[PATCH] D149711: [PowerPC] Remove asserts from the disassembler.

[Stefan Pintilie via Phabricator via llvm-commits]

stefanp updated this revision to Diff 523887.
stefanp added a comment.

Added the conditions so that we return DecodeStatus::Fail instead of asserting.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D149711/new/

https://reviews.llvm.org/D149711

Files:
  llvm/lib/Target/PowerPC/Disassembler/PPCDisassembler.cpp
  llvm/test/MC/Disassembler/PowerPC/ppc64-encoding-dfp-invalid.txt


Index: llvm/test/MC/Disassembler/PowerPC/ppc64-encoding-dfp-invalid.txt
===================================================================
--- /dev/null
+++ llvm/test/MC/Disassembler/PowerPC/ppc64-encoding-dfp-invalid.txt
@@ -0,0 +1,7 @@
+# RUN: llvm-mc --disassemble %s -mcpu=pwr10 -triple \
+# RUN:   powerpc64-unknown-linux-gnu < %s 2>&1 | FileCheck %s
+
+# Regsiter for DSUBQ cannot be greater than 30.
+# CHECK-NOT: dsubq 0, 6, 31
+# CHECK: warning: invalid instruction encoding
+0xfc 0x06 0xfc 0x04
Index: llvm/lib/Target/PowerPC/Disassembler/PPCDisassembler.cpp
===================================================================
--- llvm/lib/Target/PowerPC/Disassembler/PPCDisassembler.cpp
+++ llvm/lib/Target/PowerPC/Disassembler/PPCDisassembler.cpp
@@ -83,7 +83,8 @@
 template <std::size_t N>
 static DecodeStatus decodeRegisterClass(MCInst &Inst, uint64_t RegNo,
                                         const MCPhysReg (&Regs)[N]) {
-  assert(RegNo < N && "Invalid register number");
+  if (RegNo >= N)
+    return MCDisassembler::Fail;
   Inst.addOperand(MCOperand::createReg(Regs[RegNo]));
   return MCDisassembler::Success;
 }
@@ -115,8 +116,8 @@
 static DecodeStatus DecodeFpRCRegisterClass(MCInst &Inst, uint64_t RegNo,
                                             uint64_t Address,
                                             const MCDisassembler *Decoder) {
-  assert(RegNo <= 30 && "Expecting a register number no more than 30.");
-  assert((RegNo & 1) == 0 && "Expecting an even register number.");
+  if (RegNo > 30 || (RegNo & 1))
+    return MCDisassembler::Fail;
   return decodeRegisterClass(Inst, RegNo >> 1, FpRegs);
 }
 


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