[llvm] r344782 - [llvm-exegesis] Mark second-form X87 instructions as unsupported.

[Clement Courbet via llvm-commits]

Author: courbet
Date: Fri Oct 19 05:24:49 2018
New Revision: 344782

URL: http://llvm.org/viewvc/llvm-project?rev=344782&view=rev
Log:
[llvm-exegesis] Mark second-form X87 instructions as unsupported.

Summary:
We only support the first form because we rely on information that is
only available there.

Reviewers: gchatelet

Subscribers: tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D53430

Modified:
    llvm/trunk/tools/llvm-exegesis/lib/X86/Target.cpp

Modified: llvm/trunk/tools/llvm-exegesis/lib/X86/Target.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-exegesis/lib/X86/Target.cpp?rev=344782&r1=344781&r2=344782&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-exegesis/lib/X86/Target.cpp (original)
+++ llvm/trunk/tools/llvm-exegesis/lib/X86/Target.cpp Fri Oct 19 05:24:49 2018
@@ -26,7 +26,14 @@ static llvm::Error IsInvalidOpcode(const
   if (OpcodeName.startswith("POPF") || OpcodeName.startswith("PUSHF") ||
       OpcodeName.startswith("ADJCALLSTACK"))
     return llvm::make_error<BenchmarkFailure>(
-        "Unsupported opcode: Push/Pop/AdjCallStack");
+        "unsupported opcode: Push/Pop/AdjCallStack");
+  // We do not handle second-form X87 instructions. We only handle first-form
+  // ones (_Fp), see comment in X86InstrFPStack.td.
+  for (const Operand &Op : Instr.Operands)
+    if (Op.isReg() && Op.isExplicit() &&
+        Op.getExplicitOperandInfo().RegClass == llvm::X86::RSTRegClassID)
+      return llvm::make_error<BenchmarkFailure>(
+          "unsupported second-form X87 instruction");
   return llvm::Error::success();
 }