LLVM  6.0.0svn
AMDGPUFrameLowering.cpp
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1 //===----------------------- AMDGPUFrameLowering.cpp ----------------------===//
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 // Interface to describe a layout of a stack frame on a AMDGPU target machine.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "AMDGPUFrameLowering.h"
15 
16 using namespace llvm;
18  int LAO, unsigned TransAl)
19  : TargetFrameLowering(D, StackAl, LAO, TransAl) { }
20 
22 
24  // XXX: Hardcoding to 1 for now.
25  //
26  // I think the StackWidth should stored as metadata associated with the
27  // MachineFunction. This metadata can either be added by a frontend, or
28  // calculated by a R600 specific LLVM IR pass.
29  //
30  // The StackWidth determines how stack objects are laid out in memory.
31  // For a vector stack variable, like: int4 stack[2], the data will be stored
32  // in the following ways depending on the StackWidth.
33  //
34  // StackWidth = 1:
35  //
36  // T0.X = stack[0].x
37  // T1.X = stack[0].y
38  // T2.X = stack[0].z
39  // T3.X = stack[0].w
40  // T4.X = stack[1].x
41  // T5.X = stack[1].y
42  // T6.X = stack[1].z
43  // T7.X = stack[1].w
44  //
45  // StackWidth = 2:
46  //
47  // T0.X = stack[0].x
48  // T0.Y = stack[0].y
49  // T1.X = stack[0].z
50  // T1.Y = stack[0].w
51  // T2.X = stack[1].x
52  // T2.Y = stack[1].y
53  // T3.X = stack[1].z
54  // T3.Y = stack[1].w
55  //
56  // StackWidth = 4:
57  // T0.X = stack[0].x
58  // T0.Y = stack[0].y
59  // T0.Z = stack[0].z
60  // T0.W = stack[0].w
61  // T1.X = stack[1].x
62  // T1.Y = stack[1].y
63  // T1.Z = stack[1].z
64  // T1.W = stack[1].w
65  return 1;
66 }
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
Interface to describe a layout of a stack frame on an AMDGPU target.
AMDGPUFrameLowering(StackDirection D, unsigned StackAl, int LAO, unsigned TransAl=1)
Information about stack frame layout on the target.
static GCRegistry::Add< StatepointGC > D("statepoint-example", "an example strategy for statepoint")
unsigned getStackWidth(const MachineFunction &MF) const