeBuilder *builder, const IR::MethodCall
 }
 
 void CRCChecksumAlgorithmPNA::emitGet(EBPF::CodeBuilder *builder) {
-    builder->appendFormat("%s", registerVar.c_str());
+    if (crcWidth == 16) {
+        builder->appendFormat("%s", registerVar.c_str());
+    } else {
+        builder->appendFormat("%s ^ 0xFFFFFFFF", registerVar.c_str());
+    }
 }
 
 void CRCChecksumAlgorithmPNA::emitAddData(EBPF::CodeBuilder *builder, int dataPos,

diff --git a/backends/tc/tcExterns.h b/backends/tc/tcExterns.h
@@ -192,12 +192,14 @@ class CRCChecksumAlgorithmPNA : public EBPF::CRCChecksumAlgorithm {
  public:
     CRCChecksumAlgorithmPNA(const EBPF::EBPFProgram *program, cstring name, int width)
         : EBPF::CRCChecksumAlgorithm(program, name, width) {
+        BUG_CHECK(width == 16 || width == 32, "Must be 16 bits width or 32 bits width.");
         initialValue = "0"_cs;
     }
     void emitGet(EBPF::CodeBuilder *builder) override;
     void emitAddData(EBPF::CodeBuilder *builder, const ArgumentsList &arguments,
                      const IR::MethodCallExpression *expr);
-    void emitAddData(EBPF::CodeBuilder *builder, int dataPos, const IR::MethodCallExpression *expr);
+    void emitAddData(EBPF::CodeBuilder *builder, int dataPos,
+                     const IR::MethodCallExpression *expr) override;
 };
 
 class EBPFDigestPNA : public EBPF::EBPFDigestPSA {

diff --git a/testdata/p4tc_samples_outputs/hash_control_blocks.c b/testdata/p4tc_samples_outputs/hash_control_blocks.c
@@ -39,7 +39,7 @@ static __always_inline int process(struct __sk_buff *skb, struct my_ingress_head
             bpf_p4tc_ext_hash_crc32(&hdr->crc.f3, sizeof(hdr->crc.f3), ingress_h_reg);
             bpf_p4tc_ext_hash_crc32(&hdr->crc.f4, sizeof(hdr->crc.f4), ingress_h_reg);
                         hdr->crc.crc = /* h_0.get_hash({hdr->crc.f1, hdr->crc.f2, hdr->crc.f3, hdr->crc.f4}) */
-ingress_h_reg;
+ingress_h_reg ^ 0xFFFFFFFF;
         }
     }
     {