[NFC][LLVM][TableGen] Use decodeULEB128 for OPC_SoftFail emission

[jurahul]

• Use decodeULEB128 to decode +ve/-ve mask in OPC_SoftFail case.
• Use current I/E iterators as inputs to decodeULEB128.

[topperc]

LGTM

[llvmbot]

@llvm/pr-subscribers-tablegen

Author: Rahul Joshi (jurahul)

Changes

• Use decodeULEB128 to decode +ve/-ve mask in OPC_SoftFail case.
• Use current I/E iterators as inputs to decodeULEB128.

---

Full diff: https://github.com/llvm/llvm-project/pull/136220.diff

1 Files Affected:

• (modified) llvm/utils/TableGen/DecoderEmitter.cpp (+18-32)

diff --git a/llvm/utils/TableGen/DecoderEmitter.cpp b/llvm/utils/TableGen/DecoderEmitter.cpp
index 9c6015cc24576..0f775673e599f 100644
--- a/llvm/utils/TableGen/DecoderEmitter.cpp
+++ b/llvm/utils/TableGen/DecoderEmitter.cpp
@@ -849,8 +849,7 @@ void DecoderEmitter::emitTable(formatted_raw_ostream &OS, DecoderTable &Table,
 
       // ULEB128 encoded start value.
       const char *ErrMsg = nullptr;
-      unsigned Start = decodeULEB128(Table.data() + Pos + 1, nullptr,
-                                     Table.data() + Table.size(), &ErrMsg);
+      unsigned Start = decodeULEB128(&*I, nullptr, &*E, &ErrMsg);
       assert(ErrMsg == nullptr && "ULEB128 value too large!");
       emitULEB128(I, OS);
 
@@ -904,8 +903,7 @@ void DecoderEmitter::emitTable(formatted_raw_ostream &OS, DecoderTable &Table,
       ++I;
       // Decode the Opcode value.
       const char *ErrMsg = nullptr;
-      unsigned Opc = decodeULEB128(Table.data() + Pos + 1, nullptr,
-                                   Table.data() + Table.size(), &ErrMsg);
+      unsigned Opc = decodeULEB128(&*I, nullptr, &*E, &ErrMsg);
       assert(ErrMsg == nullptr && "ULEB128 value too large!");
 
       OS << Indent << "MCD::OPC_" << (IsTry ? "Try" : "") << "Decode, ";
@@ -934,34 +932,22 @@ void DecoderEmitter::emitTable(formatted_raw_ostream &OS, DecoderTable &Table,
     }
     case MCD::OPC_SoftFail: {
       ++I;
-      OS << Indent << "MCD::OPC_SoftFail";
-      // Positive mask
-      uint64_t Value = 0;
-      unsigned Shift = 0;
-      do {
-        OS << ", " << (unsigned)*I;
-        Value += ((uint64_t)(*I & 0x7f)) << Shift;
-        Shift += 7;
-      } while (*I++ >= 128);
-      if (Value > 127) {
-        OS << " /* 0x";
-        OS.write_hex(Value);
-        OS << " */";
-      }
-      // Negative mask
-      Value = 0;
-      Shift = 0;
-      do {
-        OS << ", " << (unsigned)*I;
-        Value += ((uint64_t)(*I & 0x7f)) << Shift;
-        Shift += 7;
-      } while (*I++ >= 128);
-      if (Value > 127) {
-        OS << " /* 0x";
-        OS.write_hex(Value);
-        OS << " */";
-      }
-      OS << ",\n";
+      OS << Indent << "MCD::OPC_SoftFail, ";
+      // Decode the positive mask.
+      const char *ErrMsg = nullptr;
+      uint64_t PositiveMask = decodeULEB128(&*I, nullptr, &*E, &ErrMsg);
+      assert(ErrMsg == nullptr && "ULEB128 value too large!");
+      emitULEB128(I, OS);
+
+      // Decode the negative mask.
+      uint64_t NegativeMask = decodeULEB128(&*I, nullptr, &*E, &ErrMsg);
+      assert(ErrMsg == nullptr && "ULEB128 value too large!");
+      emitULEB128(I, OS);
+      OS << "// +ve mask: 0x";
+      OS.write_hex(PositiveMask);
+      OS << ", -ve mask: 0x";
+      OS.write_hex(NegativeMask);
+      OS << '\n';
       break;
     }
     case MCD::OPC_Fail: {

[jurahul]

Thanks.

[llvm-ci]

LLVM Buildbot has detected a new failure on builder flang-x86_64-windows running on minipc-ryzen-win while building llvm at step 8 "test-build-unified-tree-check-flang-rt".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/166/builds/1191

Here is the relevant piece of the build log for the reference

Step 8 (test-build-unified-tree-check-flang-rt) failure: test (failure)
******************** TEST 'flang-rt-Unit :: Runtime/./RuntimeTests.exe/2/8' FAILED ********************
Script(shard):
--
GTEST_OUTPUT=json:C:\buildbot\flang-x86_64-windows\build\runtimes\runtimes-bins\flang-rt\unittests\Runtime\.\RuntimeTests.exe-flang-rt-Unit-4796-2-8.json GTEST_SHUFFLE=0 GTEST_TOTAL_SHARDS=8 GTEST_SHARD_INDEX=2 C:\buildbot\flang-x86_64-windows\build\runtimes\runtimes-bins\flang-rt\unittests\Runtime\.\RuntimeTests.exe
--

Note: This is test shard 3 of 8.

[==========] Running 28 tests from 24 test suites.

[----------] Global test environment set-up.

[----------] 1 test from AllocatableTest

[ RUN      ] AllocatableTest.AllocateSourceZeroSize

[       OK ] AllocatableTest.AllocateSourceZeroSize (0 ms)

[----------] 1 test from AllocatableTest (0 ms total)



[----------] 1 test from AdjustLRTests/0, where TypeParam = <type>

[ RUN      ] AdjustLRTests/0.AdjustL

[       OK ] AdjustLRTests/0.AdjustL (0 ms)

[----------] 1 test from AdjustLRTests/0 (0 ms total)



[----------] 1 test from CharacterComparisonTests/2, where TypeParam = <type>

[ RUN      ] CharacterComparisonTests/2.CompareCharacters

[       OK ] CharacterComparisonTests/2.CompareCharacters (0 ms)

[----------] 1 test from CharacterComparisonTests/2 (0 ms total)



[----------] 1 test from ExtremumTests/2, where TypeParam = <type>

[ RUN      ] ExtremumTests/2.MaxTests

[       OK ] ExtremumTests/2.MaxTests (0 ms)

[----------] 1 test from ExtremumTests/2 (0 ms total)

...

[jurahul]

This seems to have causes a build failure on some Windows systems, I am fixing it here:

#136310