[llvm-commits] [llvm] r168198 - in /llvm/trunk: lib/Target/NVPTX/NVPTXAsmPrinter.cpp test/CodeGen/NVPTX/global-ordering.ll

[Pawel Wodnicki]

 Justin,

> One more for 3.2. :)

I will queue it up  but merging into the 3.2 is for now suspended
as per:

http://lists.cs.uiuc.edu/pipermail/llvmdev/2012-November/055895.html

Pawel


> 
> 
> On Fri, Nov 16, 2012 at 4:03 PM, Justin Holewinski
> <jholewinski at nvidia.com>wrote:
> 
>> Author: jholewinski
>> Date: Fri Nov 16 15:03:51 2012
>> New Revision: 168198
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=168198&view=rev
>> Log:
>> [NVPTX] Order global variables in def-use order before emiting them in the
>> final assembly
>>
>> Added:
>>     llvm/trunk/test/CodeGen/NVPTX/global-ordering.ll
>> Modified:
>>     llvm/trunk/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
>>
>> Modified: llvm/trunk/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/NVPTX/NVPTXAsmPrinter.cpp?rev=168198&r1=168197&r2=168198&view=diff
>>
>> ==============================================================================
>> --- llvm/trunk/lib/Target/NVPTX/NVPTXAsmPrinter.cpp (original)
>> +++ llvm/trunk/lib/Target/NVPTX/NVPTXAsmPrinter.cpp Fri Nov 16 15:03:51
>> 2012
>> @@ -68,7 +68,54 @@
>>
>>  cl::location(llvm::InterleaveSrcInPtx));
>>
>>
>> +namespace {
>> +/// DiscoverDependentGlobals - Return a set of GlobalVariables on which
>> \p V
>> +/// depends.
>> +void DiscoverDependentGlobals(Value *V,
>> +                              DenseSet<GlobalVariable*> &Globals) {
>> +  if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
>> +    Globals.insert(GV);
>> +  else {
>> +    if (User *U = dyn_cast<User>(V)) {
>> +      for (unsigned i = 0, e = U->getNumOperands(); i != e; ++i) {
>> +        DiscoverDependentGlobals(U->getOperand(i), Globals);
>> +      }
>> +    }
>> +  }
>> +}
>>
>> +/// VisitGlobalVariableForEmission - Add \p GV to the list of
>> GlobalVariable
>> +/// instances to be emitted, but only after any dependents have been added
>> +/// first.
>> +void VisitGlobalVariableForEmission(GlobalVariable *GV,
>> +                                    SmallVectorImpl<GlobalVariable*>
>> &Order,
>> +                                    DenseSet<GlobalVariable*> &Visited,
>> +                                    DenseSet<GlobalVariable*> &Visiting) {
>> +  // Have we already visited this one?
>> +  if (Visited.count(GV)) return;
>> +
>> +  // Do we have a circular dependency?
>> +  if (Visiting.count(GV))
>> +    report_fatal_error("Circular dependency found in global variable
>> set");
>> +
>> +  // Start visiting this global
>> +  Visiting.insert(GV);
>> +
>> +  // Make sure we visit all dependents first
>> +  DenseSet<GlobalVariable*> Others;
>> +  for (unsigned i = 0, e = GV->getNumOperands(); i != e; ++i)
>> +    DiscoverDependentGlobals(GV->getOperand(i), Others);
>> +
>> +  for (DenseSet<GlobalVariable*>::iterator I = Others.begin(),
>> +       E = Others.end(); I != E; ++I)
>> +    VisitGlobalVariableForEmission(*I, Order, Visited, Visiting);
>> +
>> +  // Now we can visit ourself
>> +  Order.push_back(GV);
>> +  Visited.insert(GV);
>> +  Visiting.erase(GV);
>> +}
>> +}
>>
>>  // @TODO: This is a copy from AsmPrinter.cpp.  The function is static, so
>> we
>>  // cannot just link to the existing version.
>> @@ -893,10 +940,27 @@
>>
>>    emitDeclarations(M, OS2);
>>
>> -  // Print out module-level global variables here.
>> +  // As ptxas does not support forward references of globals, we need to
>> first
>> +  // sort the list of module-level globals in def-use order. We visit each
>> +  // global variable in order, and ensure that we emit it *after* its
>> dependent
>> +  // globals. We use a little extra memory maintaining both a set and a
>> list to
>> +  // have fast searches while maintaining a strict ordering.
>> +  SmallVector<GlobalVariable*,8> Globals;
>> +  DenseSet<GlobalVariable*> GVVisited;
>> +  DenseSet<GlobalVariable*> GVVisiting;
>> +
>> +  // Visit each global variable, in order
>>    for (Module::global_iterator I = M.global_begin(), E = M.global_end();
>> -      I != E; ++I)
>> -    printModuleLevelGV(I, OS2);
>> +       I != E; ++I)
>> +    VisitGlobalVariableForEmission(I, Globals, GVVisited, GVVisiting);
>> +
>> +  assert(GVVisited.size() == M.getGlobalList().size() &&
>> +         "Missed a global variable");
>> +  assert(GVVisiting.size() == 0 && "Did not fully process a global
>> variable");
>> +
>> +  // Print out module-level global variables in proper order
>> +  for (unsigned i = 0, e = Globals.size(); i != e; ++i)
>> +    printModuleLevelGV(Globals[i], OS2);
>>
>>    OS2 << '\n';
>>
>>
>> Added: llvm/trunk/test/CodeGen/NVPTX/global-ordering.ll
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/NVPTX/global-ordering.ll?rev=168198&view=auto
>>
>> ==============================================================================
>> --- llvm/trunk/test/CodeGen/NVPTX/global-ordering.ll (added)
>> +++ llvm/trunk/test/CodeGen/NVPTX/global-ordering.ll Fri Nov 16 15:03:51
>> 2012
>> @@ -0,0 +1,20 @@
>> +; RUN: llc < %s -march=nvptx -mcpu=sm_20 | FileCheck %s
>> --check-prefix=PTX32
>> +; RUN: llc < %s -march=nvptx64 -mcpu=sm_20 | FileCheck %s
>> --check-prefix=PTX64
>> +
>> +; Make sure we emit these globals in def-use order
>> +
>> +
>> +; PTX32:      .visible .global .align 1 .u8 a = 2;
>> +; PTX32-NEXT: .visible .global .align 4 .u32 a2 = a;
>> +; PTX64:      .visible .global .align 1 .u8 a = 2;
>> +; PTX64-NEXT: .visible .global .align 8 .u64 a2 = a;
>> + at a2 = addrspace(1) global i8 addrspace(1)* @a
>> + at a = addrspace(1) global i8 2
>> +
>> +
>> +; PTX32:      .visible .global .align 1 .u8 b = 1;
>> +; PTX32-NEXT: .visible .global .align 4 .u32 b2[2] = {b, b};
>> +; PTX64:      .visible .global .align 1 .u8 b = 1;
>> +; PTX64-NEXT: .visible .global .align 8 .u64 b2[2] = {b, b};
>> + at b2 = addrspace(1) global [2 x i8 addrspace(1)*] [i8 addrspace(1)* @b, i8
>> addrspace(1)* @b]
>> + at b = addrspace(1) global i8 1
>>
>>
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> 
> 
>