From c9ac32837df68a5347ef518a351910c708460d67 Mon Sep 17 00:00:00 2001
From: Hal Finkel <hfinkel@anl.gov>
Date: Sun, 2 Feb 2014 06:12:27 +0000
Subject: [PATCH] Replace PPC instruction-size code with MCInstrDesc getSize

As part of the cleanup done to enable the disassembler, the PPC instructions
now have a valid Size description field. This can now be used to replace some
custom logic in a few places to compute instruction sizes.

Patch by David Wiberg!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200623 91177308-0d34-0410-b5e6-96231b3b80d8
---
 .../PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp | 12 +++++-------
 lib/Target/PowerPC/PPCInstrInfo.cpp           | 19 ++++++-------------
 2 files changed, 11 insertions(+), 20 deletions(-)

diff --git a/lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp b/lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp
index f1b2802c9ec..93e6fc76322 100644
--- a/lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp
+++ b/lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp
@@ -33,10 +33,12 @@ class PPCMCCodeEmitter : public MCCodeEmitter {
   PPCMCCodeEmitter(const PPCMCCodeEmitter &) LLVM_DELETED_FUNCTION;
   void operator=(const PPCMCCodeEmitter &) LLVM_DELETED_FUNCTION;
 
+  const MCInstrInfo &MCII;
   const MCContext &CTX;
 
 public:
-  PPCMCCodeEmitter(const MCInstrInfo &mcii, MCContext &ctx) : CTX(ctx) {
+  PPCMCCodeEmitter(const MCInstrInfo &mcii, MCContext &ctx)
+    : MCII(mcii), CTX(ctx) {
   }
   
   ~PPCMCCodeEmitter() {}
@@ -90,18 +92,14 @@ public:
     // It's just a nop to keep the register classes happy, so don't
     // generate anything.
     unsigned Opcode = MI.getOpcode();
+    const MCInstrDesc &Desc = MCII.get(Opcode);
     if (Opcode == TargetOpcode::COPY_TO_REGCLASS)
       return;
 
     uint64_t Bits = getBinaryCodeForInstr(MI, Fixups, STI);
 
-    // BL8_NOP etc. all have a size of 8 because of the following 'nop'.
-    unsigned Size = 4; // FIXME: Have Desc.getSize() return the correct value!
-    if (Opcode == PPC::BL8_NOP || Opcode == PPC::BLA8_NOP ||
-        Opcode == PPC::BL8_NOP_TLS)
-      Size = 8;
-    
     // Output the constant in big endian byte order.
+    unsigned Size = Desc.getSize();
     int ShiftValue = (Size * 8) - 8;
     for (unsigned i = 0; i != Size; ++i) {
       OS << (char)(Bits >> ShiftValue);
diff --git a/lib/Target/PowerPC/PPCInstrInfo.cpp b/lib/Target/PowerPC/PPCInstrInfo.cpp
index 9e491fa19c2..b15ef1b9a6d 100644
--- a/lib/Target/PowerPC/PPCInstrInfo.cpp
+++ b/lib/Target/PowerPC/PPCInstrInfo.cpp
@@ -1436,22 +1436,15 @@ bool PPCInstrInfo::optimizeCompareInstr(MachineInstr *CmpInstr,
 /// instruction may be.  This returns the maximum number of bytes.
 ///
 unsigned PPCInstrInfo::GetInstSizeInBytes(const MachineInstr *MI) const {
-  switch (MI->getOpcode()) {
-  case PPC::INLINEASM: {       // Inline Asm: Variable size.
+  unsigned Opcode = MI->getOpcode();
+
+  if (Opcode == PPC::INLINEASM) {
     const MachineFunction *MF = MI->getParent()->getParent();
     const char *AsmStr = MI->getOperand(0).getSymbolName();
     return getInlineAsmLength(AsmStr, *MF->getTarget().getMCAsmInfo());
-  }
-  case PPC::PROLOG_LABEL:
-  case PPC::EH_LABEL:
-  case PPC::GC_LABEL:
-  case PPC::DBG_VALUE:
-    return 0;
-  case PPC::BL8_NOP:
-  case PPC::BLA8_NOP:
-    return 8;
-  default:
-    return 4; // PowerPC instructions are all 4 bytes
+  } else {
+    const MCInstrDesc &Desc = get(Opcode);
+    return Desc.getSize();
   }
 }
 
-- 
2.34.1