From 97a95bdbddfa30815645296d95a8f655bf418f60 Mon Sep 17 00:00:00 2001 From: "Vikram S. Adve" Date: Thu, 7 Aug 2003 15:01:26 +0000 Subject: [PATCH] Fix sanity-checking in 'maskUnsigned' code to be more precise: use or def-and-use operands can be substituted after one def-only operand has been substituted. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@7674 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/SparcV9/SparcV9InstrSelection.cpp | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/lib/Target/SparcV9/SparcV9InstrSelection.cpp b/lib/Target/SparcV9/SparcV9InstrSelection.cpp index b55bd4820e7..1654c5592c0 100644 --- a/lib/Target/SparcV9/SparcV9InstrSelection.cpp +++ b/lib/Target/SparcV9/SparcV9InstrSelection.cpp @@ -2859,9 +2859,19 @@ GetInstructionsByRule(InstructionNode* subtreeRoot, unsigned numSubst = 0; for (unsigned i=0, N=mvec.size(); i < N; ++i) { + + // Make sure we substitute all occurrences of dest in these instrs. + // Otherwise, we will have bogus code. bool someArgsWereIgnored = false; - numSubst += mvec[i]->substituteValue(dest, tmpI, /*defsOnly*/ true, - /*defsAndUses*/ false, + + // Make sure not to substitute an upwards-exposed use -- that would + // introduce a use of `tmpI' with no preceding def. Therefore, + // substitute a use or def-and-use operand only if a previous def + // operand has already been substituted (i.e., numSusbt > 0). + // + numSubst += mvec[i]->substituteValue(dest, tmpI, + /*defsOnly*/ numSubst == 0, + /*notDefsAndUses*/ numSubst > 0, someArgsWereIgnored); assert(!someArgsWereIgnored && "Operand `dest' exists but not replaced: probably bogus!");