From 3b2552933642c19ce5e8836d82c26c562910e239 Mon Sep 17 00:00:00 2001
From: Ulrich Weigand <ulrich.weigand@de.ibm.com>
Date: Tue, 26 Mar 2013 10:53:27 +0000
Subject: [PATCH] PowerPC: Simplify BLR pattern.

The BLR pattern cannot be recognized by the asm parser in its current form.
This complexity is due to an apparent attempt to enable conditional BLR
variants.  However, none of those can ever be generated by current code;
the pattern is only ever created using the default "pred" operand.

To simplify the pattern and allow it to be recognized by the parser,
this commit removes those attempts at conditional BLR support.

When we later come back to actually add real conditional BLR, this
should probably be done via a fully generic conditional branch pattern.

No change in generated code.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178002 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp |  3 ---
 lib/Target/PowerPC/MCTargetDesc/PPCPredicates.h   |  1 -
 lib/Target/PowerPC/PPCInstrInfo.td                | 14 ++++++--------
 3 files changed, 6 insertions(+), 12 deletions(-)

diff --git a/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp b/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp
index 3d583060d1e..985c3436962 100644
--- a/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp
+++ b/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp
@@ -115,7 +115,6 @@ void PPCInstPrinter::printPredicateOperand(const MCInst *MI, unsigned OpNo,
 
   if (StringRef(Modifier) == "cc") {
     switch ((PPC::Predicate)Code) {
-    case PPC::PRED_ALWAYS: return; // Don't print anything for always.
     case PPC::PRED_LT: O << "lt"; return;
     case PPC::PRED_LE: O << "le"; return;
     case PPC::PRED_EQ: O << "eq"; return;
@@ -129,8 +128,6 @@ void PPCInstPrinter::printPredicateOperand(const MCInst *MI, unsigned OpNo,
   
   assert(StringRef(Modifier) == "reg" &&
          "Need to specify 'cc' or 'reg' as predicate op modifier!");
-  // Don't print the register for 'always'.
-  if (Code == PPC::PRED_ALWAYS) return;
   printOperand(MI, OpNo+1, O);
 }
 
diff --git a/lib/Target/PowerPC/MCTargetDesc/PPCPredicates.h b/lib/Target/PowerPC/MCTargetDesc/PPCPredicates.h
index b0680fbb8c6..ad2b0181281 100644
--- a/lib/Target/PowerPC/MCTargetDesc/PPCPredicates.h
+++ b/lib/Target/PowerPC/MCTargetDesc/PPCPredicates.h
@@ -25,7 +25,6 @@ namespace llvm {
 namespace PPC {
   /// Predicate - These are "(BI << 5) | BO"  for various predicates.
   enum Predicate {
-    PRED_ALWAYS = (0 << 5) | 20,
     PRED_LT     = (0 << 5) | 12,
     PRED_LE     = (1 << 5) |  4,
     PRED_EQ     = (2 << 5) | 12,
diff --git a/lib/Target/PowerPC/PPCInstrInfo.td b/lib/Target/PowerPC/PPCInstrInfo.td
index 4ae6924ef05..3800e46c9ee 100644
--- a/lib/Target/PowerPC/PPCInstrInfo.td
+++ b/lib/Target/PowerPC/PPCInstrInfo.td
@@ -396,11 +396,10 @@ def memr : Operand<iPTR> {
   let MIOperandInfo = (ops ptr_rc:$ptrreg);
 }
 
-// PowerPC Predicate operand.  20 = (0<<5)|20 = always, CR0 is a dummy reg
-// that doesn't matter.
-def pred : PredicateOperand<OtherVT, (ops imm, CRRC),
-                                     (ops (i32 20), (i32 zero_reg))> {
+// PowerPC Predicate operand.
+def pred : Operand<OtherVT> {
   let PrintMethod = "printPredicateOperand";
+  let MIOperandInfo = (ops i32imm:$bibo, CRRC:$reg);
 }
 
 // Define PowerPC specific addressing mode.
@@ -478,10 +477,9 @@ def RESTORE_CR : Pseudo<(outs CRRC:$cond), (ins memri:$F),
                      "#RESTORE_CR", []>;
 
 let isTerminator = 1, isBarrier = 1, PPC970_Unit = 7 in {
-  let isCodeGenOnly = 1, isReturn = 1, Uses = [LR, RM] in
-    def BLR : XLForm_2_br<19, 16, 0, (outs), (ins pred:$p),
-                          "b${p:cc}lr ${p:reg}", BrB, 
-                          [(retflag)]>;
+  let isReturn = 1, Uses = [LR, RM] in
+    def BLR : XLForm_2_ext<19, 16, 20, 0, 0, (outs), (ins), "blr", BrB,
+                           [(retflag)]>;
   let isBranch = 1, isIndirectBranch = 1, Uses = [CTR] in
     def BCTR : XLForm_2_ext<19, 528, 20, 0, 0, (outs), (ins), "bctr", BrB, []>;
 }