Make insert_subreg a two-address instruction, vastly simplifying LowerSubregs pass. Add a new TII, subreg_to_reg, which is like insert_subreg except that it takes an immediate implicit value to insert into rather than a register.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48412 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/Target.td b/lib/Target/Target.td
index 9d49bd2..6e2ba91 100644
--- a/lib/Target/Target.td
+++ b/lib/Target/Target.td
@@ -366,6 +366,7 @@
let AsmString = "";
let Namespace = "TargetInstrInfo";
let neverHasSideEffects = 1;
+ let Constraints = "$supersrc = $dst";
}
def IMPLICIT_DEF : Instruction {
let OutOperandList = (ops unknown:$dst);
@@ -374,6 +375,13 @@
let Namespace = "TargetInstrInfo";
let neverHasSideEffects = 1;
}
+def SUBREG_TO_REG : Instruction {
+ let OutOperandList = (ops unknown:$dst);
+ let InOperandList = (ops unknown:$implsrc, unknown:$subsrc, i32imm:$subidx);
+ let AsmString = "";
+ let Namespace = "TargetInstrInfo";
+ let neverHasSideEffects = 1;
+}
//===----------------------------------------------------------------------===//
// AsmWriter - This class can be implemented by targets that need to customize