Introduce the DwarfRegAlias class for declaring that two registers have the

same dwarf number. This will be used for creating a dwarf number to register
mapping.

The only case that needs this so far is the XMM/YMM registers that unfortunately
do have the same numbers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132314 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 8 insertions, 0 deletions

diff --git a/include/llvm/Target/Target.td b/include/llvm/Target/Target.td
index 68f0515f2d..5ae4866f5e 100644
--- a/include/llvm/Target/Target.td
+++ b/include/llvm/Target/Target.td
@@ -151,6 +151,14 @@ class DwarfRegNum<list<int> Numbers> {
   list<int> DwarfNumbers = Numbers;
 }
 
+// DwarfRegAlias - This class declares that a given register uses the same dwarf
+// numbers as another one. This is useful for making it clear that the two
+// registers do have the same number. It also lets us build a mapping
+// from dwarf register number to llvm register.
+class DwarfRegAlias<Register reg> {
+      Register DwarfAlias = reg;
+}
+
 //===----------------------------------------------------------------------===//
 // Pull in the common support for scheduling
 //