From 2f57c4da2164de3dfeebb3c25d81c49e6574a12a Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Mon, 8 Aug 2005 21:24:57 +0000
Subject: [PATCH] Modify the ISD::AND opcode case to use new immediate constant
 predicates. Includes wider support for rotate and mask cases.

Patch by Jim Laskey.

I've requested that Jim add new regression tests the newly handled cases.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22712 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/PowerPC/PPCISelPattern.cpp | 81 ++++++++++++---------------
 1 file changed, 36 insertions(+), 45 deletions(-)

diff --git a/lib/Target/PowerPC/PPCISelPattern.cpp b/lib/Target/PowerPC/PPCISelPattern.cpp
index 61285901755..20dd4e8bb4a 100644
--- a/lib/Target/PowerPC/PPCISelPattern.cpp
+++ b/lib/Target/PowerPC/PPCISelPattern.cpp
@@ -1709,58 +1709,49 @@ unsigned ISel::SelectExpr(SDOperand N, bool Recording) {
     return Result;
 
   case ISD::AND:
-    switch(getImmediateForOpcode(N.getOperand(1), opcode, Tmp2)) {
-      default: assert(0 && "unhandled result code");
-      case 0: // No immediate
-        // Check for andc: and, (xor a, -1), b
-        if (N.getOperand(0).getOpcode() == ISD::XOR &&
-          N.getOperand(0).getOperand(1).getOpcode() == ISD::Constant &&
-        cast<ConstantSDNode>(N.getOperand(0).getOperand(1))->isAllOnesValue()) {
+    if (isImmediate(N.getOperand(1), Tmp2)) {
+      if (isShiftedMask_32(Tmp2) || isShiftedMask_32(~Tmp2)) {
+        unsigned SH, MB, ME;
+        Opc = Recording ? PPC::RLWINMo : PPC::RLWINM;
+        unsigned OprOpc;
+        if (isOprShiftImm(N.getOperand(0), OprOpc, Tmp3) &&
+            isRotateAndMask(OprOpc, Tmp3, Tmp2, false, SH, MB, ME)) {
           Tmp1 = SelectExpr(N.getOperand(0).getOperand(0));
-          Tmp2 = SelectExpr(N.getOperand(1));
-          BuildMI(BB, PPC::ANDC, 2, Result).addReg(Tmp2).addReg(Tmp1);
-          return Result;
+        } else {
+          Tmp1 = SelectExpr(N.getOperand(0));
+          isRunOfOnes(Tmp2, MB, ME);
+          SH = 0;
         }
-        // It wasn't and-with-complement, emit a regular and
-        Tmp1 = SelectExpr(N.getOperand(0));
-        Tmp2 = SelectExpr(N.getOperand(1));
-        Opc = Recording ? PPC::ANDo : PPC::AND;
-        BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addReg(Tmp2);
-        break;
-      case 1: // Low immediate
+        BuildMI(BB, Opc, 4, Result).addReg(Tmp1).addImm(SH)
+          .addImm(MB).addImm(ME);
+        RecordSuccess = true;
+        return Result;
+      } else if (isUInt16(Tmp2)) {
+        Tmp2 = Lo16(Tmp2);
         Tmp1 = SelectExpr(N.getOperand(0));
         BuildMI(BB, PPC::ANDIo, 2, Result).addReg(Tmp1).addImm(Tmp2);
-        break;
-      case 2: // Shifted immediate
+        RecordSuccess = true;
+        return Result;
+      } else if (isUInt16(Tmp2)) {
+        Tmp2 = Hi16(Tmp2);
         Tmp1 = SelectExpr(N.getOperand(0));
         BuildMI(BB, PPC::ANDISo, 2, Result).addReg(Tmp1).addImm(Tmp2);
-        break;
-      case 5: // Bitfield mask
-        Opc = Recording ? PPC::RLWINMo : PPC::RLWINM;
-        Tmp3 = Tmp2 >> 16;  // MB
-        Tmp2 &= 0xFFFF;     // ME
-
-        // FIXME: Catch SHL-AND in addition to SRL-AND in this block.
-        if (N.getOperand(0).getOpcode() == ISD::SRL)
-          if (ConstantSDNode *SA =
-              dyn_cast<ConstantSDNode>(N.getOperand(0).getOperand(1))) {
-
-            // We can fold the RLWINM and the SRL together if the mask is
-            // clearing the top bits which are rotated around.
-            unsigned RotAmt = 32-(SA->getValue() & 31);
-            if (Tmp2 <= RotAmt) {
-              Tmp1 = SelectExpr(N.getOperand(0).getOperand(0));
-              BuildMI(BB, Opc, 4, Result).addReg(Tmp1).addImm(RotAmt)
-                .addImm(Tmp3).addImm(Tmp2);
-              break;
-            }
-          }
-
-        Tmp1 = SelectExpr(N.getOperand(0));
-        BuildMI(BB, Opc, 4, Result).addReg(Tmp1).addImm(0)
-          .addImm(Tmp3).addImm(Tmp2);
-        break;
+        RecordSuccess = true;
+       return Result;
+      }
     }
+    if (isOprNot(N.getOperand(0))) {
+      Tmp1 = SelectExpr(N.getOperand(0).getOperand(0));
+      Tmp2 = SelectExpr(N.getOperand(1));
+      BuildMI(BB, PPC::ANDC, 2, Result).addReg(Tmp2).addReg(Tmp1);
+      RecordSuccess = false;
+      return Result;
+    }
+    // emit a regular and
+    Tmp1 = SelectExpr(N.getOperand(0));
+    Tmp2 = SelectExpr(N.getOperand(1));
+    Opc = Recording ? PPC::ANDo : PPC::AND;
+    BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addReg(Tmp2);
     RecordSuccess = true;
     return Result;