Don't use getPhysicalRegisterRegClass in PBQP. The existing checks that the

physical register can be allocated in the class of the virtual are sufficient.

I think that the test for virtual registers is more strict than it needs to be,
it should be possible to coalesce two virtual registers the class of one
is a subclass of the other.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108118 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Rafael Espindola 2010-07-12 01:45:38 +00:00
parent dfd3626b47
commit cbeb3db8fd

View File

@ -396,28 +396,23 @@ PBQPRegAlloc::CoalesceMap PBQPRegAlloc::findCoalesces() {
if (srcRegIsPhysical && dstRegIsPhysical)
continue;
// If it's a copy that includes a virtual register but the source and
// destination classes differ then we can't coalesce, so continue with
// the next instruction.
const TargetRegisterClass *srcRegClass = srcRegIsPhysical ?
tri->getPhysicalRegisterRegClass(srcReg) : mri->getRegClass(srcReg);
const TargetRegisterClass *dstRegClass = dstRegIsPhysical ?
tri->getPhysicalRegisterRegClass(dstReg) : mri->getRegClass(dstReg);
if (srcRegClass != dstRegClass)
// If it's a copy that includes two virtual register but the source and
// destination classes differ then we can't coalesce.
if (!srcRegIsPhysical && !dstRegIsPhysical &&
mri->getRegClass(srcReg) != mri->getRegClass(dstReg))
continue;
// We also need any physical regs to be allocable, coalescing with
// a non-allocable register is invalid.
if (srcRegIsPhysical) {
// If one is physical and one is virtual, check that the physical is
// allocatable in the class of the virtual.
if (srcRegIsPhysical && !dstRegIsPhysical) {
const TargetRegisterClass *dstRegClass = mri->getRegClass(dstReg);
if (std::find(dstRegClass->allocation_order_begin(*mf),
dstRegClass->allocation_order_end(*mf), srcReg) ==
dstRegClass->allocation_order_end(*mf))
continue;
}
if (dstRegIsPhysical) {
if (!srcRegIsPhysical && dstRegIsPhysical) {
const TargetRegisterClass *srcRegClass = mri->getRegClass(srcReg);
if (std::find(srcRegClass->allocation_order_begin(*mf),
srcRegClass->allocation_order_end(*mf), dstReg) ==
srcRegClass->allocation_order_end(*mf))