SparcSubtarget.cpp revision 72ad17c48c15562fe31c65f6daa09c83f42860c1 
1//===-- SparcSubtarget.cpp - SPARC Subtarget Information ------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements the SPARC specific subclass of TargetSubtargetInfo.
11//
12//===----------------------------------------------------------------------===//
13
14#include "SparcSubtarget.h"
15#include "Sparc.h"
16#include "llvm/Support/MathExtras.h"
17#include "llvm/Support/TargetRegistry.h"
18
19#define GET_SUBTARGETINFO_TARGET_DESC
20#define GET_SUBTARGETINFO_CTOR
21#include "SparcGenSubtargetInfo.inc"
22
23using namespace llvm;
24
25void SparcSubtarget::anchor() { }
26
27SparcSubtarget::SparcSubtarget(const std::string &TT, const std::string &CPU,
28                               const std::string &FS,  bool is64Bit) :
29  SparcGenSubtargetInfo(TT, CPU, FS),
30  IsV9(false),
31  V8DeprecatedInsts(false),
32  IsVIS(false),
33  Is64Bit(is64Bit) {
34
35  // Determine default and user specified characteristics
36  std::string CPUName = CPU;
37  if (CPUName.empty()) {
38    if (is64Bit)
39      CPUName = "v9";
40    else
41      CPUName = "v8";
42  }
43  IsV9 = CPUName == "v9";
44
45  // Parse features string.
46  ParseSubtargetFeatures(CPUName, FS);
47}
48
49
50int SparcSubtarget::getAdjustedFrameSize(int frameSize) const {
51
52  if (is64Bit()) {
53    // All 64-bit stack frames must be 16-byte aligned, and must reserve space
54    // for spilling the 16 window registers at %sp+BIAS..%sp+BIAS+128.
55    frameSize += 128;
56    // Frames with calls must also reserve space for 6 outgoing arguments
57    // whether they are used or not. LowerCall_64 takes care of that.
58    assert(frameSize % 16 == 0 && "Stack size not 16-byte aligned");
59  } else {
60    // Emit the correct save instruction based on the number of bytes in
61    // the frame. Minimum stack frame size according to V8 ABI is:
62    //   16 words for register window spill
63    //    1 word for address of returned aggregate-value
64    // +  6 words for passing parameters on the stack
65    // ----------
66    //   23 words * 4 bytes per word = 92 bytes
67    frameSize += 92;
68
69    // Round up to next doubleword boundary -- a double-word boundary
70    // is required by the ABI.
71    frameSize = RoundUpToAlignment(frameSize, 8);
72  }
73  return frameSize;
74}
75