[llvm] r374150 - [TableGen] Fix crash when using HwModes in CodeEmitterGen

[James Molloy via llvm-commits]

Author: jamesm
Date: Wed Oct  9 02:15:34 2019
New Revision: 374150

URL: http://llvm.org/viewvc/llvm-project?rev=374150&view=rev
Log:
[TableGen] Fix crash when using HwModes in CodeEmitterGen

When an instruction has an encoding definition for only a subset of
the available HwModes, ensure we just avoid generating an encoding
rather than crash.

Modified:
    llvm/trunk/test/TableGen/HwModeEncodeDecode.td
    llvm/trunk/utils/TableGen/CodeEmitterGen.cpp

Modified: llvm/trunk/test/TableGen/HwModeEncodeDecode.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/TableGen/HwModeEncodeDecode.td?rev=374150&r1=374149&r2=374150&view=diff
==============================================================================
--- llvm/trunk/test/TableGen/HwModeEncodeDecode.td (original)
+++ llvm/trunk/test/TableGen/HwModeEncodeDecode.td Wed Oct  9 02:15:34 2019
@@ -56,6 +56,15 @@ def bar: Instruction {
   let Inst{1-0} = 0b10;
   let AsmString = "bar  $factor";
 }
+
+def baz : Instruction {
+  let InOperandList = (ins i32imm:$factor);
+  bits<32> Inst;
+  let EncodingInfos = EncodingByHwMode<
+    [ModeB], [fooTypeEncA]
+  >;
+  let AsmString = "foo  $factor";
+}
 }
 
 // DECODER-LABEL: DecoderTable_ModeA32[] =

Modified: llvm/trunk/utils/TableGen/CodeEmitterGen.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/utils/TableGen/CodeEmitterGen.cpp?rev=374150&r1=374149&r2=374150&view=diff
==============================================================================
--- llvm/trunk/utils/TableGen/CodeEmitterGen.cpp (original)
+++ llvm/trunk/utils/TableGen/CodeEmitterGen.cpp Wed Oct  9 02:15:34 2019
@@ -367,7 +367,8 @@ void CodeEmitterGen::emitInstructionBase
     if (const RecordVal *RV = R->getValue("EncodingInfos")) {
       if (auto *DI = dyn_cast_or_null<DefInit>(RV->getValue())) {
         EncodingInfoByHwMode EBM(DI->getDef(), HWM);
-        EncodingDef = EBM.get(HwMode);
+        if (EBM.hasMode(HwMode))
+          EncodingDef = EBM.get(HwMode);
       }
     }
     BitsInit *BI = EncodingDef->getValueAsBitsInit("Inst");