The register allocator shouldn't consider allocating reserved registers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112728 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/RegAllocFast.cpp b/lib/CodeGen/RegAllocFast.cpp
index 3df4ab7..3cf1d72 100644
--- a/lib/CodeGen/RegAllocFast.cpp
+++ b/lib/CodeGen/RegAllocFast.cpp
@@ -113,6 +113,9 @@
// Allocatable - vector of allocatable physical registers.
BitVector Allocatable;
+ // Reserved - vector of reserved physical registers.
+ BitVector Reserved;
+
// SkippedInstrs - Descriptors of instructions whose clobber list was
// ignored because all registers were spilled. It is still necessary to
// mark all the clobbered registers as used by the function.
@@ -709,7 +712,7 @@
}
// Restore UsedInInstr to a state usable for allocating normal virtual uses.
- UsedInInstr.reset();
+ UsedInInstr = Reserved;
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI->getOperand(i);
if (!MO.isReg() || (MO.isDef() && !MO.isEarlyClobber())) continue;
@@ -835,7 +838,7 @@
}
// Track registers used by instruction.
- UsedInInstr.reset();
+ UsedInInstr = Reserved;
// First scan.
// Mark physreg uses and early clobbers as used.
@@ -913,7 +916,7 @@
// Track registers defined by instruction - early clobbers and tied uses at
// this point.
- UsedInInstr.reset();
+ UsedInInstr = Reserved;
if (hasEarlyClobbers) {
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI->getOperand(i);
@@ -1011,6 +1014,7 @@
UsedInInstr.resize(TRI->getNumRegs());
Allocatable = TRI->getAllocatableSet(*MF);
+ Reserved = TRI->getReservedRegs(*MF);
// initialize the virtual->physical register map to have a 'null'
// mapping for all virtual registers