llvm bug #1350, parts 1, 2, and 3.

[oota-llvm.git] / lib / Target / Target.td

diff --git a/lib/Target/Target.td b/lib/Target/Target.td
index fbc972a29284a20f0e2bd38cde95996e5b589e33..fce45a5c2d4e2fe803fabea8b1649a38377a8edc 100644 (file)
--- a/lib/Target/Target.td
+++ b/lib/Target/Target.td
@@ -41,9 +41,14 @@ class Register<string n> {
   // Aliases - A list of registers that this register overlaps with.  A read or
   // modification of this register can potentially read or modify the aliased
   // registers.
-  //
   list<Register> Aliases = [];
   
+  // SubRegs - A list of registers that are parts of this register. Note these
+  // are "immediate" sub-registers and the registers within the list do not
+  // themselves overlap. e.g. For X86, EAX's SubRegs list contains only [AX],
+  // not [AX, AH, AL].
+  list<Register> SubRegs = [];
+
   // DwarfNumber - Number used internally by gcc/gdb to identify the register.
   // These values can be determined by locating the <target>.h file in the
   // directory llvmgcc/gcc/config/<target>/ and looking for REGISTER_NAMES.  The
@@ -52,13 +57,25 @@ class Register<string n> {
   int DwarfNumber = -1;
 }
 
-// RegisterGroup - This can be used to define instances of Register which
-// need to specify aliases.
-// List "aliases" specifies which registers are aliased to this one.  This
-// allows the code generator to be careful not to put two values with 
+// RegisterWithSubRegs - This can be used to define instances of Register which
+// need to specify sub-registers.
+// List "subregs" specifies which registers are sub-registers to this one. This
+// is used to populate the SubRegs and AliasSet fields of TargetRegisterDesc.
+// This allows the code generator to be careful not to put two values with 
 // overlapping live ranges into registers which alias.
-class RegisterGroup<string n, list<Register> aliases> : Register<n> {
-  let Aliases = aliases;
+class RegisterWithSubRegs<string n, list<Register> subregs> : Register<n> {
+  let SubRegs = subregs;
+}
+
+// SubRegSet - This can be used to define a specific mapping of registers to
+// indices, for use as named subregs of a particular physical register.  Each
+// register in 'subregs' becomes an addressable subregister at index 'n' of the
+// corresponding register in 'regs'.
+class SubRegSet<int n, list<Register> regs, list<Register> subregs> {
+  int index = n;
+  
+  list<Register> From = regs;
+  list<Register> To = subregs;
 }
 
 // RegisterClass - Now that all of the registers are defined, and aliases
@@ -165,6 +182,7 @@ class Instruction {
   bit isConvertibleToThreeAddress = 0;  // Can this 2-addr instruction promote?
   bit isCommutable = 0;     // Is this 3 operand instruction commutable?
   bit isTerminator = 0;     // Is this part of the terminator for a basic block?
+  bit isReMaterializable = 0; // Is this instruction re-materializable?
   bit hasDelaySlot = 0;     // Does this instruction have an delay slot?
   bit usesCustomDAGSchedInserter = 0; // Pseudo instr needing special help.
   bit hasCtrlDep   = 0;     // Does this instruction r/w ctrl-flow chains?