Revert "[PowerPC] combine rlwinm+rlwinm to rlwinm"

This reverts commit 29f6f9b.

llvm/lib/Target/PowerPC/PPCMIPeephole.cpp

@@ -18,7 +18,6 @@
 //
 //===---------------------------------------------------------------------===//
 
-#include "MCTargetDesc/PPCMCTargetDesc.h"
 #include "MCTargetDesc/PPCPredicates.h"
 #include "PPC.h"
 #include "PPCInstrBuilder.h"
@@ -807,105 +806,6 @@ bool PPCMIPeephole::simplifyCode(void) {
                       combineSEXTAndSHL(MI, ToErase);
         break;
       }
-      case PPC::RLWINM:
-      case PPC::RLWINMo:
-      case PPC::RLWINM8:
-      case PPC::RLWINM8o: {
-        unsigned FoldingReg = MI.getOperand(1).getReg();
-        if (!Register::isVirtualRegister(FoldingReg))
-          break;
-
-        MachineInstr *SrcMI = MRI->getVRegDef(FoldingReg);
-        if (SrcMI->getOpcode() != PPC::RLWINM &&
-            SrcMI->getOpcode() != PPC::RLWINMo &&
-            SrcMI->getOpcode() != PPC::RLWINM8 &&
-            SrcMI->getOpcode() != PPC::RLWINM8o)
-          break;
-        assert((MI.getOperand(2).isImm() && MI.getOperand(3).isImm() &&
-                MI.getOperand(4).isImm() && SrcMI->getOperand(2).isImm() &&
-                SrcMI->getOperand(3).isImm() && SrcMI->getOperand(4).isImm()) &&
-               "Invalid PPC::RLWINM Instruction!");
-        uint64_t SHSrc = SrcMI->getOperand(2).getImm();
-        uint64_t SHMI = MI.getOperand(2).getImm();
-        uint64_t MBSrc = SrcMI->getOperand(3).getImm();
-        uint64_t MBMI = MI.getOperand(3).getImm();
-        uint64_t MESrc = SrcMI->getOperand(4).getImm();
-        uint64_t MEMI = MI.getOperand(4).getImm();
-
-        assert((MEMI < 32 && MESrc < 32 && MBMI < 32 && MBSrc < 32) &&
-               "Invalid PPC::RLWINM Instruction!");
-
-        APInt MaskSrc =
-            APInt::getBitsSetWithWrap(32, 32 - MESrc - 1, 32 - MBSrc);
-        APInt MaskMI = APInt::getBitsSetWithWrap(32, 32 - MEMI - 1, 32 - MBMI);
-
-        APInt RotatedSrcMask = MaskSrc.rotl(SHMI);
-        APInt FinalMask = RotatedSrcMask & MaskMI;
-        uint32_t NewMB, NewME;
-
-        // If final mask is 0, MI result should be 0 too.
-        if (FinalMask.isNullValue()) {
-          bool Is64Bit = (MI.getOpcode() == PPC::RLWINM8 ||
-                          MI.getOpcode() == PPC::RLWINM8o);
-
-          LLVM_DEBUG(dbgs() << "Replace Instr: ");
-          LLVM_DEBUG(MI.dump());
-
-          if (MI.getOpcode() == PPC::RLWINM || MI.getOpcode() == PPC::RLWINM8) {
-            // Replace MI with "LI 0"
-            MI.RemoveOperand(4);
-            MI.RemoveOperand(3);
-            MI.RemoveOperand(2);
-            MI.getOperand(1).ChangeToImmediate(0);
-            MI.setDesc(TII->get(Is64Bit ? PPC::LI8 : PPC::LI));
-          } else {
-            // Replace MI with "ANDIo reg, 0"
-            MI.RemoveOperand(4);
-            MI.RemoveOperand(3);
-            MI.getOperand(2).setImm(0);
-            MI.setDesc(TII->get(Is64Bit ? PPC::ANDIo8 : PPC::ANDIo));
-          }
-          Simplified = true;
-          NumRotatesCollapsed++;
-
-          LLVM_DEBUG(dbgs() << "With: ");
-          LLVM_DEBUG(MI.dump());
-        } else if (isRunOfOnes((unsigned)(FinalMask.getZExtValue()), NewMB,
-                               NewME)) {
-
-          // If FoldingReg has only one use and it it not RLWINMo and
-          // RLWINM8o, safe to delete its def SrcMI. Otherwise keep it.
-          if (MRI->hasOneNonDBGUse(FoldingReg) &&
-              (SrcMI->getOpcode() == PPC::RLWINM ||
-               SrcMI->getOpcode() == PPC::RLWINM8)) {
-            ToErase = SrcMI;
-            LLVM_DEBUG(dbgs() << "Delete dead instruction: ");
-            LLVM_DEBUG(SrcMI->dump());
-          }
-
-          LLVM_DEBUG(dbgs() << "Converting Instr: ");
-          LLVM_DEBUG(MI.dump());
-
-          uint16_t NewSH = (SHSrc + SHMI) % 32;
-          MI.getOperand(2).setImm(NewSH);
-          MI.getOperand(3).setImm(NewMB);
-          MI.getOperand(4).setImm(NewME);
-          MI.getOperand(1).setReg(SrcMI->getOperand(1).getReg());
-          if (SrcMI->getOperand(1).isKill()) {
-            MI.getOperand(1).setIsKill(true);
-            SrcMI->getOperand(1).setIsKill(false);
-          } else
-            // About to replace MI.getOperand(1), clear its kill flag.
-            MI.getOperand(1).setIsKill(false);
-
-          Simplified = true;
-          NumRotatesCollapsed++;
-
-          LLVM_DEBUG(dbgs() << "To: ");
-          LLVM_DEBUG(MI.dump());
-        }
-        break;
-      }
       }
     }
 

llvm/test/CodeGen/PowerPC/fold-rlwinm-1.ll

@@ -11,7 +11,8 @@ define void @foo(i32 signext %var1) {
 ; CHECK-NEXT:    xori r3, r3, 1
 ; CHECK-NEXT:    addis r4, r2, res@toc@ha
 ; CHECK-NEXT:    cntlzw r3, r3
-; CHECK-NEXT:    rlwinm r3, r3, 14, 0, 12
+; CHECK-NEXT:    srwi r3, r3, 5
+; CHECK-NEXT:    slwi r3, r3, 19
 ; CHECK-NEXT:    stw r3, res@toc@l(r4)
 ; CHECK-NEXT:    blr
 entry:
@@ -29,10 +30,10 @@ define void @foo_multiple_use(i32 signext %var1) {
 ; CHECK-NEXT:    addis r4, r2, res2@toc@ha
 ; CHECK-NEXT:    addis r6, r2, res@toc@ha
 ; CHECK-NEXT:    cntlzw r3, r3
-; CHECK-NEXT:    srwi r5, r3, 5
-; CHECK-NEXT:    rlwinm r3, r3, 14, 0, 12
-; CHECK-NEXT:    stw r5, res2@toc@l(r4)
-; CHECK-NEXT:    stw r3, res@toc@l(r6)
+; CHECK-NEXT:    srwi r3, r3, 5
+; CHECK-NEXT:    slwi r5, r3, 19
+; CHECK-NEXT:    stw r3, res2@toc@l(r4)
+; CHECK-NEXT:    stw r5, res@toc@l(r6)
 ; CHECK-NEXT:    blr
 entry:
   %cmp = icmp eq i32 %var1, 1