diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/Target/Sparc/SparcInstrSelection.cpp | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/llvm/lib/Target/Sparc/SparcInstrSelection.cpp b/llvm/lib/Target/Sparc/SparcInstrSelection.cpp index b55bd4820e7..1654c5592c0 100644 --- a/llvm/lib/Target/Sparc/SparcInstrSelection.cpp +++ b/llvm/lib/Target/Sparc/SparcInstrSelection.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!"); |
