From 429af6fa4124d8b6dd310069e0a44dcacb35fc8a Mon Sep 17 00:00:00 2001 From: Chad Rosier Date: Fri, 31 Aug 2012 17:24:10 +0000 Subject: [PATCH] Add a comment to explain what's really going on. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163005 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/ARM/AsmParser/ARMAsmParser.cpp | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp index 1fde5a2e79d..3ee3db5b028 100644 --- a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp +++ b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp @@ -5347,6 +5347,12 @@ validateInstruction(MCInst &Inst, case ARM::tMUL: { // The second source operand must be the same register as the destination // operand. + // + // In this case, we must directly check the parsed operands because the + // cvtThumbMultiply() function is written in such a way that it guarantees + // this first statement is always true for the new Inst. Essentially, the + // destination is unconditionally copied into the second source operand + // without checking to see if it matches what we actually parsed. if (Operands.size() == 6 && (((ARMOperand*)Operands[3])->getReg() != ((ARMOperand*)Operands[5])->getReg()) && -- 2.34.1