[llvm] 7e2ffe7 - [llvm-exegesis] Do not silently fail on unknown instruction encoding formats.

[Clement Courbet via llvm-commits]

Author: Clement Courbet
Date: 2020-10-28T10:06:00+01:00
New Revision: 7e2ffe7a6358820c0f1511f3405d3fa8db4c46f4

URL: https://github.com/llvm/llvm-project/commit/7e2ffe7a6358820c0f1511f3405d3fa8db4c46f4
DIFF: https://github.com/llvm/llvm-project/commit/7e2ffe7a6358820c0f1511f3405d3fa8db4c46f4.diff

LOG: [llvm-exegesis] Do not silently fail on unknown instruction encoding formats.

The addition of TILELOADD instructions with a new encoding format
triggered a hard abort instead of proper error reporting due to the use
of `llvm_unreachable` for actually reachable code.
Properly report an error when the encoding format is unknown.

Differential Revision: https://reviews.llvm.org/D90289

Added: 
    

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

Removed: 
    


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diff  --git a/llvm/tools/llvm-exegesis/lib/X86/Target.cpp b/llvm/tools/llvm-exegesis/lib/X86/Target.cpp
index 270825a8777b..827e2e27a2f8 100644
--- a/llvm/tools/llvm-exegesis/lib/X86/Target.cpp
+++ b/llvm/tools/llvm-exegesis/lib/X86/Target.cpp
@@ -53,7 +53,7 @@ static cl::opt<unsigned> LbrSamplingPeriod(
 static const char *isInvalidMemoryInstr(const Instruction &Instr) {
   switch (Instr.Description.TSFlags & X86II::FormMask) {
   default:
-    llvm_unreachable("Unknown FormMask value");
+    return "Unknown FormMask value";
   // These have no memory access.
   case X86II::Pseudo:
   case X86II::RawFrm: