From 2aa133ef72a739c39b830cdc4d322a9d2e1d09c2 Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Thu, 5 Jul 2007 07:09:09 +0000
Subject: [PATCH] - Added zero_reg def to stand for register 0. - Added two
 variants of PredicateOperand: ImmutablePredicateOperand, whose predicate does
 not change after isel; PredicateDefOperand, which represent a predicate
 defintion operand.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37892 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/Target.td | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/lib/Target/Target.td b/lib/Target/Target.td
index 43e3af8667a..723954b2e07 100644
--- a/lib/Target/Target.td
+++ b/lib/Target/Target.td
@@ -256,16 +256,33 @@ def i16imm : Operand<i16>;
 def i32imm : Operand<i32>;
 def i64imm : Operand<i64>;
 
+/// zero_reg definition - Special node to stand for the zero register.
+///
+def zero_reg;
 
 /// PredicateOperand - This can be used to define a predicate operand for an
 /// instruction.  OpTypes specifies the MIOperandInfo for the operand, and
 /// AlwaysVal specifies the value of this predicate when set to "always
-/// execute".
-class PredicateOperand<ValueType ty, dag OpTypes, dag AlwaysVal> : Operand<ty> {
+/// execute". If isOutput is true, then this is output operand. If isImmutable
+/// is true, then the operand should not change after instruction selection.
+class PredicateOperand<ValueType ty, dag OpTypes, dag AlwaysVal>
+  : Operand<ty> {
   let MIOperandInfo = OpTypes;
+  bit isOutput = 0;
+  bit isImmutable = 0;
   dag ExecuteAlways = AlwaysVal;
 }
 
+class ImmutablePredicateOperand<ValueType ty, dag OpTypes, dag AlwaysVal>
+  : PredicateOperand<ty, OpTypes, AlwaysVal> {
+  let isImmutable = 1;
+}
+
+class PredicateDefOperand<ValueType ty, dag OpTypes, dag AlwaysVal>
+  : PredicateOperand<ty, OpTypes, AlwaysVal> {
+  let isOutput = 1;
+}
+
 
 // InstrInfo - This class should only be instantiated once to provide parameters
 // which are global to the the target machine.
-- 
2.34.1