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Use malloc to allocate storage for task parameters on Windows.

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Fixes bug #55.  A number of tests were crashing on Windows due to the task
launch code using alloca to allocate space for the tasks' parameters.  On
Windows, the stack isn't generally big enough for this to be a good idea.
Also added an alignment parmaeter to ISPCMalloc() to pass the alignment
requirement along.
This commit is contained in:
Matt Pharr
2011-07-06 05:53:25 -07:00
parent 4d733af3c7
commit 6e4c165c7e
8 changed files with 80 additions and 14 deletions
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22
ctx.cpp
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@@ -757,7 +757,7 @@ FunctionEmitContext::I1VecToBoolVec(llvm::Value *b) {
llvm::Value *
FunctionEmitContext::EmitMalloc(const llvm::Type *ty) {
FunctionEmitContext::EmitMalloc(const llvm::Type *ty, int align) {
// Emit code to compute the size of the given type using a GEP with a
// NULL base pointer, indexing one element of the given type, and
// casting the resulting 'pointer' to an int giving its size.
@@ -767,12 +767,13 @@ FunctionEmitContext::EmitMalloc(const llvm::Type *ty) {
llvm::Value *poffset = llvm::GetElementPtrInst::Create(nullPtr, &index[0], &index[1],
"offset_ptr", bblock);
AddDebugPos(poffset);
llvm::Value *sizeOf = PtrToIntInst(poffset, LLVMTypes::Int64Type, "offset_int");
llvm::Value *sizeOf = PtrToIntInst(poffset, LLVMTypes::Int64Type, "offset_int");
// And given the size, call the malloc function
llvm::Function *fmalloc = m->module->getFunction("ISPCMalloc");
assert(fmalloc != NULL);
llvm::Value *mem = CallInst(fmalloc, sizeOf, "raw_argmem");
llvm::Value *mem = CallInst(fmalloc, sizeOf, LLVMInt32(align),
"raw_argmem");
// Cast the void * back to the result pointer type
return BitCastInst(mem, ptrType, "mem_bitcast");
}
@@ -1921,12 +1922,19 @@ FunctionEmitContext::LaunchInst(llvm::Function *callee,
static_cast<const llvm::StructType *>(pt->getElementType());
assert(argStructType->getNumElements() == argVals.size() + 1);
// Use alloca for space for the task args. KEY DETAIL: pass false
// to the call of FunctionEmitContext::AllocaInst so that the alloca
// doesn't happen just once at the top of the function, but happens
// each time the enclosing basic block executes.
int align = 4 * RoundUpPow2(g->target.nativeVectorWidth);
#ifdef ISPC_IS_WINDOWS
// Use malloc() to allocate storage on Windows, since the stack is
// generally not big enough there to do enough allocations for lots of
// tasks and then things crash horribly...
llvm::Value *argmem = EmitMalloc(argStructType, align);
#else
// Use alloca for space for the task args on OSX And Linux. KEY
// DETAIL: pass false to the call of FunctionEmitContext::AllocaInst so
// that the alloca doesn't happen just once at the top of the function,
// but happens each time the enclosing basic block executes.
llvm::Value *argmem = AllocaInst(argStructType, "argmem", align, false);
#endif // ISPC_IS_WINDOWS
llvm::Value *voidmem = BitCastInst(argmem, LLVMTypes::VoidPointerType);
// Copy the values of the parameters into the appropriate place in