From b449a68146c7188a20bba11db19229a5cb46938a Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Sat, 28 Mar 2009 17:03:24 +0000
Subject: [PATCH] Make code a bit less brittle by no hardcoding the number of
 operands in an address in so many places.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67945 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/X86/X86CodeEmitter.cpp   | 18 ++++++++++++------
 lib/Target/X86/X86FloatingPoint.cpp |  3 ++-
 lib/Target/X86/X86InstrInfo.cpp     |  2 +-
 3 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/lib/Target/X86/X86CodeEmitter.cpp b/lib/Target/X86/X86CodeEmitter.cpp
index bbe063b4f82..f7c8c8de451 100644
--- a/lib/Target/X86/X86CodeEmitter.cpp
+++ b/lib/Target/X86/X86CodeEmitter.cpp
@@ -32,6 +32,9 @@
 #include "llvm/Target/TargetOptions.h"
 using namespace llvm;
 
+// FIXME: This should be some header
+static const int X86AddrNumOperands = 4;
+
 STATISTIC(NumEmitted, "Number of machine instructions emitted");
 
 namespace {
@@ -642,8 +645,10 @@ void Emitter::emitInstruction(const MachineInstr &MI,
   }
   case X86II::MRMDestMem: {
     MCE.emitByte(BaseOpcode);
-    emitMemModRMByte(MI, CurOp, getX86RegNum(MI.getOperand(CurOp+4).getReg()));
-    CurOp += 5;
+    emitMemModRMByte(MI, CurOp,
+                     getX86RegNum(MI.getOperand(CurOp + X86AddrNumOperands)
+                                  .getReg()));
+    CurOp +=  X86AddrNumOperands + 1;
     if (CurOp != NumOps)
       emitConstant(MI.getOperand(CurOp++).getImm(), X86InstrInfo::sizeOfImm(Desc));
     break;
@@ -659,12 +664,13 @@ void Emitter::emitInstruction(const MachineInstr &MI,
     break;
 
   case X86II::MRMSrcMem: {
-    intptr_t PCAdj = (CurOp+5 != NumOps) ? X86InstrInfo::sizeOfImm(Desc) : 0;
+    intptr_t PCAdj = (CurOp + X86AddrNumOperands + 1 != NumOps) ?
+      X86InstrInfo::sizeOfImm(Desc) : 0;
 
     MCE.emitByte(BaseOpcode);
     emitMemModRMByte(MI, CurOp+1, getX86RegNum(MI.getOperand(CurOp).getReg()),
                      PCAdj);
-    CurOp += 5;
+    CurOp += X86AddrNumOperands + 1;
     if (CurOp != NumOps)
       emitConstant(MI.getOperand(CurOp++).getImm(), X86InstrInfo::sizeOfImm(Desc));
     break;
@@ -714,13 +720,13 @@ void Emitter::emitInstruction(const MachineInstr &MI,
   case X86II::MRM2m: case X86II::MRM3m:
   case X86II::MRM4m: case X86II::MRM5m:
   case X86II::MRM6m: case X86II::MRM7m: {
-    intptr_t PCAdj = (CurOp+4 != NumOps) ?
+    intptr_t PCAdj = (CurOp + X86AddrNumOperands != NumOps) ?
       (MI.getOperand(CurOp+4).isImm() ? X86InstrInfo::sizeOfImm(Desc) : 4) : 0;
 
     MCE.emitByte(BaseOpcode);
     emitMemModRMByte(MI, CurOp, (Desc->TSFlags & X86II::FormMask)-X86II::MRM0m,
                      PCAdj);
-    CurOp += 4;
+    CurOp += X86AddrNumOperands;
 
     if (CurOp != NumOps) {
       const MachineOperand &MO = MI.getOperand(CurOp++);
diff --git a/lib/Target/X86/X86FloatingPoint.cpp b/lib/Target/X86/X86FloatingPoint.cpp
index 8862428b226..dee57176d9f 100644
--- a/lib/Target/X86/X86FloatingPoint.cpp
+++ b/lib/Target/X86/X86FloatingPoint.cpp
@@ -616,9 +616,10 @@ void FPS::handleZeroArgFP(MachineBasicBlock::iterator &I) {
 /// handleOneArgFP - fst <mem>, ST(0)
 ///
 void FPS::handleOneArgFP(MachineBasicBlock::iterator &I) {
+  const int X86AddrNumOperands = 4;
   MachineInstr *MI = I;
   unsigned NumOps = MI->getDesc().getNumOperands();
-  assert((NumOps == 5 || NumOps == 1) &&
+  assert((NumOps == X86AddrNumOperands + 1 || NumOps == 1) &&
          "Can only handle fst* & ftst instructions!");
 
   // Is this the last use of the source register?
diff --git a/lib/Target/X86/X86InstrInfo.cpp b/lib/Target/X86/X86InstrInfo.cpp
index f5c3d1db687..86d64a6327e 100644
--- a/lib/Target/X86/X86InstrInfo.cpp
+++ b/lib/Target/X86/X86InstrInfo.cpp
@@ -763,7 +763,7 @@ unsigned X86InstrInfo::isStoreToStackSlot(const MachineInstr *MI,
         MI->getOperand(2).getReg() == 0 &&
         MI->getOperand(3).getImm() == 0) {
       FrameIndex = MI->getOperand(0).getIndex();
-      return MI->getOperand(4).getReg();
+      return MI->getOperand(X86AddrNumOperands).getReg();
     }
     break;
   }
-- 
2.34.1