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
diff --git a/lib/CodeGen/RegAllocPBQP.cpp b/lib/CodeGen/RegAllocPBQP.cpp
index 4fafd28..7e61a12 100644
--- a/lib/CodeGen/RegAllocPBQP.cpp
+++ b/lib/CodeGen/RegAllocPBQP.cpp
@@ -396,28 +396,23 @@
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))