From 7c2e03916c22d9ad1d8596ad00dee04a9f1454ed Mon Sep 17 00:00:00 2001
From: Dan Gohman <gohman@apple.com>
Date: Wed, 19 May 2010 00:53:19 +0000
Subject: [PATCH] Factor out the code for picking integer arithmetic with
 immediate opcodes into a helper function. This fixes a few places in the code
 which were not properly selecting the 8-bit-immediate opcodes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104091 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/X86/X86RegisterInfo.cpp | 47 ++++++++++++++++++++++++++------------
 1 file changed, 32 insertions(+), 15 deletions(-)

diff --git a/lib/Target/X86/X86RegisterInfo.cpp b/lib/Target/X86/X86RegisterInfo.cpp
index 2db3c703cc9..fac85c75d39 100644
--- a/lib/Target/X86/X86RegisterInfo.cpp
+++ b/lib/Target/X86/X86RegisterInfo.cpp
@@ -517,6 +517,30 @@ X86RegisterInfo::getFrameIndexOffset(const MachineFunction &MF, int FI) const {
   return Offset;
 }
 
+static unsigned getSUBriOpcode(unsigned is64Bit, int64_t Imm) {
+  if (is64Bit) {
+    if (isInt<8>(Imm))
+      return X86::SUB64ri8;
+    return X86::SUB64ri32;
+  } else {
+    if (isInt<8>(Imm))
+      return X86::SUB32ri8;
+    return X86::SUB32ri;
+  }
+}
+
+static unsigned getADDriOpcode(unsigned is64Bit, int64_t Imm) {
+  if (is64Bit) {
+    if (isInt<8>(Imm))
+      return X86::ADD64ri8;
+    return X86::ADD64ri32;
+  } else {
+    if (isInt<8>(Imm))
+      return X86::ADD32ri8;
+    return X86::ADD32ri;
+  }
+}
+
 void X86RegisterInfo::
 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
                               MachineBasicBlock::iterator I) const {
@@ -536,7 +560,7 @@ eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
       MachineInstr *New = 0;
       if (Old->getOpcode() == getCallFrameSetupOpcode()) {
         New = BuildMI(MF, Old->getDebugLoc(),
-                      TII.get(Is64Bit ? X86::SUB64ri32 : X86::SUB32ri),
+                      TII.get(getSUBriOpcode(Is64Bit, Amount)),
                       StackPtr)
           .addReg(StackPtr)
           .addImm(Amount);
@@ -548,9 +572,7 @@ eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
         Amount -= CalleeAmt;
   
       if (Amount) {
-          unsigned Opc = (Amount < 128) ?
-            (Is64Bit ? X86::ADD64ri8 : X86::ADD32ri8) :
-            (Is64Bit ? X86::ADD64ri32 : X86::ADD32ri);
+          unsigned Opc = getADDriOpcode(Is64Bit, Amount);
           New = BuildMI(MF, Old->getDebugLoc(), TII.get(Opc), StackPtr)
             .addReg(StackPtr)
             .addImm(Amount);
@@ -570,9 +592,7 @@ eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
     // something off the stack pointer, add it back.  We do this until we have
     // more advanced stack pointer tracking ability.
     if (uint64_t CalleeAmt = I->getOperand(1).getImm()) {
-      unsigned Opc = (CalleeAmt < 128) ?
-        (Is64Bit ? X86::SUB64ri8 : X86::SUB32ri8) :
-        (Is64Bit ? X86::SUB64ri32 : X86::SUB32ri);
+      unsigned Opc = getSUBriOpcode(Is64Bit, CalleeAmt);
       MachineInstr *Old = I;
       MachineInstr *New =
         BuildMI(MF, Old->getDebugLoc(), TII.get(Opc), 
@@ -690,13 +710,9 @@ void emitSPUpdate(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
                   const TargetInstrInfo &TII) {
   bool isSub = NumBytes < 0;
   uint64_t Offset = isSub ? -NumBytes : NumBytes;
-  unsigned Opc = isSub
-    ? ((Offset < 128) ?
-       (Is64Bit ? X86::SUB64ri8 : X86::SUB32ri8) :
-       (Is64Bit ? X86::SUB64ri32 : X86::SUB32ri))
-    : ((Offset < 128) ?
-       (Is64Bit ? X86::ADD64ri8 : X86::ADD32ri8) :
-       (Is64Bit ? X86::ADD64ri32 : X86::ADD32ri));
+  unsigned Opc = isSub ?
+    getSUBriOpcode(Is64Bit, Offset) :
+    getADDriOpcode(Is64Bit, Offset);
   uint64_t Chunk = (1LL << 31) - 1;
   DebugLoc DL = MBB.findDebugLoc(MBBI);
 
@@ -916,7 +932,8 @@ void X86RegisterInfo::emitPrologue(MachineFunction &MF) const {
   // size is bigger than the callers.
   if (TailCallReturnAddrDelta < 0) {
     MachineInstr *MI =
-      BuildMI(MBB, MBBI, DL, TII.get(Is64Bit? X86::SUB64ri32 : X86::SUB32ri),
+      BuildMI(MBB, MBBI, DL,
+              TII.get(getSUBriOpcode(Is64Bit, -TailCallReturnAddrDelta)),
               StackPtr)
         .addReg(StackPtr)
         .addImm(-TailCallReturnAddrDelta);
-- 
2.11.0