[clang] [llvm] [RISCV] Relax march string order constraint (PR #78120)

[Fangrui Song via cfe-commits]

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@@ -337,10 +319,79 @@ TEST(ParseArchString, AcceptsUnderscoreSplittingExtensions) {
   }
 }
 
+TEST(ParseArchString, AcceptsRelaxSingleLetterExtensions) {
+  for (StringRef Input :
+       {"rv32imfad", "rv32im_fa_d", "rv32im2p0fad", "rv32i2p1m2p0fad"}) {
+    auto MaybeISAInfo = RISCVISAInfo::parseArchString(Input, true);
+    ASSERT_THAT_EXPECTED(MaybeISAInfo, Succeeded());
+    RISCVISAInfo::OrderedExtensionMap Exts = (*MaybeISAInfo)->getExtensions();
+    EXPECT_EQ(Exts.size(), 6UL);
+    EXPECT_EQ(Exts.count("i"), 1U);
+    EXPECT_EQ(Exts.count("m"), 1U);
+    EXPECT_EQ(Exts.count("f"), 1U);
+    EXPECT_EQ(Exts.count("a"), 1U);
+    EXPECT_EQ(Exts.count("d"), 1U);
+    EXPECT_EQ(Exts.count("zicsr"), 1U);
+  }
+}
+
+TEST(ParseArchString, AcceptsRelaxMixedLetterExtensions) {
+  for (StringRef Input :
+       {"rv32i_zihintntl_m_a_f_d_svinval", "rv32izihintntl_mafdsvinval",
+        "rv32i_zihintntl_mafd_svinval"}) {
+    auto MaybeISAInfo = RISCVISAInfo::parseArchString(Input, true);
+    ASSERT_THAT_EXPECTED(MaybeISAInfo, Succeeded());
+    RISCVISAInfo::OrderedExtensionMap Exts = (*MaybeISAInfo)->getExtensions();
+    EXPECT_EQ(Exts.size(), 8UL);
+    EXPECT_EQ(Exts.count("i"), 1U);
+    EXPECT_EQ(Exts.count("m"), 1U);
+    EXPECT_EQ(Exts.count("a"), 1U);
+    EXPECT_EQ(Exts.count("f"), 1U);
+    EXPECT_EQ(Exts.count("d"), 1U);
+    EXPECT_EQ(Exts.count("zihintntl"), 1U);
+    EXPECT_EQ(Exts.count("svinval"), 1U);
+    EXPECT_EQ(Exts.count("zicsr"), 1U);
+  }
+}
+
+TEST(ParseArchString, AcceptsAmbiguousFromRelaxExtensions) {
+  for (StringRef Input : {"rv32i_zba_m", "rv32izba_m", "rv32izba1p0_m2p0"}) {
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MaskRay wrote:

Consider another test where i is after zba

https://github.com/llvm/llvm-project/pull/78120