diff options
Diffstat (limited to 'lib/CodeGen/RegisterScavenging.cpp')
| -rw-r--r-- | lib/CodeGen/RegisterScavenging.cpp | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/lib/CodeGen/RegisterScavenging.cpp b/lib/CodeGen/RegisterScavenging.cpp index 382741ee73..58f4284ac7 100644 --- a/lib/CodeGen/RegisterScavenging.cpp +++ b/lib/CodeGen/RegisterScavenging.cpp @@ -254,6 +254,8 @@ void RegScavenger::forward() { unsigned Idx = (i < NumECs) ? EarlyClobberMOs[i].second : DefMOs[i-NumECs].second; unsigned Reg = MO.getReg(); + if (MO.isUndef()) + continue; // If it's dead upon def, then it is now free. if (MO.isDead()) { @@ -262,7 +264,9 @@ void RegScavenger::forward() { } // Skip two-address destination operand. - if (MI->isRegTiedToUseOperand(Idx)) { + unsigned UseIdx; + if (MI->isRegTiedToUseOperand(Idx, &UseIdx) && + !MI->getOperand(UseIdx).isUndef()) { assert(isUsed(Reg) && "Using an undefined register!"); continue; } @@ -316,6 +320,8 @@ void RegScavenger::backward() { ? *DefMOs[i].first : *EarlyClobberMOs[i-NumDefs].first; unsigned Idx = (i < NumECs) ? DefMOs[i].second : EarlyClobberMOs[i-NumDefs].second; + if (MO.isUndef()) + continue; // Skip two-address destination operand. if (MI->isRegTiedToUseOperand(Idx)) |