Extract method for detecting constant unallocatable physregs.
It is safe to move uses of such registers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148259 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineSink.cpp b/lib/CodeGen/MachineSink.cpp
index e47360d..817e5cb 100644
--- a/lib/CodeGen/MachineSink.cpp
+++ b/lib/CodeGen/MachineSink.cpp
@@ -485,21 +485,8 @@
// If the physreg has no defs anywhere, it's just an ambient register
// and we can freely move its uses. Alternatively, if it's allocatable,
// it could get allocated to something with a def during allocation.
- if (!MRI->def_empty(Reg))
+ if (!MRI->isConstantPhysReg(Reg, *MBB->getParent()))
return NULL;
-
- if (AllocatableSet.test(Reg))
- return NULL;
-
- // Check for a def among the register's aliases too.
- for (const unsigned *Alias = TRI->getAliasSet(Reg); *Alias; ++Alias) {
- unsigned AliasReg = *Alias;
- if (!MRI->def_empty(AliasReg))
- return NULL;
-
- if (AllocatableSet.test(AliasReg))
- return NULL;
- }
} else if (!MO.isDead()) {
// A def that isn't dead. We can't move it.
return NULL;